JPS6043488A - Apparatus for producing thin film - Google Patents

Abstract

PURPOSE:To form a thin film having uniform thickness and quality over the entire part of a base body having a large area by disposing coaxially said base body to be formed thereon with the thin film as the 2nd electrode in a cylindrical body of the 1st electrode, introducing a reactive gas into said body while rotating the base body and generating glow discharge between both electrodes. CONSTITUTION:A cylindrical body 4 provided with many reactive gas introducing holes 6 is placed on an electrically insulated O-ring 3. Said body is used as the 1st electrode and a base body 18 having a large area to be formed thereon with a thin film is disposed as the 2nd electrode and is attached to a revolving shaft 17. A shielding member 19 having a cage-shaped construction is attached in proximity to the outside thereof. The body 18 is heated with a heater 2 and a reactive gaseous raw material is introduced through an introducing pipe 9 into the body 4 under vacuum. The body 18 is rotated around the shaft 17 together with the member 19 and a high frequency voltage is impressed between the body 4 and the body 18 by a power source 22 to generate glow discharge between both bodies and to convert the gaseous raw material into plasma, thereby forming uniformly the thin film on the surface of the body 18.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] Regarding the Mizumoto Amorubachi thin film manufacturing apparatus 1, more specifically, various thin films, such as photoconductive films, semiconductor films, or insulating films, are formed on the surface of a substrate by a glow discharge method. The present invention relates to a thin film manufacturing apparatus with a novel structure that can produce large area thin films with uniform film properties with high reproducibility and mass productivity.

[Technical background of the invention and its problems]

In a deposition chamber under reduced pressure, the raw material gas for thin film formation is decomposed using plasma phenomenon, and the material is formed into a predetermined shape (e.g. drum, plate).
When forming a thin film with desired characteristics on the surface of a substrate by a normal glow discharge method, especially when forming a large-area thin film during the production of an electrophotographic photoreceptor, the total area of the formed thin film is 9. It has been extremely difficult to make the thickness and electrical, optical or photoelectric film properties uniform.

For example, when silane gas (Sin-14) is decomposed by applying discharge energy to form a thin film of amorphous hydrogenated silicon (a-8i:H) on the surface of a substrate, and the electrophotographic properties of this thin film are to be utilized. Since the properties of the thin film largely depend on the plasma conditions during thin film production, in order to obtain uniform electrophotographic properties over the entire area of the thin film formed, it is necessary to It is necessary to generate a uniform plasma.

In particular, in order to prevent the movement of charges injected into the a-8t:H thin film from the substrate side, an electrically insulating charge blocking layer is interposed between the substrate and the a-8t:H thin film, and the In photographic photoreceptors, the thickness of the charge blocking layer is usually very thin, about 5000λ or less. Therefore, in the conventional thin film manufacturing apparatus using the glow discharge method, it is extremely difficult to make the film characteristics uniform and to uniformly generate plasma in the thin film forming area.

In addition, since the thickness of the charge blocking layer is extremely thin,
The fact that the glow discharge has to be stopped before the plasma generated in the endogenous chamber is stabilized, that is, within a short period of time, is another reason why the film characteristics cannot be made uniform.

For this reason, in order to reduce the rate of thin film formation, it is necessary to reduce the flow rate of the raw material gas introduced into the deposition chamber, or to reduce the discharge energy by reducing the high frequency power. is being considered.

However, it has been found that simply considering and selecting such plasma conditions not only leads to a decline in mass productivity during thin film production, but also reduces the charging and charge retention characteristics of the photosensitive layer, especially in the case of electrophotographic photoreceptors. It has been extremely difficult to uniformly form a charge blocking layer on a large area of a substrate surface with good reproducibility.

In addition, the uniformity of the film thickness, the uniformity of the film properties, the arrangement relationship between the electrode and the substrate in the deposition chamber, the structure of the electrode, and the arrangement fMK
It is known to have a significant impact on

However, conventional apparatuses do not necessarily exhibit satisfactory effects in this respect, and are particularly unsatisfactory in terms of reproducibility and mass production in the production of large-area thin films having predetermined characteristics.

[Purpose of the invention]

The present invention solves the above-mentioned problems with the conventional apparatus, and even when manufacturing a large-area thin film, the glow discharge method can produce a thin film with substantially uniform film thickness and film properties over the entire surface with good reproducibility. The object of the present invention is to provide a thin film manufacturing apparatus that can be manufactured with high mass productivity.

[Summary of the invention]

The apparatus of the present invention has a deposition chamber that can be depressurized and has a raw material gas inlet on the wall surface; it is fixed to a rotatable base fixing member installed in the deposition chamber, and the surface thereof is parallel to the inner wall of the deposition chamber. a base body disposed in; a rotatable shielding member having a plurality of openings in the wall surface, electrically connected to the base body, and disposed coaxially surrounding the base body; At least a part of the wall surface of the deposition chamber is a first electrode, and at least one of the substrate identification member, the substrate, or the shielding member is a second electrode.

The device of the present invention will be explained in more detail with reference to a longitudinal sectional view schematically showing a preferred embodiment of the device.

In the figure, 1 is a deposition chamber. The deposition chamber 1 has a cylindrical body 4 placed on a base plate 2 with an electrically insulating O ring 3 interposed therebetween, which has a structure used in a normal glow discharge deposition apparatus, and an O ring placed on top of the base plate 2. It is assembled airtight by the M5 mounted through the /g 3'. In the device of the present invention, the cylindrical body 4 serves as the first electrode.

A plurality of gas inflow ports 6, 6' having a predetermined conductance are bored in the side wall surface of the cylinder 4, and an annular gas inflow chamber 7 is provided on the outer periphery of these ports. A gas introduction pipe 9 provided with a pulp 8 for adjustment is provided. A mixed gas with a raw material gas for forming a thin film or a diluent gas is supplied at a predetermined flow rate from the gas entry tube. 10
, 11 and 12 are exhaust pipes for exhausting the inside of the deposition chamber 1, and the pulp 13, 14, and 15't (Ni) are exhaust pipes, respectively. A rotating shaft 1 that is a fixed member and extends airtightly outside the deposition chamber 1.
It can be rotated in forward and reverse directions by a drive device (not shown) via a 7'ft.

A base 18 on which a desired thin film is to be formed on the front side n1 of the fixing member 16 is fixed. At this time, the base 18
must be arranged so that its surface is parallel to the inner wall of the cylinder 4. The base body 18 thus undergoes the same rotational movement as the fixed member 16.

19 is a shielding member having a forged structure, for example, having a plurality of openings (slits arranged regularly in the figure) in the wall surface, and
8 is substantially completely coaxially encased. This shielding portion is provided to form a uniform thin film over the entire surface of the substrate.

The shielding member 19 is connected to a drive device (not shown) via a rotating shaft 20, and can freely rotate once in forward and reverse directions. The shape of the opening is not particularly limited, and may be appropriately designed such as a circular hole or a square hole◇ Also, when covering the base 18 with the shielding member 19, the inner wall of the shielding member 19 and the outer wall of the base 18 (the surface on which the thin film is to be formed) are preferably placed in contact with each other or in close proximity to each other with a small gap therebetween.

If the gap between the two becomes large, there is a tendency that a uniform thin film cannot be formed over the entire area of the base 18, which is disadvantageous.

In this case, the important thing in the device of the present invention is that the base 18
In order to prevent plasma fluctuations due to rotational movement between the base body 18 and the shielding member 19 and to form a uniform thin layer over the entire area of the base body, an electrical connection is provided between the base body 18 and the shielding member 19 by using, for example, a brush. , and hold both at the same potential.

In the present invention, at least one of the fixing member 16, the base 18, and the shielding member 19 functions as the second electrode.

A heater 21 maintains the substrate 18 at a predetermined temperature during or before and after forming the thin film. Still 2
Reference numeral 2 denotes a high frequency power source connected to the cylinder (first electrode) 4 via a coaxial cable 23, which generates glow discharge within the deposition chamber l.

The device u of the invention operates as follows.

First, 'on the surface' if necessary? Purify i'7
The base body 18 is placed on the fixing member 16 and fixed. Next, the base body 18 is covered with the shielding member 19. At this time, they are brought into contact with each other so that they are at the same electrical potential. Thereafter, the O-ring 3 and the cylindrical body 4.0-ring 3' are stacked on top of each other, and finally the lid 5 is put on to assemble the device.

Next, with all pulps closed, first pulp 1.
3 and exhaust the air from the exhaust pipe 10 to bring the inside of the deposition chamber 1 to a predetermined degree of vacuum, and then close the pulp 13. The pulp 14 is opened, and the pulp 8 is opened, and a mixed gas with the raw material gas or diluting gas is flowed from the introduction pipe 9 into the gas inflow part 7, and the mixture gas is poured into the deposition chamber 1.
Bring the internal pressure to the specified level.

The heater 21 maintains the base 18 at a predetermined temperature, the base 18 and the shielding member 19 are rotated at a predetermined number of rotations, and the power supply 22 is activated to connect the cylindrical body (first electrode) 4 and the base (second electrode). The source gas is turned into plasma by causing a glow discharge. After thin film production, turn on the power and stop the gas supply.
Open the leak pulp 15 and return the inside of the deposition chamber 1 to normal pressure to complete the entire operation. For example, the diameter is 130 m! ! ! In order to form an oxide thin film of charge blocking and (21, a-8i:■I) on the surface of an aluminum shin drum for an electrophotographic photoreceptor with a height of 340 fJ, a total of 1 m of silane was added in chamber 1. While maintaining the temperature at O.1 Torr with a gas mixture with oxygen (to:i in volume ratio) and applying a high frequency voltage of 13.56 MHz between the cylinder 4 and the drum 18, the drum was heated at 16 rpm with an electric shielding member. 19 was rotated in the opposite direction at 7 rpm and operated for about 6 minutes, a thin film of about t,ooo thick was formed on the surface of the drum.The film forming rate was 160 to 100 min.The thickness of this thin film was determined by the thickness of the drum. When measured over the entire area, the thickness error was ±2.0
'A was very uniform. Furthermore, when a photoreceptor was made from the obtained drum, its characteristics as a photoreceptor were measured and found to be very good, with no variation in characteristics depending on location.

〔Effect of the invention〕

As is clear from the above explanation, even if the substrate has a large surface area, the apparatus of the present invention can provide a thin film with uniform thickness and film properties over the entire surface area, and moreover, Since it can be obtained at a relatively high production speed, it is suitable for mass production and has great industrial value.

[Brief explanation of the drawing]

The figure is a polar diagram showing one example of the device of the present invention. l...Deposition chamber, 2...Pace plate, 3, 3'.
...0 ring, 4... cylinder (first electrode), 5... l
(, 6, 6'... Gas inlet, 7... Gar inlet chamber,
8,13,14.15...Pulp, 9...Gas introduction pipe, 10,11.12...Cedar gas 1゛varnish, 16...
・Base fixing member, 1.7, 20... Rotating shaft, 18.
... Base body, 19 ... Shielding member, 21 ... Heater, 2
2...High frequency power supply, 23...Coaxial cable.

Claims (1)

[Scope of Claims] A depressurizable deposition chamber having a raw material gas inlet on the wall surface; fixed to a rotatable base fixing member installed in the deposition chamber so that the surface thereof is parallel to the inner wall of the deposition chamber. A rotatable shielding part having a plurality of openings in the wall surface, electrically connected to the base body, and coaxially enclosing the base body; A thin film manufacturing apparatus characterized in that at least a part of the wall surface of the deposition chamber is a first electrode, and at least one of the substrate fixing member, the substrate, or the shielding part is a second electrode.