JPH02250975A - Glow-discharge decomposing device - Google Patents

Abstract

PURPOSE:To enable the formation of a film with a uniform characteristic simultaneously on plural substrates by providing the second electrode having a number of gas passage ports around the gas outlet pipe 9 of the first electrode. CONSTITUTION:The second electrode formed by a cylindrical mesh electrode 46 having numerous of gas passage ports 10 is arranged between the first electrode pierced with plural gas injection ports 10 and plural substrates 2 in a reaction chamber 1. A film forming gas is introduced from a gas inlet 11 and spouted toward the mesh electrode 46 through the gas outlet ports 10. The substrate 2 is heated and rotated, and a high-frequency voltage is impressed between the gas outlet pipe 9 and the mesh electrode 46. A glow-discharge is generated, and the resultantly decomposed product proceeds to the substrate 2 through the gas passage port of the mesh electrode 46 and is vapor-deposited around the substrate. The utilization efficiency of the film forming gas is enhanced by the glow-discharge decomposing device.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a glow discharge decomposition apparatus that can simultaneously manufacture a plurality of amorphous silicon or amorphous silicon alloy photosensitive drums, for example.

(Prior art and its problems) Fig. 7 and Fig. 8 show the first conventional example, Fig. 9 and Fig. 1θ show the second conventional example, and Fig. 13 and Fig. 1 show the second conventional example.
FIG. 4 shows a third conventional example.

FIG. 7 is a schematic plan view of the first conventional example, and FIG. 8 is a schematic partial cross-sectional view thereof.

1 is a cylindrical reaction chamber, and inside this reaction chamber 1, 16 cylindrical film-forming substrates 2 are arranged substantially on a circumferential line and at equal intervals, and each substrate 2 is placed on the substrate support part 3, and a dummy ring 4 is placed on the substrate 2, and the dummy ring 4 is rotationally driven by the motor 5 via the shaft 6, so that the substrate 2 is coated with a film. Rotate medium. Further, a heater 7 is provided inside each substrate 2 so that the substrate is heated to a required temperature during film formation.

There is an insulating lid 8 on the top surface of the reaction chamber l, and this lid 8
A cylindrical gas ejection pipe 9 is connected to the cylindrical gas ejection pipe 9, and a large number of gas ejection ports 1O are formed in this pipe 9. 11 and 12 are a gas inlet and a gas outlet, respectively.

13 is a high frequency power supply, 14 is a matching box, one output terminal of this matching box 14 is electrically connected to the gas ejection pipe 9, and the other output terminal is connected to the reaction chamber l, Moreover, the reaction chamber 1 is electrically connected to the substrate 2 via the shaft 6.

Thus, according to the glow discharge decomposition apparatus having the above configuration, amorphous silicon or amorphous silicon alloy-based (hereinafter abbreviated as a-Si-based) film-forming gas is supplied to the gas inlet 11.
Then, the substrate 2 is heated to a required temperature and rotated, and the gas ejection tube 9 is used as a common electrode for each substrate. When high frequency power is applied between the substrate 9 and the substrate 2, a glow discharge occurs, and gas decomposition products are deposited on the peripheral surface of the substrate 2. The residual gas of the decomposition products exits through the gas outlet 12. Note that the arrows in the figure indicate gas flow paths.

However, according to the glow discharge decomposition apparatus described above, it is difficult to set the film formation rate to be uniform over the circumferential direction of the substrate 2, and the photoconductive properties of the a-3i film are also It is difficult to set it evenly over the circumferential direction. When the substrate 2 is rotated to solve this problem, the film thickness and properties are improved, but the results are still not satisfactory.

For example, further improvements are required when forming a composite alloy using various gases or when forming a laminated film.

The above problem also applies to the second conventional example.

FIG. 9 is a schematic plan view, and FIG. 10 is a schematic partial cross-sectional view thereof.

The second conventional example differs in the arrangement of the substrates from the first conventional example, in that a plurality of substrates 16 are arranged symmetrically in two rows inside the reaction chamber 15, and both rows of substrates 16 are supported. It is placed on the body 17. The other various components have the same functions as those in the first conventional example, and the individual components include a substrate support section 18, a dummy ring 19, an insulating lid body 20, and a dummy ring 20.
1 is a gas ejection pipe, 22 is a gas ejection port, 23 is a gas inlet, 24 is a gas outlet, 25 is a high frequency power source, and 26 is a matching box.

The reaction chamber 15 is formed with an inlet 27 and an outlet 28 for carrying in or out the substrate support 17 .

Thus, according to the glow discharge decomposition apparatus having the above configuration, the substrate support 17 on which the substrate 16 is placed is introduced into the reaction chamber 15 through the loading port 27, and the a-Si film forming gas is introduced into the gas inlet 23. The gas is introduced into the substrate 16 through the gas ejection port 22, and the gas ejection tube 21 and the substrate 16 are
High frequency power is applied between the substrate 16 and the rotation driving means (
(not shown) to form a film as glow discharge occurs. When the film formation is completed, the substrate support 17 is taken out from the outlet 28 with the substrate 16 placed thereon.

By the way, the problem that arises in the first and second conventional examples is that the substrate 2.16 for film formation has a cylindrical shape, and this substrate is used as an individual electrode, and the gas jet pipe 9.21 is used as a common electrode, and both electrodes are used as separate electrodes. This is caused by generating a glow discharge between the two, and this will be explained with reference to FIGS. 11 and 12.

When the product of the gas pressure P (torr) and the interelectrode distance d (cm) reaches a predetermined value, that is, the value (torr-cm), the glow discharge starting voltage becomes the minimum value, and the voltage becomes most stable near this value. The discharge can be sustained.

This phenomenon is known as Paschen's law, and P×d and V
The relationship between s (discharge starting voltage) is shown in FIG.

According to experiments repeatedly conducted by the present inventor, when monosilane gas is introduced and a high frequency power of 13M)1z is applied to generate a glow discharge, k 0.35 ± 0.2, and the gas pressure P If = 0.1 torr, electrode open circuit jl
It was confirmed that d was 3.5 cai.

In this way, the value can be an indicator of the most stable discharge conditions, but if the substrate for film formation is cylindrical and only one electrode is used, the distance d between the electrodes will not be constant, and the periphery of the substrate will This results in non-uniform discharge conditions over the surface.

That is, as shown in FIG.
When high frequency power is applied between 0.31 and 0.31, the distance d between the electrodes is d! However, the film formation rate is not uniform at points A-H in the circumferential direction of the substrate, and the photoconductive properties are also not uniform.

Therefore, in view of the problems of the first and second conventional examples, a third conventional example was proposed.

FIG. 13 is a schematic plan view, and FIG. 14 is a schematic partial cross-sectional view thereof.

The reaction chamber 32 includes eight cylindrical electrode plates 3 with one side open.
3 are installed on the circumferential line and at equal intervals, and a cylindrical substrate 34 is installed inside each electrode plate 33.

This substrate 34 is placed on a lower dummy ring 35,
Further, an upper dummy ring 36 is placed on the substrate 34, and a motor 37 rotates the upper dummy ring 36 via a shaft 38, thereby rotating the substrate 34.

Further, a heater 39 is arranged inside the substrate 34, thereby heating the substrate 34 to a required temperature during film formation.

The a-5i film forming gas is supplied from the gas inlet 40 to the reaction chamber 32.
This gas enters the inside of the electrode plate 33 and is ejected to the substrate 34 from a gas ejection port 41 formed in the electrode plate 33, and the remaining gas from the film formation is exhausted from a gas exhaust port 42.

43 is a high frequency power supply, 44 is a matching box,
One terminal is connected to the electrode plate 33 through the circumferential surface of the reaction chamber 320.
and the other terminal is electrically connected to the substrate 34 through the lower surface of the reaction chamber 32, thereby making the substrate 34
High frequency power is applied between the electrode plate 33 and the electrode plate 33 . In addition, 4
5 is an insulating ring.

Thus, according to the glow discharge decomposition apparatus having the above configuration, a glow discharge region is formed between the substrate 34 and the electrode plate 330, thereby making it possible to keep the distance d between the electrodes constant and to achieve a uniform film formation rate over the circumferential direction of the substrate. In addition, photoconductive properties and the like can be obtained.

However, in the case of the third conventional example, the electrode plates are arranged to cover each substrate, and as a result, the internal volume of the reaction chamber is determined by the diameter of the electrode plate, and the number of substrates is limited. As a result, there is a problem in that the number of substrates to be placed in a single reaction chamber is reduced.

In addition, since each board is equipped with a cylindrical electrode plate, it is difficult to attach and detach the board.
Manufacturing workability decreases and manufacturing efficiency decreases.

Furthermore, when a film-forming gas such as monosilane gas is decomposed, radical species are generated, which adhere to the substrate, but also adhere to the inner surface of the electrode plate 33;
For example, if the diameter of the electrode is twice the diameter of the substrate, the area ratio will be four times that of the substrate, and the adhesion efficiency on the peripheral surface of the substrate will be approximately 25χ, making it difficult to use such a film-forming gas. Low efficiency is also cited as a problem.

[Purpose of the invention]

Therefore, the present invention has been completed in view of the above, and its purpose is to be able to simultaneously form a film on a plurality of substrates using a single device, and to be able to form a film on a plurality of substrates at the same time, as well as between the individual substrates and on the film-forming surface of the substrate. It is an object of the present invention to provide a glow discharge decomposition device in which it is easy to obtain the same growth rate throughout the film and in which uniform film characteristics can be obtained.

Another object of the present invention is to provide a glow discharge decomposition apparatus that can improve workability during manufacturing and improve the utilization efficiency of film-forming gas, thereby improving manufacturing efficiency and manufacturing cost.

[Means for solving problems]

The glow discharge decomposition apparatus of the present invention includes a first electrode portion in which a plurality of gas jet ports are formed inside a reaction chamber, a plurality of substrates for film formation, and a plurality of substrates disposed between the substrate and the first electrode portion. A second electrode part is provided in which a plurality of gas passage ports are formed, and the gas ejected between the first electrode part and the second electrode part is decomposed by glow discharge, and the decomposed gas is passed through the gas passage ports to the substrate surface. It is characterized by being formed into a film by spraying it on.

〔Example〕

The present invention will be explained below with reference to Examples.

The glow discharge decomposition apparatus shown in FIGS. 1 and 2 is a first example, and the apparatus shown in FIGS. 3 and 4 and the apparatus shown in FIGS. 5 and 6 are other embodiments. , and are referred to as the second and third examples, respectively.

According to the first example, FIG. 1 is a schematic plan view, and FIG. 2 is a schematic partial cross-sectional view thereof, and the first conventional example (FIG. 7,
8) is characterized in that a cylindrical mesh electrode 46 with a large number of gas passage ports is arranged around the gas ejection pipe 9. Note that the same parts as in the first conventional example are given the same reference numerals.

In the above configuration, one output terminal of the matching box 14 is connected to the reaction chamber 1, and the reaction chamber 1 is electrically connected to the mesh electrode 46.

According to the glow discharge decomposition apparatus described above, an a-Si film forming gas is introduced from the gas inlet 11, and is ejected toward the mesh electrode 46 through the gas ejection port 10, and then the substrate 2 is removed as required. When heated and rotated to a temperature of 2, and evaporate on the peripheral surface thereof. The residual gas of the decomposition products exits from the gas outlet 12.

When forming an a-5i film using the glow discharge decomposition apparatus with the above configuration, electrons have sufficiently large kinetic energy in the glow discharge region, and raw materials such as monosilane are collided with high-speed electrons. and this results in
A large number of ionic species (SiH-), luminescent species (SiH,"), and neutral species (SiH,) are generated, and in response to such -order reactions, the above-mentioned reactive species further collide with each other, resulting in decomposition and synthesis. repeated (called a secondary reaction).

Under steady-state conditions, the reactive species generally have a spatial density as follows:

Ionic species (Sillxl)...approximately 10'/cm" Luminescent species (SiH,")...approximately 10'/cs+3 Neutral species (SiIlK)...approximately 101~10*/cm
3. Therefore, the main reactive species are neutral species, which are transported to the substrate side by diffusion without being affected by the electric field (drift movement), and are formed into a film. This neutral species mainly contains Si+S
There are iH+ 5illt+ SiH3, etc., among which the S i 113 radical has the longest life and is therefore present in large numbers, and the next most abundant radical is the 5il12 radical.

Thus, such neutral species are transported by concentration diffusion and deposited on the peripheral surface of the substrate.

According to the glow discharge decomposition apparatus of the first example, the substrate 2 does not serve as one of the electrodes, and therefore the film formation rate tends to be uniform on the circumferential surface of the substrate and between the individual substrates (in addition, the film formation rate is uniform). A film with photoconductive properties is obtained.

Further, there is no need to arrange electrode plates corresponding to individual substrates, so that the problems described in the third conventional example can be solved, and as a result, manufacturing efficiency and manufacturing cost can be improved.

Next, according to the second example, FIG. 3 is a schematic plan view, FIG. 4 is a schematic partial cross-sectional view thereof, and FIG.
10) is characterized in that a planar mesh-like electrode 47 with a large number of gas passage ports is disposed between the gas ejection pipe 21 and the substrate 160. Note that the same parts as in the second conventional example are given the same reference numerals.

In the above configuration, one output terminal of the matching box 26 is connected to the reaction chamber 15;
is electrically connected to the mesh-like electrode 47.

According to the glow discharge decomposition apparatus described above, an a-Si film forming gas is introduced from the gas inlet 23 and ejected toward the mesh electrode 47 through the gas ejection port 22, and then the substrate 16 is removed as required. When heated to a temperature of The vapor is directed toward the substrate 16 and deposited on the peripheral surface thereof. The residual gas of the decomposition products exits from the gas outlet 24.

The third example differs from the second example in the position of the gas outlet. FIG. 5 is a schematic plan view, and FIG. 6 is a schematic partial cross-sectional view thereof, in which the same parts as in the second example are given the same reference numerals.

According to the third example, a gas outlet 48 is formed on the side surface of the reaction chamber, whereby all the neutral species mentioned above head toward the substrate, and their effective use increases the rate of film formation. , the film formation rate can be increased.

The inventor repeatedly conducted various experiments on the glow discharge decomposition devices of the first to third examples, and found that the common electrode (
The gas ejection pipe 9.21) and the mesh electrode 46.47 are arranged at substantially the same distance, and the distance is 10 to 300 mm.
It has been found that setting am preferably within the range of 30 to 100II11 is advantageous in that stable discharge can be maintained.

Further, the distance between the substrate 2.16 and the mesh electrode 46.47 is set within the range of 1 to 100 m5-1, preferably 5 to 20 mm.

It has also been found that it is desirable to do so, and that a high film formation rate can be obtained within this range.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to simultaneously form a film on a plurality of substrates using a single device, and moreover, the growth rate can be varied over the film-forming surface of the substrate and between the individual substrates. In addition, it was possible to provide a glow discharge decomposition device in which uniform film characteristics were obtained.

Furthermore, the glow discharge decomposition apparatus of the present invention has improved manufacturing workability and film-forming gas utilization efficiency, thereby improving manufacturing efficiency and manufacturing cost.

Furthermore, the glow discharge decomposition apparatus of the present invention also has the following advantages.

(i)...The substrate for film formation is not used as an electrode, thereby,
There is no need for a conductive means for the substrate, making it easier to transport the substrate, and as a result, an in-line mass production system becomes possible.

(ii) When the substrate for film formation is a cylindrical substrate with a relatively small diameter, the problem described in the third conventional example can be solved most noticeably, and therefore, multiple (The board can be arranged, and it is excellent in mass production.

(iii)...The reaction chamber, the mesh-like electrode, and the substrate can be electrically connected and grounded to the same potential state, which eliminates the need for shielding means to shield the reaction chamber to prevent radio wave radiation. , it becomes a compact film deposition device.

(iv)...The base does not serve as one of the electrodes, and as a result, ions generated by glow discharge decomposition do not collide with the base while being accelerated by the electric field, and the temperature of the base does not rise due to this, resulting in This makes it easier to control the temperature of the substrate to set it to a desired temperature, and eliminates the need for cooling means for the substrate, which has conventionally been used as needed.

(v) Even if the substrate has various shapes other than a cylindrical shape, uniform film formation is possible.

(vi)...The base does not need to be conductive and may be made of an insulator.

(vi)... Conventionally, an AI drum was used as a substrate for film formation for electrophotographic photoreceptors, and because the drum had the function of an electrode, a large thick substrate was used, which made the substrate thinner. Although the deformation of the substrate caused by direct exposure to plasma was minimized, the above-mentioned problems were solved in the present invention, and a thin drum made by A! could be used.

Note that the present invention is not limited to the above embodiments,
Various modifications may be made without departing from the spirit of the present invention.
There is no difference in any improvements.

[Brief explanation of drawings]

1 and 2 are a schematic plan view and a partial cross-sectional schematic diagram of an example of the cylinder 1 of the present invention, respectively; FIGS. 3 and 4 are a schematic plan view and a schematic partial cross-section of an example of the cylinder 2 of the present invention, respectively; 5 and 6 are a schematic plan view and a schematic partial cross-sectional view of an example of the cylinder 3 of the present invention, respectively. Further, FIGS. 7 and 8 are a schematic plan view and a partial cross-sectional view of the first conventional example, respectively, and FIGS. 9 and 10 are a schematic plan view and a partial cross-sectional view of the second conventional example, respectively. Figure 11 is a diagram explaining Paschen's law, Figure 12 is an explanatory diagram explaining film formation unevenness caused by discharge between a cylindrical substrate and a substrate electrode, and Figures 13 and 14 are respectively the third conventional example. FIG. 2 is a schematic plan view and a schematic partial cross-sectional view. 2.16.34...Substrate 9.21...Gas ejection pipe 10.22.41...Gas ejection port 11.23.40...Gas inlet 12.24.42. ．． 4B...Gas exhaust port 46.
47 ...Mesh-shaped electrode patent applicant (663) Kinju Anjo, representative of Kyocera Corporation

Claims (1)

[Claims] A first gas outlet in which a plurality of gas outlets are formed inside the reaction chamber.
An electrode part, a plurality of substrates for film formation, a second electrode part disposed between the substrate and the first electrode part and formed with a plurality of gas passage ports, and the first electrode part and the second electrode part are provided. A glow discharge decomposition device characterized in that gas ejected between the parts is decomposed by glow discharge and the decomposed gas is sprayed onto the surface of the substrate through the gas passage port to form a film.