JPS5938377A - Plasma cvd device - Google Patents

Abstract

PURPOSE:To provide a titled device which can form films on a base body at a uniform thickness distribution by the constitution wherein many holes are provided on the wall surface of a cylindrical electrode in the arrays parallel with the central axis thereof and a gaseous raw material is released through said holes toward the base body of a counter electrode under rotation around the central axis. CONSTITUTION:Many holes 11 for releasing a gaseous raw material are provided on the wall surface of a cylindrical cathode electrode 1 constituting a vacuum chamber in the form of the arrays parallel with the central axis thereof and pipes 13 for supplying the gaseous raw material are provided, each piece for one array of the holes, on the outside wall surface of the electrode 1 in a plasma CVD device which forms deposited films on a base body 2 of an anode electrode under rotation around the central axis of the electrode 1 by blowing the gaseous raw material toward said body 2. Screw holes are worked in said holes 11 and adequate screws are fitted therein according to need to permit the adjustment of the distribution of the thickness in the deposited films. It is also possible to improve productivity by disposing plural pieces of rotary cylindrical base bodies in the vacuum chamber with their central axes in parallel with the axial center of the vacuum chamber.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a plasma CVD apparatus for forming a deposited film on a substrate, for example, for continuously producing electrophotographic photoreceptor drums, and in particular for forming a deposited film on a cylindrical substrate surface using plasma CVD technology. Plasma CVD equipment that can be used to deposit an amorphous nitride film and continuously produce photoreceptor drums (silicon nitride (SIN)) by appropriately supplying various raw material gases into the same reaction chamber.
membrane, silicon oxynitride (SiON) membrane, silicon oxide (S102) membrane, silicon carbide (
A glazma CVD i-type device in which a SiC) film is continuously stacked and deposited on the surface of the photoreceptor drum to improve the charging characteristics of the photoreceptor drum and also to improve the moisture resistance and abrasion resistance characteristics of the photoreceptor drum surface. It is related to.

In the following explanation, the present invention will mainly be explained with reference to an embodiment in which the substrate on which the deposited film is formed is a cylindrical substrate for electrophotography. Arranged to form a polygon, it can also be used for the purpose of depositing amorphous photoreceptor films and amorphous semiconductor films for arithmetic elements, and can also be used to deposit ultra-hard materials on the surfaces of tools that easily wear out, such as molds and bits. By depositing a film, it can also be used to improve wear resistance and extend life.

A typical example of such a conventional cylindrical plasma CVD apparatus is schematically shown in FIG. In Figure 1, ] is 1% of the cylindrical cand that makes up the vacuum chamber! A pole, 2 is a cylindrical base constituting an anode electrode as a counter electrode arranged concentrically with the pole so as to rotate around the central axis of the vacuum chamber, 3 is the upper and lower walls of the vacuum chamber, 4 is a donut-shaped insulating insulator for insulating the wall body from the cathode electrode, 5 is a high frequency power source, 6 is a raw material gas supply pipe, 7 is an exhaust system, 8 is a heater, and 9 is the cylindrical base mentioned above. In the rotating mechanism, ]0 indicates the ground, and Jl indicates the raw material gas discharge hole.

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

First, a cylindrical base 2 is set in a vacuum chamber,
The inside of the chamber is evacuated by the exhaust system 7. At the same time, the base 2 is heated by the heater 8, and the base 2? ]1-Rotated by the rotation mechanism 9 to make the temperature distribution of the substrate uniform.

At this time, the heater is fixed. When the substrate temperature reaches a certain level, raw material gas is supplied from the gas supply pipe 6 into the vacuum chamber. The raw material gas is released toward the base 2 from a large number of gas release holes in the cylindrical electrode. 13.56 when gas is stably supplied to the vacuum chamber.
A high-frequency voltage is applied to the can-do' awakening electrodes 1 by the high-frequency power source 5 of M1 (z), a glow discharge is generated between the earthed base 20, and the electrons ejected from the cathode electrode collide with gas molecules. Gas molecules are subjected to a radical reaction and deposited on the substrate to form a deposited film, such as an amorphous silicon film, on the substrate 2.

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 the raw material gas, the film deposition rate depending on the magnitude of high-frequency power during discharge, the degree of vacuum, and the raw material. varies depending on the position of the gas outlet.

Considering the purpose of using an amorphous silicon photoreceptor film, uniformity of the 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. affect the film characteristics, so they cannot be used as means for adjusting the film thickness distribution. It is also difficult to freely change the position of the exhaust port due to the device configuration. That is, the easiest way to adjust the film thickness distribution is to adjust the hole diameter and position of the gas discharge port.

On the other hand, with Zolaz-F 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 the hole diameter and position of the gas release hole can be freely selected. It is required that the quality is high. Most of the conventional cylindrical wall discharge type plasma CVD devices have a large number of irregularly opened raw material gas discharge holes, or have many rows of openings in the direction of the rotation axis. It was difficult to select the optimal hole position for uniform thickness distribution. 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. Therefore, as the effective angle range becomes wider, it becomes difficult to adjust the film thickness distribution.

The present invention aims to eliminate the drawbacks of the above-mentioned conventional cylindrical type CVD apparatus, and to significantly improve the film thickness distribution adjustment in the plasma CVD apparatus. A large number of raw material gas discharge holes are opened in the wall of the gun electrode in rows parallel to the central axis of the electrode, and one gas supply pipe is connected to each row of holes on the opposite side of the counter electrode. This is because the electrodes are placed on the wall surface.

Therefore, the gas release holes opened in the wall surface of the cathode electrode are arranged in a JO row in proportion to the surface area of the substrate, and the film thickness distribution and gas release holes are By clarifying the correlation with the aperture position, adjustment can be facilitated, and by rotating the substrate around the central axis, uniform film thickness can be ensured. Furthermore, by drilling a screw hole in the gas release hole and providing a screw with a different hole diameter to attach to this hole, fine adjustment of the film thickness distribution becomes possible, allowing amorphous silicon to be exposed to large-area substrates. This allows uniform deposition of body membranes. Another advantage of the present invention is that the gas supply system is integrated with the cathode and the electrodes, and the electrical insulation is in a simple structure, making it possible to easily disassemble the device components and place them inside the vacuum chamber. This makes it possible to easily remove deposits such as polysilane and simplify cleaning inside the chamber.

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

FIG. 2 shows a first embodiment of a plasma CVD apparatus according to the present invention. In the figures, parts similar to parts in the apparatus shown in FIG. 1 are designated by the same reference numerals. In the figure, 1
iI'i A cylindrical cathode electrode constituting a vacuum chamber, a cylindrical substrate constituting an anode electrode arranged concentrically with the pole, 2 rotating around the central axis of the vacuum chamber; 3 is a wall forming a vacuum chamber above and below the cathode electrode; 4 is a donut-shaped insulating insulator for insulating the wall from the cathode electrode; 5
is a frequency power supply for supplying high frequency power to the cathode electrode to cause glow emission; 6 is a raw material gas supply pipe; 7 is a
10 is an exhaust system for keeping the vacuum chamber in a vacuum; 8 is a heater for heating the cylindrical substrate; 9 is a rotation mechanism for rotating the cylindrical substrate to make the thickness of the deposited film uniform; 10 1J indicates a source gas discharge hole, and 12 indicates a motor for rotating the cylindrical substrate.

The cathode electrode 1 is formed in a cylindrical shape that also serves as a part of the vacuum chamber 9-, and has a large number of raw material gas discharge holes 11 arranged in four rows located in the direction of its central axis. A grooved gas chamber 1& is provided in the lower flange portion of the cathode electrode 1, and in order to supply raw material gas to this gas chamber from the outside, a hole is provided to connect the gas chamber 1& with the mounting portion of the gas supply arm 6. One location is opened, and raw material gas is supplied into the gas chamber la from the gas supply 9 id 6. However, the raw material provided on the wall surface of the cylindrical cathode electrode has one gas supply, 9 ignition holes, and 1
3 is disposed on the wall surface of the cathode electrode opposite to the anode electrode, that is, on the atmospheric side wall surface of the cathode electrode, and this gas supply pipe 13 is used to supply gas from the gas chamber 1 to each gas discharge hole. It is made of metal or ino and has a semicircular cross section that is welded to the atmospheric side wall of the cathode electrode to prevent vacuum leaks.

The raw material gas discharge holes 11 are arranged at equal intervals,
Each raw material gas discharge hole is threaded, and when adjusting the thickness distribution of the film deposited on the surface of the cylindrical substrate,
An unnecessary hole can be closed with a screw, and a gas release port is provided in the center of the screw that is attached to the screw hole that is used to spray raw material gas, and a screw with a different hole diameter of the release port is installed in the screw hole. This makes it possible to adjust the film thickness distribution by changing the amount of gas released.

FIG. 3 is a diagram showing a cross section of the cylindrical cathode electrode in the above embodiment, where 1 indicates the wall of the cathode electrode, and 1
] is the raw material gas discharge hole provided with the cathode as the pole, and 13 is the cathode 1! This is a metal base tube for gas supply that has a semicircular cross section and is welded to the atmospheric side wall of the Lffl so that there is no vacuum leakage.

The raw material gas discharge holes 1] are threaded and opened at equal intervals.

Figures 4(a) and 4(b) show hexagonal socket screws for attachment to the gas discharge hole of the above device. In Fig. 4 (a), ] 4 is a hexagonal socket screw with a gas release port, 15 is a gas release port υ, and by replacing the screw with a different hole diameter, the amount of gas released can be changed and the film thickness can be controlled. can be done.

In FIG. 4(B), 16 is a hexagonal screw without a gas discharge port, and is used for closing an unnecessary gas discharge port when adjusting the film thickness distribution.

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

First, set the cylindrical base 2 in the vacuum chamber (
〜The inside of the chamber is evacuated by the exhaust system 7. At the same time, the substrate 2 is heated by the heater 8 and rotated by a rotating shaft connected to the motor 12, thereby making 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 into the vacuum chamber from the gas supply) or the eve 6. The raw material gas passes through a hole made in a part of the electrically insulating insulator 4, enters the gas chamber 1a provided in the lower flange of the cathode electrode 1, goes around the flange, and is sent to each metal pie f13.

Here, since the space between the pipes is narrow, the raw material gas is prevented from flowing, and the gas is evenly supplied to each pipe.

The gas flowing through the Noribu is released from the release hole] towards the base. The amount of gas released from each discharge hole is controlled by the diameter of the gas discharge port drilled in the screw attached to the discharge hole. With gas being stably supplied into the vacuum chamber, a high frequency voltage is applied to the cathode electrode 1 by a 13.56 MHz high frequency power source 5 to generate a glow discharge between the grounded bases 2, and the cathode The collision of the deuterons ejected from the electrodes with the gas molecules causes the gas molecules to undergo a radical reaction and is deposited on the substrate, forming a deposited film such as an amorphous silicon film.

FIG. 5 shows another embodiment of the invention. This example is
Basically, the structure is similar to the embodiment shown in Fig. 2, in which the power hood electrode also serves as a part of the wall of the vacuum chamber, and the number of rows of raw material gas discharge ports opened in the cathode electrode and the number of rows housed in the vacuum chamber are determined. The only difference is the number of cylindrical bases and the rotation mechanism of the cylindrical base, and other parts have similar structures, so similar parts will be designated by the same reference numerals and a detailed description thereof will be given. is omitted.

The difference between the embodiment shown in FIG. 5 and the embodiment shown in FIG. 2 is that four cylindrical base bodies 2 a r 2 b *2
c and 2d are placed on the circumference that shares the central axis of the cathode 1#L pole, and are rotated around the central axis by a cylindrical base rotation mechanism 13' placed on the central axis of the cathode 1#L pole. In addition, since there are four cylindrical substrates and the deposition area has become wider, it is necessary to adjust the film thickness distribution over a wider range. In conjunction with this, there are eight rows of semicircular metal pipes 12 welded to the atmospheric side wall of the cathode electrode.

The basic operation of each part of the embodiment shown in FIG. 5 is the same, but the base rotation mechanism (3' rotates each base 2^).

2b, 2c, and 2d rotate around their axis and enable uniform film formation.

As explained above, the plasma CVD apparatus according to the present invention reduces the number of raw material gas discharge ports opened in the cathode electrode, and by arranging them in series parallel to the rotation axis of the cylindrical substrate, the film thickness in the rotation axis direction is increased. This has the effect of facilitating distribution adjustment. Furthermore, by opening gas discharge ports with different hole diameters in the hexagonal socket screws attached to the gas discharge ports, the amount of gas released can be adjusted after the rotation axis, making it possible to adjust the film thickness distribution. effective. In addition, each row of raw material gas discharge ports opened to the cathode electrode is equipped with an independent semicircular metal pipe for gas supply, so changes in gas flow due to the opening and closing of gas discharge ports in other rows can be avoided. This has the effect of making it easier to adjust the gas release amount at the same time 1j, that is, adjust the film thickness distribution.

In addition, by using the present invention, it is not only easy to adjust the film thickness distribution, but also improve the uniformity of the deposited film thickness, even when depositing a film on a large area substrate, for which adjustment of the film thickness distribution is complicated using conventional equipment. This has the effect of improving the reproducibility of characteristics, and has the effect of making it possible to mass-produce electrophotographic photosensitive drums, which is one of the purposes for which this apparatus is used, at low cost and stably.

[Brief explanation of drawings]

Figure 1 shows a typical example of a conventional circular plasma CVD device.
FIG. 2 is a partially cut-away perspective view showing an embodiment of the CVD apparatus of the present invention, FIG. 3 is a cross-sectional view of cathode electrical connection, and FIGS. 4 (A) and (B). are hexagon socket head screws that are installed in the gas release holes, and Figure 5 is the plastic X of the present invention.
7 is a partially cut-away perspective view showing a second embodiment of the CVD device; FIG. 1... Cathode electrode 2... Substrate (anode electrode) 3... Wall of vacuum chamber 4... Insulating insulator 5... High frequency power supply 6... Raw material gas supply/f-ve 7 ...Exhaust system 8...Heater 9...Rotation mechanism 10...Earth 11...
・Raw material gas discharge hole 12...Motor] 3...Raw material gas supply pipe 14...Nezu with a discharge port 15...Gas discharge port 1
6... Screw horse 2 figure AA figure without discharge port Figure 4 Figure 5

Claims (4)

[Claims] (1) A vacuum chamber is equipped with a cylindrical electrode and a counter electrode arranged to rotate around the central axis of the vacuum chamber, and raw material gas is released from a number of holes provided in the above electric wire. In a plasma CVD apparatus that sprays raw material gas onto a substrate on the counter electrode to form a deposited film on the substrate, a row of the cylindrical electrodes is formed on the wall surface of the cylindrical electrode parallel to the central axis of the pole. A plasma CVD technology characterized in that a large number of raw material gas discharge holes are opened so as to form a hole, and one gas supply pipe for each row of holes is arranged on the wall surface of the electrode opposite to the counter electrode. . (2) The plasma CVD apparatus according to claim (1), wherein a plurality of cylindrical substrates are arranged in the vacuum chamber so that their central axes are parallel to the central axis of the vacuum chamber. (3) A patent that allows threaded holes to be machined in the holes for blowing the raw material gas, so that when adjusting the thickness distribution of the film deposited on the surface of a cylindrical substrate, unnecessary holes can be closed using a saw. Plasma CVD according to claim (1)
Device. (4) A gas release port is provided at the center of the screw hole that is attached to the screw hole of the reservoir for spraying raw material gas, and a screw with a different hole diameter for the release port is installed in the screw hole to change the amount of gas released. A plasma CVD apparatus '6' according to claim (2), wherein the thickness distribution can be adjusted.