US20060081478A1

US20060081478A1 - Plating apparatus and plating method

Info

Publication number: US20060081478A1
Application number: US11/251,799
Authority: US
Inventors: Tsuyoshi Sahoda; Tsutomu Nakada; Nobutoshi Saito; Junichiro Yoshioka; Fumio Kuriyama; Masunobu Onozawa
Original assignee: Individual
Current assignee: Ebara Corp
Priority date: 2004-10-19
Filing date: 2005-10-18
Publication date: 2006-04-20

Abstract

A plating apparatus employs a dipping method with good gas-bubble releasability and, by regulating the flow of plating solution in a plating tank, can enhance the in-plane uniformity of a thickness of a plated film. The plating apparatus includes a plating tank for holding a plating solution, a plating solution jet nozzle having a slit-like plating solution jet orifice for jetting the plating solution toward a surface to be plated of an object to be plated disposed in the plating tank, and a plating solution supply section for supplying the plating solution to the plating solution jet nozzle.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention
The present invention relates to a plating apparatus and a plating method for plating a surface (surface to be plated) of a substrate, such as a semiconductor wafer, and more particularly to a plating apparatus and a plating method useful for forming embedded interconnects by embedding a conductive material (interconnects material), such as copper or silver, in interconnects recesses, such as fine trenches and via holes, provided in a surface of a semiconductor wafer, or for forming bumps (protruding electrodes), to which package electrodes or the like are electrically connected, on a surface of a semiconductor wafer.
The plating apparatus and the plating method of the present invention are also useful for embedding of via holes in the production of an interposer or a spacer, for example, which has, in its interior, a large number of vertically-penetrating via plugs and is used for so-called three-dimensional mounting of e.g. a semiconductor chip.
2. Description of the Related Art
In a tape automated bonding (TAB) or flip chip, for example, it has been widely conducted to deposit copper, solder, nickel or multi-layered materials thereof at prescribed areas (electrodes) on the surface of a semiconductor chip having interconnects, thereby forming protruding connecting electrodes (bumps). Such bumps electrically connect the semiconductor chip with package electrodes or TAB electrodes electrically. There are various methods for forming these bumps, including electroplating method, printing method, and ball bump method The electroplating method has become in wide use due to its relatively stable performance and capability of forming fine connections, in view of the recent tendency to increasing number of I/O terminals on semiconductor chips and to finer pitch.
The electroplating method includes a spurting or cup method in which a substrate, such as a semiconductor wafer, is positioned horizontally with a surface (surface to be plated) facing downward and a plating solution is spurted from below; and a dipping method in which the substrate is placed vertically in a plating tank and immersed in a plating solution, while a plating solution is supplied from the bottom of the plating tank and is allowed to overflow the tank. According to the dipping method of electroplating, bubbles, which can adversely affect the quality of the plating, are easily removed and the footprint is small. The dipping method is therefore considered to be suited for bump plating in which holes to be filling by the plating are relatively large and which requires a fairly long plating time.
In recent years, instead of using aluminum or aluminum alloys as a material for forming interconnects circuits on a semiconductor substrate, there is an eminent movement towards using copper (Cu) that has a low electric resistivity and high electromigration resistance. Copper interconnects are generally formed by filling copper into fine interconnects recesses provided in a surface of a substrate. Various techniques for forming such copper interconnects are known, including CVD, sputtering, and plating. According to any such techniques, a copper film is formed in a substantially entire surface of a substrate, followed by removal of unnecessary copper by performing chemical mechanical polishing (CMP).
FIG. 1 shows a conventional electroplating apparatus that employs a dipping method. The electroplating apparatus 600 includes a plating tank 602 for holding therein a plating solution 601, and an overflow tank 604 for holding the plating solution that has overflowed the upper end of the overflow weir 603 of the plating tank 602. In the plating tank 602, a substrate W, which is held by a substrate holder 605, and an anode 606, both immersed in the plating solution 601, are disposed vertically and opposite to each other at a predetermined distance. Paddles (stirrers) 607 are disposed vertically between the substrate W and the anode 606. The paddles 607 are mounted to a paddle shaft 608. The paddle shaft 608 can be reciprocated parallel to the substrate W so as to stir the plating solution in the plating tank 602.
The plating solution 601, after filling the plating tank 602, overflows the overflow weir 603 and flows into the overflow tank 604, and is discharged from the overflow tank 604. The plating solution 601 then passes through a circulation pump 609, a constant-temperature unit 610 and a filter 611, all provided in a circulation line 612, and again flows into the plating tank 602 from its bottom. The plating solution 601 circulates in this manner. A plating power source 613 is connected to the substrate W and the anode 606 to apply a direct-current voltage between the substrate W and the anode 606, and pass a plating current from the anode 606 to the substrate W, thereby forming a plated film on the surface of the substrate W. The plating solution between the substrate W and the anode 606 is stirred by the paddles 607 during plating in order to form a uniform plated film (see, for example, Japanese Patent Laid-Open Publication No. 2004-162129).
As described above, in the conventional plating apparatus that employs a dipping method, the paddles 607 are reciprocated parallel to the substrate W during plating to stir the plating solution between the substrate W and the anode 606 in order to form a uniform plated film. However, since the plating solution 601 is supplied from the bottom of the plating tank 602 and is caused to overflow the upper end of the overflow weir 603, a flow of the plating solution 601 is created. The flow of the plating solution 601 strongly affects the formation of a plated film, which imposes a limitation on the in-plane uniformity of the plated film. The same holds also for an electroless plating apparatus.
FIG. 2 shows another conventional electroplating apparatus that employs a dipping method. The electroplating apparatus includes a plating tank 312 a for holding therein a plating solution, and a vertically-movable substrate holder 314 a for detachably holding a substrate W with its peripheral portion sealed watertightly and its front surface (surface to be plated) exposed. In the plating tank 312 a, an anode 324, which is held by an anode holder 326, is disposed vertically. Further, a regulation plate 328 having a central hole 328 a, composed of a dielectric material, is disposed such that when a substrate W, held by a substrate holder 314 a, is disposed opposite the anode 324, it is positioned between the anode 324 and the substrate W.
In operation, the anode 324, the substrate W and the regulation plate 328 are immersed in the plating solution in the plating tank 312 a while the anode 324 is connected via a conducting wire 330 a to the anode of a plating power source 332 and the substrate W is connected via a conducting wire 330 b to the cathode of the plating power source 332. Due to the potential difference between the substrate W and the anode 324, metal ions in the plating solution receive electrons from the surface of the substrate W, whereby the metal deposits on the substrate W and forms a plated film (metal film).
According to this plating apparatus, the regulation plate 328, having the central hole 328 a, is disposed between the anode 324 and the substrate W, disposed opposite the anode 324, in order to regulate the electric potential distribution in the plating tank 312 a with the regulation plate 328. This makes it possible to regulate to some extent the thickness distribution of the plated film formed on the surface of the substrate W.
FIG. 3 shows yet another conventional electroplating apparatus that employs a dipping method. This electroplating apparatus differs from the embodiment shown in FIG. 2 in that a regulation plate is not provided, but a ring-shaped dummy cathode (dummy electrode) 334 is provided such that it surrounds the periphery of a substrate W held by the substrate holder 314 a. Upon plating, the dummy cathode 334 is connected via a conducting wire 330 c to the cathode of the plating power source 332.
According to this plating apparatus, the uniformity of a metal film formed on the surface of the substrate W can be improved by regulating the electric potential of the dummy cathode 334.
FIG. 4 shows yet another conventional electroplating apparatus that employs a dipping method. This electroplating apparatus differs from the embodiment shown in FIG. 2 in that a regulation plate is not provided, but a paddle shaft (stirring mechanism) 336, located above the plating tank 312 a, is disposed between the substrate holder 314 a and the anode 324 in parallel to them. A plurality of stirring paddles (stirrers) 338 is suspended substantially vertically from the lower surface of the paddle shaft 336. During plating, the paddles 338 are reciprocated parallel to the substrate W by the paddle shaft 336 so as to stir a plating solution in the plating tank 312 a.
According to this plating apparatus, by reciprocating the paddles 338 parallel to the substrate W by the paddle shaft 336, the flow of the plating solution along the surface of the substrate W can be uniformized (directionality of the flow of plating solution eliminated) over the entire surface of the substrate W. This enables the formation of a plated film having a uniform thickness over the entire surface of the substrate W.
It has generally been quite difficult with conventional plating apparatuses to securely fill in via holes having a high aspect ratio and a large depth, such as those having a diameter of 10 to 20 μm and a depth of 70 to 150 μm, provided in a substrate, with a metal film by plating while preventing the formation of defects, such as voids, in the metal film.
For example, when filling in via holes having a high aspect ratio of not less than 1 and a large depth with a metal film by plating by using, for example, the plating apparatus shown in FIG. 4, and carrying out plating while strongly stirring a plating solution by the paddles 338, the flow of plating solution will not reach the bottoms of the via holds. Thus, as shown in FIG. 5, when carrying out plating under such conditions on a surface of a barrier layer 344 covering an insulating film 342 in which a via hole 340 is provided, plating deposition progresses preferentially around the open end of the via hole 340, whereby the open end can be closed up with a metal film (plated film) 346 and a void 348 can be formed in the metal film 346 embedded in the via hole 340.
On the other hand, there is a demand for an apparatus which itself is of a simple structure and has an easily-maintained structure or mechanism. The plating apparatus shown in FIG. 3, for example, needs operations for adjustment of the dummy electrode and removal of the plated metal that has adhered to the dummy electrode. A plating apparatus, which is free from such a complication in operation or maintenance and is easier to handle and maintain, is now in demand.
In carrying out electroplating, the plating rate can be increased by increasing the current density during plating. Merely increasing the current density, however, could cause plating problems such as burnt plating, plating defects, passivation in a surface of an anode, etc.

SUMMARY OF THE INVENTION

The present invention has been made in view of the above situation in the related art. It is therefore a first object of the present invention to provide a plating apparatus and a plating method which employ a dipping method with good gas-bubble releasability and which, by regulating the flow of plating solution in a plating tank, can enhance the in-plane uniformity of a thickness of a plated film.
It is a second object of the present invention to provide a plating apparatus and a plating method which, with a relatively simple construction, can securely fill in via holes or the like with a metal film without the formation of voids in the embedded metal film even when the via holes or the like have a high aspect ratio and a large depth.
In order to achieve the above object, the present invention provides a plating apparatus comprising: a plating tank for holding a plating solution; a plating solution jet nozzle having a slit-like plating solution jet orifice for jetting the plating solution toward a surface to be plated of an object to be plated disposed in the plating tank; and a plating solution supply section for supplying the plating solution to the plating solution jet nozzle.
A plated film having a uniform thickness can be formed on a surface to be plated of an object to be plated by carrying out plating while jetting a high-velocity plating solution from the plating solution jet orifice of the plating solution jet nozzle toward the surface to be plated. Either a single plating solution jet orifice or a plurality of plating solution jet orifices, arranged in series, may be provided in the plating solution jet nozzle.
Preferably, a plurality of the plating solution jet nozzles is disposed in parallel with each other in the plating tank.
By disposing a plurality of plating solution jet nozzles in parallel with each other, a plated film having a more uniform thickness can be formed on a surface to be plated of an object to be plated.
The plating apparatus may further comprise a flow rate distribution section for distributing the flow rate of the plating solution to the plurality of plating solution jet nozzles in consideration of the flow conductance of the plating solution.
This makes it possible to regulate, according to the plating situation, the flow rate of the plating solution jetted from the plating solution jet orifice of each plating solution jet nozzle, thus enabling the optimal plating.
Preferably, the plating solution jet nozzle is moved parallel to the surface to be plated of the object to be plated.
A plated film having a more uniform thickness can be formed on the surface to be plated of a object to be plated by carrying out plating while moving the plating solution jet nozzle parallel to the surface to be plated.
In a preferred embodiment of the present invention, the plating apparatus further comprises a flow rate control section for controlling the flow rate of the plating solution jetted from the plating solution jet orifice, and the plating solution jet orifice has a width of 0.05 to 1.0 mm.
According to this embodiment, a high-velocity plating solution, in the form a thin belt having a thickness of 0.05 to 1.0 mm, can be jetted from the plating solution jet orifice toward the surface to be plated of a object to be plated to form a plated film having a uniform thickness on the surface to be plated.
The velocity of the plating solution, jetted from the plating solution jet orifice of the plating solution jet nozzle, preferably is 5 to 20 m/sec in the vicinity of the plating solution jet orifice.
A plated film having a uniform thickness can be formed on the surface to be plated of the object to be plated also by thus regulating the flow velocity of the plating solution.
In a preferred embodiment of the present invention, the plating apparatus further comprises a flow rate monitor section for monitoring the flow rate of the plating solution jetted from the plating solution jet orifice and/or a pressure monitor section for monitoring the pressure in the plating solution jet nozzle.
This makes it possible to regulate the flow rate of the plating solution and/or the pressure in the plating solution jet nozzle according to the plating situation, enabling the optimal plating.
In a preferred embodiment of the present invention, the plating apparatus further comprises a flow rate sensor for detecting the flow rate of the plating solution jetted from the plating solution jet orifice and/or a pressure sensor for detecting the pressure in the plating solution jet nozzle, and a plating solution flow rate regulation section for regulating the flow rate of the plating solution by feeding back a detection signal of the flow rate sensor and/or the pressure sensor to the plating solution supply section.
The flow rate of the plating solution can thus be regulated according to the plating situation, so that the optimal plating can be effected.
The distance between the front end of the plating solution jet orifice and the object to be plated is preferably 1 to 30 mm.
This enables the plating solution jetted from the plating solution jet orifice to easily reach, without turbulence, the surface to be plated of a object to be plated, thereby forming a plated film having a uniform thickness on the surface to be plated.
In a preferred embodiment of the present invention, the plating apparatus further comprises an anode disposed between the plating solution jet nozzle and the object to be plated.
Thus, an electroplating apparatus is constructed.
The anode may be disposed within the plating solution jet nozzle.
This eliminates the need to separately provide an anode in the plating tank and thus can provide a simplified smaller-sized electroplating apparatus.
In a preferred embodiment of the present invention, the plating solution supply section includes a pump for feeding out the plating solution discharged from the plating tank, and a plating solution supply pipe connecting the pump with the plating solution jet nozzle, and at least part of the plating solution supply pipe is formed of a flexible material so that it can follow a movement of the plating solution jet nozzle.
This makes it possible, with a simple construction, to supply the plating solution to the plating solution jet nozzle while allowing the plating solution supply pipe to follow a movement of the plating solution jet nozzle.
The present invention provides a plating method comprising: disposing an object to be plated and a plating solution jet nozzle having a slit-like plating solution jet orifice opposite to each other in a plating solution in a plating tank; and jetting the plating solution from the plating solution jet orifice while moving the plating solution jet nozzle parallel to a surface to be plated of the object to be plated.
The present invention provides another plating apparatus comprising: a plating tank for holding a plating solution; a holder for holding an object to be plated, feeding electricity to the object to be plated, and bringing a surface to be plated of the object to be plated into contact with the plating solution in the plating tank; an anode disposed in the plating solution in the plating tank; a plating solution stirring section, disposed between the anode and the object to be plated held by the holder, for stirring the plating solution in the plating tank; and a plating power source for periodically applying a voltage between the object to be plated and the anode; wherein the plating solution is stirred by the plating solution stirring section when no voltage is applied between the object to be plated and the anode, whereas the stirring of the plating solution by the plating solution stirring section is stopped when the voltage is applied between the object to be plated and the anode.
By stirring the plating solution by the plating solution stirring section in the non-plating time when no voltage is applied between the object to be plated and the anode, the plating solution in via holes or the like can be replaced with a fresh plating solution. By stopping the stirring of the plating solution in the plating time when a voltage is applied between the object to be plated and the anode, on the other hand, plating can be carried out without supply of a fresh plating solution to via holes or the like. This can prevent a metal film (plated film) from being deposited preferentially at the open ends of via holes or the like and can fill in the via holes or the like with a void-free metal film.
Preferably, the plating solution stirring section is comprised of a paddle which reciprocates parallel to the surface to be plated of the object to be plated held by the holder.
The plating solution between the object to be plated and the anode can be stirred by reciprocating the paddle, whereas the stirring of the plating solution between the object to be plated and the anode can be stopped by stopping the movement of the paddle.
Alternatively, the plating solution stirring section may be comprised of a plating solution jet nozzle for jetting the plating solution toward the surface to be plated of the object to be plated held by the holder.
The plating solution between the object to be plated and the anode can be stirred by jetting the plating solution from the plating solution jet nozzle toward the surface to be plated of the object to be plated, whereas the stirring of the plating solution between the object to be plated and the anode can be stopped by stopping the jetting of the plating solution from the plating solution jet nozzle.
The plating solution jet nozzle may be provided integrally with the paddle so that it moves together with the paddle, or disposed fixedly in the plating tank.
Preferably, the voltage is applied between the object to be plated and the anode so that the current density becomes 0.1 to 0.8 A/dm².
It has been confirmed experimentally that plating at such a low current density attains good embedding property of plated film.
The present invention provides another plating method comprising: disposing an object to be plated and an anode opposite to each other in a plating solution in a plating tank; periodically applying a voltage between the object to be plated and the anode; and stirring the plating solution between the object to be plated and the anode when no voltage is applied between the object to be plated and the anode, and stopping the stirring of the plating solution between the object to be plated and the anode when the voltage is applied between the object to be plated and the anode.
Preferably, the plating solution is stirred by reciprocating a paddle, disposed between the object to be plated and the anode, parallel to the object to be plated, and the stirring of the plating solution is stopped by stopping the movement of the paddle.
Alternatively, the plating solution is stirred by jetting the plating solution from a plating solution jet nozzle, disposed between the object to be plated and the anode, toward the object to be plated, and the stirring of the plating solution is stopped by stopping the jetting of the plating solution from the plating solution jet nozzle.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic vertical sectional view of a conventional plating apparatus;
FIG. 2 is a schematic perspective view of another conventional plating apparatus;
FIG. 3 is a schematic perspective view of yet another conventional plating apparatus;
FIG. 4 is a schematic perspective view of yet another conventional plating apparatus;
FIG. 5 is a diagram illustrating embedding of a metal film by plating as carried out by a conventional plating apparatus;
FIG. 6 is a schematic vertical sectional view of a plating apparatus according to an embodiment of the present invention;
FIG. 7 is a plan view showing the arrangement of a substrate holder, an anode and plating solution jet nozzles in the plating apparatus shown in FIG. 6:
FIG. 8A is a plan view of a plating solution jet nozzle, FIG. 8B is a front view of the plating solution jet nozzle, and FIG. 8C is a cross-sectional view taken along line B-B of FIG. 8B;
FIG. 9A is a plan view of another plating solution jet nozzle, and FIG. 9B is a front view of the plating solution jet nozzle;
FIG. 10A is a plan view of yet another plating solution jet nozzle, FIG. 10B is a front view of the plating solution jet nozzle, and FIG. 10C is a cross-sectional view taken along line C-C of FIG. 10B;
FIG. 11 is a plan view showing the arrangement of substrate holders and plating solution jet nozzles in a plating apparatus according to another embodiment of the present invention;
FIG. 12 is an overall plan view of a substrate processing apparatus incorporating a plating apparatus according to the present invention;
FIG. 13 is a diagram illustrating the flow of air in the substrate processing apparatus shown in FIG. 12;
FIG. 14 is an overall plan view of an interconnects-forming apparatus incorporating a plating apparatus according to the present invention;
FIG. 15 is a flow chart of the interconnects-forming apparatus of FIG. 14;
FIGS. 16A and 16B are diagrams illustrating the process of the formation of interconnects in a substrate;
FIG. 17 is an overall plan view of a semiconductor manufacturing apparatus incorporating a plating apparatus according to the present invention;
FIGS. 18A through 18C are diagrams illustrating, in a sequence of process steps, a process for forming interconnects in a semiconductor device;
FIG. 19 is an overall plan view of a substrate processing apparatus incorporating a plating apparatus according to the present invention;
FIGS. 20A through 20E are diagrams illustrating, in a sequence of process steps, a process for forming bumps;
FIG. 21 is an overall plan view of a plating processing facility incorporating a plating apparatus according to yet another embodiment of the present invention;
FIG. 22 is a schematic diagram of a transport robot provided in a plating space of the plating processing facility shown in FIG. 21;
FIG. 23 is a schematic sectional view of the plating apparatus provided in the plating processing facility shown in FIG. 21;
FIG. 24 is a diagram illustrating piping around a plating tank of the plating apparatus shown in FIG. 21;
FIG. 25 is a plan view showing the arrangement of a substrate, paddles, a regulation plate and an anode in the plating apparatus shown in FIG. 21;
FIG. 26 is a graph illustrating a voltage applied between the anode and the substrate in the plating apparatus shown in FIG. 21;
FIGS. 27A through 27D are diagrams illustrating, in a sequence of process steps, a process for producing an interposer or a spacer having vertically-penetrating via plugs of copper therein; and
FIG. 28 is a schematic cross-sectional view of a plating apparatus according to yet another embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Preferred embodiments of the present invention will now be described with reference to the drawings. The following description illustrates the case of using a substrate, such as a semiconductor wafer, as an object to be plated.
FIG. 6 is a schematic vertical sectional view of a plating apparatus according to an embodiment of the present invention, and FIG. 7 is a plan view showing the arrangement of a substrate holder, an anode and plating solution jet nozzles in a plating tank. The plating apparatus 10 is an electroplating apparatus, and includes a plating tank 11 for holding therein a plating solution Q, and an overflow tank 13 for holding the plating solution Q that has overflowed the upper end of the overflow weir 12 of the plating tank 11. In the plating tank 11, a substrate W, which is held by a substrate holder 14, and an anode 15, both immersed in the plating solution Q, are disposed vertically and opposite to each other at a predetermined distance. Plating solution jet nozzles 16, for jetting the plating solution Q, are disposed vertically between the substrate W and the anode 15. The distance between the front end of each plating solution jet nozzle 16 and the surface of the substrate W is, for example, 1 to 30 mm.
The plating apparatus 10 is provided with a plurality (e.g. two) of the plating solution jet nozzles 16 whose upper ends are fixed to a shaft 17 at predetermined intervals. A rack 18 is provided on the lower surface of the shaft 17. By rotating a pinion 19, engaging with the rack 18, in opposite directions by a motor 20, the shaft 17 reciprocates in the direction of arrow A and the plating solution jet nozzles 16 also reciprocate in the same direction.
FIG. 8A is a plan view of the plating solution jet nozzle 16, FIG. 18B is a front view of the plating solution jet nozzle 16, and FIG. 8C is a cross-sectional view taken along the line B-B of FIG. 8B. The plating solution jet nozzle 16 is long, has a generally-rectangular cross section with a raised portion 16 b in one side, and centrally has a plating solution supply hole 16 a extending in the length direction. A plurality of slit-like plating solution jet orifices 16 c, arranged in series and communicating with the plating solution supply hole 16 a, is formed at the top of the raised portion 16 b. By supplying the plating solution to the plating solution supply hole 16 a at a predetermined pressure, the plating solution in the form of a belt (flat plate), corresponding to the shape of the plating solution jet orifices 16 c, is jetted from the plating solution jet orifices 16 c.
Each plating solution jet nozzle 16 is connected to a branch pipe (plating solution supply pipe) 22 branching off from a flow rate manifold 21, as a flow rate distribution section, for distributing the flow rate of plating solution, and the flow rate manifold (flow rate distribution section) 21 is in turn connected to a flow rate/pressure meter 24 via a flexible pipe (plating solution supply pipe) 23. The flow rate/pressure meter 24 is connected via piping 26 a to the discharge opening of a pump 25, and the suction opening of the pump 25 is connected via piping 26 b to the plating solution discharge outlet of the overflow tank 13. By the pump 25, the plating solution Q discharged into the overflow tank 13 is supplied through the piping 26 a, the piping 26 b, the flow rate/pressure meter 24, the flexible pipe 23, the flow rate manifold 21 and the branch pipe 22 into each plating solution jet nozzle 16, and is jetted from the slit-like plating solution jet orifices 16 of the plating solution jet nozzle 16 c toward the substrate W. The plating solution Q, after filling the plating tank 11, overflows the upper end of the overflow wire 12 and flows into the overflow tank 13.
By connecting the substrate W held by the substrate holder 14 and the anode 15 to a direct-current plating power source 27, and applying a predetermined direct-correct voltage from the plating power source 27 to between the substrate W and the anode 15, a plating current flows from the anode 15 to the substrate W, and a plated film is formed on the surface of the substrate W. During the plating processing of the substrate W, each plating solution jet nozzle 16, mounted to the shaft 17, jets the plating solution from the plating solution jet orifices 16 c toward the surface of the substrate W while reciprocating parallel to the substrate W with a predetermined stroke by a nozzle movement mechanism consisting of the rack 18, the pinion 19 and the motor 20. Each plating solution jet nozzle 16 thus performs the function of uniformly supplying the plating solution to the surface (surface to be plated) of the substrate W and the function of supplying the plating solution Q into the plating tank 11.
The jet velocities of plating solutions q1, q2, q3 . . . jetted from the plating solution jet orifices 16 c of the plating solution jet nozzle 16 are determined by the flow rate and the pressure of the plating solution Q supplied from the pump 25 to the flow rate manifold 21. Accordingly, the jet velocities and the flow rates of plating solution q1, q2, q3 . . . jetted from the plating solution jet orifices 16 c of the plating solution jet nozzle 16 can be controlled by feeding back the flow rate and the pressure detected by the flow rate/pressure meter 24 to the pump 25. The flow rate manifold 21 distributes the flow rate of plating solution to the plating solution jet nozzles 16 in consideration of the flow conductance of the plating solution Q.
The flexible pipe 23 has such a length that the shaft 17, or the plating solution jet nozzles 16 can reciprocate with a predetermined stroke safely without trouble and the flexible pipe 23 can smoothly follow the movement of the plating solution jet nozzles 16. Though in this embodiment the combination of the rack 18 and the pinion 19 is employed as a nozzle movement mechanism for reciprocating the shaft 17, the present invention is not limited to such nozzle movement mechanism. Any drive mechanism, such as a nozzle movement mechanism comprised of a rack and a worm, a drive mechanism comprised of a linear slider, etc., which allows the shaft 17 to reciprocate with a predetermined stroke, can be employed.
The plating solution jet nozzle 16 is not limited to the one shown in FIGS. 8A through 8C, having the plurality of slit-like plating solution jet orifices 16 c arranged in series, but may be one as shown in FIGS. 9A and 9B, having a single long slit-like plating solution jet orifice 16 d. FIG. 9A is a plan view of the plating solution jet nozzle 16 having the single long slit-like plating solution jet orifice 16 d, and FIG. 9B is a front view of the plating solution jet nozzle 16 having the single long slit-like plating solution jet orifice 16 d. The slit width of the slit-like plating solution jet orifice 16 c or 16 d is, for example, 0.05 to 1.0 mm. Though in this embodiment the plating solution jet nozzle 16 has a generally-rectangular cross section, a plating solution jet nozzle having any cross-sectional shape may be employed insofar as the plating solution jet nozzle has slit-like plating solution jet orifices arranged in series or a single slit-like plating solution jet orifice and can jet a belt-like (flat plate-like) plating solution from the plating solution jet orifice(s).
A monitor section (not shown) may be provided which, based on the flow rate and the pressure of the plating solution detected by the flow rate/pressure meter 24, calculates and monitors at least one of the flow rate of the plating solution jetted from the plating solution jet orifices 16 c or the orifice 16 d of each plating solution jet nozzle 16 and the pressure in each plating solution jet nozzle 16. By continually monitoring at least one of the jet flow rate of the plating solution and the pressure in the plating solution jet nozzle 16 with the monitor section, it becomes possible to maintain the optimum plating conditions.
Using the plating apparatus 10 having the above construction, plating was carried out on a substrate W, having openings (holes) with a diameter of 100 μm and a depth of 50-200 μm, and having a copper seed film (without a resist) formed-over the entire surface, under the following conditions. As a result, the openings were filled in with the plating without the formation of voids.
Nozzle Installation Conditions

- Number of plating solution jet nozzles 16: 2
- Distance between plating solution jet nozzles 16, 16: 100 mm
- Frequency of reciprocation of plating solution jet nozzles 16: 30 rpm
- Distance between the front ends of plating solution jet nozzles 16 and the substrate W: 10 mm
- Flow rate of plating solution at the front end of slit-like plating solution jet orifice: 10 m/sec
  Composition of Plating Solution
- CuSO₄.5H₂O (inorganic component): 150-250 g/L
- H₂SO₄: 5-100 g/L
- Cl: 30-60 ppm
- Polymer (organic component): PPG 500 ppm
- Carrier (organic component): SPS 5 ppm
- Leveler (organic component): polyethyleneimine 1 ppm
  Plating Conditions
- Plating current density: DC 5 mA/cm²
- Plating time: 1-10 hrs

For comparison, using a conventional plating apparatus, plating was carried out on a substrate, having a copper seed layer formed over the entire surface and having openings (holes) with a diameter of 10 μm and a depth of 50 μm, by passing an electric current from a plating power source at a current density of DC 5 mA/cm². As a result, the openings were not fully filled in with the plating: voids were formed at the bottoms of the openings.
FIG. 10A is a plan view showing yet another plating solution jet nozzle for use in a plating apparatus according to the present invention, FIG. 10B is a front view of this plating solution jet nozzle, and FIG. 10C is a cross-sectional view taken along line C-C of FIG. 10B. The plating solution jet nozzle 16 has a single slit-like plating solution jet orifice 16 d communicating with a plating solution supply hole 16 a and thus is constructionally the same in this regard as the plating solution jet nozzle 16 shown in FIGS. 9A and 9B, but has a bar-like anode 28 centrally in the plating solution supply hole 16 a. The anode 28 is thus provided integrally with the plating solution jet nozzle 16, and hence there is no need to separately dispose an anode, opposite to a substrate, in the plating tank 11. When the plating solution jet nozzle 16 is moved parallel to a substrate W, the anode 28 also moves concomitantly. Though not shown diagrammatically, it is also possible to provide the bar-like anode 28 in the plating solution supply hole 16 a of the plating solution jet nozzle 16 shown in FIGS. 8A through 8C, having the plurality of slit-like plating solution jet orifices 16 c.
FIG. 11 is a plan view schematically showing the internal construction of the plating tank 11 of a plating apparatus which uses the plating solution jet nozzle 16 shown in FIGS. 10A through 10C, i.e. a layout plan of a substrate holder and the plating solution jet nozzle. Two substrates W, each held by one of two substrate holders 14, are disposed at a predetermined distance from each other in the plating solution Q in the plating tank 11. Between the substrates W, disposed opposite to each other, is disposed a nozzle movement mechanism 32 which includes a nozzle supporting belt 31 which is supported by sprockets 29, 30 and rotationally moves parallel to the substrates W. The plating solution jet nozzles 16, each having the construction shown in FIGS. 10A through 10C, are mounted at predetermined intervals to the nozzle supporting belt 31 of the nozzle movement mechanism 32. By thus disposing two substrates W at a predetermined distance from each other in the plating solution Q in the plating tank 11 (depiction omitted in FIG. 11), and moving the nozzle supporting belt 31 while jetting the plating solution Q from the plating solution jet nozzles 16 toward the two substrates W, a plated film having a uniform thickness can be formed on the surface of each substrate W.
Instead of rotationally moving the nozzle supporting belt 31 of the nozzle movement mechanism 32 in one direction, it is also possible to reciprocate the plating solution jet nozzles 16 with a predetermined moving distance (stroke) by rotating the sprockets 29, 30 in opposite directions. This enables supply of the plating solution to each plating solution jet nozzle 16 to be dealt with by the use of a flexible plating solution supply pipe, and also enables electrical connection from a plating power source to the anode 28 to be dealt with by the use of a flexible feeding cable, thus simplifying the apparatus construction.
FIG. 12 is a layout plan view of a substrate processing apparatus incorporating the plating apparatus having the construction shown in FIGS. 6 and 7. The substrate processing apparatus comprises loading/unloading sections 40, each pair of cleaning/drying sections 41, first substrate stages 42, bevel-etching/chemical cleaning sections 43 and second substrate stages 44, a water-washing section 45 provided with a mechanism for reversing the substrate through 180°, and four plating sections (plating apparatuses) 46. The substrate processing apparatus is also provided with a first transport device 48 for transferring a substrate between the loading/unloading sections 40, the cleaning/drying sections 41 and the first substrate stages 42, a second transport device 49 for transferring a substrate between the first substrate stages 42, the bevel-etching/chemical cleaning sections 43 and the second substrate stages 44, and a third transport device 50 for transferring the substrate between the second substrate stages 44, the water-washing section 45 and the plating section 46.
The substrate processing apparatus has a partition wall 51 for dividing the substrate processing apparatus into a plating space 53 and a clean space 52. Air can individually be supplied into and exhausted from each of the plating space 53 and the clean space 52. The partition wall 51 has a shutter (not shown) capable of opening and closing. The pressure of the clean space 52 is lower than the atmospheric pressure and higher than the pressure of the plating space 53. This can prevent the air in the clean space 52 from flowing out of the plating apparatus and can prevent the air in the plating space 53 from flowing into the clean space 52.
FIG. 13 is a schematic view showing an air current in the substrate processing apparatus. In the clean space 52, a fresh external air is introduced through a pipe 54 and pushed into the clean space 52 through a high-performance filter 55 by a fan. Hence, a down-flow clean air is supplied from a ceiling 56 a to positions around the cleaning/drying sections 41 and the bevel-etching/chemical cleaning sections 43. A large part of the supplied clean air is returned from a floor 56 b through a circulation pipe 57 to the ceiling 56 a, and pushed again into the clean space 52 through the high-performance filter 55 by the fan, to thus circulate in the clean space 52. A part of the air is discharged from the cleaning/drying sections 41 and the bevel-etching/chemical cleaning sections 43 through a pipe 48 to the exterior, so that the pressure of the clean space 52 is set to be lower than the atmospheric pressure.
The plating space 53 having the water-washing sections 45 and the plating sections 46 therein is not a clean space (but a contamination zone). However, it is not acceptable to attach particles to the surface of the substrate W. Therefore, in the plating space 53, a fresh external air is introduced through a pipe 59, and a down-flow clean air is pushed into the plating space 53 through a high-performance filter 60 by a fan, for thereby preventing particles from being attached to the surface of the substrate W. However, if the whole flow rate of the down-flow clean air is supplied by only an external air supply and exhaust, then enormous air supply and exhaust are required. Therefore, the air is discharged through a duct 62 to the exterior, and a large part of the down-flow is supplied by a circulating air through a circulation pipe 63 extended from a floor 61 b, in such a state that the pressure of the plating space 53 is maintained to be lower than the pressure of the clean space 52.
Thus, the air returned to a ceiling 61 a through the circulation pipe 63 is pushed again into the plating space 53 through the high-performance filter 60 by the fan. Hence, a clean air is supplied into the plating space 53 to thus circulate in the plating space 53. In this case, air containing chemical mist or gas emitted from the water-washing sections 45, the plating sections 46, the third transport device 50, and a plating solution regulating tank 64 is discharged through the duct 62 to the exterior. Thus, the pressure of the plating space 53 is controlled so as to be lower than the pressure of the clean space 52. When the shutters (not shown) are opened, therefore, air flows successively through the loading/unloading sections 40, the clean space 52, and the plating space 53. Air discharged from the clean space 52 and the plating space 53 flows through the ducts 62, 58 to the exterior.
FIG. 14 shows a layout plan view of an interconnects-forming apparatus incorporating the above-described plating apparatus and an electrolytic etching apparatus. The interconnects-forming apparatus comprises pairs of loading/unloading sections 70, cleaning/drying sections 71, temporary storage sections 72, plating sections (electroplating apparatuses) 73, water-washing sections 74 and etching sections 75, a first transport mechanism 76 for transferring a substrate W between it and the loading/unloading sections 70, the cleaning/drying section 71 and the temporary storage sections 72, and a second transport mechanism 77 for transferring the substrate W between it and the temporary storage sections 72, the plating sections 73, the water-washing sections 74 and the etching sections 75. The plating apparatus 10 having the construction shown in FIGS. 6 and 7 is disposed in each plating section 73.
Interconnects-forming processing by the interconnects-forming apparatus will now be described with reference to FIGS. 14 and 15. First, substrates W having a surface seed layer are taken one by one by the first transport mechanism 76 out of the loading/unloading section 70, and the substrate W is carried in the plating section 73 via the temporary storage section 72 (step ST1).
Next, plating is carried out in the plating section 73 to form a copper layer 7 on the surface of the substrate W, as shown in FIGS. 16A and 16B (step ST2). Taking as the first priority a reduction of recesses 7 a formed in the copper layer 7 due to the presence of large holes, a plating solution having an excellent leveling property, for example, one having such a high concentration of copper sulfate as 100 to 300 g/L and such a low concentration of sulfuric acid as 10 to 100 g/L, and containing an additive for enhancing the leveling property, such as a polyalkyleneimine, a quaternary ammonium salt or a cationic dye, is used in the plating. The term “leveling property” herein refers to a property of promoting bottom-up growth of plating in holes.
By thus carrying out plating of the surface of the substrate W by using a plating solution having an excellent leveling property, the bottom-up growth of plating in large holes can be promoted, resulting in the formation of copper layer 7 having a larger thickness t₂in a large-hole area than the thickness t₁of a flat area, as shown in FIG. 16B. Thus, large holes can be filled in with a plated film having the small thickness t₁. The substrate W after the plating processing is transported to the water-washing section 74 to water-wash the substrate W, as necessary (step ST3). The substrate W after water-washing is then transported to the etching section 75.
Next, electrolytic etching of the surface (plated surface) of the substrate W is carried out in the etching section 75 to etch the surface copper layer 7 of the substrate W (step ST4) In the etching, an etching solution is used containing an additive which acts as an etching promoter, such as pyrophosphoric acid, ethylenediamine, aminocarboxylic acid, EDTA, DTPA, iminodiacetic acid, TETA, or NTA, an additive which acts as an etching inhibitor, such as a copper complex with a quaternary ammonium salt or a polymer, or an organic complex or its derivative, or an additive which makes the copper corrosion potential base, such as thiourea or its derivative. An acid such as sulfuric acid, hydrochloric acid, an aqueous solution of sulfuric acid and hydrogen peroxide or an aqueous solution of hydrofluoric acid and hydrogen peroxide, or an alkali such as an aqueous solution of ammonia and hydrogen peroxide, may be used as abase bath, though not limited thereto.
Raised portions of the copper layer 7 can be selectively etched by the electrolytic etching, thereby enhancing the flatness of the copper film 7. The electrolytic etching enables a later CMP processing to be carried out in a short time without resorting to a high polishing rate, and thus without suffering from dishing. Next, the substrate W after the etching processing is transported to the water-washing section 74 to water-wash the substrate W, as necessary (step ST5). The substrate W after water-washing is transported to the cleaning/drying section 71, where the substrate W is cleaned and dried (step ST6). Thereafter, the substrate W is returned by the first transport mechanism 76 to the cassette of loading/unloading section 70 (step ST7).
It is possible to repeatedly carry out plating and etching several times to selectively etch raised portions of the copper film (copper layer 7) after each plating processing, thereby further enhancing the flatness of the copper film. Though in this embodiment the plating processing and the etching processing are carried out successively in the same interconnects-forming apparatus, it is also possible to carry out the two processings separately by independent apparatuses.
In this embodiment, the electroplating apparatus and the electrolytic etching apparatus used have the same construction, but use different electrolytic solutions and apply voltages of opposite polarities between a substrate W and an electrode (anode or cathode). It is also possible to use only a electroplating apparatus and employ the electroplating apparatus also as an electrolytic etching apparatus by changing the polarity of the voltage applied between a substrate W and the anode 15 (see FIG. 2), i.e., making the substrate W serve as an anode and the anode 15 serve as a cathode.
FIG. 17 is a plan view showing the overall construction of a semiconductor manufacturing apparatus using the above-described electroplating apparatus. The semiconductor manufacturing apparatus includes, at one end of the space on a rectangular floor, a first polishing unit 80 a and a second polishing unit 80 b disposed side by side and, at the other side, a loading/unloading section 82 for placing thereon substrate cassettes 81 a, 81 b each housing substrates W, such as semiconductor wafers. Two transport robots 83 a, 83 b are disposed on a line connecting the polishing units 80 a, 80 b and the loading/unloading section 82.
The semiconductor manufacturing apparatus also includes, on one side of the transport line, a first plating unit (electroplating apparatus) 84 for embedding of copper, a film thickness detection unit 85 provided with a reversing machine and a pre-processing unit 86 provided with a reversing machine and, on the other side, a rinsing/drying device 87, a second plating unit (electroless plating apparatus) 88 for forming a protective film and a cleaning unit 89 provided with a roll sponge. On the transport line sides of the polishing units 80 a, 80 b are provided vertically- movable pushers 90, 90 for transferring the substrate W between them and the polishing units 80 a, 80 b.
A process for forming interconnects of a semiconductor device by the above semiconductor manufacturing apparatus will now be described with reference to FIGS. 18A through 18C. A substrate W, as shown in FIG. 18A, is provided which has been prepared by depositing an insulating film 2 of, for example, SiO₂on a conductive layer 1 a, in which semiconductor devices are formed, on a semiconductor base 1, forming via holes 3 and trenches 4 in the insulating film 2 by, for example, the lithography/etching technique, and then forming a barrier layer 5 of Ta, TaN, or the like and a seed layer 6, which serves as an electric supply layer in electroplating, in this order over the entire surface by, for example, sputtering.
Such substrates W having the surface seed layer 6 are taken one by one by the transport robot 83 a out of the substrate cassettes 81 a, 81 b, and the substrate W is carried in the first plating unit 84. In the first plating unit 84, a copper layer 7 is deposited on the surface of the substrate W, thereby filling in the via holes 3 and the trenches 4 with copper, as shown in FIG. 18B. The formation of copper layer 7 by copper plating is carried out after subjecting the substrate W to a treatment for making the surface hydrophilic. After the plating, as described previously, it is possible to carry out etching of the surface of the copper layer 7 by using the first plating unit 84 as an electrolytic etching apparatus by changing the polarity of the voltage applied. After the formation of copper layer 7, the substrate W is rinsed or cleaned in the first plating unit 84 and, if time permits, may be dried.
The copper-embedded substrate W is transported to the film thickness detection unit 85, where the thickness of the copper layer 7 is measured and, if necessary, the substrate W is reversed by the reversing machine. Thereafter, the substrate W is transported by the transport robot 83 b onto the pusher 90 of the polishing unit 80 a or 80 b.
In the polishing unit 80 a or 80 b, polishing of the substrate W is carried out by pressing the polishing surface of the substrate W against a polishing table while supplying an abrasive liquid to the polishing surface. The polishing is terminated, for example, when the end point is detected by a monitor for detecting the finish of the substrate W. The substrate W after the polishing is returned onto the pusher 90, and cleaned by pure water-spraying. The substrate W is then transported by the transport robot 83 b to the cleaning unit 89, where the substrate W is cleaned e.g. with a roll sponge. Interconnects 8, as shown in FIG. 18C, consisting of the seed layer 6 and the copper layer 7, are thus formed in the insulating film 2.
Next, the substrate W is transported to the pre-processing unit 86, where the substrate W is subjected to pre-processing, such as application of a Pd catalyst, removal of an oxide film from the exposed surfaces of interconnects, etc. Thereafter, the substrate W is transported to the second plating unit (electroless plating apparatus) 88. In the second plating unit 88, electroless COWP plating, for example, is carried out on the surfaces of interconnects 8 exposed after polishing to thereby form a protective film (plated film) 9 of a COWP alloy selectively on the exposed surfaces of interconnects 8 to protect the interconnects 8, as shown in FIG. 18C. The thickness of the protective film 9 is about 0.5 to 500 nm, preferably about 1 to 200 nm, more preferably about 10 to 100 nm.
FIG. 19 shows a layout plan view of another substrate processing apparatus for forming, for example, bumps. As shown in FIG. 19, the substrate processing apparatus includes two cassette tables 430 each setting a cassette housing substrates such as semiconductor wafers, an aligner 431 for aligning an orientation flat or a notch of a substrate W in a predetermined direction, and a rinse drier 432 for rinsing the substrate W after plating and drying the substrate W by rotating it at a high speed. Among the two cassette tables 430, the aligner 431 and the rinse drier 432 is disposed a movable first transport robot 433 for transferring the substrate W therebetween. The first transport robot 433 has a hand of, for example, the vacuum attraction type or the drop-in type, and transfers the substrate W in the horizontal position.
The substrate processing apparatus of this embodiment also includes four plating units 434 disposed in series. Each plating unit 434 includes a plating tank 435 and a water-washing tank 436 disposed adjacent to each other. Above the plating tank 435 and the water-washing tank 436, a substrate holder 437 for detachably holding the substrate W in the vertical position is disposed vertically movably by a vertical movement mechanism section 438 and laterally movably by a lateral movement mechanism section 444. In front of the plating units 434 is disposed a movable second transport robot 439 for transferring the substrate W between the aligner 431, the rinse drier 432 and the substrate holder 437 of each plating unit 434. The second transport robot 439 has a hand which holds the substrate W by, for example, mechanical chucking and which is provided with a reversing mechanism 440 for 90°-reversing the substrate W between the horizontal position and the vertical position, and transfers the substrate W in the horizontal position between it and the aligner 431 or the rinse drier 432 and in the vertical position between it and the substrate holder 437.
In each plating tank 435, an anode 441 is disposed in such a position that when the substrate W held by the substrate holder 437 is disposed in a predetermined position in the plating tank 435, the anode 441 faces the front surface of the substrate W. Further, between the substrate W and the anode 441 are disposed plating solution jet nozzles 443 which are mounted to a shaft 445 that reciprocates by the actuation of a nozzle movement mechanism 442. A plating solution is jetted from the plating solution jet nozzles 443 toward the substrate W. The plating apparatus, including the plating tank 435, the anode 441 and the plating solution jet nozzles 443, has the same construction as the plating apparatus shown in FIGS. 6 and 7.
A series of plating processings for the formation of bumps by the substrate processing apparatus having the above construction will now be described. First, a substrate W, as shown in FIG. 20A, is provided which has been prepared by forming a seed layer 420 as an electric supply layer on a surface, coating an entire surface of the seed layer 420 with a resist 421 having a thickness H of e.g. 20 to 120 μm, and forming openings 421 a having a diameter of e.g. about 20 to 200 μm at predetermined positions in the resist 421. Such substrates W are housed in a cassette with their front surfaces (surfaces to be plated) upward, and the cassette is mounted on the cassette table 430.
One substrate W is taken by the first transport robot 433 out of the cassette mounted on the cassette table 430, and the substrate W is placed on the aligner 431 to align an orientation flat or a notch in a predetermined direction. The thus-oriented substrate W by the aligner 431 is taken by the second transport robot 439 out of the aligner 431 and is 90′-reversed from the horizontal position to the vertical position by the reversing mechanism 440, and the reversed substrate W is then transferred to the substrate holder 437 of one of the plating units 434.
In this embodiment, transfer of the substrate W is carried out above the water-washing tank 436. Thus, the substrate holder 437 has been raised by the vertical movement mechanism section 438 and moved to a position above the water-washing tank 436 by the lateral movement mechanism section 444 when it receives the substrate W from the second transport robot 439 and holds the substrate W in the vertical position.
The substrate holder 437 holding the substrate W in the vertical position is moved to the plating tank 435 side by the lateral movement mechanism section 444. The plating tank 435, on the other hand, is filled with a plating solution. The substrate holder 437 holding the substrate W is lowered by the vertical movement mechanism section 438 to immerse the substrate W held by the substrate holder 437 in the plating solution in the plating tank 435. A plating voltage is applied between the anode 441 and the substrate W, and the plating solution is jetted from the plating solution jet nozzles 443 toward the substrate W while reciprocating the plating solution jet nozzles 443 parallel to the surface of the substrate W by the nozzle movement mechanism 442, thereby carrying out plating of the surface of the substrate W. After the completion of plating, the application of the plating voltage, the jetting of the plating solution and the reciprocation of the plating solution jet nozzles 443 are stopped, and the substrate holder 437 holding the substrate W after plating is raised and pulled up from the plating tank 435 by the vertical movement mechanism section 438.
After the plating processing, the substrate holder 437 holding the substrate W in the vertical position is moved to the water-washing tank 436 side by the lateral movement mechanism section 444. The substrate holder 437 holding the substrate W is lowered into the water-washing tank 436 by the vertical movement mechanism section 438 and, while pulling up the substrate holder 437, pure water is jetted from jet nozzles (not shown) toward the substrate holder 437 to clean off the plating solution remaining on the substrate W and the substrate holder 437. Alternatively, the water-washing tank 436 is filled with pure water in advance, and the substrate holder 437 holding the substrate W is immersed in the pure water. The pure water in the water-washing tank 436 is then withdrawn rapidly to thereby clean off the plating solution remaining on the substrate W and the substrate holder 437. It is, of course, possible to use the two water-washing methods in combination.
The second transport robot 439 receives the substrate W in the vertical position from the substrate holder 437 above the water- washing tank 436, 90′-reverses the substrate W from the vertical position to the horizontal position, and transports the reversed substrate W to the rinse drier 432, where the substrate W is rinsed and spin-dried (water-drained) by high-speed rotating of the substrate. Thereafter, the substrate W is returned to the cassette mounted on the cassette table 430, thereby completing the series of operations. The substrate W in which a plated film 422 has been grown in the openings 421 a provided in the resist 421, as shown in FIG. 20B, is thus obtained.
Though the foregoing description illustrates the embedding of fine trenches and via holes with a plated film and the formation of bumps (protruding electrodes) composed of a plated film formed in resist openings by the plating apparatus shown in FIGS. 6 and 7, it is also possible to use an electroplating apparatus having the construction shown FIG. 11, in which two substrates W, each held by the substrate holder 14, are disposed opposite to each other in the plating tank 11, and the plating solution jet nozzles 16, mounted to the nozzle supporting belt 31, are disposed opposite the substrates.
FIG. 21 shows an overall layout of a plating facility having a plating apparatus according to yet another embodiment of the present invention. The plating facility is designed so as to automatically perform all the plating processes including pre-processing of a substrate, plating, and post-plating processing, in a successive manner. The interior of an apparatus frame 110, having an armored panel attached thereto, is divided by a partition plate 112 into a plating space 116 for performing a plating process of a substrate and processings of the substrate to which a plating solution is attached, and a clean space 114 for performing other processes, i.e. processes not directly involving a plating solution. Two substrate holders 160 (see FIG. 22) are arranged in parallel, and substrate attachment/detachment stages 162 to attach a substrate to and detach a substrate from each substrate holder 160 are provided as a substrate delivery section on a partition portion partitioned by the partition plate 112, which divides the plating space 116 from the clean space 114. Loading/unloading ports 120, on which substrate cassettes housing substrates are mounted, are connected to the clean space 114. Further, the apparatus frame 110 has a console panel 121 provided thereon.
In the clean space 114, there are disposed at four corners an aligner 122 for aligning an orientation flat or a notch of a substrate with a predetermined direction, two cleaning/drying apparatuses 124 for cleaning a plated substrate and rotating the substrate at a high speed to spin-dry the substrate, and a pre-processing apparatus 126 for carrying out a pre-processing of a substrate, e.g., according to the present embodiment, a rinsing pretreatment including injecting pure water toward a front face (surface to be plated) of a substrate to thereby clean the substrate surface with pure water and, at the same time, wet the substrate surface with pure water so as to enhance a hydrophilicity of the substrate surface. Further, a first transport robot 128 is disposed substantially at the center of these processing apparatus, i.e. the aligner 122, the cleaning/drying apparatuses 124, and the pre-processing apparatus 126, to thereby transfer and deliver a substrate between the processing apparatuses 122, 124, and 126, the substrate attachment/detachment stages 162, and the substrate cassettes mounted on the loading/unloading ports 120.
The aligner 122, the cleaning/drying apparatuses 124, and the pre-processing apparatus 126 disposed in the clean space 114 are designed so as to hold and process a substrate in a horizontal state in which a front face of the substrate faces upward. The transport robot 128 is designed so as to transfer and deliver a substrate in a horizontal state in which a front face of the substrate faces upward.
In the plating space 116, in the order from the partition plate 112 side, there are disposed a stocker 164 for storing or temporarily storing the substrate holders 160, an activation treatment apparatus 166 for etching, for example, an oxide film, having a large electric resistance, on a seed layer formed on a surface of a substrate with a chemical liquid such as sulfuric acid or hydrochloric acid to remove the oxide film, a first water-washing apparatus 168 a for water-washing the surface of the substrate with pure water, a plating apparatus 170 for carrying out plating, a second water-washing apparatus 168 b, and a blowing apparatus 172 for dewatering the plated substrate. Two second transport robots 174 a and 174 b are disposed beside these apparatuses so as to be movable along a rail 176. One of the second transport robots 174 a transfers the substrate holders 160 between the substrate attachment/detachment stages 162 and the stocker 164. The other of the second transport robots 174 b transfers the substrate holders 160 between the stocker 164, the activation treatment apparatus 166, the first water-washing apparatus 168 a, the plating apparatus 170, the second water-washing apparatus 168 b, and the blowing apparatus 172.
As shown in FIG. 22, each of the second transport robots 174 a and 174 b has a body 178 extending in a vertical direction and an arm 180 which is vertically movable along the body 178 and rotatable about its axis. The arm 180 has two substrate holder retaining portions 182 provided in parallel for detachably retaining the substrate holders 160. The substrate holder 160 is designed so as to hold a substrate W in a state such that a front face of the substrate is exposed while a peripheral portion of the substrate is sealed, and to be capable of attaching the substrate W to the substrate holder 160 and detaching the substrate W from the substrate holder 160.
The stocker 164, the activation treatment apparatus 166, the water- washing apparatuses 168 a, 168 b, and the plating apparatus 170 are designed so as to engage with outwardly projecting portions 160 a provided at both ends of each substrate holder 160 to thus support the substrate holders 160 in a state such that the substrate holders 160 are suspended in a vertical direction. The activation treatment apparatus 166 has two activation treatment tanks 183 for holding a chemical liquid therein. As shown in FIG. 22, the arm 180 of the second transport robot 174 b holding the substrate holders 160, which are loaded with the substrates W, in a vertical state is lowered so as to engage the substrate holders 160 with upper ends of the activation treatment tanks 183 to support the substrate holders 160 in a suspended manner. Thus, the activation treatment apparatus 166 is designed so that the substrate holders 160 are immersed together with the substrates W in the chemical liquid in the activation treatment tanks 183 to carry out an activation treatment.
Similarly, the water- washing apparatuses 168 a and 168 b have two water-washing tanks 184 a and two water-washing tanks 184 b which hold pure water therein, respectively, and the plating apparatus 170 has a plurality of plating tanks 186 which hold a plating solution therein. The water- washing apparatuses 168 a, 168 b and the plating apparatus 170 are designed so that the substrate holders 160 are immersed together with the substrates W in the pure water in the water- washing tanks 184 a, 184 b or the plating solution in the plating tanks 186 to carry out water-washing treatment or plating in the same manner as described above. The arm 180 of the second transport robot 174 b holding the substrate holders 160 with substrates W in a vertical state is lowered, and air or inert gas is injected toward the substrates W mounted on the substrate holders 160 to blow away a liquid attached to the substrate holders 160 and the substrates W and to dewater the substrates W. Thus, the blowing apparatus 172 is designed so as to carry out blowing treatment.
As shown in FIG. 23, each plating tank 186 of the plating apparatus 170 is designed to hold a certain amount of plating solution 188. The substrate W, held by the substrate holder 160 with its peripheral portion watertightly sealed and its front surface (surface to be plated) exposed, is to be immersed in the plating solution 188.
According to this embodiment, two plating solution discharge lines 190 are connected to the bottom of the plating tank 186, as shown in FIG. 24. Each plating solution discharge line 190 branches into two plating solution supply lines 192. A pump 194, a flow rate meter 196 and a flow rate regulation valve 198 are provided in each plating solution supply line 192. Further, one plating solution supply line 192, on its way from the pump 194 to the flow rate meter 196, branches into a return line 200 connected to the bottom of the plating tank 186. A low rate regulation valve 202 and a filter 204 are provided in the return line 200. The plating tank 186, on its side, is provided with a plating solution circulation line 212 having a flow rate regulation valve 206, a pump 208 and a chiller 210 interposed therein.
Thus, the plating solution 188 in the plating tank 186 circulates by the actuation of the pump 194 provided in each plating solution supply line 192, and the flow rate of the plating solution 188 flowing along each plating solution supply line 192 is regulated by the flow rate regulation valve 198. Part of the plating solution 188 is returned through the filter 204 into the plating tank 186 via the return line 200. Further, the plating solution 188 in the plating tank 186 circulates by the actuation of the pump 208 provided in the plating solution circulation line 212 and is cooled by the chiller 210 to a predetermined temperature.
As shown in FIG. 23, a disk-shaped anode 214, conforming to the shape of the substrate W, is held by an anode holder 216 and disposed vertically in the plating tank 186. The anode 214, when filling the plating tank 186 with the plating solution 188, is immersed in the plating solution 188 and faces the substrate W held by the substrate holder 160 and disposed in a predetermined position in the plating tank 186. Further, positioned between the anode 214 and the substrate holder 160 disposed in a predetermined position in the plating tank 186, a regulation plate 218 having a central hole 218 a, composed of a dielectric material, for regulating the electric potential distribution in the plating tank 186 is disposed in the plating tank 186.
Further, positioned between the regulation plate 218 and the substrate holder 160 disposed in a predetermined position in the plating tank 186, vertically-extending paddles 220, in the same numbers as the plating solution supply lines 192 (i.e. four), are disposed at an even pitch in the plating tank 186. The paddles 220 constitute a plating solution stirring section. A paddle shaft 222, extending parallel to the substrate W held by the substrate holder 160 and reciprocatable in its axial direction, is disposed above the plating tank 186. The upper ends of the paddles (plating solution stirring section) 220 are coupled to the paddle shaft 222.
Thus, as shown in FIG. 25, as the paddle shaft 222 reciprocates, the paddles 220 reciprocate parallel to and in front of the substrate W held by the substrate holder 160. The plating solution 188 in the plating tank 186 is thus stirred by reciprocating the paddles 220, and the stirring of the plating solution 188 in the plating tank 186 is stopped by stopping the reciprocation of the paddles 220.
A number of plating solution jet nozzles 224, oriented toward the substrate W held by the substrate holder 160, are provided as a plating solution stirring section in each paddle 220 at a given pitch along its length direction. Each plating solution supply line 192 is individually connected to the top of each paddle 220, and the plating solution supply line 192 communicates with the plating solution jet nozzles (plating solution stirring section) 224 via a flow passage formed within the paddle 220.
Thus, by the actuation of the pump 194 provided in each plating solution supply line 192, the plating solution 188 flows along the plating solution supply line 192, and jetted from the plating solution supply nozzles 224 toward the substrate W held by the substrate holder 160 and circulates. The plating solution 188 in the plating tank 186 is thus stirred and circulated by jetting the plating solution 188 toward the substrate W, and the stirring of the plating solution 188 in the plating tank 186 is stopped by stopping the jetting of the plating solution 188.
The paddles 220 and the plating solution jet nozzles 224 are preferably formed of a dielectric resin material, such as PVC, PP, PEEK, PES, HT-PVC, PFA, PTFE, etc. This can prevent the electric field distribution in the plating tank 186 from being disturbed by the presence of the paddles 220 and the plating solution jet nozzles 224.
The plating apparatus 170 is provided with a plating power source 230, whose anode is connected via a conducting wire 228 a to the anode 214 and whose cathode is connected via a conducting wire 228 b to the substrate W during plating. The plating power source 230 is connected to a control section 250 and, based on a signal from the control section 250, applies a pulse voltage, as shown in FIG. 26, comprising a periodical repetition of voltage V₁and voltage 0 (stoppage of voltage application), between the anode 214 and the substrate W. In particular, after elapse of a predetermined time (t₁), voltage V₁is applied between the anode 214 and the substrate W for a predetermined time T₁, and the application of the voltage is stopped for a predetermined time T₂, which procedure is repeated periodically. The pulse width (time) T₁of the voltage V₁is, for example, 10 to 160 seconds, preferably 20 to 120 seconds, more preferably 40 to 80 seconds. The pulse width T₂of voltage 0 (voltage stop time) is, for example, 5 to 120 seconds, preferably 15 to 100 seconds, more preferably 30 to 80 seconds.
The voltage V₁applied between the substrate W and the anode 214 is generally such a voltage as to make the current density 0.1 to 0.8 A/dm². It has been confirmed experimentally that plating at such a relatively low current density attains better embedding property. The voltage V₁is preferably such a voltage as to make the current density 0.2 to 0.6 A/dm² ₁and more preferably such a voltage as to make the current density 0.25 to 0.4 A/dm².
The control section 250 controls the movement of the paddles 220 as a plating solution stirring section and the jetting of the plating solution from the plating solution jet nozzles 224 in synchronization with the periodical voltage application between the anode 214 and the substrate W. In particular, the paddles 220 are reciprocated and the plating solution 188 is jetted from the plating solution jet nozzles 224 to stir the plating solution 188 during the time T₂when no voltage is applied between the substrate W and the anode 214. The reciprocation of the paddles 220 and the jetting of the plating solution 188 from the plating solution jet nozzles 224 are stopped during the time T₁when the voltage V₁is applied between the substrate W and the anode 214, thereby stopping the stirring of the plating solution 188.
By thus stirring the plating solution 188 in the non-plating time when no voltage is applied between the substrate W and the anode 214, the plating solution in via holes or the like can be replaced with a fresh plating solution. By stopping the stirring of the plating solution 188 in the plating time when a voltage is applied between the substrate W and the anode 214, on the other hand, plating can be carried out without supply of a fresh plating solution to via holes or the like. This can prevent a metal film (plated film) from being deposited preferentially at the open ends of via holes or the like and can fill in via holes or the like with a void-free metal film.
In the operation of the plating apparatus 170, the plating tank 186 is first filled with a predetermined amount of plating solution 188. Then, the substrate holder 160 holding a substrate W is lowered to place the substrate W in a predetermined position in the plating tank 186 where the substrate W is immersed in the plating solution 188. Thereafter, the pumps 194 of the plating solution supply lines 192 are actuated to jet the plating solution 188 from the plating solution jet nozzles 224 toward the surface of the substrate W, thereby circulating the plating solution 188 within the plating tank 186. At the same time, the paddles 220 are reciprocated by the paddle shaft 222. Further, if necessary, the pump 208 of the plating solution circulation line 212 is actuated to circulate the plating solution 188 within the plating tank 186 while cooling the plating solution 188 to keep it at a predetermined temperature.
After elapse of a predetermined time, a pulse voltage comprising a periodical repetition of voltage V₁and voltage 0 (stoppage of voltage application) is applied between the anode 214 and the substrate W, thereby repeating plating with the application of voltage V₁between the anode 214 and the substrate and stoppage of plating without application of a voltage. In synchronization with the pulse voltage application, the paddles 220 are reciprocated and the plating solution 188 is jetted from the plating solution jet nozzles 224 toward the substrate W to stir the plating solution 188 in the non-plating time when no voltage is applied between the substrate W and the anode 214, whereas the reciprocation of the paddles 220 and the jetting of the plating solution 188 from the plating solution jet nozzles 224 are stopped to stop the stirring of the plating solution 188 in the plating time when the voltage V₁is applied between the substrate W and the anode 214.
After elapse of a predetermined period of time, the periodical voltage application between the anode 214 and the substrate W is stopped, and the reciprocation of the paddles 220 and the jetting of the plating solution 188 from the plating solution jet nozzles 224 are stopped to terminate the plating.
A series of plating processes for the formation of copper interconnects by the plating facility thus constructed will be described below with reference to FIGS. 18A through 18C. First, a substrate W shown in FIG. 18A is prepared. Substrates W thus prepared are housed in a substrate cassette in a state such that front faces (surfaces to be plated) of the substrates W face upward. The substrate cassette is mounted on the loading/unloading port 120.
One of the substrates W is taken out of the substrate cassette mounted on the loading/unloading port 120 by the first transport robot 128 and placed on the aligner 122 to align an orientation flat or a notch of the substrate with a predetermined direction. The substrate W thus aligned by the aligner 122 is transferred to the pre-processing apparatus 126 by the first transport robot 128. In the pre-processing apparatus 126, a pre-processing (water-washing pretreatment) using pure water as a pre-processing liquid is carried out. On the other hand, two substrate holders 160, which have been stored in a vertical state in the stocker 164, are taken out by the second transport robot 174 a, rotated through 90° so that the substrate holders 160 are brought into a horizontal state, and then placed in parallel on the substrate attachment/detachment stages 162.
Then, the substrates W, which have been subjected to the aforementioned pre-processing (water-washing pretreatment), are loaded into the substrate holders 160 placed on the substrate attachment/detachment stages 162 in a state such that peripheral portions of the substrates W are sealed. The two substrate holders 160, which have been loaded with the substrates W, are simultaneously retained, lifted, and then transferred to the stocker 164 by the second transport robot 174 a. The substrate holders 160 are rotated through 90° into a vertical state and lowered so that the two substrate holders 160 are held (temporarily stored) in the stocker 164 in a suspended manner. The above operation is carried out repeatedly in a sequential manner, so that substrates are sequentially loaded into the substrate holders 160, which have been stored in the stocker 164, and the substrate holders 160 are sequentially held (temporarily stored) in the stocker 164 at predetermined positions in a suspended manner.
On the other hand, the two substrate holders 160, which have been loaded with the substrates and temporarily stored in the stocker 164, are simultaneously retained, lifted, and then transferred to the activation treatment apparatus 166 by the second transport robot 174 b. Each substrate is immersed in a chemical liquid, such as sulfuric acid or hydrochloric acid, held in the activation treatment tank 183 to thereby etch an oxide film, having a large electric resistance, formed on the surface of the seed layer so as to expose a clean metal surface. The substrate holders 160, which have been loaded with the substrates, are transferred to the first water-washing apparatus 168 a in the same manner as described above to water-wash the surfaces of the substrates with pure water held in the water-washing tanks 184 a.
The substrate holders 160, which have been loaded with the water-washed substrates, are transferred to the plating apparatus 170 in the same manner as described above. Each substrate W is supported in a suspended manner by the plating tank 186 in a state such that the substrate W is immersed in the plating solution 188 held in the plating tank 186 to thus carry out plating on the surface of the substrate W. After a predetermined period of time has elapsed, the substrate holders 160, which have been loaded with the substrates, are retained again and pulled up from the plating tank 186 by the second transport robot 174 b. Thus, the plating process is completed.
Thereafter, the substrate holders 160 are transferred to the second water-washing apparatus 168 b in the same manner as described above. The substrate holders 160 are immersed in pure water in the water-washing tanks 184 b to clean the surfaces of the substrates with pure water. Then, the substrate holders 160, which have been loaded with the substrates, are transferred to the blowing apparatus 172 in the same manner as described above. In the blowing apparatus 172, inert gas or air is injected toward the substrates to blow away a plating solution and water droplets attached to the substrate holders 160. Thereafter, the substrate holders 160, which have been loaded with the substrates, are returned to predetermined positions in the stocker 164 and held in a suspended state in the same manner as described above.
The second transport robot 174 b sequentially performs the above operation repeatedly so that the substrate holders 160, which have been loaded with the plated substrates, are sequentially returned to predetermined positions in the stocker 164 and held in a suspended manner.
On the other hand, the two substrate holders 160, which have been loaded with the plated substrates and returned to the stocker 164, are simultaneously retained and placed on the substrate attachment/detachment stages 162 by the second transport robot 174 a in the same manner as described above.
The first transport robot 128, disposed in the clean space 114, takes the substrate out of the substrate holders 160, placed on the substrate attachment/detachment stages 162, and transfers the substrate to either one of the cleaning/drying apparatuses 124. In the cleaning/drying apparatus 124, the substrate held in a horizontal state such that the front face of the substrate faces upward is cleaned with pure water or the like and rotated at a high speed to spin-dry the substrate. Thereafter, the substrate is then returned to the substrate cassette mounted on the loading/unloading port 120 by the first transport robot 128. Thus, a series of plating processes is completed. The substrate W in which copper has been embedded in the via holes 3 and the trenches 4 and the copper layer 7 has been deposited on the insulating film 2, as shown in FIG. 18B, is thus obtained.
The spin-dried substrate W, as described above, is then transferred to a chemical mechanical polishing (CMP) apparatus, where the copper layer 7, seed layer 6 and the barrier layer 5 on the insulating film 2 are removed by chemical mechanical polishing (CMP) so as to make the surface of the copper layer 7 filled in the via holes 3 and the trenches 4 and the surface of the insulating film 2 lie substantially on the same plane. Interconnects 8 composed of the copper layer 7 and the seed layer 6 are thus formed, as shown in FIG. 18C, and the exposed surfaces of interconnects 8 are protected by the protective film 9, as necessary.
A process for producing an interposer or a spacer having vertically-penetrating via plugs of copper will now be described with reference to FIGS. 27A through 27D. A substrate W, as shown in 27A, is provided which has been prepared by depositing an insulating film 512 of e.g. SiO₂on a surface of a base 510 of silicon or the like, and forming upwardly-open via holes 514 in the insulating film 512 by, for example, the lithography/etching technique. The diameter d of the via holes 514 is, for example, 10 to 20 μm and the depth h is, for example, 70 to 150 μm. Thereafter, as shown in FIG. 27B, a barrier layer 516 of TaN or the like and a (copper) seed layer 518, which serves as an electric supply layer in electroplating, are formed in this order over the surface of the substrate W by, for example, sputtering.
Thereafter, copper plating of the surface of the substrate W is carried out in the above-described manner to fill in the via holes 514 of the substrate W with copper (plated film) and deposit a copper film 520 on the surface of the insulating film 512, as shown in FIG. 27C.
Thereafter, as shown in FIG. 27D, the extra copper film 520 on the insulating film 512, the seed layer 518 and the barrier layer 516 are removed while, at the same time, the back surface side of the base 510 is polished away until the bottom of the copper filled in the via holes 514 becomes exposed by, for example, chemical mechanical polishing (CMP), thereby completing the production of an interposer or a spacer having the vertically-penetrating via plugs 522 of copper.
It has been confirmed that even via holes having a high aspect ratio and a large depth, such as those having a diameter d of 10 to 20 μm and depth h of 70 to 150 μm, can be filled in with copper (plated film) in, for example, about 5 hours without the formation of defects, such as voids, by carrying out copper plating using the plating apparatus of the present invention.
According to this embodiment, transfer of a substrate in the plating space 116 is carried out by the second transport robots 174 a, 174 b disposed in the plating space 116, and transfer of a substrate in the clean space 114 is carried out by the first transport robot 128 disposed in the clean space 114. This can improve the cleanness around a substrate in the plating processing apparatus which sequentially carries out all the plating steps of pre-processings, plating and post-plating processings of a substrate, can increase the throughput of the plating processing apparatus, and can reduce the burden on facilities associated with the plating processing apparatus, leading to downsizing of the plating processing apparatus.
Further, the use in the plating apparatus 170 of the plating tank 186 of a small footprint according to this embodiment makes it possible to downsize the plating apparatus 170 having the large number of plating tanks 186 and to reduce the burden on incidental facilities of the plant. Turning back to FIG. 21, one of the two cleaning/drying apparatuses 124 may be replaced with a pre-processing apparatus.
FIG. 28 shows a plating apparatus according to yet another embodiment of the present invention. This plating apparatus uses paddles 220 having no plating solution jet nozzle. Such facilities as a plating solution supply line, which will be needed in association with provision of a plating solution jet nozzle, are therefore not provided. The other construction is the same as the embodiment shown in FIGS. 23 through 25. This embodiment can thus simplify the construction.
According to the present invention, a metal film (plated film) can be prevented from preferentially depositing at the open ends of via holes or the like. Thus, it becomes possible with the present invention to securely fill in via holes with a metal film without the formation of voids in the embedded metal film even when the via holes or the like have a high aspect ratio and a large depth.
While the present invention has been described with reference to the embodiments thereof, it will be understood by those skilled in the art that the present invention is not limited to the particular embodiments described, but changes could be made therein within the technical concept of the present invention.

Claims

1. A plating apparatus comprising:

a plating tank for holding a plating solution;

a plating solution jet nozzle having a slit-like plating solution jet orifice for jetting the plating solution toward a surface to be plated of an object to be plated disposed in the plating tank; and

a plating solution supply section for supplying the plating solution to the plating solution jet nozzle.

2. The plating apparatus according to claim 1, wherein a plurality of the plating solution jet nozzles is disposed in parallel with each other in the plating tank.

3. The plating apparatus according to claim 2, further comprising:

a flow rate distribution section for distributing the flow rate of the plating solution to the plurality of plating solution jet nozzles in consideration of the flow conductance of the plating solution.

4. The plating apparatus according to claim 1, further comprising a nozzle movement mechanism for moving the plating solution jet nozzle parallel to the surface to be plated of the object to be plated.

5. The plating apparatus according to claim 1, wherein the plating apparatus further comprises a flow rate control section for controlling the flow rate of the plating solution jetted from the plating solution jet orifice, and the plating solution jet orifice has a width of 0.05 to 1.0 mm.

6. The plating apparatus according to claim 1, wherein the velocity of the plating solution, jetted from the plating solution jet orifice of the plating solution jet nozzle, is 5 to 20 m/sec in the vicinity of the plating solution jet orifice.

7. The plating apparatus according to claim 1, further comprising a flow rate monitor section for monitoring the flow rate of the plating solution jetted from the plating solution jet orifice and/or a pressure monitor section for monitoring the pressure in the plating solution jet nozzle.

8. The plating apparatus according to claim 1 further comprising;

a flow rate sensor for detecting the flow rate of the plating solution jetted from the plating solution jet orifice and/or a pressure sensor for detecting the pressure in the plating solution jet nozzle; and

a plating solution flow rate regulation section for regulating the flow rate of the plating solution by feeding back a detection signal of the flow rate sensor and/or the pressure sensor to the plating solution supply section.

9. The plating apparatus according to claim 1, wherein the distance between the front end of the plating solution jet orifice and the object to be plated is 1 to 30 mm.

10. The plating apparatus according to claim 1, further comprising an anode disposed between the plating solution jet nozzle and the object to be plated.

11. The plating apparatus according to claim 1, further comprising an anode disposed in the plating solution jet nozzle.

12. The plating apparatus according to claim 1, wherein the plating solution supply section includes a pump for feeding out the plating solution discharged from the plating tank, and a plating solution supply pipe connecting the pump with the plating solution jet nozzle, and at least part of the plating solution supply pipe is formed of a flexible material so that it can follow a movement of the plating solution jet nozzle.

13. A plating method comprising:

disposing an object to be plated and a plating solution jet nozzle having a slit-like plating solution jet orifice opposite to each other in a plating solution in a plating tank; and

jetting the plating solution from the plating solution jet orifice while moving the plating solution jet nozzle parallel to a surface to be plated of the object to be plated.

14. A plating apparatus comprising:

a plating tank for holding a plating solution;

a holder for holding an object to be plated, feeding electricity to the object to be plated, and bringing a surface to be plated of the object to be plated into contact with the plating solution in the plating tank;

an anode disposed in the plating solution in the plating tank;

a plating solution stirring section, disposed between the anode and the object to be plated held by the holder, for stirring the plating solution in the plating tank; and

a plating power source for periodically applying a voltage between the object to be plated and the anode;

wherein the plating solution is stirred by the plating solution stirring section when no voltage is applied between the object to be plated and the anode, whereas the stirring of the plating solution by the plating solution stirring section is stopped when the voltage is applied between the object to be plated and the anode.

15. The plating apparatus according to claim 14, wherein the plating solution stirring section is comprised of a paddle which reciprocates parallel to the surface to be plated of the object to be plated held by the holder.

16. The plating apparatus according to claim 14, wherein the plating solution stirring section is comprised of a plating solution jet nozzle for jetting the plating solution toward the surface to be plated of the object to be plated held by the holder.

17. The plating apparatus according to claim 14, wherein the voltage is applied between the object to be plated and the anode so that the current density becomes 0.1 to 0.8 A/dm².

18. A plating method comprising:

disposing an object to be plated and an anode opposite to each other in a plating solution in a plating tank;

periodically applying a voltage between the object to be plated and the anode; and

stirring the plating solution between the object to be plated and the anode when no voltage is applied between the object to be plated and the anode, and stopping the stirring of the plating solution between the object to be plated and the anode when the voltage is applied between the object to be plated and the anode.

19. The plating method according to claim 18, wherein the plating solution is stirred by reciprocating a paddle, disposed between the object to be plated and the anode, parallel to the object to be plated, and the stirring of the plating solution is stopped by stopping the movement of the paddle.

20. The plating method according to claim 18, wherein the plating solution is stirred by jetting the plating solution from a plating solution jet nozzle, disposed between the object to be plated and the anode, toward the object to be plated, and the stirring of the plating solution is stopped by stopping the jetting of the plating solution from the plating solution jet nozzle.

21. The plating method according to claim 18, wherein the voltage is applied between the object to be plated and the anode so that the current density becomes 0.1 to 0.8 A/dm².