JPS5938374A - Plasma cvd device - Google Patents

Abstract

PURPOSE:To deposit uniformly a photoreceptor film, etc. having good reproducibility on a base body, by forming a cathode electrode disposed in a vacuum chamber into a discoid double construction to form a gas chamber, and providing gas releasing ports to the electrode in a radial array. CONSTITUTION:A discoid base body 2 is set in a vacuum chamber 3, and a cathode electrode 1 formed with a gas chamber by a discoid double-walled construction is disposed to the body 2. Gas releasing holes 11 are opened in a radial array from the center of such electrode 1. A gaseous raw material is fed through a gas supply pipe 8 to the gas chamber in the electrode 1 to fill the chamber; thereafter, the gas is released through the respective holes 1 toward the body 2. Screw holes are worked in the holes 11 and the unnecessary holes 11 are closed with screws, etc. whereby the flow rate of the releasing gas is controlled. An amorphous silicon film, etc. having good uniformity and reproducibility in the thickness of the vapor deposited film are formed on the body 2 by the above- mentioned device.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides plasma C for forming a deposited film on a substrate.
It relates to VD equipment, for example, the production of photodetectors using amorphous silicon photoreceptors, and in particular, the production of photodetectors by depositing an amorphous silicon film on the surface of a flat substrate using plasma CVD technology. Silicon nitride (
SiN ) k, silicon oxynitride (81O
N) film, silicon oxide (5iO2) M, and silicon carbide (SiC) film are continuously deposited on the photoreceptor fitting surface to improve the moisture resistance and wear resistance characteristics of the light receiving element. This relates to CVD equipment.

In the following description, the present invention will mainly be explained with reference to an embodiment in which the substrate on which a film is formed is a flat substrate for a light receiving element. By depositing a hard film such as silicon carbide (SiC) film on the surface of acrylic materials, etc., it can be used to improve the wear resistance of tools and extend their service life. Silicon oxide (s) is used as an undercoat material on the surface of spherical lenses, etc.
It can also be used for the purpose of depositing a film such as to2)g and enabling the deposition of an optical thin film on the surface of an acrylic aspheric lens.

FIG. 1 shows a typical example of a conventional parallel plate wall emission type plasma CVD apparatus used as an apparatus for forming a deposited film on a substrate as described above.

In the figure, 1 is a cathode electrode, 2 is a circular plate-shaped base forming an anode electrode, 3i43 empty chamber, 4 is an insulating insulator, 5 is a heater for heating the base, 6 is a motor for rotating the base, 7 is an exhaust system, 8 is a raw material gas supply/minor, 9 is a high frequency power source for generating glow discharge in vacuum, 1o
11 is the ground for using the circular flat plate base as the anode electrode L pole, and 11 is the discharge hole for the raw material gas. As shown in the figure, the cathode electrode and the hole have a circular flat plate double structure, inside which the raw material gas is A chamber is formed in which the gas is supplied.

The operation of the above device is as follows.

First, a disc-shaped base 2 is placed inside the chamber 3.

Then, the exhaust system 7 evacuates the inside of the puller and pumper.

At the same time, the substrate 2 is heated by the heater 5 and rotated by the motor 6 to make the production distribution of the substrate uniform. When ξ, the heater is fixed. When the substrate temperature becomes constant, raw material gas is supplied into the vacuum chamber 3 from the gas supply/mother tube 8. The gas is discharged from the discharge hole 11 toward the substrate, and while the raw material gas is supplied into the vacuum chamber 3, a high frequency voltage of 13.56 Mllz is applied to the cathode electrode 1 by the high frequency power supply 9, and the cathode electrode 1 is connected to the earth ground lO. Glow emission iFL is generated between the substrates 2, and electrons ejected from the cathode iB4 collide with gas molecules to cause a radical reaction in the gas molecules and deposit them on the substrate, forming an amorphous silicon film. O In the above-mentioned plasma CVD apparatus, the thickness distribution of the deposited film depends on the position of the exhaust port of the apparatus, the flow rate of raw material gas, the film deposition rate depending on the magnitude of high-frequency power during discharge, and also the degree of vacuum, It changes depending on the position of the raw material gas discharge port.

Considering the purpose of using an amorphous silicon photoreceptor film, uniformity of film thickness distribution over a wide range is required on a large-area substrate.

In a plasma CVD apparatus, the gas flow rate, the magnitude of high-frequency power, the degree of vacuum, etc. cannot be used as means for adjusting the film thickness distribution because they affect the film characteristics. It is also difficult to freely change the position of the exhaust port due to the device configuration. That is, adjusting the hole diameter and position of the gas discharge port is considered to be the easiest means for adjusting the film thickness distribution.

On the other hand, in plasma CVD equipment, it is necessary to select the gas flow rate and flow rate in order to obtain specific film characteristics, and the film thickness distribution also changes each time, so there is a high degree of freedom in selecting the hole diameter and position of the gas outlet. ◎Most conventional parallel plate wall-emission plasma CVD equipment has a large number of irregularly opened raw material gas discharge holes or a large number of openings on the circumference. Because the number of holes was too large, it was difficult to select the optimal hole positions to make the film thickness distribution uniform. Furthermore, since little consideration was given to the degree of freedom of the hole diameter, adjustment of the film thickness distribution relied only on the selection of hole positions. For this reason, the conventional apparatus had the disadvantage that it became difficult to adjust the film thickness distribution in proportion to the widening of the effective deposition range.
This is intended to significantly improve film thickness distribution adjustment in VD equipment, and gas release holes opened in the cathode electrode wall.
Openings are formed in a row of gas discharge holes from the center of the side surface of the electrode, and the rows of gas discharge holes are arranged in 1 to 10 rows in proportion to the interfacial area of the base, thereby creating a gas chamber within the disk-shaped double-walled electrode. form,
By limiting the numerical aperture to a level that causes no problems with the film thickness distribution, it is possible to clarify the correlation between the film thickness distribution and the opening position of the gas discharge port, making it possible to easily adjust the film thickness distribution. It is. However, by rotating the above-mentioned substrate around the central axis, uniformity of the film thickness is also ensured. Furthermore, by providing gas discharge holes with different hole diameters on the screws attached to the gas discharge holes, fine adjustment of the film thickness distribution is possible.For example, uniform deposition of an amorphous silicon photoreceptor film on a large area substrate is possible. It is what makes it possible.

The present invention will be described in detail below based on an example device.

FIG. 2 shows an example of a plasma CVD apparatus according to the present invention. In the figure, parts similar to those in the apparatus shown in FIG. , which is rotated by a rotation motor during the deposition process. 3 is a vacuum chamber, 4 is an insulating insulator for electrically insulating the cathode electrode, the vacuum chamber, and the anode electrode, and 5 is attached to the anode electrode. A heater for heating the substrate; 6 is a motor for rotating the inner lining-shaped substrate; 7 is an exhaust system for keeping the chamber in vacuum; 8 is a raw material gas supply pipe; 9 is a heater between the cathode electrode and the anode electrode. A high frequency power source is used to generate glow discharge, 10 is a ground for grounding the anode electrode and the vacuum chamber, and 11 is a hole for releasing raw material gas to supply raw material gas during glow discharge.

A disk-shaped substrate 2 constituting an anode electrode is arranged in a vacuum chamber 3, and a cathode electrode 1 is configured as a disk-shaped double-walled electrode arranged in parallel to the substrate. A gas chamber is formed in the Holes 11 for releasing the raw material are opened in a radial row (six rows in the illustrated example) from the center of the electrode side surface on the side surface of the disk-shaped electrode 1. The hole 11 through which the raw material gas is released is threaded, so that when adjusting the film thickness distribution of the film deposited on the surface of the substrate, an unnecessary hole can be installed with a screw. . In addition, a screw with a gas release port in the center is attached to the threaded hole 11 described above, and a screw with a diameter of the hole of the release port is installed, so that the amount of gas released is t! The J film thickness distribution can be adjusted by adjusting the J film thickness distribution.

In this way, the amount of gas released from each row of gas release holes can be adjusted independently. Figure 3 shows the cathode electrode of the disc-shaped double wall structure of the above device, viewed from the anode side. , 1 is a cathode electrode, and 11 is a screw-processed gas discharge hole opened in six rows radially from the center in the anode side wall of the double-walled cathode electrode.

FIG. 4 shows disconnection of the cathode electrode of the above device;
In the figure, 1a is a vacuum chamber side force sword electrode wall, 1b is an anode side cathode electrode wall, and 11 is a threaded gas discharge hole.

A gas chamber is configured within the cathode electrode by walls on the vacuum chamber side and the bunode side.

Figures 5(a) and 5(b) show hexagonal socket screws for attachment to the gas discharge hole of the above device. In Figure 5 0),
Reference numeral 12 indicates a hexagon socket head screw provided with a gas release port, and 13 indicates a gas release port. By replacing the screw with a different hole diameter, the amount of gas released can be changed and the film thickness can be controlled.

In FIG. 5(b), 14 is a hexagon socket head screw without a gas discharge port, and is used for the purpose of closing the gas discharge port that is no longer needed when adjusting the film thickness distribution.

Next, the operation of each part of the above device will be explained in order.

First, a disk-shaped base 2 is set in a chamber, and the chamber is evacuated by the exhaust system 7.

At the same time, the substrate 2 is heated by the heater 5 and rotated by the motor 6 to make the temperature distribution of the substrate uniform. At this time, the heater is fixed. When the substrate temperature becomes constant, raw material gas is supplied from the gas supply pipe 8 into the nitrogen chamber A.

The feed gas is fed to the cathode-1 surrounded by a disc-shaped double wall.
He was sent to the gas chamber inside the palace. Here, since the gas supply/P Inno 8 is attached to the center of the cathode electrode,
The raw material gas sent to the gas chamber is not directly discharged from the gas discharge hole, but once fills the gas chamber and is discharged from the valley gas discharge hole toward the substrate. The amount of gas released from each discharge hole is controlled by the diameter of the hole drilled in the screw attached to the discharge hole. While gas is stably supplied into the vacuum chamber, a high frequency voltage of 13.56 MHy is applied to the cathode electrode 1 by the sieve frequency power supply 9, and a glow discharge is generated between the grounded bases 2. The collision of electrons ejected from the cathode with gas molecules causes the force molecules to undergo a radical reaction and deposit on the substrate, forming an amorphous silicon film.

As explained above, in the zero plasma CVD apparatus according to the present invention, the raw material opened in the cathode electrode has a reduced number of sulfur discharge holes, and is arranged in a straight line in the direction normal to the rotational direction of the disk-shaped substrate. This has the effect of facilitating adjustment of the film thickness distribution in the normal direction.

Furthermore, by opening the hexagon socket head screws with different hole diameters to be attached to the force gas discharge port, the amount of gas released can be adjusted along the direction of the force, and the film thickness distribution can be controlled. Another effect is that it allows copying to be smoothed.
By using the present invention, the film thickness distribution, i+, l
This not only makes the process easier, but also improves the uniformity of the deposited film thickness and the reproducibility of the deposited film characteristics. There are effects that can be achieved.

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway perspective view showing a conventional plasma CVD apparatus, Fig. 2 is a partially cutaway perspective view showing an embodiment of the plasma CVD apparatus of the present invention, and Fig. 3 is shown in Fig. 2. FIG. 4 is a cross-sectional view of the cathode electrode, and FIGS. 5(a) and 5(b) are side views of a hexagon socket head screw attached to a gas discharge hole, respectively. 1 is a cathode electrode with a disc-shaped double wall structure, 2 is a disc-shaped base, 3 is a vacuum chamber, 4 is an electrically insulated insulator, 5 is a base heater, 6 is a motor for rotating the base, 7 is an exhaust system, and 8 is a Raw material gas supply pipe, 9 is a high frequency power supply, 1O is earth, 11 is a gas discharge hole. 12 is a hexagon socket screw having a gas discharge port, 13 is a gas discharge port, and 14 is a hexagon socket screw for closing the gas discharge port. Horse 2

Claims (3)

[Claims] (1) A disc-shaped base is placed in a vacuum chamber, and a hole for releasing raw material gas is provided in the side wall surface of the base of an electrode with a disc-shaped double-walled structure that is placed parallel to and facing the base. A plasma CVD apparatus characterized in that a large number of openings are formed in a radial row from the center of the electrolyte, and a gas chamber is formed within the tube of the disc-shaped double wall structure. (2) When adjusting the film thickness distribution of the film deposited on the surface of the disk-shaped substrate by drilling screw holes in the holes through which the raw material gas is released, the unnecessary holes can be closed with screws. A plasma CVD apparatus according to claim (1). (3) Machine a screw hole in the hole that releases the raw material gas,
By inserting a screw with a gas release port in the center into this screw hole, and attaching a screw with a different diameter hole to the screw hole, the film thickness distribution can be adjusted by changing the gas release liquid. A plasma CVD apparatus according to claim (1).