JPS616278A - Plasma cvd device - Google Patents

Abstract

PURPOSE:To form films having uniform quality by vapor deposition on the surfaces of plural drums by ejecting a gaseous raw material from one of plate electrodes on both sides of the drum array and sucking the gas with the other plate electrode in the stage of forming the films by a plasma CVD method on the surfaces of said drums. CONSTITUTION:The plural Al drums 15 heated to a prescribed temp. are installed in a reaction chamber 21 and the plate electrodes 22, 23 are disposed on both sides of the drums 15 in parallel with the array of the drums. The electrodes 22, 23 are connected to the negative electrode of a high-frequency power source and the drums 15 are grounded 10 to provide a negative electrode with respect to the electrodes 22, 23. The gaseous raw material such as gaseous silane is ejected from many gas ejecting ports 24 provided to the electrode 22 and is passed at average density on the outside circumferences of the drums 15 over the entire surface. The gas is sucked through many gas intake ports 25 provided to the electrode 23. The silane is decomposed by the plasma discharge in this state and the amorphous Si films having uniform quality and uniform thickness are formed by vapor deposition on the surfaces of the drums 15.

Description

Detailed Description of the Invention [Technical Field 1] The present invention relates to the production of electrophotographic photosensitive drums, for example, by depositing a film of amorphous silicon or the like on the surface of a cylindrical substrate such as a drum using plasma CVD technology. Regarding a plasma CVD device that can continuously produce, in particular, a plasma CVD device that can appropriately process the raw material gas and uniformly deposit an amorphous silicon film on the drum surface.
It is related to the device.

[Prior art 1] This type of device has a structure similar to a conventional capacitively coupled plasma CVD device if classified based on the electrode arrangement method of the plasma CVD device, but this structure is mainly used for manufacturing photosensitive drums for electrophotography. When applied to a commercial plasma CVD apparatus, the cathode electrode and the anode electrode (drum) are arranged concentrically, which limits the number of drums that can be accommodated and complicates the apparatus structure.

Therefore, in consideration of the above-mentioned problems, in order to create a mass production device for electrophotographic photoreceptor drums that mainly uses amorphous silicon photoreceptor material, the complicated device structure of the conventional example described in L was significantly simplified. By increasing the number of drums that can be stored and improving the electrode arrangement method and shape,
An apparatus has been proposed that advantageously enables mass production of electrophotographic drums and the like and high-speed film formation, which has been difficult with conventional apparatuses.

FIG. 1 shows such a plasma CVD apparatus, and in the figure 1
Reference numeral 5 denotes a drum as a cylindrical base body, which is an aluminum substrate formed into a drum shape so as to form an amorphous silicon film on its surface.

1 is a heating chamber for heating the drum, 2 is a reaction chamber provided following heating chamber 1 and for forming an amorphous silicon film on the surface of drum +5 by plasma CVD method, and 3 is a reaction chamber in reaction chamber 2. A cooling chamber is provided next to the drum for cooling the drum after film formation. These chambers1.
2 and 3 have an airtight structure. 6 rotates a plurality of drums 15 around their axes and holds them upright so that their central axes are on the same plane and parallel to each other, and further includes a drum rotation conveyance mechanism. It is a holding frame.

Reference numeral 4 denotes a pair of heaters arranged in the heating chamber 1 so as to be continuous with the chambers 1, 2 and 3 to the right.

The pair of heaters 4 are arranged upright so as to be parallel to each other, and heat a drum 15 arranged between them so that the arrangement direction is parallel to the heaters 4. Reference numeral 5 denotes an exhaust system provided on one side wall of each chamber and equipped with a filter and baffle for keeping each chamber in a vacuum. A pair of flat electrodes 7 serve as cathode electrodes, and are arranged upright in the reaction chamber 2 so as to be parallel to each other. This pair of electrodes 7 has a double structure for supplying raw material gas,
The drum 15 has a large number of holes over its entire inner surface that ejects gas toward the drum 15, which is arranged so that its arrangement direction is parallel to the electrodes 7, and is further heated by a heater. 8
is a raw material gas supply pipe connected to the outside of the flat electrode 7 for supplying raw material gas into the double structure of the electrode 7;
8 is a power source for supplying high frequency power to the electrode 7 via the pipe 8, and IO is a ground for making the drum 15 held by the holding frame 6 into a 7-node electrode.

A pair of cooling plates 11 are arranged upright in the cooling chamber 3 so as to be parallel to each other. A pair of cooling plates 1
1 has a refrigerant flow path for water or the like inside to cool the drum 15 between which the film formation has been completed. 12 is a refrigerant such as water to be supplied into the cooling plate II; 13 is a gate that isolates each chamber 1, 2 and 3 and is controlled so that the drum 15 is in a flat state when it moves together with the holding frame 6; A valve 14 is a refrigerant valve provided in the exhaust system 5 of the heating chamber 1 and the cooling chamber 3 to return each chamber 1 and 3 to the atmosphere.

The drum 15 fixed to the holding frame 6 enters the heating chamber 1 through the gate valve 13 at the left end in FIG. It is heated by a heater 4. heated drum 1
5 passes through the gate-valve 13 between the chambers 1 and 2 and enters the reaction chamber 2, which is kept in vacuum by the exhaust system 5, together with the holding frame 8. The drum 15 that has entered the reaction chamber 2 is connected to earth 10 and forms a 7-node electrode for a pair of electrodes 7 as cathode electrodes connected to a high frequency power source 8 .

An amorphous silicon film is formed on the surface of the drum 15, which forms an electric field with the electrode 7 and is heated by a heater, by decomposing a source gas such as silane sent from the source gas supply pipe 8 in the plasma. The drum 15 after film formation is placed at the gate φ between the reaction chamber 2 and the cooling chamber 3.
The cooling chamber passes through the valve 13 and enters the cooling chamber 3 kept in a vacuum by the exhaust system 5, is cooled by exchanging heat with the refrigerant 12 via the cooling plate 11, and is returned to the atmosphere by the leak valve 14. 3, passes through the gate ψ valve 13 at the right end in FIG. 1, and is taken out of the cooling chamber s to complete the vapor deposition process.

However, the plasma CVD apparatus having the above configuration has the following drawbacks. That is, FIG. 2 shows a cross section of the reaction chamber 2, and as shown by the arrow in the figure, the raw material gas is ejected toward the drum 15 from the gas ejection holes 7A formed over the entire surface inside the flat electrode 7. The raw material gas ejected from the flat electrode 7 on the right side of the figure is transferred to the drum 1.
5, and is exhausted to the exhaust system 5 through the periphery of the flat electrode 7 on the left side.

On the other hand, the raw material gas ejected from the flat plate-shaped electrode 7 on the left side of the figure comes into contact with mainly the left half circumference of the drum 15, passes around the left side flat plate-shaped electrode 7, and is exhausted to the exhaust system 5.

In this way, in the reaction chamber 2, as shown in FIG. The raw material gas tends to stagnate, and as a result, the density of the raw material gas tends to become uneven around the drum 15, and as a result, the thickness and quality of the amorphous silicon film obtained on the surface of the drum 15 become uneven. Cheap.

[Objective 1] The object of the present invention is to solve the following problems and to provide a plasma CVD apparatus that can form an appropriate flow of raw material gas and obtain a cylindrical substrate such as a drum with uniform film thickness and film quality. It is about providing.

[Example] FIG. 3 is a plan view of the main parts of a plasma CVD apparatus according to an embodiment of the present invention, and FIG. 4 is a sectional view of the main parts of the same apparatus.6 In the plasma CVD apparatus according to the present invention, The structure is similar to that of the plasma CVD apparatus shown in FIG. 1 except for the electrodes in the reaction chamber and the structure for supplying and exhausting raw material gas, so the reaction chamber will mainly be described below.

That is, as shown in FIGS. 3 and 4, in the reaction chamber 21 of the plasma CVD apparatus according to the present invention, a pair of flat electrodes 22 and 23 with flat insides are provided, similar to the conventional flat electrode 7. are placed upright and parallel to each other. One of the flat electrodes 22, like the conventional electrode 7, has a double structure for supplying raw material gas, and has numerous holes 24 for gas ejection over the entire inner surface.
has.

The other flat electrode 23 has a double structure for exhausting raw material gas, and has a large number of holes 25 for gas suction over the entire inside surface.

By appropriately setting the distance between the positions of the holes 24 and 25, the hole diameter, and the number of holes, the density of the raw material gas in the reaction chamber 21 can be made uniform in the axial direction of the drum 15, as will be described later.

A raw material gas supply pipe 26 for supplying raw gas 4 into the double structure is connected to the outside of the flat electrode 22 on the - side, and a raw material gas supply pipe 26 for supplying raw gas 4 into the double structure is connected to the outside of the flat electrode 23 on the other side. The electrodes 22 and 23 are connected to the pipes 23 and 27 to connect the raw material gas exhaust pipe 27 for sucking the raw material gas into the heavy structure through the hole 25 and exhausting it outside the reaction chamber 21.
are connected to the high-frequency electrode 9 through the electrode, and these are used as cathode electrodes.

A heater 4 is attached to the outside of both electrodes 22 and 23.

The raw material gas supply pipe 26 is connected to a raw material gas supply source (not shown), and the raw material gas exhaust pipe 27 is connected to an exhaust device (not shown).

Drum +5 is grounded, making it a 7-node electrode.

The operation of the plasma CVD apparatus of the present invention having the above configuration will be explained next. As shown by the arrows in FIGS. 3 and 4, the raw material gas ejected from the inner hole 24 of one electrode 22 into the reaction chamber 21 toward the drum 5 flows through the pair of flat electrodes 22 and 23. It flows through the space between the drums at right angles to the axial center direction of the drum 15, passes around the drum 15, and is then sucked into the hole 25 inside the other electrode 23.
3 and the reaction chamber 21 via the exhaust pipe 27.
Exhausted outside. In this way, the raw material gas flows through the holes 2 of the electrode 22.
4 and onto the surface of the drum 15.
It contributes to the formation of a silicon film and forms a smooth flow without stagnation along the direction perpendicular to the axis of the drum 15 until it is sucked into the hole 25 of the electrode 23.

As a result, the gas density around the drum 15, especially in the downward direction -L, becomes uniform, and an amorphous silicon film with uniform thickness and quality is formed on the surface of the drum 15.

Note that the gas density in the arrangement direction of the drums 15 can also be appropriately controlled by appropriately setting the spacing and number of the holes 24 for blowing out raw material gas and the holes 25 for suctioning the same gas. I can do it. Therefore, the decomposition efficiency of the raw material gas in the arrangement direction of the drums 15 can also be efficiently controlled.

The processing of the drum 15 in the heating chamber 1 and the cooling chamber 3 is the same as in the conventional case.

Furthermore, in the above embodiment, the pair of electrodes 22 and 23 were both connected to the high frequency power source 8 to serve as the cathode electrode, but it is also possible to use one of these electrodes as the cathode electrode and the other to be grounded without being connected to the high frequency power source 8. Alternatively, it may be used as an anode electrode (the drum 15 is grounded in either case).

[Effect 1] As explained above, according to the present invention, it is possible to efficiently obtain a cylindrical substrate having a film of amorphous, silicon, etc. on the surface, which has uniform film thickness and film quality, and has excellent electrical properties. I can do it. Further, according to the present invention, the gas density in the arrangement direction of the cylindrical substrates can be appropriately controlled.

[Brief explanation of drawings]

FIG. 1 is a schematic plan view of a conventional plasma CVD apparatus for manufacturing electrophotographic photoreceptor drums, FIG. 2 is a longitudinal sectional view of a reaction chamber in the same apparatus, and FIG. 3 is a diagram of the present invention for manufacturing electrophotographic photoreceptor drums. plasma C applied to
FIG. 1 is a plan view showing an embodiment of a VD device. FIG. 4 is a longitudinal sectional view of the reaction chamber in the same apparatus. 15... Drum, 21... Reaction chamber, 22. 23... Flat electrode, 24... Hole for injection of raw material gas, 25... Hole for suction of raw gas 4, 26. ... Raw material gas supply pipe.

Claims (1)

[Claims] A pair of parallel plate electrodes arranged parallel to each other and having a raw material gas ejection part formed inside one and a raw material gas suction part formed inside the other; and a substrate holding means for arranging a plurality of cylindrical substrates between the pair of parallel plate electrodes so as to be located on the same plane parallel to and parallel to each other. Device.