JP2005089781A - Thin film forming equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To more quickly deposit a film by a chemical vapor deposition method used without mutually mixing two or more kinds of gaseous starting materials. <P>SOLUTION: The thin film deposition system is provided with a first gas discharge part 121 and a second gas discharge part 123 extending to a direction different from the moving direction of a substrate W, arranged at the gas feeding face of a gas feeding head 102, and each feeding first gas and second gas to the surface of the substrate W. The gas A and gas B are linearly fed to the surface of the moving substrate W in succession. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a thin film forming apparatus for forming a high-quality gate insulating film used for a thin film transistor.

  An active matrix liquid crystal display device using a thin film transistor (hereinafter abbreviated as “TFT”) formed on a glass substrate as a switching element has been developed as a high-quality flat display. Since a TFT used as a switching element is formed on a glass substrate with low heat resistance, for example, the gate insulating film is formed by a plasma CVD (Chemical Vapor Deposition) method in which high-temperature treatment is not performed.

However, a film formed by the CVD method has many crystal defects in the film, and is not very reliable because it is not dense enough. For this reason, the TFT has a problem that the characteristics of the transistor are not so good, such as a large change with time.
As a technique for solving such a problem, a technique for forming a gate insulating film by an atomic layer growth method has been proposed (see Patent Documents 1 and 2). The atomic layer growth method is a technique for forming a thin film in units of atomic layers by alternately supplying a raw material of each element constituting a film to be formed to a substrate.

  In the atomic layer growth method, only one layer or n layer is adsorbed on the surface while the raw materials for each element are being supplied, so that excess raw materials do not contribute to the growth. This is called self-stopping action of growth. In the atomic layer growth method, for example, it is not necessary to increase the processing temperature to about 300 ° C., and a high-quality film can be formed.

The applicant has not yet found prior art documents related to the present invention by the time of filing other than the prior art documents specified by the prior art document information described in this specification.
JP-A-1-179423 JP-A-5-160152

However, the above-described atomic layer growth method requires a lot of purge time in order to prevent the mixing of the raw material gases of each element in the reaction furnace in which the film is grown. As described above, in the chemical vapor deposition method in which two or more kinds of source gases need to be used without being mixed with each other, a lot of time is required for replacing the source gases. There was a problem that it took a long time.
The present invention has been made to solve the above-described problems, and it is possible to form a film more rapidly by chemical vapor deposition using two or more kinds of source gases without mixing each other. The purpose is to.

A thin film forming apparatus according to the present invention includes a substrate mounting table on which a substrate to be processed is mounted, a gas supply head having a gas supply surface facing a surface on which the substrate of the substrate mounting table is mounted, and a substrate And a moving means for moving at least one of the mounting table and the gas supply head in a predetermined movement direction along the gas supply surface. The gas supply head extends in a direction different from the movement direction and extends to the gas supply surface. And a first gas discharge part and a second gas discharge part for supplying the first gas and the second gas respectively onto the substrate mounting table.
According to this apparatus, the first gas and the second gas are continuously and alternately supplied in a linear form on the substrate that is placed on the substrate mounting table and moves. Is in a state in which the first gas and the second gas can sequentially react with each other. Therefore, for example, a first material film formed by decomposing the first gas and a second material film formed by decomposing the second gas are sequentially stacked on the substrate. It will be done.

In the thin film forming apparatus, the moving means may be any means that moves the substrate mounting table in the moving direction.
The thin film forming apparatus further includes a barrier gas discharge unit that is disposed between the first gas discharge unit and the second gas discharge unit and supplies an inert gas onto the substrate mounting table. Mixing with the second gas is suppressed. Further, an exhaust port disposed between the first gas discharge unit, the barrier gas discharge unit, and the second gas discharge unit adjacent to each other, and the gas supplied from each gas discharge unit in communication with the exhaust port is exhausted. You may make it suppress mixing with 1st gas and 2nd gas by providing the exhaust means which exhausts more.

  As described above, in the present invention, the first gas discharge that extends in a direction different from the moving direction and is arranged on the gas supply surface and supplies the first gas and the second gas onto the substrate mounting table, respectively. And a second gas discharge unit, for example, the substrate is moved relative to these. Thus, according to the present invention, the first gas and the second gas can be alternately and continuously supplied onto the substrate, and the chemicals used without mixing two or more kinds of source gases can be used. By the chemical vapor deposition method, an excellent effect that a desired thin film can be formed more quickly than before can be obtained.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic configuration diagram (a), a partial plan view (b), a perspective view (c), and a schematic configuration example of the entire apparatus, illustrating a configuration example of a thin film forming apparatus according to an embodiment of the present invention. It is a block diagram (d) shown in figure. In this apparatus, first, a film forming chamber 101 in which processing is performed, a gas supply head 102 accommodated in the film forming chamber 101, and a substrate W to be processed so as to face the gas supply surface of the gas supply head 102. And a substrate moving unit 103 that moves along the gas supply surface. The substrate W is, for example, a glass substrate or a silicon single crystal substrate.

  The gas supply head 102 includes a gas A discharge unit 121 that supplies the gas A toward the substrate W to be processed, a gas B discharge unit 122 that supplies the gas B toward the substrate W to be processed, and the substrate W to be processed. A barrier gas discharge part 123 for supplying an inert barrier gas such as argon is provided. The gas A discharge part 121, the gas B discharge part 122, and the barrier gas discharge part 123 are formed in stripes extending in a vertical direction different from the direction in which the substrate W moves. For example, each gas discharge part is provided with a plurality of discharge holes 102a at a predetermined interval over about 10 cm in the extending direction. Moreover, the gas A discharge part 121, the gas B discharge part 122, and the barrier gas discharge part 123 are arranged on the gas supply surface of the gas supply head 102, for example, for three cycles.

  The gas A discharge unit 121 and the gas B discharge unit 122 are alternately arranged, and the barrier gas discharge unit 123 is disposed therebetween. The gas A discharge part 121, the barrier gas discharge part 123, and the gas B discharge part 122 should just be arranged by the space | interval of 0.5-2.0 cm. Further, an exhaust port 124 is provided between these gas discharge portions. In the above description, the gas discharge holes 102a are provided over 10 cm in each gas discharge portion. However, the present invention is not limited to this. These lengths may be appropriately changed according to the dimensions of the substrate to be processed.

Gas A is supplied to each gas A discharge part 121 from the gas A supply part 104 via a pipe, and gas B is supplied to each gas B discharge part 122 from the gas B supply part 105 via a pipe. Barrier gas is supplied to each barrier gas discharge part 123 from the barrier gas supply part 106 via piping. The gas A is, for example, tetraisocyanate silane (Si (NCO) ₄ ) gas, and the gas B is, for example, tetraethylamine (N (C ₂ H ₅ ) ₃ ). With these combinations, a SiO ₂ film can be formed on the substrate W. In the above case, the gas A may be gasified by heating to about 40 ° C.

  Each gas discharged from each discharge hole 102 a of the gas discharge unit is supplied to the surface of the substrate W to be processed being moved by the substrate moving unit 103, and then acts on the surface of the gas supply head 102 through the exhaust port 124. It is taken in and exhausted by an exhaust mechanism 107 such as a vacuum pump through a pipe. Gas A and gas B are supplied together with an inert carrier gas such as argon. The carrier gas is not always necessary.

  FIG. 2 is a cross-sectional view schematically showing a thin film forming process by the thin film forming apparatus of the present embodiment. First, the substrate W is opposed to the gas supply surface of the gas supply head 102 with a distance of about 1 to 2 mm and is moving at a speed of 5 to 20 cm / sec from the right to the left in FIG. To do. Further, it is assumed that the temperature of the substrate W is controlled to about 150 ° C., for example. For example, the temperature of the substrate W is controlled by a temperature control mechanism (not shown) provided in the substrate moving unit 103 that also serves as the substrate mounting table. In this state, each gas is discharged from each gas discharge section, and exhaust is performed from the exhaust port 124.

Further, the inside of the film forming chamber 101 in which the substrate W is disposed is set to a pressure of about 2 to 3 Pa. Note that the supply flow rates of the gas A and the gas B may be 10 to 500 sccm, and the supply amount of the barrier gas may be 10 to 1000 sccm. sccm is a unit of flow rate and indicates that a fluid at 0 ° C. and 1 atm flows 1 cm ³ per minute.

  Here, since the barrier gas is supplied between the point 211 and the point 212 and the gas is exhausted on both sides of the supply of the barrier gas, the gas A supplied at the point 211 and the point 212 are The supplied gas B is not mixed on the substrate. These are the same between the point 212 and the point 213.

  As described above, while the gas A and the gas B are supplied without mixing, the Si monoatomic layer is formed on the moving substrate W by the gas A supplied onto the substrate at the point 211. A thin film 201 is formed. On the thin film 201, the oxygen monoatomic thin film 202 is formed by the gas B supplied onto the substrate at the point 212. On the thin film 202, the Si monoatomic layer thin film 203 is formed by the gas A supplied onto the substrate at the point 213.

The formation of each of these layers is repeated with each gas ejected from each gas ejection unit arranged on the left side of the paper not shown in FIG. 2, and the thin film and gas by gas A are formed on the moving substrate W. A thin film made of B is laminated to form a thin film of SiO ₂ .
For example, in the apparatus shown in FIG. 1, a thin film of SiO ₂ can be formed to a thickness of about 10 to 20 nm by reciprocating the substrate W, for example, 10 times.

The thin film forming apparatus shown in FIG. 1 is not limited to the above-described SiO ₂ thin film, and for example, an aluminum oxide thin film can be formed. For example, if the gas A is trimethylaluminum (TMA) vapor and the gas B is water vapor, the thin films 201 and 203 are aluminum monoatomic layers and the thin film 202 is oxygen monoatomic layers. Therefore, in this case, an aluminum oxide film is formed on the substrate W according to the thin film forming apparatus shown in FIG. For TMA and water vapor, argon gas may be supplied as a carrier gas, and argon gas may be used as the barrier gas. The substrate W may be heated to about 400 ° C.

In the above description, the thin film is formed by moving the substrate W linearly, but the present invention is not limited to this. For example, as shown in FIG. 3, a gas A discharge unit 310, a gas B discharge unit 320, and a barrier gas discharge unit 330 are provided on a circular wafer 301 and the wafer 301 is rotated so that the wafer is the same as described above. A thin film may be formed on 301.
Also, as shown in FIGS. 4A and 4B, a gas A discharge unit 410, a gas B discharge unit 420, and a barrier gas discharge unit 430 are provided on a circular wafer 401, and the wafer 401 is rotated. Thus, a thin film may be formed on the wafer 401 as described above.

In the above-described embodiment, the gas A discharge unit, the barrier gas discharge unit, the gas B discharge unit,... Are arranged, and the exhaust unit is arranged between the discharge units. It is not a thing. The gas A discharge unit, the exhaust unit, the gas A discharge unit, the barrier gas discharge unit, the gas B discharge unit, the exhaust unit, the gas B discharge unit, the barrier gas discharge unit,.
In the above description, two types of gas are used. However, the present invention is not limited to this, and three or more types of gas discharge portions that discharge three or more types of gas are sandwiched between the barrier gas and the main portion. You may make it arrange.

In the above description, the substrate is moved. However, it goes without saying that the gas supply head may be moved. Moreover, in the apparatus of FIG. 1, although the exhaust port 124 was provided between each gas supply part, it is not restricted to this. The exhaust part should just be provided so that gas A and gas B may be exhausted without being mixed on the substrate. Moreover, when the gas A and the gas B may be mixed, it is not necessary to provide an exhaust part near each gas supply part, and it is not necessary to supply barrier gas.
In the above description, the atomic layer growth method has been described as an example. However, the present invention is not limited to this, and the present invention may be applied to other chemical vapor deposition methods.

FIG. 1 is a schematic configuration diagram (a), a partial plan view (b), a perspective view (c), and a schematic configuration example of the entire apparatus showing a configuration example of a thin film forming apparatus in an embodiment of the present invention. It is a figure (d). It is sectional drawing which shows typically the thin film formation process by the thin film forming apparatus of this Embodiment. It is a perspective view which shows partially the other structural example of the thin film formation apparatus in embodiment of this invention. It is a top view which shows partially the other structural example of the thin film forming apparatus in embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 ... Film-forming chamber, 102 ... Gas supply head, 102a ... Discharge hole, 103 ... Substrate moving part, 104 ... Gas A supply part, 105 ... Gas B supply part, 106 ... Barrier gas supply part, 107 ... Exhaust mechanism, 121 ... Gas A discharge part, 122 ... Gas B discharge part, 123 ... Barrier gas discharge part, 124 ... Exhaust port, W ... Substrate.

Claims (4)

A substrate mounting table on which a substrate to be processed is mounted;
A gas supply head provided with a gas supply surface facing the surface on which the substrate of the substrate mounting table is mounted;
Moving means for moving at least one of the substrate mounting table and the gas supply head in a predetermined moving direction along the gas supply surface;
The gas supply head extends in a direction different from the moving direction, is arranged on the gas supply surface, and supplies a first gas and a second gas on the substrate mounting table, A thin film forming apparatus, comprising: a second gas discharge unit. The thin film forming apparatus according to claim 1,
The moving means moves the substrate mounting table in the moving direction. The thin film forming apparatus, wherein The thin film forming apparatus according to claim 1 or 2,
A thin film forming apparatus, comprising: a barrier gas discharge unit that is disposed between the first gas discharge unit and the second gas discharge unit and supplies an inert gas onto the substrate mounting table. The thin film forming apparatus according to claim 3.
An exhaust port disposed between the first gas discharge unit, the barrier gas discharge unit, and the second gas discharge unit adjacent to each other;
A thin film forming apparatus comprising: an exhaust unit communicating with the exhaust port and exhausting the gas supplied from each gas discharge unit through the exhaust port.

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