KR100228588B1 - Plasma processing system - Google Patents

Abstract

A support having a means for supplying microwaves, a reaction vessel with a microwave inlet opening, a microwave introduction window for introducing microwaves from the microwave supply means into the reaction vessel at the microwave inlet, and a support for supporting the microwave introduction window. Plasma processing apparatus characterized in that it comprises.

The microwave introduction window is partitioned in correspondence with a region divided by the support.

Strengthen the pressure resistance of the microwave introduction window during plasma generation and reduce the possibility of breakage of the large-area microwave introduction window. As a result, the plasma apparatus can be uniformly stabilized with a large-area semiconductor substrate, LCD substrate, and the like.

Description

Plasma processing equipment

1 (a) is a schematic plan view of a plasma processing apparatus using this dielectric layer.

FIG. 1 (b) is a longitudinal cross-sectional view of the portion A-A of FIG. 1 (a).

FIG. 2 (a) is a schematic plan view of the plasma processing apparatus of Example 1. FIG.

FIG. 2 (b) is a longitudinal cross-sectional view of the portion B-B of FIG. 2 (a).

FIG. 3 (a) is a schematic plan view of the support shown in FIG. 2 (b).

3 (b) is a longitudinal cross-sectional view of the portion C-C of FIG. 3 (a).

4 is a diagram showing a measurement result of ion current density distribution of the plasma processing apparatus of Example 1. FIG.

5 is a schematic longitudinal sectional view of the plasma processing apparatus of Example 2. FIG.

FIG. 6 (a) is a schematic longitudinal cross-sectional view of the horn portion shown in FIG.

Fig. 6 (b) is a schematic longitudinal sectional view of the horn portion shown in Fig. 5;

7 (a) is a schematic longitudinal sectional view of the plasma processing apparatus of Example 3. FIG.

7 (b) is a schematic plan view showing a gas supply method into a reaction vessel of the plasma processing apparatus of Example 3. FIG.

FIG. 8 (a) is a schematic plan view of the support body shown in FIG. 7 (a).

FIG. 8 (b) is a longitudinal cross-sectional view of the portion D-D of FIG. 8 (a).

9 is a diagram showing a measurement result of ion current density distribution in the plasma processing apparatus of Example 3. FIG.

10 (a) is a schematic longitudinal sectional view of the plasma processing apparatus of Example 4. FIG.

10 (b) is a schematic plan view showing a method for supplying microwaves into a reaction vessel of the plasma processing apparatus of Example 4. FIG.

FIG. 11 (a) is a schematic plan view of the support shown in FIG. 10 (a).

FIG. 11 (b) is a longitudinal cross-sectional view of the portion E-E of FIG. 11 (a).

FIG. 12 (a) is a diagram showing a measurement result of distribution of the ion current density in the X1 direction of the plasma processing apparatus of Example 4. FIG.

FIG. 12 (b) is a diagram showing a measurement result of distribution in the X2 direction of ion current density in the plasma processing apparatus of Example 4. FIG.

* Explanation of symbols for main parts of the drawings

1: reaction vessel 3: microwave inlet

4: microwave introduction window 5: support

5a, 5b, 5c: support 6: hole

7,11: ○ ring 12: gas introduction hole

13: exhaust port 14: sample stand

15: distribution channel 20: space

21 dielectric layer 22 metal plate

23 waveguide 24 microwave oscillator

31: Hoon 32: Hoon Cover

41 gas introduction hole 42 gas introduction path

43: gas supply hole 211: inlet

212: taper portion 213: flat plate portion

S: sample

The present invention relates to a plasma processing apparatus suitable for use in processes such as etching, ashing and CVD in the manufacture of large scale integrated circuits (LSI) and liquid crystal displays (LCDs).

Plasma generated by high frequency or microwave is widely used in manufacturing processes such as LSI and LCD. In particular, dry etching technology using plasma is indispensable in manufacturing processes such as LSI and LCD.

Conventionally, high frequency plasma has been used more often than microwave plasma. Although microwave plasma has the advantage of obtaining a high density plasma at low temperatures, it is difficult to produce a uniform plasma in a large area. The uniformity of the plasma affects the uniformity of the plasma treatment of etching, ashing and CVD.

In this regard, as one of the plasma processing apparatuses capable of generating a uniform microwave plasma in a large area, the present applicant has proposed a plasma processing apparatus using a dielectric layer (Japanese Patent Laid-Open No. 62-5600, Japanese Patent Laid-Open No. 62-99481).

FIG. 1 (a) is a schematic plan view of the plasma processing apparatus using this dielectric layer, and FIG. 1 (b) is an A-A partial longitudinal section thereof.

In the plasma processing apparatus shown in FIGS. 1 (a) and 1 (b), microwaves generated by the microwave oscillator 24 are introduced into the dielectric layer 21 through the waveguide 23. An electric field is formed in the space 20 below by the microwaves propagating through the dielectric layer 21. This electric field passes through the microwave introduction window 4 and is supplied into the reaction vessel 1 from the microwave introduction port 3. The gas is excited by this electric field to generate plasma. Plasma treatment is performed on the surface of the sample S by this plasma. The dielectric layer 21 is made of fluoro resin such as Teflon (registered trademark in Japan). The microwave introduction window 4 is made of a material having heat resistance and microwave permeability and low dielectric loss, such as quartz or ceramics (SiN, Al ₂ O ₃ ).

The dielectric layer 21 is composed of an introduction portion 211, a taper portion 212, and a flat plate portion 213. The microwaves are introduced from the waveguide 23 into the dielectric layer 21 at the introduction portion 211, and are extended in the width direction from the taper portion 212 and introduced into the flat plate portion 213. By doing so, the microwaves can be uniformly propagated in the width direction in the large-area flat plate portion 213.

In the plasma processing apparatus using this dielectric layer, a large-area plasma can be easily generated by increasing the flat plate portion 213, the microwave introduction window 4, and the microwave introduction port 3 of the dielectric layer 21.

Like a plasma processing apparatus using this dielectric layer, a device for uniformly generating plasma under a large-area microwave introduction window can perform plasma treatment using a high density and high activity plasma generated directly under the microwave introduction window. Has an advantage.

In recent years, the glass substrates for liquid crystal displays are gradually increasing, and the demand of the apparatus which can process the glass substrate more than 400mmx400mm uniformly becomes high. In the above-described plasma processing apparatus, plasma uniformity is obtained by using a large-area microwave introduction window. For this reason, in order to perform plasma processing on a sample with a large processing area, it is necessary to enlarge the microwave introduction window according to the size of the sample.

However, since plasma is generated in the reaction vessel under reduced pressure, the microwave introduction window is required to withstand the pressure difference between the inside and outside of the reaction vessel (hereinafter referred to as "pressure resistance"). When the dimension of the microwave introduction window becomes larger, it is necessary to increase the pressure resistance strength and to make the microwave introduction window thicker.

When the microwave introduction window is thickened, the temperature difference between the surface in the reaction vessel and the opposite side of the microwave introduction window is increased by plasma heating during plasma generation. Therefore, there arises a problem that the microwave introduction window breaks due to thermal deformation.

In addition to this, thickening the microwave introduction window increases the weight of the microwave introduction window and makes handling difficult. Microwave introduction windows, such as quartz and aluminum, are expensive, so increasing their thickness increases the cost of the device.

In addition, a plate such as quartz or aluminum, which is used as a microwave introduction window, is difficult to make a homogeneous one when it has a large area. For this reason, if the microwave introduction window becomes too large, there is an increased possibility that the microwave introduction window is inhomogeneously heated and damaged by thermal deformation.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and one object of the present invention is to provide a plasma processing apparatus which does not need to use a thick microwave introduction window even when the microwave introduction window is enlarged.

The plasma processing apparatus of the present invention is characterized by including a support for supporting the microwave introduction window.

Support the microwave introduction window by the support to reinforce the pressure resistance of the microwave introduction window. Therefore, even the microwave introduction window of a large area can make thickness of a micro introduction window thin compared with the thickness required by breakdown strength. As a result, it is possible to reduce the possibility that the microwave introduction window breaks due to thermal deformation during the plasma treatment. In addition, since the increase in the thickness of the microwave introduction window can be suppressed, it is possible to solve the disadvantage that the handling is not difficult and the cost of the apparatus increases.

The outer frame and the body according to the shape of the support and the outer rim of the microwave inlet of the reaction vessel are hereinafter referred to as the support. The reason is that the support supports the microwave introduction window. This support may be formed integrally with the reaction vessel.

The plasma processing apparatus of the present invention is characterized in that the microwave introduction window is divided in correspondence with the region divided by the support.

Since the microwave introduction window is divided, the area of each microwave introduction window is smaller than the area of the microwave introduction window in the case of not dividing. For this reason, since the breakdown voltage required for each microwave introduction window becomes small, the possibility that a microwave introduction window is damaged by heat deformation during plasma processing can be made smaller.

Moreover, since the area of each microwave introduction window is small, it is possible to use a homogeneous microwave introduction window. As a result, the problem caused by the heterogeneity of a microwave introduction window can also be eliminated.

The number of areas divided by the support and the number of divisions of the microwave introduction window do not have to match. For example, when the number of regions divided by the support is four, the division of the microwave introduction window may be divided into two and three.

On the other hand, the use of the support causes the following problems. Since the support is made of a metal such as stainless steel in terms of strength, no plasma is generated directly under the support. If the sample is placed directly under the support, the distribution of the plasma treatment speed becomes a distribution reflecting the shape of the support. In order to perform a uniform plasma treatment on the sample, it is necessary to drop the sample from the support by a distance where the plasma is sufficiently diffused.

However, the density of ions and active species in the plasma and their active state decrease as they fall near the microwave introduction window mainly generated by the plasma. For this reason, if the sample is dropped too far from the support, problems such as a decrease in the plasma processing speed may occur.

Still another object of the present invention is to provide a plasma processing apparatus which can irradiate a sample of high activity plasma to a near distance by alleviating the difference in the plasma generation state in the vicinity of the support and the portion other than the support even when a support having a support is used. Is to provide.

The plasma processing apparatus of the present invention is characterized in that gas is introduced from the support. Gas is supplied into the reaction vessel from the portion of the support where the amount of plasma is generated is small, and the gas density near the support is increased to increase the amount of plasma generated near the support. At the time of diffusion, the amount of plasma generated near the support supplied directly below the support increases, so that the plasma becomes uniform even if the distance from the support is short. In addition, since the gas can be supplied from the support to the center of the reaction vessel, even in the case of a large reaction vessel, the overall gas distribution becomes uniform.

The large-area microwave introduction window made possible by the support of the present invention is particularly useful when applied to a plasma processing apparatus using a dielectric layer.

In the plasma processing apparatus using the dielectric layer, since the microwaves propagate the dielectric layer, the microwaves can be uniformly propagated even in the flat plate portion of the large dielectric layer. For this reason, microwaves can be uniformly introduced even in a large-area microwave introduction window. Therefore, the advantage of increasing the microwave introduction window by the support can be particularly saved in the plasma processing apparatus using the dielectric layer.

In the plasma processing apparatus using the dielectric layer, the dielectric layer is located in parallel with the microwave introduction window. The microwave mainly propagates through the dielectric layer, and the electric field leaking from the dielectric layer is introduced into the reaction vessel through the microwave introduction window in the direction perpendicular to the propagation direction of the microwave. Therefore, compared with the case where a microwave introduction window is provided in the direction of propagation of microwaves and a microwave is directly introduced into the reaction vessel, the electric field strength near the microwave introduction window is smaller. Therefore, even if a support (metal) is provided in the vicinity of the microwave introduction window, the reflection influence of the microwave is small.

Moreover, the objective of this invention is providing the plasma processing apparatus which can irradiate a sample of high activity plasma to a plasma processing apparatus using a dielectric material.

The plasma processing apparatus of the present invention is characterized in that the structure of the support stand is as follows. The length of the short side of the hole in the form of a slit between the support and the support or the support and the outer frame is not less than 1/6 of the wavelength of the microwave and less than the wavelength of the microwave. These slit-shaped holes line up at intervals below the wavelength of the microwaves.

By making the length of the short side of the hole in the slit form at 1/6 or more of the wavelength of the microwave, the microwave can propagate the hole to generate plasma. The length of the short side of the slit-shaped hole is less than or equal to the wavelength of the microwave, and it is arranged at intervals less than or equal to the wavelength of the microwave, thereby dispersing the support of the support behind the microwave and supplying the electric field to each of the slit-shaped holes. Strengthen the strength By doing so, the nonuniform period of the electric field distribution can be made small and the plasma can be made uniform at a short distance from the support. Microwave diffraction effect can also be utilized by arrange | positioning this slit-shaped hole at intervals below a microwave wavelength.

EMBODIMENT OF THE INVENTION Hereinafter, this invention is concretely demonstrated based on drawing which shows the Example.

Example 1

FIG. 2 (a) is a schematic plan view of the plasma processing apparatus of Example 1, and FIG. 2 (b) is a B-B partial longitudinal section thereof. In this embodiment, the support body 5 which consists of a + -shaped support stand and an outer frame is provided. The number of holes between the support and the outer frame is four (two in the microwave propagation direction and two in the width direction of the dielectric layer). The microwave introduction window is divided into four sections corresponding to the area to be divided into the support (that is, the hole between the support and the outer frame). The microwave introduction window is mounted to cover each hole.

The reaction vessel is in the shape of a hollow cuboid. The reaction vessel 1 is mainly formed of a metal such as aluminum or stainless steel. The circumferential wall of the reaction vessel 1 has a double structure, and a flow passage 15 for cooling water is formed therein. Inside the reaction vessel 1, a sample table 14 on which the sample S is placed is provided. In the peripheral wall of the reaction vessel 1, two gas introduction ports 12 for gas supply are provided at each wall. An exhaust port 13 connected to an exhaust pump (not shown) is provided on the bottom wall.

At the top of the reaction vessel 1 is a microwave inlet 3. The support 5 is fixed to the upper wall surrounding the microwave inlet 3 so as to sandwich the ring 11 between the upper wall and the upper wall. On the support 5, the microwave introduction window 4 is mounted so as to support the ring 7 between the support 5 as well. In this way, when the inside of the reaction vessel 1 is depressurized, the inside of the reaction vessel 1 is hermetically sealed. The microwave introduction window 4 is made of a material having microwave permeability, low dielectric loss and heat resistance, such as quartz or ceramics (SiN, Al ₂ O _3, etc.).

The dielectric layer 21 and the metal plate 22 are provided above the reaction vessel 1 so as to cover the microwave introduction window 4 so as to face the microwave introduction window 4. The dielectric layer 21 is made of a dielectric material having a low dielectric loss, such as fluororesin, polystyrene, polyethylene, or the like. The metal plate 22 is made of aluminum or the like. One end of the dielectric layer 21 is connected to the microwave oscillator 24 through the waveguide 23. The microwaves generated by the microwave oscillator 24 are introduced into the dielectric layer 21 via the waveguide 23, and are introduced into the reaction vessel 1 through the microwave introduction window 4.

The dielectric layer 21 includes an introduction portion 211, a taper portion 212, and a flat plate portion 213. In the introduction portion 211, the microwave is introduced into the dielectric layer 21 in the waveguide 23, extends in the width direction in the tapered portion 212, and the expanded microwave is introduced into the flat plate portion 213. With this configuration, the microwaves can be uniformly propagated in the width direction in the large-area flat plate portion 213.

FIG. 3 (a) is a schematic plan view which shows the support body shown in FIG. 2 (b), and FIG. 3 (b) is a C-C partial longitudinal cross-sectional view of FIG. 3 (a). In addition, this figure shows the state in which the microwave introduction window 4 is loaded.

The support 5 is composed of an outer frame 5a having a ring-shaped quadrilateral shape corresponding to the shape of the upper wall of the reaction vessel 1 and a central + -shaped support 5b that divides the area into four parts. Four holes 6 are formed by the outer frame 5a and the + -shaped support 5b. On the support 5, the microwave introduction window 4 is mounted along four holes. As described above, a ring 7 is disposed between the support 5 and the microwave introduction window 4 so as to surround the hole 6. The ring 7 is sandwiched by the support 5 and the microwave introduction window 4 at the time of depressurization, so that the upper part of the reaction vessel 1 is hermetically sealed.

The support body 5 is made of stainless steel, and is produced by coating aluminum on the surface exposed to plasma.

The method of performing a plasma process on the sample S using this apparatus is demonstrated based on FIG. 2 (a) and FIG. 2 (b). The cooling water is circulated in the flow path 15. The sample S is placed on the sample stage 14. After the inside of the reaction vessel 1 is exhausted from the exhaust port 13, gas is introduced into the gas introduction hole 12 and set to a predetermined pressure. Microwaves are generated by the microwave oscillator 24 and introduced into the dielectric layer 21 through the waveguide 23. The microwave passes through the microwave introduction window 4 through the space 20, passes through the hole 6 of the support 5, and is introduced into the reaction vessel 1. Plasma is generated by the electric field of this microwave. Plasma treatment is performed on the sample S by the generated plasma.

The ion current density distribution was measured in order to evaluate the uniformity of the plasma generated using the apparatus of this example.

The main part dimensions and materials of the apparatus used are as follows. The plasma generation area (the area of the microwave inlet 3) is 500 mm X 500 mm. The area of the hole 6 of the support 5 is 210 mm X 210 mm, and the width of the support 5b is 80 mm. The area of one microwave introduction window 4 is 290 mm X290 mm, the thickness is 20 mm, and the material is quartz. The dimensions of the flat plate portion 213 of the dielectric layer 21 are 700 mm long, 500 mm wide, and 20 mm thick, and the material is Teflon.

The measurement of plasma generation conditions and ion current density distribution is as follows. Ar gas was introduced and the pressure was set to 10 mm Torr, and plasma was generated by microwave power (frequency: 2.45 GHz, pulse wave (frequency: 60 Hz)) of 1 KW. At each position 60mm (symbol □), 80mm (symbol ㅿ) and 100mm (symbol ○) away from the support, the ion current density at a plurality of measuring points on the diagonal (× 1) (see also third (a)) in the reaction vessel. Was measured.

In the measurement of the ion current density, a probe of a round plate electrode having a diameter of 2.0 mm made of stainless steel was used. The measurement was performed by applying a DC voltage of -50V between the probe and the reaction vessel wall to measure the current i flowing into the probe. The ion current density was obtained by dividing the current i at this time by the electrode area of the probe.

4 is a diagram showing a measurement result of ion current density distribution. At the position 60mm (□) and 80mm (ㅿ) away from the support, the ion current density decreases at the center of the reaction vessel (support of the support), which affects the support. On the other hand, the ion current was almost uniform over the entire area measured at a position 100 mm (○) away from the support. In other words, in the apparatus of this embodiment, the plasma is uniformed by the diffusion of the plasma when it is 100 mm or more away from the support.

At the same time, under the above-described conditions, the effect of thermal deformation on the microwave introduction window was tested by repeating this for 25 times by discharging for 5 minutes and stopping for 1 minute for 1 cycle, but no cracking or the like was observed at all. .

Example 2

FIG. 5 is a schematic longitudinal sectional view showing the plasma processing apparatus of Example 2. FIG. The zone embodiment is an application example in which the microwave introduction method is different from the first embodiment in the plasma processing apparatus. The introduction part of this microwave is demonstrated. The other part of the reaction vessel has the same structure as that of the apparatus of Example 1, and thus the description thereof is omitted.

As in the first embodiment, a support 5 having a support for hermetically sealing four holes 6 with a microwave introduction window 4 is fixed to the upper wall of the reaction vessel 1. The horn 31 is provided above the microwave introduction window 4, respectively. Another end of the horn 31 is connected to the microwave oscillator 24 via a waveguide 23. A distributor (not shown) is provided between the waveguide 23 and the microwave oscillator 24.

The microwaves generated by the microwave generator 24 are distributed to four waveguides 23 in a distributor (not shown), introduced into the horn 31 and expanded through the respective waveguides 23. The expanded and uniformed microwaves are introduced into the reaction vessel 1 through the microwave introduction window 4. The horn cover 32 can prevent the shape of the horn 31 from twisting and facilitate the installation.

FIG. 6 (a) is a schematic longitudinal cross-sectional view which shows the part of horn 31 shown in FIG. 5, and FIG. 6 (b) is the same schematic bottom view.

The present invention relates to a device requiring a large area microwave introduction window. Therefore, the present invention can be applied not only to plasma apparatuses using dielectric layers, but also to plasma processing apparatuses and ECR plasma processing apparatuses of such microwave introduction methods.

Example 3

FIG. 7 (a) is a schematic longitudinal sectional view of the plasma processing apparatus of Example 3, and FIG. 7 (b) is a schematic plan view showing a gas supply method into the reaction vessel. In the apparatus of this embodiment, a gas introduction hole 41 is provided in the portion of the support 5b to promote plasma uniformity. Other configurations are the same as those of the first embodiment, so description is omitted.

In FIG. 7 (b), the arrow shows the gas introduction direction. Gas is introduced in the direction of the sample S disposed at the center of the reaction vessel 1 in eight gas introduction holes 12 provided in the wall of the reaction vessel 1. In addition, gas is introduced into the peripheral edge of the sample S from eight gas introduction holes 41 provided in the support base 5b shown by the dotted line. As a result, the gas density around the support 5b can be increased to promote uniformity due to the diffusion of plasma.

FIG. 8 (a) is a schematic plan view which shows the support body shown in FIG. 7 (a), and FIG. 8 (b) is its D-D partial longitudinal cross-sectional view.

The gas introduction path 42 is provided inside the + -shaped support base 5b, and the gas introduction hole 41 is provided in eight places. The gas is introduced into the gas supply hole 43, introduced into the gas introduction path 42 at the center of the + -shaped support 5b, and introduced into the reaction vessel 1 from the gas introduction hole 41.

In order to evaluate the uniformity of the plasma generated by the apparatus of this example, the ion current density distribution was measured.

The main part dimensions and materials of the apparatus used for the measurement are as follows. The plasma generation area (the area of the microwave inlet 3) is 600 mm x 600 mm. The area of the hole 6 of the support 5 is 250 mm x 250 mm, and the width of the support 5b is 100 mm. Each microwave introduction window 4 is 300 mm x 300 mm, 20 mm thick, and the material is quartz. The plate portion 213 of the dielectric layer 21 is 800 mm x 600 mm, the thickness is 20 mm, and the material is Teflon.

The plasma generation conditions are as follows. Ar gas was introduced into the reaction vessel 1 with a total of 500 sccm at the eight gas introduction holes 12 of the peripheral wall and a total of 500 sccm at the eight gas introduction holes 8 of the support 5b. The pressure is 10m Torr. Microwave power is 1 KW (frequency: 2.45 GHz, continuous wave).

The measurement of ion current density distribution is as follows. The ion current was measured and calculated | required by the several measurement point on the x3 (refer also to 8th (a)) axis | shaft 60 mm from the support body.

In addition, as a comparative example, the same measurement was performed about the fact that Ar gas was introduce | transduced into the gas introduction hole 8 of the support stand 5b in total by 1s1m in total only in eight gas introduction holes 12 of the reaction vessel wall.

9 is a diagram showing a measurement result of ion current density distribution. Symbol 는 is the result of this example, and symbol 이다 is the result of the comparative example. In addition to the walls of the reaction vessel, a gas was introduced from the support of the support to obtain a uniform plasma distribution even at a position close to 60 mm from the support.

Example 4

FIG. 10 (a) is a schematic longitudinal sectional view of the plasma processing apparatus of Example 4, and FIG. 10 (b) is a schematic plan view showing a method of supplying microwaves into a reaction vessel. In the apparatus of this embodiment, the holes 6 of the support 5 are in the form of slits in order to promote uniformity of the plasma. Other configurations are the same as those of the first embodiment, so description is omitted.

In FIG. 10 (b), the slanted portion is the wall of the reaction vessel 1, the support 5b and the support 5c, and is a portion behind the microwaves. Longitudinal slit-shaped holes 6 formed by the support stand are provided in a line in the traveling direction of the microwaves. By doing so, the support behind the introduction of the microwaves is effectively dispersed to suppress the nonuniformity of the electric field distribution, and the electric field strength supplied to each of the holes 6 in the slit form is strengthened. As a result, the plasma can be generated uniformly at a short distance from the support.

FIG. 11 (a) is a schematic plan view which shows the support body shown in FIG. 10 (a), and FIG. 11 (b) is its E-E partial longitudinal cross section. The support 5 has a ring-shaped quadrilateral outer frame 5a corresponding to the detective of the upper wall of the reaction vessel 1, a central + -shaped support 5b dividing the area into four quarters, and a slit-shaped hole. It consists of the support stand 5c which forms (6). As a result, three slit-shaped holes 6 are formed in each of the four divided regions, and all twelve slit-shaped holes 6 are formed.

In order to evaluate the uniformity of the plasma generated by the apparatus of this example, the ion current density distribution was measured.

The main part dimensions and materials of the apparatus used for the measurement are as follows. The plasma generation area (the area of the microwave inlet 3) is 600 mm x 600 mm. The width of the + -shaped support 5b of the support 5 is 100 mm, and the width of the support 5c is 50 mm. The slit-shaped hole 6 is 250 mm x 50 mm. Each microwave introduction window 4 is 300 mm x 300 mm, 20 mm thick, and the material is quartz. The plate portion of the dielectric layer 21 is 800 mm x 600 mm, the thickness is 20 mm, and the material is Teflon.

The plasma generation conditions are as follows. Ar gas was introduced into a total of 1s1m reaction vessels from eight gas introduction holes 12 on the peripheral wall. The pressure is 10m Torr. Microwave power is 1 KW (frequency: 2.45 GHz, continuous wave).

The measurement of ion current density distribution is as follows. At a position 60 mm away from the support, the ion current was measured at a plurality of measurement points on the X1 and X2 axes (see also the eleventh (a)). In addition, as a comparative example, the same measurement was performed about having provided four holes of 250 mm S250mm in the support body 5, without providing the support stand 5c.

FIG. 12 (a) is a figure which shows the distribution measurement result of the ion current density of the plasma processing apparatus of Example 4 in the X1 direction, and FIG. 12 (b) is a figure which shows the distribution measurement result of the X2 direction. The symbol ○ is a result when there is a support 5c, and the symbol? Is a result when there is no support 5c.

In the comparative example (□), the ion current density of the center part which becomes behind the support stand 5c in either X1 and X2 directions was low.

In Example (○) of the present invention, the ion current density of the hole 6 in which the ion current density was high in the comparative example (□) was lowered, and the ion current density of the center support 5b in which the ion current density was low was increased, As a whole, the distribution of the ion current density was uniform.

Moreover, in the apparatus using this dielectric layer, when the short side length of the slit-shaped hole 6 was 20 mm or less, the ion current density rapidly decreased. When the frequency of the microwave is 2.45 GHz, the free-space wavelength is 122.45 mm, so that the short side length of the slit-shaped hole 6 is preferably 1/6 or more of the wavelength of the microwave to efficiently generate the plasma.

Further, by shortening the length of the short side of the slit-shaped hole to be equal to or less than the wavelength of the microwave and disposing it at intervals less than or equal to the wavelength of the microwave, the support behind the microwave can be dispersed to promote uniformity of the plasma.

As described above, even when the microwave introduction window was supported by the support, it was confirmed that the plasma could be generated sufficiently uniformly, and that the possibility of damage of the microwave introduction window could be reduced by the support.

That is, in the plasma processing apparatus of the present invention, a large-area semiconductor substrate, an LCD glass substrate, and the like can be stabilized and processed uniformly without the possibility of damaging the microwave introduction window.

In the above embodiment except for the fourth embodiment, all of the support bases 5b had a + shape, and the holes 6 were arranged in two rows in the microwave traveling direction and two rows in the width direction of the dielectric layer. Of course, the shape of) is good other than this. For example, the shape of the support 5b may be three rows of support in the direction of microwave propagation, ie, four holes 6 may be provided in the direction of microwave propagation. In addition, in the said Example except Example 4, although the number of the holes 6 is four in all, if the number of the holes 6 is plural, it may be other than four. The shape, that is, the number and arrangement of the supports 5b may be determined according to the plasma generation area, the required plasma uniformity, and the strength of the microwave introduction window 4.

In the above embodiment, the microwave introduction window 4 is divided into four in correspondence with the holes 6, but may be divided into two, or may be made into one sheet as the size corresponding to the outer frame member 5a. good. However, of course, the smaller the area of the microwave introduction window 4 is, the smaller the possibility of damage to the microwave introduction window 4 becomes.

In addition, in the above-mentioned embodiment, although the support body 5 which has a support stand was a component independent from the reaction container 1, of course, you may form integrally with the reaction container 1, of course.

Claims (5)

A plurality of means for supplying microwaves, a reaction vessel having a microwave inlet, and a sample stand disposed therein, a microwave introduction window for introducing microwaves from the means for supplying microwaves into the reaction vessel from the microwave inlet, and a microwave inlet. And a support for supporting a microwave introduction window having a support divided into an area of the support frame and an outer frame, wherein the microwave introduction window is divided corresponding to the area divided by the support. Means for supplying microwaves, a dielectric layer into which microwaves are introduced from the means for supplying microwaves, a reaction vessel having a microwave inlet, and a sample stage disposed therein, and microwaves disposed opposite to the dielectric layer to propagate the dielectric layer. A microwave introduction window introduced from the microwave inlet into the reaction vessel, a support for dividing the microwave inlet into a plurality of regions, and a support for supporting the microwave introduction window with an outer frame, the region corresponding to the region divided by the support; And the microwave introduction window is divided. The plasma processing apparatus of claim 1, further comprising means for introducing a gas from the support into the reaction vessel. The length of the short side of the slit-shaped hole between the support and the support of the support or between the support and the outer frame is not less than 1/6 of the wavelength of the microwave and less than or equal to the wavelength of the microwave. A plasma processing apparatus, characterized in that the support is provided so as to line up at intervals below the wavelength of the microwave. 3. The plasma processing apparatus of claim 2, further comprising means for introducing gas from the support into the reaction vessel.