JP2000058294A - Plasma treatment device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plasma treatment device which uniformly supplies a reaction gas into a chamber and can prevent plasma discharge between shower plates. SOLUTION: Shower plates 17 and 18 in two stages provided with a number of holes for dispersing a reaction gas in a plasma generating space 6 are installed between a gas introducing port 20 provided at a chamber 2 and the plasma generating space 6 formed therein 2. The first stage shower plate 17 in the upstream has a function to disperse the reaction gas uniformly in the space 23 formed with respect to the second stage shower plate 18 in the downstream, while the second stage shower plate 18 has a function to disperse the reaction gas uniformly in the plasma generating space 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma processing apparatus such as a CVD apparatus and an etching apparatus used in a manufacturing process of a semiconductor substrate, a liquid crystal substrate and the like, and more particularly to a plasma processing apparatus suitable for a microwave plasma excitation system. is there.

[0002]

2. Description of the Related Art In recent years, in a CVD apparatus used in a manufacturing process of a liquid crystal substrate or the like, a radial line capable of obtaining a large-diameter uniform and high-density plasma in order to meet a demand for a larger substrate and a higher processing speed. A microwave plasma CVD apparatus provided with a slot antenna has been proposed. Radial Line Slot Ant
enna) is a disk-shaped conductor surface in which a number of slots for microwave radiation are formed concentrically or spirally, and emits microwaves fed from the back side from the slot forming surface. It is.

In the microwave plasma CVD apparatus, a reaction gas required for film formation is introduced into a chamber, and a microwave is emitted to generate plasma, and radicals generated by dissociation of the reaction gas in the plasma. Causes a chemical reaction on the substrate surface to form a film.
Usually, a substrate to be processed is supported on a susceptor provided at a lower portion in the chamber, and a space above the substrate is a plasma generation space. In addition, a reaction gas is supplied from one or several places in the upper part of the chamber to supply the reaction gas to the plasma generation space.

However, when the reaction gas is supplied from one or several places in the chamber, it is extremely difficult to supply the gas so that the reaction gas is uniformly diffused throughout the plasma generating space. In particular, it is even more significant that the chamber becomes larger with the increase in the size of the substrate to be processed. Therefore, no matter how much the reaction gas is supplied from the peripheral part of the chamber, the gas becomes uneven at the peripheral part and the central part of the chamber, and when the gas (pressure) becomes uneven, the plasma discharge becomes unstable. Would. As a result, there has been a problem that the in-plane variation of the film thickness on the substrate to be processed becomes large.

Therefore, a plate body provided with a large number of holes for ejecting a gas, a so-called shower plate, is provided below the reaction gas inlet at the upper part of the chamber, and the gas is dispersed and supplied from the large number of holes in the shower plate. A device with is proposed. In the case of the microwave plasma CVD apparatus, since it is necessary to supply the microwave while supplying the reaction gas to the plasma generation space in the chamber, the substrate to be processed is supported by the susceptor on the lower side of the chamber, and In general, the gas is supplied from the shower plate on the side, and the microwave is supplied from the radial line slot antenna provided further above the shower plate through the shower plate.

[0006]

However, when a high frequency is used for plasma excitation, there is no problem even if the space between the chamber and the shower plate is wide. However, in the case of the above-described apparatus using microwaves for plasma excitation, microwaves are used. Power is greater than the high frequency, so if the space between the chamber and the shower plate, that is, the space defined by the shower plate, is large enough, microwaves of high power will be transmitted in the presence of gas in this space. However, there is a possibility that a plasma discharge is generated in this minute space where plasma should not be generated. As a result, problems such as a film formation reaction occurring in this space occur.

Further, if the space between the chamber and the shower plate is reduced to prevent plasma discharge, the pressure difference of the gas in this space becomes large, so that when the gas is blown out from many holes of the shower plate, the gas is discharged. Is not uniformly supplied into the chamber. Therefore, in order to reduce the pressure difference in the space while suppressing the plasma discharge, the pressure in the space may be made larger than a predetermined value from the relationship between the discharge starting voltage and the gas pressure. For that purpose, the diameter of the gas ejection hole may be reduced, or the number of the gas ejection holes may be reduced. However, the reduction of the hole diameter is limited to about 0.5 mm due to the processing of the shower plate, and if the number of holes is reduced, the original function of the shower plate to uniformly eject gas is impaired. Therefore, in practice, it has been difficult to prevent plasma discharge in this space by increasing the pressure in the space between the chamber and the shower plate.

That is, in a plasma CVD apparatus in which a shower plate is installed in a chamber, a reaction gas is uniformly supplied to a plasma generation space in the chamber, and a plasma discharge in a space between the chamber and the shower plate is prevented. There was a problem that it was difficult to balance both. As described above, the case of the plasma CVD apparatus has been described as an example, but other plasma processing apparatuses such as a microwave plasma etching apparatus have the same problem.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is a primary object of the present invention to uniformly supply a reaction gas into a chamber and prevent plasma discharge between a chamber and a shower plate. It is an object of the present invention to provide a plasma processing apparatus suitable for increasing the diameter of the apparatus and increasing the processing speed.

[0010]

In order to achieve the above object, a plasma processing apparatus according to the present invention comprises a reaction gas introducing port provided in a chamber and a plasma generating space inside the chamber. At least two-stage shower plates having a large number of holes for diffusing the gas into the plasma generation space are provided. Conventionally, in a general reaction gas supply mechanism, it was common sense to provide only one stage of a shower plate for diffusing a gas into a chamber, whereas in the plasma processing apparatus of the present invention, at least two or more stages of a shower plate were provided. The configuration was provided.

[0011] With this configuration, even if it is not necessary to diffuse the reaction gas at one time with the one-stage shower plate, the one-stage shower plate is moved from the upstream-stage shower plate to the downstream-stage shower plate along the flow of the reaction gas. What is necessary is to spread sequentially one by one. That is, among the shower plates, the upstream shower plate upstream of the most downstream shower plate sequentially distributes the reaction gas uniformly in a space between the next shower plate downstream of the upstream shower plate. The shower plate at the most downstream stage may have a large number of holes for diffusing the reaction gas almost uniformly into the plasma generation space. Therefore, according to the present invention, it is possible to supply a sufficiently uniform reaction gas to the plasma generation space of the chamber.

The present invention can of course be applied to a plasma processing apparatus using a high frequency as the plasma exciting means, but it is also possible to use a microwave as the plasma exciting means and to use a radial line slot antenna or the like described in the section of the prior art. It is more suitable to be applied to a plasma processing apparatus provided with the antenna for microwave radiation described above. As described above, when microwaves are used for the plasma excitation means, plasma discharge easily occurs in the space between the chamber and the shower plate because the microwaves themselves have large power. Therefore, it is necessary to narrow the gap between the chamber and the shower plate. However, the conventional shower plate having only one stage cannot achieve a sufficient uniformity with respect to gas diffusion, and thus the gap cannot be narrowed. However, in the present invention, a configuration in which a sufficient gas diffusion uniformity is finally obtained through a plurality of stages of shower plates is achieved. As a result, a shower plate for each stage does not require so high uniformity.
Therefore, the spacing between the chamber and the shower plate,
Alternatively, the distance between the shower plates can be reduced, and plasma discharge in these spaces can be prevented.

When installing at least two or more shower plates, the same shower plate may be used. However, if shower plates having different arrangements of holes for ejecting reaction gas are used in combination, the present invention is not applicable. The effect of the invention becomes more remarkable. As described above, it is necessary to diffuse the reaction gas uniformly in the plasma generation space in the shower plate at the most downstream stage, but it is necessary to diffuse the reaction gas between the shower plate in the upstream stage and the next shower plate in the upstream stage. It is necessary to diffuse as uniformly as possible into the space.

Here, considering that a configuration in which the reaction gas is supplied from the peripheral portion of the chamber to the shower plate at the most upstream stage is generally used, a hole is temporarily formed at the peripheral portion of the shower plate at the upstream stage side. If there are many, the reaction gas passes through the holes around the shower plate before diffusing sufficiently into the space between the chamber and the shower plate, or into the space between the shower plate and the shower plate. It flows one after another downstream, and it is difficult to sufficiently diffuse gas. Therefore, in the shower plate in the upstream stage, if the gas ejection holes are distributed more in the central portion than in the peripheral portion in the shower plate surface, the reaction gas can be sufficiently diffused in the space.

For the same reason, in order to sufficiently diffuse the reaction gas in the above space, the holes of the upstream shower plate should be distributed less than the holes of the next shower plate on the downstream side. desirable.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [First Embodiment] A first embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a diagram showing an overall configuration of a plasma CVD apparatus 1 (plasma processing apparatus) of the present embodiment. The plasma CVD apparatus 1 is an apparatus of a microwave plasma excitation type provided with a radial line slot antenna for radiating microwaves.

As shown in FIG. 1, a radial line slot antenna 3 is provided above a chamber 2.
A susceptor 5 for supporting the substrate to be processed 4 is provided below the chamber 2 so as to face the susceptor. Therefore, the plasma generating space 6 is located above the substrate 4 to be processed, and microwaves are radiated from the radial line slot antenna 3 toward the space 6.
The radial line slot antenna 3 is provided with a slot plate 9 having a large number of slot holes provided on a surface of a conductor 7 via a dielectric 8 serving as a microwave slow-wave material.
2.45 GH generated by microwave generation system 10
The microwave of z is configured to be fed from the back side of the conductor 7 through the waveguide 11 and the coaxial waveguide converter 12.
The conductor 7 of the radial line slot antenna 3 is provided with a cooling pipe (not shown) for flowing cooling water for preventing heating by microwave power supply.

The arrangement of the slot holes 13 of the radial line slot antenna 3 is as shown in FIG. 2. A large number of pairs of slot holes 13 are arranged concentrically, and microwaves are radiated from these slot holes 13 into space. You. Note that reference numeral 14 in FIG. 2 is a screw hole.

As shown in FIG. 1, a first dielectric 15 and a second dielectric 16 are sequentially fixed on the surface of the radial line slot antenna 3, and the first dielectric 15 is fixed on the surface of the second dielectric 16.
First stage shower plate 17, Second stage shower plate 1
8 are fixed sequentially. In the present embodiment, two shower plates having different arrangements of holes for ejecting the reaction gas are used in combination. As shown in FIGS. 3 and 4, each shower plate 17, 18 has a large number of minute holes 1.
9 are arranged at regular intervals in a grid pattern over the entire surface of the plate.
The gap between the holes 19 is smaller in the stage shower plate 18,
That is, the holes 19 are densely formed. Note that the first dielectric 15 and the second dielectric 16 have a property of transmitting microwaves, and are made of a material having a small dielectric constant and a small dielectric loss and a high strength.

A gas introduction port 20 (reaction gas introduction port) is provided on the upper side of the chamber 2 on the side of each of the shower plates 17 and 18, and a gas supplied from a reaction gas supply source (not shown) is provided. The gas reaches the gas diffusion plate 22 through the pipe 21, and a space 23 (hereinafter, referred to as a space) between the second dielectric 16 and the first-stage shower plate 17 from the gas diffusion plate 22.
For convenience of description, this is referred to as a first space). More specifically, the gas diffusion plate 22 is formed of an annular plate, and is provided with a groove along the circumferential direction, and the gas reaching the gas diffusion plate 22 is diffused into the groove. Further, gas passages 27 are provided at a plurality of locations spaced in the circumferential direction from the grooves 22 a of the gas diffusion plate 22 toward the first-stage shower plate 17, and the gas passages 27 are provided at the edges of the first-stage shower plate 17. A groove 17a extending radially in communication with each of the passages 27 is provided. That is, the reaction gas is supplied to the gas introduction port 20 and the groove 2 of the gas diffusion plate 22.
Since the reaction gas is supplied into the first space 23 through the path of the groove 2a, the gas passage 27, and the groove 17a of the first-stage shower plate 17, the reaction gas is introduced from one gas introduction port 20 when entering the apparatus. However, when they enter the first space 23, they are introduced from a plurality of circumferential locations of the first-stage shower plate 17. As described above, the gas diffusion plate 22 has a function of diffusing the reaction gas introduced from the pipe 21 to a part of the gas introduction port 20 in the circumferential direction of the chamber 2. Further, the reaction gas is 1
After passing through the first-stage shower plate 17 and being supplied to a space 24 between the first-stage shower plate 17 and the second-stage shower plate 18 (hereinafter referred to as a second space for convenience of description), It is supplied to the plasma generation space 6 in the chamber 2 after passing through the stage shower plate 18.

An exhaust port 25 is provided below the chamber 2, and the inside of the chamber 2 is depressurized by a vacuum exhaust source (not shown) such as a vacuum pump connected to the exhaust port 25. A load lock chamber 26 is provided on the side of the chamber 2 for loading and unloading the substrate 4 to be processed without opening the inside of the chamber 2 to the atmosphere.

In the plasma CVD apparatus 1 having the above-described structure, a reaction gas, such as SiH, required for film formation via a path of the gas introduction port 20, the gas diffusion plate 22, the first-stage shower plate 17, and the second-stage shower plate 18. ₄ , P
A gas such as H ₃ is supplied into the chamber 2. And
1. Radiated from the radial line slot antenna 3
Plasma is generated in the plasma generation space 6 by the microwave of 45 GHz, and a radical generated by dissociation of the reaction gas causes a chemical reaction on the substrate surface, thereby forming a desired film such as a Si film.

The plasma CVD apparatus 1 according to the present embodiment includes two stages of shower plates 17 and 18, and the number of holes 19 of the first stage shower plate 17 on the upstream side is equal to the number of holes 19 of the second stage shower plate 18. Since the number is smaller than 19, the pressure of the reaction gas increases in the first space 23,
First, the reaction gas is sufficiently diffused in the first space 23. Thereafter, the reaction gas is supplied to the holes 19 of the first-stage shower plate 17.
When the reaction gas reaches the second space 24 after passing through, the reaction gas is further diffused in the second space 24 and then jetted into the plasma generation space 6.

Therefore, the plasma CV of the present embodiment
According to the D apparatus 1, it is possible to greatly improve the uniformity of the diffusion of the reaction gas into the plasma generation space 6 of the chamber 2 as compared with a conventional apparatus having only one shower plate. Generally, when microwaves are used as plasma excitation means, plasma discharge is likely to occur in the space between shower plates due to the high power of the microwaves themselves. However, in the case of the present embodiment, sufficient uniformity of gas diffusion is obtained by using the two-stage shower plates 17 and 18, so that a shower plate for each stage does not require so high uniformity. The distance between the shower plates 17 and 18 can be reduced.
Plasma discharge in the second spaces 23 and 24 can be prevented. That is, both the improvement of the uniformity of gas diffusion to the plasma generation space 6 in the chamber 2 and the prevention of plasma discharge in the space between the shower plates 17 and 18 can be achieved.

[Second Embodiment] Hereinafter, a second embodiment of the present invention will be described.
Will be described with reference to FIGS. 5 and 6. FIG. This embodiment is also an example of a microwave plasma CVD apparatus having a two-stage shower plate as in the first embodiment, and the present embodiment is different from the first embodiment in that Only the arrangement of the reaction gas outlets is provided. Therefore, description of the overall configuration of the plasma CVD apparatus is omitted, and only the configuration of the shower plate will be described with reference to FIGS.

As shown in FIG. 5, the configuration of the shower plate in the present embodiment is the first-stage shower plate 3.
0 is arranged so that the density of the holes 32 is sparse at the peripheral portion and becomes higher toward the central portion. As shown in FIG. 6, the second-stage shower plate 31 is similar to the first embodiment,
Holes 32 are arranged at equal intervals over the entire surface of the plate.

Since the reaction gas is supplied to the first shower plate 30 from the peripheral portion of the chamber 2 through the gas diffusion plate 22, the first shower plate 30 is temporarily reversed from the present embodiment. If many holes 32 are provided in the peripheral portion, the reaction gas passes through the holes 32 in the peripheral portion of the first shower plate 30 and enters the second space 24 before sufficiently diffusing in the first space 23. It flows. Then, the reaction gas is non-uniformly supplied from the second-stage shower plate 31 to the plasma generation space 6 without being sufficiently diffused finally. However, in the case of the present embodiment, the number of holes 32 of the first-stage shower plate 30 is larger in the central part than in the peripheral part in the surface of the shower plate, and the pressure of the reaction gas is high in the peripheral part and low in the central part. 1 space 2
The flow of the reactant gas in the lateral direction within 3 becomes large, and the gas can be more uniformly diffused as compared with the first embodiment.

[0028]

[Experiment 1] Next, an experiment for verifying the effect of the plasma processing apparatus of the present invention was conducted, and the results will be described below. In this experiment, two-stage shower plate 1
7 and 18 (Example 1, FIG. 7
7), two-stage shower plates 17 and 18 shown in FIG.
Among them, a plasma CVD apparatus provided with only the first-stage shower plate 17 (conventional example 1) and a plasma CVD provided with a gas diffusion plate 22 for supplying gas from the periphery of the chamber 2
The same device (conventional example 2; see FIG. 8) and a plasma CVD device (conventional example 3; see FIG. 9) for supplying gas from one location in chamber 2 (leftmost gas introduction port 20 in FIG. 9). An a-Si (amorphous silicon) film was formed under the conditions, and the thickness distribution of the a-Si film on the substrate was measured.

The two-stage shower plate 51, 52 of Example 1 shown in FIG. 7 is similar to the first-stage shower plate 51 as described in the first embodiment (see FIGS. 3 and 4).
The density of the holes 19 in both the second shower plate 52 (corresponding to the second shower plate 18 in FIG. 4) and the second shower plate 52 (corresponding to the first shower plate 17 in FIG. 3) is uniform in the plane.
Moreover, the holes 19 are denser in the second-stage shower plate 52 than in the first-stage shower plate 51, and the first-stage shower plate 51 has a hole diameter of 0.5 mm and a hole interval of 20 m.
m, the second-stage shower plate 52 has a hole diameter of 0.5 mm and a hole interval of 10 mm. The film formation conditions are as follows: the reaction gas flow rate is 50 sccm for SiH ₄ , 800 sccm for Ar, and 150 for H _2.
The pressure in the chamber was 700 mTorr.

FIG. 10 is a diagram showing the measurement results of the film thickness distribution of the a-Si film. The horizontal axis indicates the film thickness measurement position (m) on the substrate.
m) and the vertical axis is the film thickness (nm). As is clear from FIG. 10, in the conventional example 3 in which the gas is supplied from one place in the chamber, the film thickness distribution is about 800 n closer to the gas supply side.
m, extremely large variations of about 100 nm and about 700 nm were observed on the far side. Further, in the conventional example 2 including the gas diffusion plate, the film thickness varies in the range of about 330 to 600 nm, and in the conventional example 1 including only one shower plate, the film thickness varies in the range of about 380 to 550 nm. Was. On the other hand, in the apparatus of Example 1 provided with the two-stage shower plate, the variation in the film thickness was able to be suppressed to a very small value of 420 to 440 nm as compared with the conventional examples 1 to 3.

[Experiment 2] Next, in the plasma CVD apparatus according to the present invention provided with a two-stage shower plate, it was examined how much the thickness variation varies depending on the arrangement of the holes in each shower plate. Of the two-stage shower plates 51 and 52 shown in FIG. 7, as described in the first embodiment (see FIGS. 3 and 4), the first-stage shower plate 51 (the first-stage shower plate in FIG. 3). 17), the second-stage shower plate 52 (corresponding to the second-stage shower plate 18 in FIG. 4) has a uniform hole density in the plane, and is 2 times larger than the first-stage shower plate 51.
The staircase shower plate 52 has a denser hole,
The first-stage shower plate 51 has a hole diameter of 0.5 mm, the hole interval is 20 mm, and the second-stage shower plate 52 has a hole diameter of 0.5 m.
m and a hole interval of 10 mm were used in the apparatus of Example 1 (Experiment 1).
(Same as the device of Example 1).

On the other hand, as described in the second embodiment (see FIGS. 5 and 6), the first-stage shower plate 51 (corresponding to the first-stage shower plate 30 in FIG. 5) has a peripheral portion. The density of the holes is low and dense toward the center.
The second-stage shower plate 52 (corresponding to the second-stage shower plate 31 in FIG. 6) has a uniform hole density in the plane, the first-stage shower plate 51 has a hole diameter of 0.5 mm, and the second-stage shower plate 52 has a hole diameter. 0.5mm, hole interval 10mm,
Was used as the apparatus of Example 2.

Using these apparatuses, an a-Si film was formed under the same conditions, and the thickness distribution of the a-Si film on the substrate was measured. The film forming conditions were exactly the same as those in Experiment 1, and the reaction gas flow rates were 50 sccm for SiH ₄ , 800 sccm for Ar, and H ₂ :
The pressure was set to 150 sccm, and the pressure in the chamber was set to 700 mTorr.

FIG. 11 is a diagram showing the measurement results of the film thickness distribution of the a-Si film. The horizontal axis indicates the film thickness measurement position (m
m) and the vertical axis is the film thickness (nm). As is clear from FIG. 11, in the apparatus of Example 1 including the two-stage shower plate in which the holes are equally spaced, the film thickness distribution is 417.
In contrast, the film thickness distribution was 417 nm in the apparatus of Example 2 having the first-stage shower plate in which the holes became denser from the peripheral part toward the central part.
As compared with Example 1, the variation in the film thickness was able to be suppressed to a small value such as about 424 nm. The reason for this is that the holes of the first-stage shower plate in Example 2 are sparse and dense from the peripheral part toward the central part.
It can be inferred that the flow of the reactant gas in the first space in the first space described in the above-described embodiment becomes larger, and the gas is more uniformly diffused as compared with the apparatus of the first embodiment.

The technical scope of the present invention is not limited to the above embodiment, and various changes can be made without departing from the spirit of the present invention. For example, in the above embodiment, an example in which two shower plates are provided has been described. However, it is needless to say that three or more shower plates may be provided. Further, the diameter, number, interval, arrangement, and the like of the gas ejection holes of the shower plate are not limited to the above-described embodiment, and can be appropriately changed in design.
As described above, the configuration of the present invention is suitable for a microwave plasma processing apparatus, but can also be applied to various plasma processing apparatuses such as a high-frequency plasma excitation type CVD apparatus and an etching apparatus.

[0036]

As described above in detail, according to the plasma processing apparatus of the present invention, the uniformity of the diffusion of the reaction gas into the plasma generation space of the chamber is greatly improved as compared with the conventional apparatus. Therefore, processing with high in-plane uniformity of the substrate to be processed can be performed. Further, even when microwaves are used for the plasma excitation means, plasma discharge between shower plates can be prevented. That is, since both the improvement of the uniformity of gas diffusion to the plasma generation space in the chamber and the prevention of plasma discharge in the space between the shower plates can be achieved at the same time, it is suitable for a microwave plasma excitation type processing apparatus. And
As a result, an apparatus suitable for increasing the diameter of a substrate to be processed and increasing the processing speed can be provided.

[Brief description of the drawings]

FIG. 1 shows a plasma C according to a first embodiment of the present invention.
It is sectional drawing which shows a VD apparatus.

FIG. 2 is a plan view showing a radial line slot antenna of the plasma CVD apparatus.

FIG. 3 is a plan view showing a first-stage shower plate of the plasma CVD apparatus.

FIG. 4 is a plan view showing the second-stage shower plate.

FIG. 5 shows a plasma C according to a second embodiment of the present invention.
It is a top view showing the 1st stage shower plate of a VD device.

FIG. 6 is a plan view showing the second-stage shower plate.

FIG. 7 is a cross-sectional view illustrating a main part of the apparatus according to the first embodiment, which is an apparatus used for an effect verification experiment of the plasma processing apparatus of the present invention.

FIG. 8 is a cross-sectional view showing a main part of the device of Conventional Example 2;

FIG. 9 is a cross-sectional view showing a main part of the device of Conventional Example 3;

FIG. 10 shows a film formed by using each apparatus in Experiment 1.
FIG. 9 is a diagram showing a measurement result of a film thickness distribution of a -Si film.

FIG. 11 is a diagram illustrating a film formed by using each apparatus in Experiment 2.
FIG. 9 is a diagram showing a measurement result of a film thickness distribution of a -Si film.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Plasma CVD apparatus (plasma processing apparatus) 2 Chamber 3 Radial line slot antenna 6 Plasma generation space 17,30 First-stage shower plate 18,31 Second-stage shower plate 19,32 (gas ejection) hole 20 Gas introduction port (reaction) Gas inlet) 22 Gas diffusion plate 23 First space 24 Second space

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01L 21/3065 H01L 21/31 C 21/31 21/302 B (72) Inventor Koichi Fukuda Sendai, Miyagi 3-31 Akimitsu-ku, Ichizumi-ku, Japan Frontech Co., Ltd. (72) Tadahiro Omi 2-1-17-301 Yonegabukuro, Aoba-ku, Sendai, Miyagi Prefecture F term (reference) 4K030 AA06 AA16 AA17 BA30 EA05 EA06 FA01 JA07 4K057 DA11 DM29 DM37 DM40 DN01 5F004 AA01 BA04 BB14 BC08 BD03 BD04 5F045 AA09 BB02 DP03 EF05 EF08 EH02

Claims (5)

[Claims] An at least two-stage shower plate having a number of holes for diffusing a reaction gas into the plasma generation space between a reaction gas inlet provided in the chamber and a plasma generation space inside the chamber. A plasma processing apparatus, comprising: 2. The shower plate at the most downstream stage among the shower plates has a large number of holes for diffusing the reaction gas almost uniformly into the plasma generation space, and the upstream of the shower plate at the most downstream stage is upstream of the shower plate at the most downstream stage. 2. The stage shower plate has a number of holes for sequentially and uniformly diffusing the reaction gas into a space between the upstream stage shower plate and the next stage shower plate downstream of the upstream stage shower plate. The plasma processing apparatus as described in the above. 3. The plasma processing apparatus according to claim 2, wherein a large number of holes in the upstream shower plate are distributed more in a central portion than in a peripheral portion in a surface of the shower plate. . 4. The hole of the upstream shower plate,
The plasma processing apparatus according to claim 2, wherein the plasma processing apparatus is provided so as to be distributed less than holes of the shower plate in the next stage on the downstream side. 5. The plasma processing apparatus according to claim 1, further comprising an antenna for transmitting microwaves transmitted through the shower plate and supplied to the plasma generation space.