JPH11100672A - Plasma gas phase reactor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plasma gas phase reaction apparatus in which the degree of freedom in selecting an electrode material is high, a plurality of openings are formed with high precision, and uniform processing can be performed in various places. It is an object. SOLUTION: A reaction vessel 421 that can be maintained at a reduced pressure of 1 atm or less, first and second electrodes 431 and 441 opposed to each other in the reaction vessel 421, gas introducing means for introducing gas, A gas-phase reaction apparatus 1 comprising exhaust means 403 for exhausting gas.
And a main electrode plate 447 laminated on the gas adjustment plate 449. The gas adjustment plate 449 and the main electrode plate 447 for guiding the gas from the gas introduction means to the substrate to be processed are provided. Includes a plurality of openings 445 therethrough.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a plasma gas phase reaction apparatus such as a plasma CVD apparatus and a plasma etching apparatus.

[0002]

2. Description of the Related Art A plasma gas phase reaction apparatus, for example, a plasma CVD apparatus, is widely used in manufacturing processes of semiconductor devices, liquid crystal display devices and the like. In particular, in a flat display device such as a liquid crystal display device, an amorphous silicon (a-Si: H) film having a uniform thickness is formed on a large-sized glass substrate of 500 mm × 600 mm.
Silicon oxide (SiO2) film or silicon nitride (SiNx)
Since it is necessary to form a film, a substrate to be processed is arranged between a pair of electrode substrates arranged opposite to each other, and a raw material gas is plasma-excited by uniform strong electrolysis between the electrode substrates to form a desired film on the substrate. The method of deposition is adopted.

In order to deposit a uniform thickness over a large area, it is necessary to make the electric field intensity uniform at various places and to control the introduced source gas uniformly at various places. According to the above-described method, uniform electrolysis is realized by controlling the positional accuracy of the pair of electrode substrates and the conductivity of the material. Further, by providing a plurality of openings in one electrode and guiding the source gas to the substrate to be processed through the openings, the source gas can be uniformly controlled in various places.

[0004]

In such a plasma CVD apparatus, how to provide a plurality of openings with high precision on one electrode substrate to make the conductance uniform is to obtain a uniform film thickness distribution. Important above.

At present, the opening is formed by machining or laser processing the electrode substrate itself, but it is difficult to form the opening accurately.
For this reason, after the opening is formed in the electrode substrate, measurement and fine adjustment of each hole diameter are required, which requires a great deal of labor and cost.

[0006] When the film formation is repeated, unnecessary reaction products adhere to the openings of the electrode substrate and gradually close the openings.
Along with this, the flow rate of the source gas changes and the conductance becomes non-uniform, so that it is difficult to ensure uniformity of the film thickness distribution. Therefore, it is necessary to introduce an etching gas such as CF4 to periodically remove this unnecessary reaction product, or to remove it by washing.

For this purpose, it is necessary to ensure that the electrode substrate has sufficient anti-corrosion properties for plasma cleaning etching and cleaning, so that a material which is difficult to process such as Hastelloy must be used. Therefore, it is difficult to form a plurality of openings with high accuracy.

The present invention has been made in view of the above-mentioned technical problems, and has a high degree of freedom in selecting an electrode material and enables a plurality of openings to be formed with high accuracy, thereby achieving uniformity in various places. It is an object of the present invention to provide a plasma gas phase reaction apparatus capable of performing various processes.

[0009]

According to the present invention, a reaction vessel capable of maintaining a reduced pressure of 1 atm or less;
Plasma gas phase reaction comprising first and second electrodes opposed to each other in the reaction vessel, gas introduction means for introducing a desired gas into the reaction vessel, and exhaust means for exhausting the inside of the reaction vessel. In the apparatus, the first electrode includes a stage on which a substrate to be processed is arranged, and the second electrode includes the first electrode.
A gas adjustment plate facing the electrode, and a main electrode plate stacked on the gas adjustment plate, wherein the gas adjustment plate and the main electrode plate for guiding the gas from the gas introduction unit to the substrate to be processed; And a plurality of openings penetrating through. According to such a configuration, it is possible to form a plurality of openings with high precision, thereby obtaining a plasma gas phase reaction apparatus capable of performing uniform processing at various locations.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a plasma CVD apparatus according to one embodiment of the present invention will be described in detail with reference to the drawings. This plasma CVD apparatus 1 has a SiNx film on a 500 mm × 600 mm glass substrate used for a liquid crystal display.
An a-Si: H film is configured to be sequentially deposited. As shown in FIG.
1, a load / unload chamber 201 and a heating chamber which are hermetically connected via shutters 211, 311, 411, respectively.
301 and a film forming chamber 401. The film forming chamber 401 can be appropriately increased as required.

The common chamber 101 has chambers 201, 301, 401
A transfer arm 121 for arranging a substrate to be processed is disposed on the substrate. Although not shown, the common chamber 101 is connected to an exhaust system for maintaining a reduced pressure at a predetermined pressure, and is connected to, for example, a nitrogen gas (N 2) supply system to make the room a nitrogen atmosphere.

The film forming chamber 401 will be described with reference to FIG. The film forming chamber 401 is connected to an exhaust system 403 and can be depressurized. The vacuum chamber 421 is connected to a source gas supply system 461 for supplying various source gases, and a processing target disposed in the vacuum vessel 421. It includes a pair of electrode substrates 431 and 441 larger than the substrate. The pair of electrode substrates 431 and 441 are
It is connected to a high-frequency power source 451 for exciting the source gas introduced into the vacuum vessel 421 into plasma. One electrode 431 also serves as a stage on which a substrate to be processed is arranged.
The other electrode substrate 441 is connected to a source gas supply system 461 and has a cavity 443 for mixing the source gas, and a 0.4 mm diameter formed at a pitch of approximately 10 mm provided through the cavity 443. A plurality of openings 445.

More specifically, as shown in FIG. 3, a main electrode plate 447 made of Hastelloy and having a thickness of about 10 mm.
And a gas adjusting plate 449 of about 0.1 mm thickness made of Inconel connected to the surface by spot welding. As the main electrode plate 447, besides Hastelloy, aluminum, aluminum alloy, Inconel, or the like can be used. As the gas adjusting plate 449, stainless steel or the like can be used. The gas adjustment plate 449 is preferably a thin plate in consideration of workability, and is at least a thinner plate than the main electrode plate 447, preferably 0.2 mm or less, more preferably 0.1 mm or less. Is desirable.

The opening formed in the main electrode plate 447 is
At a depth of 5 mm from the cavity 443, a third opening having a diameter of about 3 mm and a second opening having a diameter of about 0.4 mm formed at the same pitch.
And an opening, and the third opening is formed by machining.
The second opening is formed sequentially by laser machining or electric discharge machining.

The first openings formed in the gas adjustment plate 449 are formed at the same pitch as the above-described second and third openings, and have a diameter of about 0.1 mm which is sufficiently smaller than these openings. . This first opening is formed by photolithography.
It is formed by etching and is patterned with an accuracy of about ± 0.2 μm.

According to this embodiment, since the gas flow rate can be controlled with high accuracy by the first opening of the gas adjusting plate 449 with high accuracy, the gas adjusting plate 449 is slightly larger than the outer dimensions of the substrate to be processed. The protruding amount could be suppressed to 7 mm, and thus the external dimensions of the device could be made sufficiently small.

Next, a film forming method using the plasma CVD apparatus 1 will be described. First, the load / load shown in FIG.
Transfer arm for substrate to be processed from unload chamber 201
In 121, it is led to the heating chamber 301 and heat-treated.

Thereafter, the substrate to be processed is transferred from the heating chamber 301 to the film forming chamber 401. First, the film forming chamber 401 is evacuated by the exhaust system 403, the shutter 411 is opened, the substrate to be processed is transferred to the film forming chamber 401, and the shutter 411 is closed. After that, 200scc as raw material gas
m silane (SiH4), 1000 sccm ammonia (NH3),
7000 sccm of nitrogen (N2) is led from the source gas supply system 461,
After adjusting the pressure to a predetermined pressure, the space between the pair of electrode substrates 431 and 441
A high-frequency voltage of 1300 W is applied to excite the source gas to plasma, and a silicon nitride (SiNx) film is formed on the substrate to be processed.
Deposit to a thickness of 100 nm. Although not shown, one electrode substrate 431 has a heater function, and the substrate temperature is set to about 300 ° C.

When the desired film formation is completed in this way, the application of the high-frequency voltage is stopped, the film formation chamber 401 is evacuated by the exhaust system 403, and 400 sccm silane (SiH4) and 1400 sccm hydrogen are used as raw material gases. The gas (H2) is led from the source gas supply system 461 and set at a predetermined pressure. Then, a high-frequency voltage of 1500 W is applied between the pair of electrode substrates 431 and 441 to excite the source gas by plasma, and a
Deposit a 50 nm thick Si: H film; The substrate temperature is set at 300 ° C.

When the desired film formation is completed, the application of the high-frequency voltage is stopped, and the film formation chamber 401 is evacuated by the exhaust system 403. Then, the shutter 411 is opened, and the substrate to be processed is transferred by the transfer arm 121 to the load / unload chamber 201 via the common chamber 101.

By sequentially repeating such a series of steps, a desired film is sequentially deposited on the substrate to be processed. According to the above-described embodiment, the thickness of each formed film was uniform at various points on a glass substrate of 550 mm × 650 mm as measured by an optical film thickness meter, and furthermore, measured by an optical film quality meter. However, it was confirmed that the film quality was also uniform.

By the way, according to the plasma CVD apparatus 1 of this embodiment, with respect to a plurality of film formations in each of the film formation chambers 401, unnecessary reaction products in the vacuum vessel 421, the electrode substrates 431, 441 and the like are shown in FIG. Deposited as shown. However, in this embodiment, the gas flow rate is maintained at a desired value by the gas adjusting plate 449, whereby the conductance can be maintained uniform, so that a uniform film thickness distribution and film quality can be ensured even in a plurality of film formations.

In the above-described embodiment, the openings 445 formed in the electrode substrate 441 are formed at the same diameter and pitch at various places. However, as in this embodiment, the electrode substrate 441 is formed by the main electrode plate 447 and the gas adjusting plate 449. Thus, as shown in FIG. 5, for example, the central region of the electrode substrate 441 is formed.
The diameter and pitch of the 442a and the peripheral region 442b can be different. For example, in the central region 442a, the third opening has a diameter of 0.2 mm as in the above-described embodiment. Openings 445 are formed at a pitch of 1 mm and a pitch of 10 mm. That is, the peripheral region 442b is
The configuration is such that the gas flow rate is increased as compared with.

With such a configuration, the area of the electrode substrate 441 can be made closer to the outer dimensions of the substrate to be processed, and the size of the apparatus can be further reduced. Further, the shape such as the pitch and diameter of the openings 445 may be configured so that the flow rate is gradually changed. In any case, the openings formed in the gas adjustment plate 449 are formed with high precision by photolithography, and this determines the electric field distribution between the substrates and the final flow rate.
Various forms can be easily realized.

The present invention is not limited to the embodiment described above, but can be similarly applied to an in-line type plasma CVD apparatus. In each of the above embodiments, a plasma CVD apparatus has been described as an example. However, it is needless to say that a plasma etching apparatus can be configured by changing the material gas in the same configuration.

[0026]

As described above, according to the present invention, a plasma gas phase reaction apparatus having a high degree of freedom in selecting an electrode material, forming a plurality of openings with high precision, and enabling uniform processing in various places. Is obtained.

[Brief description of the drawings]

FIG. 1 is a plasma CVD of one embodiment of the present invention.
It is a schematic structure figure of an apparatus.

FIG. 2 is a partial schematic cross-sectional view of the plasma CVD apparatus of FIG.

FIG. 3 is a partial schematic cross-sectional view of an electrode substrate.

FIG. 4 is a partial schematic front view of an electrode substrate according to another embodiment.

[Explanation of symbols]

 1 Plasma CVD apparatus 101 Common chamber 201 Load / unload chamber 301 Heating chamber 401 Film forming chamber 447 Main electrode plate 449 Gas pressure adjusting plate

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI H01L 21/31 H01L 21/302 C

Claims (9)

[Claims] 1. A reaction vessel capable of maintaining a reduced pressure of 1 atm or less, first and second electrodes opposed to each other in the reaction vessel, and gas introduction means for introducing a desired gas into the reaction vessel. And a gas-phase reaction apparatus provided with an exhaust unit for exhausting the inside of the reaction vessel, wherein the first electrode includes a stage on which a substrate to be processed is arranged, and the second electrode is a gas facing the first electrode. An adjusting plate, and a main electrode plate laminated on the gas adjusting plate, a plurality of holes penetrating the gas adjusting plate and the main electrode plate for guiding the gas from the gas introducing means to the substrate to be processed. A plasma gas phase reaction device comprising an opening. 2. The plasma gas phase reaction apparatus according to claim 1, wherein an opening of said gas adjusting plate is smaller than an opening of said main electrode plate. 3. The gas adjusting plate has an opening of 0.5 mm.
3. The plasma gas phase reactor according to claim 2, wherein: 4. The plasma gas phase reaction apparatus according to claim 1, wherein said opening of said gas adjusting plate is formed by photolithography. 5. The plasma vapor reactor according to claim 1, wherein the opening of the main electrode plate is formed by machining. 6. The plasma gas phase reactor according to claim 1, wherein the gas adjusting plate has a thickness of 0.5 mm or less. 7. The plasma gas phase reaction apparatus according to claim 1, wherein the gas adjustment plate is larger than an outer dimension of the substrate to be processed, and has a protrusion amount of 10 mm or less. 8. The plasma gas phase reactor according to claim 1, wherein the gas adjusting plate is mainly composed of Ni. 9. The plasma gas phase reactor according to claim 1, wherein the gas adjusting plate is made of Inconel.