JPS5990629A - Plasma chemical vapor deposition device - Google Patents

Abstract

PURPOSE:To improve the uniformity in the distribution of a film thickness by dividing an evacuation port to plural pieces, and providing a valve for regulating the rate of evacuation to each of the divided evacuation ports. CONSTITUTION:An evacuation pipe is divided by partition plates 301a, 301b to three spaces 302a, 302b, 302c. The respective pipes have many evacuation ports 303, and pipes 304a, 304b, 304c evacuate the gas introduced through the evacuation ports respectively into the spaces 302a, 302b, 302c. Conductance valves are provided between the pipes and pumps so that the rate of evacuation can be independently controlled. The gaseous mixture is introduded, through a gas introducing pipe 205, into a discharge electrode 202, and is released through a gas releasing port 204 toward a base material 201 of a drum. High frequency electric discharge is generated between the material 201 and the electrode 202, whereby an alpha-Si film is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a vacuum evacuation system that includes a discharge electrode, a gas introduction system, an exhaust port, and a base material for forming a thin film.
The present invention relates to a BWOZMA CVD apparatus in which the uniformity of film thickness distribution is improved by dividing an exhaust port into a plurality of parts and equipping each of the divided exhaust ports with an exhaust volume adjusting pulp.

In recent years, there has been active research into thin film devices based on amorphous silicon (hereinafter written as -8j) using the PZM CVD method. Among these, photoreceptors for copying machines are one of the devices that is attracting particular attention.

br Figure 1 shows an example of a conventional α-8i photoconductor manufacturing equipment.
This diagram shows the relationship among the discharge electrode, the photosensitive drum base material, and the exhaust port, and also shows a cross section taken along a plane perpendicular to the central axis of the photosensitive drum.

In the figure, 101 is a photosensitive drum, 102 is a discharge electrode, 103 is a hollow part of the discharge electrode, 104 is a gas discharge port, 105 is a gas introduction pipe, 106 is an exhaust port, and 107i
l-1: Exhaust nob.

In such a system arranged in a vacuum chamber, α-s i is supplied from the gas inlet pipe 105 to the space of the discharge electrode, and the gas necessary for the production, that is, a mixed gas of hydrogen, argon, monosilane, methane, diborane, etc. 103. This gas is discharged from a number of discharge ports 104 to the photosensitive drum base material. At this time, when high frequency discharge is caused between the discharge electrode 102, the photosensitive drum base material 101, and (7) 1143,
Monosilano, methane, and diborane gas are decomposed to produce hydrogen,
A z-s7 film containing carbon and boron is deposited on the surface of the drum substrate 101.

The drum substrate is rotated during deposition to ensure film thickness uniformity. The remaining gas is exhausted by a pump through the air outlet 1.6 and the exhaust pipe 107.

When a large number of photosensitive drums are manufactured using such an apparatus, there is a drawback that sufficient uniformity in film thickness distribution between individual drums and within one drum cannot be obtained.

The reason for this is that the distance from each drum base material to the exhaust pipe 107 and the distance to the gas introduction pipe 105 are different, which causes a difference in the gas flow rate near the drum layer phase, which is caused by a difference in film thickness. It appears.

Further, the distribution of gas in the direction of the center axis of the drum is not necessarily uniform, and this also appears as non-uniformity in the thickness of B within one photosensitive drum.

In the case of a device with 5 wood slots as shown in Fig. 1, if the photosensitive drum is manufactured under normal manufacturing conditions, the film thickness of the photosensitive drum with I grooves on both ends will be larger than that of the photosensitive drum placed in the center. 15
% thinner.

Furthermore, when looking at the film thickness distribution within one photosensitive drum in the direction of the central axis of the cylinder, the variation is about ±5%.

Such a large variation in film thickness distribution is a major problem in mass production, as it causes variation in charging potential.

The present invention eliminates these drawbacks, and its purpose is to improve the uniformity of film thickness.

FIG. 2 is a diagram showing the relationship among the discharge electrode, the photosensitive drum base material, and the exhaust gas in the photosensitive member manufacturing apparatus of the present invention.

Further, FIG. 3 shows the exhaust port portion of FIG. 2 in detail.

In FIGS. 2 and 3, 2o1 is a photosensitive drum base material, 202 is a discharge electrode, 203 is a vacuum chamber, 204 is a gas discharge port, 2o5 is a gas introduction pipe 206 is an exhaust port, and 2o
7 is an exhaust pipe, and 208 is a gap between discharge electrodes.

Further, FIG. 3 shows an example of the JIF vent of the present invention, which is divided into three parts.

In FIG. 3, the exhaust pipe is connected to the partition plate 301at3o.
By xb, three spaces, 3o2a.

It is divided into 302b and 302c. The pipe is divided into three parts, each having a large number of L air ports 303. Vias '304a, 304b, 304C connect spaces 302a, 302b, and 302c, respectively.
This is a pipe for exhausting gas introduced through the exhaust port.

A conductance valve is installed between each pipe and the pump so that the displacement can be controlled independently.

In this device, a mixed gas of monosilane, diborane, methane, hydrogen, and argon is introduced into the discharge electrode 202 through the gas introduction v205.

The discharge electrode 202 has a hollow portion made of two metal plates. The mixed gas introduced into this hollow portion is released from the drum base material 2 through a gas discharge port 204 provided on the inner surface of the electrode.
It is released towards 01.

Furthermore, this gas flows between the discharge electrode gap 208 and the exhaust port 206.
is exhausted through the

At this time, the exhaust port 206 is divided into a plurality of blocks as shown in FIG. 3, and the exhaust amount of each block is controlled independently. That is, the distribution of the gas flow rate can be controlled in the cylindrical axial direction of the photosensitive drum 201.

In this state, high-frequency discharge occurs between the photosensitive drum base material 201 and the discharge electrode 202, and monosilane gas, diborane gas, and methane gas are decomposed and the photosensitive drum profiteer 20
α-si containing carbon, hydrogen, and boron on the surface of 1
A film is formed.

In order to make the film thickness uniform in the circumferential direction within the photosensitive drum, the photosensitive drum base material is rotated around the cylindrical axis.

As can be seen from Fig. 2, the relative position fil relationship from the gas discharge D 204 to the 206 dimension is to which discharge electrode.
The same is true. Therefore, the impedance to the gas flow discharged from each discharge electrode is the same, and the way the gas flows is also the same.

Further, the air opening is also divided into a plurality of parts, and by adjusting the displacement amount of each part, the film ff can be controlled in the direction of the cylindrical axis of the photosensitive drum.

In this device, the flow rate of the mixed gas was set at 200°C for each electrode.
C07m, in, and each electrode was subjected to high-frequency discharge at a power of 500 W for about 4 hours. The α-Si layer of the photosensitive drum obtained was approximately 20 μm, and the variation within the photosensitive drum was approximately ±3 well off in the central axis direction, compared to the conventional ±5
It has improved considerably by %. Further, the variation between photosensitive drums within a lot was within ±8%, which was also about half of the conventional range of ±15.

In this way, the present invention provides a plasma CVD apparatus (
7. The thickness of the VD film is reduced to about half of the conventional one,
This is a very effective device for mass production.

Furthermore, although the above description has been made regarding the a-8i photoconductor, the value of the present invention is not necessarily limited to the α-8i photoconductor, but can also be used for the production of insulating films such as SiO2 and 5J3N4. The scope of application of the present invention is sufficiently wide.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the relationship among a discharge electrode, a photosensitive drum base material, and an exhaust port in a conventional α-S<photoreceptor manufacturing apparatus, and FIG. 2 is a diagram showing the relationship among a discharge electrode, a photosensitive drum base material, and an exhaust port in the photoreceptor manufacturing apparatus of the present invention. Moreover, FIG. 3 is a diagram showing the exhaust port portion of FIG. 2 in detail. 201...Photosensitive drum layer phase 202...Discharge electrode 203.@-vacuum chamber 204..Gas discharge port 205...Gas introduction pipe 206.Fist.Exhaust port 207...Exhaust pipe 208...・Gap between discharge electrodes 301a~b・・Partition plate 302a~C・・Space 303−・・Exhaust port 304α~C・・Vibrator or above Applicant Shikiri Seikosha Co., Ltd. = 15: Figure 3-154-

Claims (1)

[Claims] [1] A discharge electrode, a gas introduction system, an exhaust port in the vacuum exhaust system,
and PWOZMA GV, which has a base material for forming thin films.
The Pwozu 7 CV D device is characterized in that the exhaust port is divided into a plurality of parts, and each of the divided exhaust ports is provided with a displacement adjustment valve. 121. The plasma CV according to claim 1, characterized in that the exhaust port is arranged at the center of the vacuum chamber, and a discharge electrode, a gas introduction system, and a profiteer are arranged around it.
D device.