WO2008018159A1

WO2008018159A1 - Microwave line plasma generation system with two power supply

Info

Publication number: WO2008018159A1
Application number: PCT/JP2006/318403
Authority: WO
Inventors: Takayuki Fukasawa; Raju Ramasamy; Tohru Yasuda; Ryohei Itatani; Hiroshi Kajiyama; Tsutae Shinoda
Original assignee: Adtec Plasma Technology Co., Ltd.
Priority date: 2006-08-08
Filing date: 2006-09-15
Publication date: 2008-02-14
Also published as: JPWO2008018159A1

Abstract

A microwave line plasma generation system in which a uniform plasma density can be attained in the plasma processing region. The microwave line plasma generation system comprises a waveguide (1), first and second microwave generation sources (2, 3), a first microwave transmission path (4) connected between the first microwave generation source and the opening on one end side of the waveguide and supplying a microwave into the waveguide, a second microwave transmission path (5) connected between the second microwave generation source and the opening on the other end side of the waveguide and supplying a microwave into the waveguide, transmission path length adjusting means (10, 11) respectively provided in the way of the first and second microwave transmission paths in order to adjust the transmission path length of the microwave transmission path, gas sources (12, 13), and a plasma generation means (16). The plasma generation means (16) has a plasma generation chamber extending in the propagating direction of microwave in the waveguide, and a plasma discharge opening for discharging a plasma generated in the plasma generation chamber in the shape of a line.

Description

Specification

Microwave line plasma generator with two power supplies

Technical field

TECHNICAL FIELD [0001] The present invention relates to a microwave plasma generator that generates plasma by exciting a plasma generating gas with a microwave, and particularly a large display panel having a large area such as a long film. The present invention relates to a microwave line plasma generator for generating line-shaped plasma suitable for plasma processing of an object to be processed.

Background art

FIG. 11 is a diagram showing an overall configuration of an example of a conventional microwave line plasma generator, and FIG. 12 is a perspective view of a main part of the microwave line plasma generator of FIG. Referring to FIG. 11, the microwave plasma generator includes a waveguide 51, a microwave generation source 53, a tapered waveguide 60 and a microwave supply source 53 that supply microwaves from the microwave generation source 53 to the waveguide 51. And an L-shaped waveguide 59, a gas source 55, and a gas supply tube 54 for supplying gas from the gas source 55 to the waveguide 51.

The starting end of the waveguide 51 is connected to the microphone mouth wave source 53 via the tapered waveguide 60 and the L-shaped waveguide 59. An isolator 57 and a sleeving tab 58 are attached to the L-shaped waveguide 59 from the microwave generation source 53 side. A short circuit plunger 62 is connected to the end of the waveguide 51 via a tapered waveguide 61.

Referring to FIG. 12, waveguide 51 also has a flat rectangular waveguide force formed so that width a is larger than thickness b in a cross section perpendicular to the central axis. The side surface 51a defining the width a of the waveguide 51 forms an H surface, the side surface 51b defining the thickness b forms an E surface, and the slit 52 is the E of the waveguide 51. It is provided on the surface.

The microwave line plasma generator further includes plasma generation means for converting an electromagnetic field generated in the waveguide 51 into gas ionization energy. The plasma generating means is formed on the side wall of the waveguide 51 and extends in the vicinity of the slit 52 extending from the gas source 55 to the slit 52 extending in the microwave propagation direction (the arrow X direction in FIG. 12). Gas supply It consists of a gas supply pipe 54.

[0004] The gas supply pipe 54 is formed of a dielectric, and includes a buffer tank 56 formed in a dielectric casing at a portion upstream of the vicinity of the slit 52 of the waveguide 51. A certain amount of introduced gas can be stored. The portion 54e downstream of the buffer tank 56 of the gas supply pipe 54 is configured as a single pipe having an elongated rectangular cross section, while the upstream side of the gas supply pipe 54 from the buffer tank 56 includes a plurality of pipes 54a to 54a. It is configured as an aggregate of 54d.

A portion 54e of the gas supply pipe 54 on the downstream side of the notfer tank 56 is disposed outside the waveguide 1 and in proximity to the side wall 5 lb provided with the slit 52 in the waveguide 51. The slit 52 extends in the vertical direction with a width that covers the entire length 52, and the lower end of the downstream portion 54 e of the gas supply pipe 54 extends beyond the slit 52 by a certain length.

The notfer tank 56 has a cylindrical shape with both end openings closed, and the upper peripheral wall portion of the notfer tank 56 is connected to one end of the upstream side portion of the gas supply pipe 54 that also has the collective force of the four tubes 54a to 54d. The other ends of the four tubes 54a to 54d are connected to the gas source 55. The gas stored in the notfer tank 56 is uniformly introduced into the downstream portion 54e of the gas supply pipe 54 over the entire elongated rectangular cross section, and supplied to the vicinity of the slit 52 of the waveguide 51.

[0005] In this way, the microwave force generated by the microwave generation source 53 is introduced into the waveguide 51 through the L-shaped waveguide 59 and the tapered waveguide 60, and gas is supplied from the gas source 55 to the gas supply. It is supplied to the vicinity of the slit 52 of the waveguide 51 through the tube 54. The gas passing through the gas supply pipe 54 (downstream portion 54e) is converted into plasma by the electromagnetic field radiated from the slit 52, and the opening force at the lower end of the gas supply pipe 54 is also released (see Patent Document 1).

[0006] Fig. 13 is a graph showing the plasma density along the width direction of the gas supply pipe 54 (in the direction of the slit 52), measured for the plasma generated by this microwave line plasma generator. ) Is a graph in the plasma generation region (region in the vicinity of the slit 52 of the waveguide 51 inside the gas supply pipe 54), and (B) is a plasma processing region (30mn! ~ From the lower end opening of the gas supply pipe 54). Each graph is shown in the area about 40mm away) ing. In the graph of FIG. 13, the distance in the z-axis direction represents the distance in the width direction in which one end force of the gas supply pipe 54 is also measured. In addition, since it is difficult to directly measure the plasma density in the plasma generation region, a graph of the plasma density in the plasma generation region predicted based on the measured plasma density measured in the vicinity of the plasma generation region is shown in FIG. It is shown in 13 (A).

In the conventional microwave line plasma generator, the plasma density is significantly increased along the width direction of the gas supply pipe 54 in the conventional microwave line plasma generator so that the graph force of FIG. In the plasma processing region, there is no position where the plasma density is zero, but there is considerable unevenness along the width direction of the gas supply pipe 54. Has produced. As described above, if the plasma density of the generated line-shaped plasma is not uniform in the plasma processing region, there is a problem that the efficiency of the plasma processing of the object to be processed is significantly reduced.

Patent Document 1: Japanese Patent Laid-Open No. 2005-340079

Disclosure of the invention

Problems to be solved by the invention

[0008] Accordingly, an object of the present invention is to provide a microwave line plasma generator capable of obtaining a uniform plasma density in a plasma processing region.

Means for solving the problem

[0009] In order to solve the above-mentioned problems, the first invention provides a waveguide, first and second microwave generation sources, the first microwave generation source, and one end opening of the waveguide. Connected between the first microwave transmission path for supplying microwaves into the waveguide, and between the second microwave generation source and the other end opening of the waveguide. A second microwave transmission path for supplying microwaves into the waveguide, and a transmission path for the microwave transmission paths provided in the middle of each of the first and second microwave transmission paths. A transmission path length adjusting means for adjusting the length of the gas, a gas source for supplying a plasma generating gas, a plasma generation chamber provided in the waveguide, extending in a propagation direction of microwaves in the waveguide, and Plasma emission that emits plasma generated in the plasma generation chamber in a line shape Has the supplied gas for plasma generation to the gas MinamotoTsutomu the plasma generating chamber, subjected to the wave guide And a plasma generating means for generating plasma by exciting the supplied microwave and emitting the plasma outlet force. is there.

[0010] In the configuration of the first invention, the first and second microwave transmission lines are each formed of a second waveguide, and the transmission line length adjusting means is a U-shaped third waveguide. The third waveguide further includes a pair of parallel portions connected to the upstream portion and the downstream portion of the first and second microwave transmission paths, respectively, and the It is preferable that a pair of parallel portions are slidable with respect to them and a U-shaped portion that is fitted so that microwaves do not leak to the outside, and is a force.

Alternatively, each of the first and second microwave transmission paths is formed of a waveguide, and the transmission path length adjusting means includes a circulator inserted in the middle of the first and second microwave transmission paths. Preferably, the short circuit plunger connected to the circulator is in force, or the first and second microwave transmission paths are each formed from a waveguide, and the transmission path length adjusting means is It is preferable to use Magic T.

[0011] In order to solve the above-mentioned problem, the second invention also includes a waveguide, first and second microwave generation sources, one end side of the first microwave generation source and the waveguide. A first microwave transmission path connected to the opening for supplying microwaves into the waveguide, and between the second microwave generation source and the other end opening of the waveguide. A second microwave transmission path for supplying a microwave to the waveguide, a gas source for supplying a plasma generating gas, and a microwave in the waveguide. A plasma generation chamber extending in the direction of propagation of the plasma, and a plasma discharge port for discharging the plasma generated in the plasma generation chamber in a line shape, and the gas source gas includes a plasma generation gas supplied to the plasma generation chamber. Excited by microwaves fed into the waveguide Plasma generating means for generating a plasma and releasing the plasma from the plasma emission locus; and provided in the vicinity of a plasma emission port of the plasma generation means, and at least partially blocking the plasma emitted from the plasma emission locus. And a plasma density adjusting means for adjusting the density of the plasma. Made.

[0012] In the configuration of the second invention, preferably, the plasma density adjusting means is below the plasma discharge port and on one side or both sides of the plasma discharge port in the longitudinal direction of the plasma discharge port. The rods are arranged in spaced-apart manner along the axis and support the rods, and the rods are arranged in the axial direction of each of the rods independently and across the plasma discharge port. Plasma emission locusr It has rod body moving means for moving between a first position where the emitted plasma is at least partially shielded and a second position where the rod body does not contact the plasma. Alternatively, the plasma density adjusting means includes a horizontal plate assembly disposed on one side or both sides of the plasma discharge port below the plasma discharge port, and the plate assembly includes A plurality of plate elements arranged adjacent to each other in the longitudinal direction of the plasma emission port, and further supporting the plate element, and each of the plate elements independently across the plasma emission port. Plate element moving means for moving between a first position at least partially blocking the plasma emitted from the plasma emission locus and a second position where the plate element does not contact the plasma. It is preferable that

[0013] In the configurations of the first and second inventions, the waveguide has a flat rectangular waveguide force formed so that a width thereof is larger than a thickness in a cross section perpendicular to a central axis thereof. The width a of the waveguide is equal to the wavelength of the microwave in the vacuum free space.

0

A relational expression established between the wavelength of the microwave and the width a of the waveguide,

g

Preferably, the width a corresponds to the wavelength λ of the microwave inside the waveguide longer than the length of the plasma to be generated.

g

[0014] Preferably, the waveguide is formed with a vertically long opening extending in a microwave propagation direction, and the plasma generating means is made of a dielectric mounted in the opening of the waveguide. A discharge tube, and a part of the peripheral wall of the discharge tube approaches or penetrates the internal space of the waveguide, and the peripheral wall portion exposed to the outside of the waveguide in the discharge tube A plasma discharge port is formed, and a gas for generating plasma is supplied into the discharge tube from the gas source, and the plasma generating gas is excited in the discharge tube by microwaves, and the generated plasma is Plasma emission loca is also emitted.

[0015] Further preferably, the opening of the waveguide is provided on the H surface of the waveguide, the discharge tube is along the opening, and a part of the peripheral wall is inside the waveguide. The plasma discharge port of the discharge tube is preferably installed so as to be close to or enter a space, and is preferably a vertically long opening extending in the length direction of the discharge tube! /.

The invention's effect

[0016] According to the first invention, the microwaves are supplied from each of the both end openings of the waveguide, and a superimposed wave of the two microwaves is generated in the waveguide, and is provided in the microwave supply path. By shifting the phase of each microwave by means of the transmission path length adjusting means, the waveform of the superimposed wave is changed to adjust the plasma density in the plasma generation chamber (plasma generation region), thereby plasma processing outside the plasma emission port It is possible to obtain a line plasma with a uniform density in the region.

In addition, according to the second invention, microwaves are supplied from both ends of the waveguide, and a superimposed wave of the two microwaves is generated in the waveguide, and the plasma generation chamber (plasma generation) is generated by the superimposed wave. By generating plasma in the region) and adjusting the density of the plasma emitted from the plasma discharge port by the plasma density adjusting means, a line plasma with a uniform density can be obtained in the plasma processing region.

Thus, according to the present invention, it is possible to irradiate a workpiece with a line plasma having a uniform density, so that it is possible to perform a plasma treatment very efficiently and uniformly on a workpiece having a large area. Become.

Brief Description of Drawings

FIG. 1 is a diagram showing a schematic configuration of a microwave line plasma generator according to one embodiment of the present invention.

FIG. 2 is a diagram showing several embodiments of transmission path length adjusting means. FIG. 3 is a sectional view taken along line m-m in FIG.

4 is a cross-sectional view taken along line ii in FIG.

FIG. 5 is a cross-sectional view taken along the line II-II in FIG.

FIG. 6 is a graph showing the plasma density along the length direction of the plasma (the length direction of the plasma generation chamber of the discharge tube 25) for the line-shaped plasma generated by the apparatus of FIG. ) Shows a graph in the plasma generation chamber, and (B) shows a graph in the plasma processing region.

[Fig. 7] Plasma density in the length direction of the plasma, measured at three different positions below the plasma emission port, for the line-shaped plasma generated by the microwave line plasma generator shown in Fig. 1. It is the shown graph.

FIG. 8 is a perspective view showing a schematic configuration of a microwave line plasma generator according to another embodiment of the present invention.

FIG. 9 is a view similar to FIG. 3 of the microwave line plasma generator shown in FIG. 8.

FIG. 10 is a perspective view showing a schematic configuration of a microwave line plasma generator according to another embodiment of the present invention.

FIG. 11 is a diagram showing an overall configuration of an example of a conventional microwave line plasma generator

FIG. 12 is a perspective view of the main part of the microwave line plasma generator shown in FIG. 11.

FIG. 13 is a graph showing the plasma density in the length direction of the plasma measured for the line-shaped plasma generated by the microwave line plasma generator shown in FIG. A graph in the plasma generation region and (B) show a graph in the plasma processing region, respectively.

Explanation of symbols

1 discharge tube

2 First microwave source

3 Second microwave source

4 First microwave transmission line

5 Second microwave transmission line 6a, 6b taper waveguide

7a, 7b L-shaped waveguide

8a, 8b isolators

9a, 9b Three tab

10, 11 Transmission path length adjustment means

12, 13 Gas source

14, 15 Gas supply pipe

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a diagram showing a schematic configuration of a microwave line plasma generator according to one embodiment of the present invention. Referring to FIG. 1, according to the present invention, a flat rectangular waveguide 1 and first and second microphone mouth wave sources 2 and 3 are provided. The first microwave transmission path 4 is connected between the first microwave generation source 2 and the opening at one end of the waveguide 1 so that the microwave is supplied into the waveguide 1. In addition, a second microwave transmission path 5 is connected between the second microwave generation source 3 and the opening at the other end of the waveguide 1, and the microwave is inserted into the waveguide 1. They are starting to supply waves.

The first and second microwave transmission lines 4 and 5 are composed of tapered waveguides 6a and 6b and L-shaped waveguides 7a and 7b. Isolators 8a and 8b and sleeving tabs 9a and 9b are attached to the L-shaped waveguides 7a and 7b from the microwave sources 2 and 3 side.

[0020] In the middle of each of the first and second microwave transmission paths 4, 5, transmission path length adjusting means 10, 11 for adjusting the lengths of the transmission paths of the microphone mouth transmission paths are further provided. Is provided. 2A to 2C show several embodiments of the transmission path length adjusting means 10 and 11. FIG. In the embodiment of FIG. 2 (A), the transmission path length adjusting means comprises a U-shaped waveguide 19. The U-shaped waveguide 19 is further connected to the upstream and downstream portions of the L-shaped waveguides 7a and 7b of the first and second microwave transmission lines 4 and 5, respectively. A pair of parallel parts 20a, 20b and a U-shaped part 21 fitted to the pair of parallel parts 20a, 20b so that they can slide relative to each other and microwaves do not leak outside. And In this case, the U-shaped portion 21 has a portion that fits with the parallel portions 20a and 20b in the axial direction. A large number of pleats 21a are formed, and these pleats 21a and the inner wall surfaces of the parallel parts 20a, 20b always come into contact with each other!

In this configuration, when the U-shaped portion 21 slides with respect to the pair of parallel portions 20a and 20b, the transmission path lengths of the first and second microwave transmission paths 4 and 5 are extended or increased. Shortened.

In the embodiment of FIG. 2 (B), the transmission path length adjusting means is the first and second microwave transmission paths.

It comprises a circulator 22 inserted in the middle of 4 and 5 and a short circuit plunger 23 connected to the circulator 22.

In this configuration, the microwave propagated upstream of the first and second microwave transmission lines 4 and 5 is bent at a right angle by the circulator 22 and introduced into the short circuit plunger 23. The microwave introduced into the short circuit plunger 23 is then reflected at the end of the short circuit plunger 23 and directed toward the circuit 22. Then, it is bent at a right angle again and guided to the downstream side of the first and second microwave transmission paths 4 and 5. In other words, the transmission path length is increased by the amount of microwaves traveling back and forth in the short circuit plunger 23. Thus, the short circuit plunger 23 adjusts the transmission line lengths of the first and second microwave transmission lines.

In the embodiment of FIG. 2 (C), the transmission path length adjusting means is composed of a magic T19 ′. In this configuration, the microwave propagated from the upstream side of the first and second microwave transmission lines 4 and 5 is bent at a right angle by the branch portion of the magic T19 ', then reflected and branched again. Come back to the department. Then, half of the microwaves are transmitted downstream of the first and second microphone mouth wave transmission lines 4 and 5, and the other half are transmitted upstream. In other words, the transmission path length becomes longer as the microwave propagates back and forth in the magic T19 ′. Thus, the transmission line lengths of the first and second microwave transmission lines are adjusted by the magic T19 ′.

The waveguide 1 is provided with plasma generating means 16. The plasma generation means 16 has a plasma generation chamber extending in the microwave propagation direction in the waveguide 1 and a plasma discharge port for discharging the plasma generated in the plasma generation chamber in a line shape.

FIG. 3 is a cross-sectional view taken along the line III--X in FIG. 1, and shows the configuration of the plasma generating means 16 in more detail. 4 is a cross-sectional view taken along line II in FIG. 3, and FIG. It is sectional drawing along the π-π line.

As shown in FIG. 3, the waveguide 1 is formed so that the width “a” is larger than the thickness “b” in a cross section perpendicular to the central axis thereof. The width a of the waveguide is determined by the wavelength λ of the microwave in vacuum, the wavelength λ of the microwave inside the waveguide, and the width a of the waveguide a.

0 g

A relational expression established between

[Number 1]

Thus, the width a corresponds to the microwave wavelength within the waveguide longer than the length of the plasma to be generated.

g

[0025] Further, in the H surface of the waveguide 1 (the lower surface corresponds in this embodiment), a vertically long opening extending in the propagation direction of the microwave is formed, and the discharge tube 25 is formed in this opening. Installed. The discharge tube 25 is formed of a dielectric material such as quartz glass or ceramic, and both ends are closed, and the middle portion has an inverted U-shaped cross section. The discharge tube 25 is disposed such that a part 25 ′ of the peripheral wall enters the internal space of the waveguide 1, and a vertically long opening facing the part 25 ′ of the peripheral wall faces downward. In this embodiment, a plasma generation chamber is formed in the discharge tube 25, and the vertically long opening of the discharge tube 25 forms a plasma emission port 17. In this embodiment, a part 25 ′ of the peripheral wall of the discharge tube 25 is configured to enter the internal space of the waveguide 1, but a part 25 ′ of the peripheral wall is close to the internal space of the waveguide 1. A discharge tube 25 may be used.

The waveguide 1 is supported by the support block B, and the discharge tube 25 is held by the support block B. On both sides of the support block B, gas introduction paths Gl and G2 for supplying gas to the discharge tube 25 are provided. As shown in FIG. 4, a plurality of gas introduction paths Gl and G2 are arranged at equal intervals along the longitudinal direction of the support block B against the peripheral wall of the discharge tube 25 by force.

G1 is a gas introduction path for plasma generation, and is connected to a gas source 12 for plasma generation gas supply via a gas supply pipe 14, and G2 is a reaction gas introduction path, which is connected to a gas supply pipe 15 To the reactive gas supply gas source 13. W is a coolant reflux path for cooling the heat generated in the discharge tube 25 by plasma. This coolant circulation path W is for preventing the waveguide 1 and the support block B from becoming hot due to the plasma heat in the discharge tube 25. It can be provided between the gas introduction paths G1 or on the side of the discharge tube 25.

As shown in FIG. 5, a slit-like gas introduction opening 25 ”is provided along the longitudinal direction at the side of the discharge tube 25. This slit-like gas introduction opening. In order to maintain the mechanical strength of the discharge tube 25, 25 "is a burrow-like opening row. Further, the plasma generating gas introduction path G1 is provided with an expansion portion G1 ′ in the vicinity of the gas introduction portion to the discharge tube 25, and is connected to the gas introduction opening 25 ″ at the expansion portion G1 ′. The gas introduced from the plasma generating gas introduction path G1 is diffused in the lengthwise direction of the discharge tube 25 in the expanded portion G1 ′ and introduced into the discharge tube 25. Although not shown, the reaction gas introduction path is provided. The connecting portion between G2 and the discharge tube 25 has the same configuration.

Sl and S2 are baffle plates arranged in the expansion part G1 'of the gas introduction paths Gl and G2, that is, a gas diffusion plate having a large number of holes, and the flow of gas introduced from the gas introduction paths Gl and G2 It is spread in the longitudinal direction of the discharge tube 25 and guided uniformly into the discharge tube 25.

Thus, one end of the waveguide 1 through the first microwave transmission path 4 (the L-shaped waveguide 7a and the tapered waveguide 6a) generated by the first microwave generation source 2 The microwaves supplied from the side into the waveguide 1 and generated by the second microwave generation source 3 are transferred to the second microwave transmission path 5 (the L-shaped waveguide 7b and the tapered waveguide). It is supplied into the waveguide 1 from the other end side of the waveguide 1 through the wave tube 6b). In the waveguide 1, a superimposed wave of two microwaves is generated.

[0029] Further, the plasma generating gas is supplied from the gas source 12 into the discharge tube 1 through the gas supply tube 14 and the gas introduction path G1. Then, the plasma generation gas is excited in the plasma generation chamber of the discharge tube 25 by the electromagnetic field generated by the superimposed wave generated in the waveguide 1, and is plasma-treated.

Further, the reaction gas is supplied from the gas source 13 into the discharge tube 1 through the gas supply tube 15 and the gas introduction path G2. The reactive gas is generated by the electromagnetic field generated by the superimposed wave in the waveguide 1 and the plasma production. The plasma generated by the excitation of the forming gas is excited in the plasma generation chamber of the discharge tube 25 and turned into plasma.

Thus, the plasma force of the mixed gas of the plasma generating gas and the reactive gas is discharged in a line form from the plasma discharge port 17.

[0030] At this time, if the transmission path length of the first microwave transmission path 4 is changed by the transmission path length adjusting means 10, the microwave supplied into the waveguide 1 through the transmission path 4 is changed. When the phase is shifted and the transmission path length of the second microwave transmission path 5 is changed by the transmission path length adjusting means 11, the phase of the microwave supplied into the waveguide 1 through the transmission path 5 is changed. Is shifted, and the waveform of the superimposed wave in the waveguide 1 is changed.

In the plasma generation chamber, a plasma having an energy density corresponding to the plasma is generated and emitted from the plasma discharge port 17, and a line-shaped plasma having a uniform density is obtained in the plasma processing region below the plasma generation region. .

[0031] Fig. 6 is a graph showing the plasma density along the length direction of the plasma (the length direction of the plasma generation chamber of the discharge tube 25) for the line-shaped plasma generated by this apparatus. , (A) shows a graph in the plasma generation chamber, and (B) shows a graph in the plasma processing region. In the graph of FIG. 6, the distance in the z-axis direction represents the distance in the length direction in which one end force of the plasma is also measured. Referring to the graph of Fig. 6, if the phase of the two microwaves is adjusted so that the plasma density of the line plasma generated in the plasma generation chamber has peaks at both ends of the plasma, the plasma processing region A line-shaped plasma having a uniform plasma density can be obtained.

In this way, a uniform plasma density can be obtained in the plasma processing region because the plasma diffuses from both ends of the plasma to the center, or between the both ends of the plasma and both ends of the plasma plasma generation chamber. This is thought to be due to recombination due to interaction.

[0032] In this embodiment, the gas for generating plasma is introduced into G1 and the reaction gas is introduced into G2, and both gases may be mixed and introduced simultaneously from both gas introduction paths Gl and G2. In this way, gas mixing in the discharge tube 14 is improved, which can contribute to plasma stabilization. When no reactive gas is used in the plasma treatment, either a gas for generating plasma is supplied to both gas introducing paths Gl and G2, or the reactive gas introducing pipe G Let's close 2 though.

In FIG. 1, 18 is a plasma processing chamber for performing plasma processing by irradiating an object to be processed with plasma emitted from the plasma generating means 16.

When the apparatus is operated under atmospheric pressure, the mounting portion between the waveguide 1 and the discharge tube 25, the joint between the support block B and the discharge tube 25, and the support block B and the plasma processing chamber 18 A hermetic seal such as a conventional vacuum plasma processing apparatus is required when operating in a low pressure state of a pressure S below atmospheric pressure to several _Torr .

Next, an experiment was performed in which the above-described microwave line plasma generator was actually operated to measure the density of the line plasma generated. The apparatus used in this experiment comprises a waveguide with a width a of approximately 62 mm and a length c of approximately 600 mm, and a discharge tube with a width of approximately 10 mm, a depth of approximately 20 mm, and a length c ′ of approximately 500 mm. It was. In the experiment, the gas introduction path G2 was closed, He gas was supplied from the gas introduction path G1 as a plasma generation gas, and lkW, 2.45 GHz microwave was introduced from both ends of the waveguide under a pressure of 2 Torr. did.

[0035] Then, the y-axis (unit: mm) is set downward with the upper end of the inner wall of the discharge tube 25 as the origin (see Fig. 3). At three positions where the y-coordinates are 25mm, 35mm, and 40mm, respectively, The plasma density was measured along the length direction of the plasma (the length direction of the plasma generation chamber of the discharge tube 25). In this case, since it is difficult to directly measure the plasma density in the plasma generation chamber, it is necessary to predict the behavior of the plasma density graph in the plasma generation chamber using the measured value of the plasma density at the position y = 20 mm. And!

The measurement results are shown in FIG. In the graph of Fig. 7, the distance in the z direction on the horizontal axis represents the distance in the length direction that also measured one end force of the line-shaped plasma. “Sono”, “Fist”, and “▲” represent the measured values at the positions of 25 mm, 35 mm, and 40 mm, respectively. From the graph of FIG. 7, as described above, if a line-shaped plasma having a peak plasma density at both ends in the plasma generation chamber is generated, the position is 35 mm from the upper end of the inner wall of the discharge tube 25, that is, It can be seen that the plasma density is uniform at a position 15 mm below the plasma discharge port 17. If a plasma treatment region is provided at this position, a line plasma with uniform density can be obtained.

FIG. 8 is a schematic configuration of a microwave line plasma generator according to another embodiment of the present invention. FIG. 9 is a view similar to FIG. 3 of the microwave line plasma generator shown in FIG. This embodiment differs from the embodiment shown in FIG. 1 only in the means for making the line plasma density uniform in the plasma processing region. Therefore, in FIG. 8 and FIG. 9, the same constituent elements as those shown in FIG. For the sake of clarity, the microwave generation source and the microwave transmission path are omitted in FIG.

With reference to FIGS. 8 and 9, in this embodiment, means for making the density of the line plasma uniform in the plasma processing region is provided in the vicinity of the plasma discharge port 17 of the plasma generation means 16. The plasma discharge means 17 comprises plasma density adjusting means for adjusting the density of the plasma by at least partially blocking the plasma emitted from the plasma discharge port 17. In this embodiment, the plasma density adjusting means 31 is a conductor or dielectric that is arranged below the plasma discharge port 17 and on both sides of the plasma discharge port 17 at intervals along the longitudinal direction of the plasma discharge port 17. Are provided on the body rod 30 and the side walls 18a and 18b of the plasma processing chamber 18, and support the rod 30 and each rod 30 independently in its axial direction and across the plasma outlet 17. Slide motion is possible between the first position where the rod 30 at least partially blocks the plasma emitted from the plasma outlet 17 and the second position where the rod 30 does not contact the plasma. And bearings (not shown) for guiding!

[0038] According to this configuration, the plasma portion shielded by the rod body 30 is not shielded by the rod body 30, and the plasma density is lower in the plasma processing region than the plasma portion. Therefore, by manually adjusting the position of each rod 30, a line plasma with a uniform density can be obtained in the plasma processing region.

FIG. 10 is a perspective view showing a schematic configuration of a microwave line plasma generator according to another embodiment of the present invention. This embodiment is different from the embodiment shown in FIG. 8 only in the configuration of the plasma density adjusting means. Therefore, in FIG. 10, the same components as those shown in FIG. 8 are denoted by the same reference numerals, and detailed description thereof is omitted.

Referring to FIG. 10, in this embodiment, the plasma density adjusting means 31 ′ has a horizontal plate assembly disposed below the plasma discharge port 17 and on both sides of the plasma discharge port 17. is doing. The plate assembly is arranged adjacent to the longitudinal direction of the plasma emission port 17. And a plurality of conductor or dielectric plate elements 32a to 32d. The plasma density adjusting means 31 ′ is further provided on the side walls 18 a and 18 b of the plasma processing chamber 18 to support the plate elements 32 a to 32 d and to each plate element 32 a to 32 d independently of the plasma discharge port 17. Between the first position where the plate elements 32a to 32d at least partially block the plasma emitted from the plasma outlet 17 and the second position where the plate elements 32a to 32d do not contact the plasma. It has a guide means (not shown!) That guides it so that it can slide.

Also in this configuration, as in the case of the rod 30 in the embodiment of FIG. 8, the plasma portion blocked by the plate elements 32a to 32d is compared with the plasma portion not blocked by the plate elements 32a to 32d. The plasma density is lowered in the region. Therefore, the density of the line plasma can be made uniform in the plasma processing region by manually adjusting the position of each plate element 32a to 32d.

Claims

The scope of the claims

[1] a waveguide;

First and second microwave sources;

A first microwave transmission path connected between the first microwave generation source and one end opening of the waveguide and supplying microwaves into the waveguide;

A second microwave transmission path connected between the second microwave generation source and the other end side opening of the waveguide, and supplying microwaves into the waveguide;

Transmission path length adjusting means provided in the middle of each of the first and second microwave transmission paths, for adjusting the lengths of the transmission paths of the microwave transmission paths;

A gas source for supplying a plasma generating gas;

The gas source includes a plasma generation chamber provided in the waveguide and extending in a microwave propagation direction in the waveguide, and a plasma discharge port for discharging the plasma generated in the plasma generation chamber in a line shape. A plasma generating means for generating a plasma by exciting a plasma generating gas supplied to the plasma generating chamber with a microwave supplied into the waveguide, and for releasing the plasma from the plasma discharge locuser; The microwave line plasma generator characterized by comprising.

[2] Each of the first and second microwave transmission paths is formed of a second waveguide, and the transmission path length adjusting means is a U-shaped third waveguide, The waveguide further includes a pair of parallel portions connected to the upstream portion and the downstream portion of the first and second microwave transmission lines, respectively, and the pair of parallel portions with respect to them. 2. The microwave line plasma generating apparatus according to claim 1, wherein a U-shaped portion fitted so as to be slidable and so that the microwave does not leak to the outside, and a force! /.

[3] The first and second microwave transmission paths are each formed of a waveguide, and the transmission path length adjusting means is a circulator inserted in the middle of the first and second microwave transmission paths. 2. The microwave line plasma generator according to claim 1, further comprising: a short circuit plunger connected to the circulator.

[4] The first and second microwave transmission paths are each formed by a waveguide force, and the transmission 2. The microwave line plasma generating apparatus according to claim 1, wherein the path length adjusting means includes a magic T.

[5] waveguide,

First and second microwave sources;

A gas source for supplying a plasma generating gas;

The gas source includes a plasma generation chamber provided in the waveguide and extending in a microwave propagation direction in the waveguide, and a plasma discharge port for discharging the plasma generated in the plasma generation chamber in a line shape. A plasma generating means for generating a plasma by exciting a plasma generating gas supplied to the plasma generating chamber with a microwave supplied into the waveguide, and discharging the plasma from the plasma discharge port When,

Plasma density adjusting means provided in the vicinity of the plasma emission port of the plasma generating means for adjusting the density of the plasma by at least partially blocking the plasma emitted from the plasma emission port. A microwave line plasma generator characterized by this.

[6] The plasma density adjusting means is a rod body that is arranged below the plasma discharge port and at one side or both sides of the plasma discharge port at intervals along the longitudinal direction of the plasma discharge port. And supporting the rod body, and the rod body at least partially blocks the plasma emitted from the plasma emission locus in the axial direction of the rod body and in a direction transverse to the plasma emission port. A rod moving means for moving between the first position and the second position when the rod does not contact the plasma is provided! Item 6. The microwave line plasma generator according to Item 5.

[7] The plasma density adjusting means includes a horizontal plate assembly disposed on one side or both sides of the plasma discharge port below the plasma discharge port, and the plate assembly includes: A plurality of plates arranged adjacent to each other in the longitudinal direction of the plasma emission port The plate element further supports the plate element, and the plate element at least partly emits the plasma emitted by the plasma emission locus in a direction transversely across the plasma emission opening of each of the plate elements. 6. A plate element moving means for moving between a first position where the plate element is obstructed and a second position where the plate element does not contact the plasma. The microwave line plasma generator described in 1.

The waveguide is a flat rectangular waveguide formed so that its width is greater than its thickness in a cross section perpendicular to its central axis, and the width a of the waveguide is within the vacuum free space. The microwave wavelength, the microwave wavelength inside the waveguide, and the front

0 g

A relational expression established between the width a of the waveguide,

[Number 1]

The width a corresponds to the wavelength λ of the microwave inside the waveguide, which is longer than the length of the plasma to be generated.

g

The microwave line plasma generator according to any one of claims 7 to 8.

[9] The waveguide has an elongated opening extending in the microwave propagation direction, and the plasma generating means has a dielectric discharge tube attached to the opening of the waveguide. In the discharge tube, a part of the peripheral wall thereof approaches or enters the internal space of the waveguide, and the plasma emission port is formed in the peripheral wall portion exposed to the outside of the waveguide in the discharge tube. The gas source and the plasma generation gas are supplied into the discharge tube, the plasma generation gas is excited in the discharge tube by microwaves, and the generated plasma is also released from the plasma emission locusr. The microwave line plasma generator according to any one of claims 1 to 8, wherein the microwave line plasma generator is configured as described above.

[10] The opening of the waveguide is provided on the H-plane of the waveguide, and the discharge tube is close to the internal space of the waveguide along the opening. 10. The microwave line plasma generator according to claim 9, wherein the microwave line plasma generator is mounted so as to penetrate. 11. The microwave line plasma generating device according to claim 9, wherein the plasma discharge port of the discharge tube is a vertically long opening extending in a length direction of the discharge tube.