JPS6036660A - Plasma CVD equipment - Google Patents

Abstract

PURPOSE:To form a uniform film without uneven electric discharge with a device which forms a deposited film on the outside surface of a rotary drum by the discharge of an outside circumferential cathode electrode in a gaseous raw material by moving vertically and controllably the cylindrical cathode electrode. CONSTITUTION:A drum 2 which is rotated by a shaft 9 in a vacuum 7 chamber 13 insulated by an insulator 4 is heated to an adequate temp. by an electric heater. A doping gas 6 such as gaseous silane flows out from fine holes 11 formed on the inside circumferential surface of a cylindrical cathode 1. When a high frequency voltage is impressed to the cathode electrode 1, the radical reaction of the emitted electrons with gaseous molecules is performed by which a deposited film is formed on the outside surface of the drum 1. The cathode 1 is vertically moved at an adequate control speed by a revolving shaft 12, by which the uneven discharge of the deposited film is eliminated and a uniform film is formed on the outside circumferential surface of the drum 2.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a so-called plasma 0VT) device, and in particular to a plasma 0VD device that can be suitably used for depositing an amorphous silicon film on the surface of a cylindrical substrate and producing photoreceptor drums. .

Conventionally, the photosensitive drum constructions that have been proposed for electronic Lf applications using plasma (0VA) can be roughly divided into inductively coupled types and U-coupled types.

In the former method, a coil is arranged to surround the drum base, high-frequency power is fed to the coil, and the raw material gas (gas) is turned into plasma by electromagnetic energy.
However, uneven discharge is likely to occur due to deviations in coil diameter, spacing, etc. and standing waves in the coil.
The formed film has non-uniform thickness and electrical properties.

On the other hand, the latter type uses double coaxial cylindrical electrodes using the drum base itself as the internal electrode inside a cylindrical deposition tank that also serves as the external electrode. A direct current or alternating current electric field is applied between the drums, gas plasma is formed by glow discharge at this time, and a deposited film is formed on the drum base I-.

In this way, the conventional cylindrical plasma CVD device σ)
An outline of a typical example is shown in FIG. In Figure 1, ■ is the cylindrical cathode electrode that constitutes the vacuum chamber, and 2
8 is a cylindrical base constituting an anode electrode which is a counter electrode arranged concentrically with the central axis of the vacuum chamber so as to rotate around the central axis; 8 is a top and bottom wall of the vacuum chamber; A donut-shaped insulating insulator for insulating the wall body from the cathode electrode, 5 a high-frequency power source, 6 a raw material gas supply pipe, 7 a ventilation system, 8 a heater, and 9 a cylindrical insulator as indicated in -1-. A rotation mechanism for rotating the base body, 10 is a ground, and 11 is a raw material gas discharge hole.

The operation of the above plasma CVD apparatus will be briefly explained below.

First, place seven cylindrical substrates 2 in a vacuum chamber.
,, Make the inside of Senyanbar a vacuum using the JIJI gas system 7. At the same time, the substrate 2 is heated by the heater 8 and rotated by the rotation mechanism 9 to make the temperature distribution of the substrate uniform. At this time, the heater is fixed. When the bulk temperature reaches -4r, the gas supply vibro to the original r1
Gas is supplied into the vacuum chamber. Raw material gas is yen r;
It enters through the many dregs discharge holes of the i-shaped electrode (; toward the body 2).
released. While gas is stably supplied into the vacuum chamber, the cathode electrode 1 is connected to the high frequency power source 5.
1.3.56 Apply a high frequency voltage of MT-Tz to generate a glow discharge between it and the grounded base 2,
The side impact of electrons ejected from the cathode electrode onto gas molecules causes the gas molecules to undergo a radical reaction and is deposited on the substrate 2-1, thereby forming a deposited film, for example, an amorphous silicon film, on the substrate 2-1-.

In the plasma CVD equipment described above, the film thickness distribution of the deposited film is determined by the position of the equipment exhaust [1], the raw material waste flow rate,
The film deposition rate varies depending on the magnitude of high-frequency power during discharge, the degree of vacuum, and the position of the source gas discharge hole. Considering the purpose of use of the amorphous silicon photoreceptor film, uniformity of the film thickness distribution over a wide range of the large area 11 is required.

In a plasma CVD apparatus, the gas flow h1, the magnitude of high-frequency power, the degree of vacuum, etc. affect the film characteristics, and therefore cannot be used as means for adjusting the film thickness distribution. It is possible to freely change the position of the exhaust gas [l] depending on the device configuration. In other words, adjusting the diameter and position of the gas release holes is considered to be the easiest method for adjusting the film thickness distribution.

On the other hand, in plasma C■■) equipment, it is necessary to select the gas flow 1B and flow rate in order to obtain specific film characteristics, and the film thickness distribution also changes each time, so the hole diameter and position of the gas release hole must be selected. A high degree of freedom is required. Conventional cylindrical wall discharge type plasma CVD equipment has a large number of holes for releasing raw material gas (most of them have irregularly controlled numbers of holes), and those that have many holes spaced in multiple rows in the direction of the rotation axis. Therefore, it was difficult to select the optimal hole position 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 was made by adjusting the hole position. Therefore, as the effective deposition range becomes wider, it becomes more difficult to adjust the film thickness distribution.

The present invention has been made in consideration of these "1F" problems, and is a novel 4R plasma OVD that solves the problems described above.
The main purpose is to provide equipment.

Another object of the present invention is to provide a photoconductive film for electrophotographic photoreceptors, which has excellent electrical properties and environmental stability, and can provide good images over the entire area of the photoreceptor, at low cost and with high yield. Suitable for manufacturing'1. r plasma 0VI) device.

The second object is achieved by the present invention as follows.

A first electrode and a second electrode are provided in a chamber that can be evacuated, an electric discharge is generated between the first electrode and the second electrode, and the electric discharge is introduced into the chamber. In the apparatus for forming a deposited film on a substrate installed in the chamber as necessary from the raw material gas, the first electrode has a cylindrical shape and can move up and down. Plasma CV11 is characterized by
)Device.

In the present device, it is preferred that the first electrode can be moved up and down at a controlled speed, and it is especially preferred that the first electrode can be moved up and down continuously.

The first electrode is preferably moved once to several times at a speed of 5 to 22 m/7 minutes.

In the following description, the present invention will mainly be explained with reference to an embodiment in which the substrate on which the deposited layer is formed is a cylindrical substrate for electrophotography (drill). It can also be used for ``I'' purposes, in which an amorphous photoreceptor film or an amorphous semiconductor film for an arithmetic element is deposited on the counter electrode -1- in the form of a polygon.
Furthermore, by depositing an ultra-hard film on the surface of tools that are prone to wear, such as molds and bits, it can be used to improve wear resistance and extend the life of tools.

FIG. 2 shows an embodiment of a plasma CVD apparatus according to the present invention. In the figures, similar parts to those in the apparatus shown in FIG. 1 are designated by the same reference numerals.

In the figure, 1 is a cylindrical cathode electrode with a vertical movement mechanism;
2 is a JI (body) constituting a cylindrical anode electrode arranged concentrically with the central axis of the vacuum chamber so as to rotate around the central axis; 8 is an upper 1.
σ) Wall body, 4+ is a donut-shaped insulating insulator for insulating the wall body from the cathode electrode, 5 is a high frequency power source for supplying high frequency power to the cathode electrode to cause glow discharge, 6 is a raw material gas supply A pipe, 7 is an exhaust system for keeping the vacuum chamber in a vacuum, 8 is a l-liter for heating the cylindrical substrate, and 9 is a rotating cylindrical substrate to make the thickness of the deposited film uniform. 10 is a ground for installing the substrate, 1 is a source gas discharge hole, and 12 is a drive mechanism for lowering the quad electrode.

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

First, a cylindrical base 2 is set in a vacuum chamber,
The inside of the chamber is evacuated by the exhaust system 7. Generally, a rotary pump, a mechanical booster pump, a diffusion pump, or a combination thereof is used for the exhaust system, depending on the desired degree of vacuum and productivity. At the same time as vacuuming the chamber, the substrate 2
is heated by a heater 8, and the substrate 2 is rotated by a rotating shaft 9 connected to a motor, usually for several to several tens of seconds, to make the temperature distribution of the substrate uniform. At this time, the heater is fixed. Further, the cathode electrode is placed in advance at the lower end or upper end 1a of the substrate. When the temperature of the substrate becomes constant, a raw material gas is supplied into the vacuum chamber using a gas supply vibro. The raw material gas enters the gas chamber 1a provided inside the cathode electrode and is released from the release hole 11 toward the substrate. Here, the gas supply pipe is a flexible tube in the vacuum chamber so that it can follow the downward movement of the cathode electrode 1. Further, the amount of gas released from each discharge hole is also controlled by the hole diameter of the discharge port. While gas is being stably supplied into the vacuum chamber, the high frequency power source 5 is used to connect the cathode.

A high-frequency voltage is applied to the anode electrode]-4 (grounded), and a glow discharge is generated between the anode electrode]-4 (grounded), and the collision of the electrons ejected from the cathode electrode with the gas molecules causes the gas molecules to undergo a radical reaction. The cathode electrode is moved at a speed of 5 to 22 min/min by the cathode electrode drive mechanism 12.The cathode electrode is moved in such a way as to obtain the required film thickness. Do this one to several times.

In the plasma CVD apparatus of the present invention, by changing the movement speed of the cathode electrode, the number of movements, the raw material gas supply meter, etc., it is possible to form a deposited film with uniform thickness on a large area substrate with good reproducibility. can.

13. Introducing source gas into the plasma CVD apparatus of the present invention and maintaining the temperature of the substrate at 100°C to 850°C.
When a high-frequency voltage was applied to the cathode electrode using a 56 MHz high-frequency power source to form a film, smooth glow discharge continued even when the type of gas was changed at any time, making it a highly uniform photoreceptor for electrophotography. Film formation was possible at low cost and with good yield. In addition, as raw material gas,
Silane (SjJ) as an amorphous silicon film forming material
T4.5j-2T (6,513TTs, Sl, i r
ho, etc.), T12 as a base gas, rare gas, Sco-F4 for introducing fluorine, B2■I6 for controlling p or n conduction, ■)■■3, AsTl3, N2 for nitrogen doping, N H3, N20 for oxygen doping, NO1 hydrogen for carbon doping, for example, CH4,021T4, and various other gases known to be dopable by plasma CVD are controlled in a predetermined manner using a mass flow controller, etc. A mixture of the following ratios can be used.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a typical example of a conventional cylindrical plasma CVD apparatus, and FIG. 2 is a sectional view showing an embodiment of the plasma CVD apparatus of the present invention. Patent applicant Canon Co., Ltd. 11- Figure 2

Claims (1)

[Claims] 1) C (a chamber to be emptied 11 is provided with a first electrode and a second electrode, and a discharge is caused between the first electrode and the second electrode) , in an apparatus for forming a deposited film from the raw material gas introduced into the chamber by this discharge on a substrate installed in the chamber as necessary, the first electrode has a cylindrical shape; 2) A plasma 0VD device characterized in that the first electrode is capable of operating up and down. The plasma 0VD device according to scope 1. 6.) The plasma OVA') apparatus according to claim 1 or 2, characterized in that the first electrode can be moved up and down continuously.