JP3061852B2 - Apparatus for forming a deposited film by microwave plasma CVD - Google Patents

Description

Description: TECHNICAL FIELD The present invention is useful for functionally deposited films, particularly semiconductor devices, electrophotographic photoreceptor devices, image input line sensors, imaging devices, photovoltaic devices, etc. The present invention relates to an improved apparatus for forming a deposited film by microwave plasma CVD of a highly crystalline or amorphous functional deposited film.

[Description of conventional technology]

Conventionally, semiconductor devices, photoreceptor devices for electrophotography,
As an element member used for an image input line sensor, an imaging device, a photovoltaic device, other various electronic elements, optical elements, etc., amorphous silicon, for example, hydrogen or / and halogen (for example, fluorine, chlorine, etc.)
Amorphous silicon compensated by [A-Si (H,
X)) or a monocrystalline deposited film such as a diamond thin film, some of which have been put to practical use.

Such a deposited film is decomposed by a plasma CVD method, that is, a raw material gas is decomposed by direct current or high frequency or glow discharge by microwave, and the deposited film is formed on a substrate such as glass, quartz, heat-resistant synthetic resin film, stainless steel, and aluminum. It is known that it is formed by a forming method, and various apparatuses have been proposed.

Especially, plasma using microwave glow discharge decomposition in recent years
The CVD method, that is, the microwave plasma CVD method has attracted industrial attention.

The microwave plasma CVD method has the advantages of a higher deposition rate and higher source gas utilization efficiency than other methods. Microwave plasma CV taking advantage of these advantages
One example of the D apparatus is described in JP-A-60-186849. The device described in the above publication is, in general, arranged so as to surround a means for introducing microwave energy so as to form an internal chamber (that is, a discharge space) so as to enhance gas utilization efficiency. . Japanese Patent Application Laid-Open No. 63-69980 discloses that a microwave transmission window is divided into a plurality of layers in a microwave transmission direction and laminated to have a function of adjusting a resonance frequency of the microwave transmission window, thereby providing a microwave transmission window. A technique for reducing reflection loss is disclosed. Furthermore, Japanese Patent Application Laid-Open No. 63-147581 discloses that the surface of the microwave transmission window inside the reactor is made rough to maintain a high microwave transmittance for a long time and maintain a stable glow discharge. To disclose the technology.

These conventional methods make it possible to produce a relatively thick photoconductive material with a relatively high deposition rate and a high source gas utilization efficiency. Such a conventional deposition film forming apparatus using a microwave plasma CVD method, for example, in the case of manufacturing a cylindrical electrophotographic photosensitive member, typically,
A schematic longitudinal sectional view of FIG. 2 (A) and a schematic transverse sectional view of FIG. 2 (B) [FIG. 2 (B) is a schematic cross-section of a plane shown in FIG. 2 (A). Plan view].

2A and 2B, reference numeral 201 denotes a reaction furnace, which has a vacuum tight structure. Also, 202
The microwave transmission window is made of a material (for example, quartz glass, alumina ceramics, or the like) capable of efficiently transmitting microwave power into the reaction furnace and maintaining vacuum tightness. Reference numeral 203 denotes a microwave power transmission unit which is formed of a waveguide and is connected to a microwave power supply (not shown) via a stub tuner (not shown) and an isolator (not shown). The microwave transmission window 202 is hermetically sealed to the wall of the waveguide 203. Reference numeral 204 denotes an exhaust pipe having one end open into the reaction furnace 201 and the other end communicating with an exhaust device (not shown). Reference numeral 206 denotes a discharge space formed by being surrounded by the plurality of cylindrical substrates 205. Each of the cylindrical substrates is placed on a cylindrical holder containing a heater 207, and each holder can be appropriately rotated by a driving means (rotary motor) 210.

Next, FIG. 4 is a view for explaining in detail the conventional microwave introduction part in this device. In the figure,
Reference numeral 401 denotes an outer tube of the waveguide, 402 and 402 'denote dielectric windows having a two-layer structure, and 403 denotes a ring for vacuum sealing. It functions to keep the reactor and the dielectric window airtight. 405 is the inside of the reactor (microwave plasma space), 404 is the inner tube of the waveguide that functions to fix the dielectric window on the atmosphere side, and 407 is the jig that fixes the dielectric window 402 'on the vacuum side (Hereinafter referred to as a microwave transmission window holder), 406 indicates a microwave.

In the conventional deposited film forming apparatus shown in FIG. 2 having a microwave transmitting window shown in FIG. 4, the deposited film is formed as follows.

First, the reactor 201 is evacuated by a vacuum pump (not shown) through the exhaust pipe 204, and the pressure in the reactor, that is, the internal pressure is adjusted to about 1 × 10 ⁻⁷ Torr or less. Then heater 20
According to 7, the cylindrical substrate 205 is heated and held at a temperature suitable for film deposition. Therefore, in the case of forming a deposited film of, for example, A-Si (H, X) through a gas introduction pipe (not shown), the raw material gas such as silane gas (SiH ₄ ) and hydrogen gas (H ₂ ) is used. Is introduced into the reaction furnace 201. Simultaneously therewith, a microwave having a frequency of 500 MHz or more, preferably 2.45 GHz is generated by a microwave power supply (not shown) and introduced into the reactor 201 through the microwave waveguide 203 and the dielectric window 202. I do. Thus, in the discharge space 206 formed by being surrounded by the plurality of cylindrical substrates 205, the source gas is excited by microwave energy and dissociated, and a deposition film is formed on the surface of all the cylindrical substrates 205. Becomes
At this time, by rotating all the cylindrical substrates 205 in the circumferential direction of the substrates by the rotating motor 210, a deposited film is formed on the entire surface of each cylindrical substrate.

According to such a conventional deposition film forming apparatus using a microwave plasma CVD method, it is possible to obtain a deposition film having practical characteristics and uniformity with a certain thickness.
However, in these conventional deposited film forming apparatuses by the microwave plasma CVD method, particularly for the production of devices requiring a relatively large thickness such as an electrophotographic photoreceptor, a device requiring a thick film is required. There is a problem that considerable skill is required to constantly and stably obtain a product having a uniform film quality and a small number of image defects (charge-defective regions caused by spherical protrusions) at a high yield (high yield).

One of the factors that affect the yield of an electrophotographic photoreceptor is an image defect due to empty projections. The resistance at the boundary between the spherical projections is reduced, and the charging ability is reduced. For this reason, in the electrophotographic photosensitive member, image omission occurs. Also,
In the electrophotographic process, there is a step of rubbing a cleaning blade against the photoconductor and scraping off the toner in order to remove the toner remaining on the photoconductor after the image is transferred to paper. When a large number of spherical projections are present, there arises a problem that the durability of the cleaning blade is significantly reduced.

It has been confirmed that dust, such as dust and dirt, adhering to the deposition surface triggers the growth of the spherical projections and starts to grow. For this reason, the substrate before film formation is precisely cleaned, and set in a reaction furnace in a dust-controlled environment such as a clean room, so that dust adheres to the substrate as much as possible. However, dust that causes spherical projections is not limited to dust that has adhered to the substrate before the start of film formation. In the first place, in an electrophotographic photoreceptor using A-Si (H, X), the thickness of the deposited film is usually about 30 to 50 microns in order to improve the charging ability. Since A-Si (H, X) has a large internal stress, when the film thickness is large, the film often peels without being able to withstand the stress. In the current electrophotographic photoreceptor, in order to prevent film peeling, a countermeasure is provided by providing an adhesion layer between the base and the functional film, or adjusting the stress by doping various elements. Further, the temperature of the substrate is optimized and the surface is mirror-finished to improve the adhesion of the deposited film.
However, the deposited film is not deposited only on the substrate, but also adheres to the structure of the reaction furnace, for example, the inner wall of a vacuum chamber or a microwave transmission window. These structures are much more easily peeled off because the temperature is not optimized and the surface properties are not controlled as in the case of the base. In particular, in the apparatus shown in FIGS. 2 (A) and 2 (B), since the film formation space is surrounded by a cylindrical substrate, the influence of peeling of the film on the inner wall of the reaction furnace is small, but the microwave is not affected. Since the transmission window is close to the substrate, the effect of peeling therefrom is very large.
Further, in the case of a cylindrical substrate, since a film is formed over the entire circumference while rotating the substrate, when a film of 30 to 50 microns is deposited on the substrate, the microwave transmission window which is stationary has a 3 As a result, a film having a thickness of about 4 times, that is, as large as 100 to 200 microns is deposited, and the film is very easily peeled.

For this reason, in the conventional deposited film forming apparatus, the dielectric window on the reactor side of the microwave transmitting window has to be replaced with a new one every time a film is formed, and the dielectric window can be easily attached and detached. It must be possible to divide in the microwave transmission direction. Further, even if a new dielectric window is used, the deposited film is easily peeled off from the microwave transmitting window during film formation, and there is a problem that it is difficult to improve the yield.

[Object of the Invention] An object of the present invention is to overcome the above-described problems in the conventional deposition film forming apparatus, and to provide a semiconductor device, an electrophotographic photoconductor device, an image input line sensor, an imaging device, and a photovoltaic device. Microwave plasma-enhanced functional deposition films with excellent properties useful for devices, device elements used for various electronic elements, optical elements, etc.
It is an object of the present invention to provide an improved deposited film forming apparatus which can be formed stably with a high yield by the method.

Further, an object of the present invention is to reduce image defects in an electrophotographic photosensitive member by suppressing generation of dust due to peeling of a deposited film during film formation and reducing abnormal growth (spherical projections) of the deposited film. Along with improving the durability of the cleaning blade installed inside the copier, the substantial quality of the electrophotographic photosensitive member is improved,
The purpose is to increase the yield of good products.

[Structure and effect of the invention]

The deposition film forming apparatus of the present invention has a substrate holding means inside a reaction furnace, is provided with a raw material gas supply means and an exhaust means, and allows passage of a microwave from a microwave power supply into the reaction furnace. An apparatus for forming a functional deposition film by a microwave plasma CVD method, wherein the microwave transmitting window allows a part of a wall of the reaction furnace, wherein the microwave transmitting window is detachable by at least two. A dielectric laminated window in which at least one dielectric is deposited, the dielectric laminated window having a surface exposed in the reactor, and the dielectric laminated window is fixed by a fixing member on the side of the reactor. The surface of the fixing member is continuous with the exposed surface of the dielectric laminated window without any step, and the exposed surface of the dielectric laminated window and the surface of the fixing member are rough. Surface.

The present inventors conducted the following experiment to overcome the above-mentioned problems in the conventional method and apparatus for forming a deposited film and achieve the above object.

Experiment A-Si was fabricated using the deposition apparatus shown in FIGS. 1 (A) and 1 (B) and the conventional microwave transmission window shown in FIG.
(H, X) Created a drum. Film formation follows the conventional method,
Gas flow rate and other parameters are as shown in Table 1.
A total of 30 lots were created. However, in each lot,
By changing the flow rate of the H ₂ gas from 0 to 1000 sccm, the easiness of peeling of the deposited film is changed. For this reason, although film peeling of the photoreceptor itself was not seen, film peeling was sometimes seen from the microwave transmission window in the film forming furnace. At this time, the degree of film peeling of the microwave transmission window and the level of image defects were classified into 0 to 5 levels, and the correlation was examined. The results are shown in FIG. From this result, it is understood that as the film peeling from the structure increases, the level of the image defect also deteriorates in proportion thereto.

The following summarizes the experimental results and the results of observing the microwave transmission window in more detail.

The image defect worsens as the degree of film peeling from the microwave transmitting window increases.

The portion of the microwave transmission window where the film has been peeled off is particularly large in the concave portion inside the microwave transmission window retainer fixing the dielectric window on the reaction furnace side.

When the surface of the dielectric window is observed with an optical microscope, huge spherical projections are densely formed, and there are portions that have dropped off in some places.

The reason is considered as follows. In an A-Si (H, X) device using a microwave plasma CVD method, the stress of the film itself is adjusted in order to deposit a thick film on a substrate without peeling off the film. This is performed, for example, by doping the film with boron, oxygen, or another element. Since an electrophotographic photoreceptor usually uses a cylindrical substrate, it is adjusted so as to minimize the stress when deposited on a convex portion. This means that the stress in the film deposited in the concave portion is the largest. For this reason, the concave portion inside the microwave transmission window holder is most easily peeled off.

As described above, in the conventional deposited film forming apparatus, the surface is roughened in order to improve the adhesion of the deposited film deposited on the microwave transmission window and obtain stable microwave transmission characteristics. ing. Generally, in order to roughen the surface of a ceramic dielectric window having high hardness, the surface is polished with an abrasive such as an irregular ceramic or metal, or similarly, is blasted by blowing an irregular projection material at a high pressure. It is. In this method, since the polishing is performed using irregular ceramic particles or metal powder, a part of the abrasive is often dropped and cut into the surface of the dielectric window. For this reason, these foreign matters became a nucleus and spherical projections grew. In particular, since the thickness of the film deposited on the dielectric window is three to four times as thick as that of the cylindrical substrate, the spherical projections also grew enormously, and some of them seemed to fall off without being able to withstand the stress. It is considered that such a detachment of the spherical projection causes dust to be generated because the surrounding film is also peeled off at the same time, thereby causing the spherical projection.

From the above considerations, the present inventor has concluded that it is essential to prevent film peeling from the microwave transmitting window in order to eliminate structural defects such as spherical protrusions in a device requiring a thick deposited film. For this purpose, it is necessary not only to simply roughen the surface of the microwave transmission window, but also to control the surface to a shape that does not cause abnormal growth. It was found that it was necessary to eliminate the step with the body window.

As a result of studying the optimal surface treatment method for this purpose, it is found that the best method is to use spherical beads as the blast material and blast them mechanically or blow them with compressed air at high pressure. There was found. As a result of detailed observation of the surface properties of the microwave transmitting window roughened by blasting using this spherical projection material with an optical microscope, a spherical depression was formed, and it was like a surface polished with an irregular abrasive. No abrasive residue was observed. After forming the film through the microwave transmission window finished by this method, when the surface and cross section are observed with an optical microscope, no peeling or huge spherical projections are seen, and the spherical structure is well developed from the cross section observation. It has been found. Furthermore, as a result of examining the size of the formed spherical depression, when the product of the depth D of the depression and the curvature R: D × R is too small, the surface roughness decreases and the film is easily peeled. Therefore, in the present invention, 0.2 ≦ D × R is suitable.

The microwave transmission window according to the present invention not only suppresses peeling of the deposited film, but also has an unexpected effect of stabilizing the plasma state.

We currently consider the reason for this as follows. In the conventional deposited film forming apparatus, the edge portion of the microwave transmission window retainer was located very near the strong electric field region through which the microwave was transmitted. The plasma tends to concentrate on such an edge portion, and thus tends to cause abnormal discharge, which makes the discharge unstable. In the microwave transmission window according to the present invention, since such an edge portion does not exist in the structure,
It seems that the discharge was stabilized as a secondary effect.

Hereinafter, the microwave transmission window of the deposited film forming apparatus according to the present invention will be described in detail with reference to FIGS. 1 (A) and 1 (B). In the drawing, reference numerals 101 to 107 are exactly the same as those described in the conventional apparatus diagram (FIG. 4). The components that characterize the present invention are a dielectric window 102 'and a microwave transparent window retainer 107. The surfaces of the dielectric window 102 'and the microwave transmission window retainer 107 are formed by blowing spherical beads at a high pressure with compressed air to form spherical depressions on the surface. Further, in the case of the microwave transmission window holder 107A, the tapered portion of the
A 'is pressed against the atmospheric side dielectric window 102, the microwave transmission window retainer 107 and the dielectric window 102A' do not form a step, and the surface on the reactor side is aligned and does not form a recess. It has become.

FIG. 1 (B) is a different specific example having the same effect. Here, a notch is formed in the reactor-side dielectric window, and a microwave transmission window holder 107B that fits exactly into the notch
And no steps are formed on the reaction furnace side.

As the material of the microwave transmission window retainer in the present invention, if it is a metal, stainless steel, Al, Cr, Mo, Au, Nb,
Anything can be used, such as Te, V, Ti, Pt, Pd, and Fe. Also,
Alumina (Al ₂ O ₃ ), aluminum nitride (AlN), boron nitride (BN), silicon nitride (SiN), silicon carbide (SiC), silicon oxide (SiO ₂ ), beryllium oxide (BeO), glass, quartz, etc. Ceramic materials, polymer materials such as Teflon, polyimide, and polycarbonate can also be used.

The material for the microwave introduction window in the present invention is alumina (Al ₂ O ₃ ), aluminum nitride (AlN), boron nitride (BN), silicon nitride (SiN), silicon carbide (SiC), silicon oxide (SiO ₂ ). ), Beryllium oxide (BeO), Teflon, polystyrene, and other materials that are less susceptible to microwave damage.

As the material of the projection material in the present invention, if it is spherical, alumina (Al ₂ O ₃ ), aluminum nitride (AlN), boron nitride (BN), silicon nitride (SiN), silicon carbide (SiC), silicon oxide (SiO) ₂ ), beryllium oxide (BeO), glass, silica sand,
Ceramic materials such as quartz, stainless steel for metal, A
Any material such as l, Cr, Mo, Au, Nb, Te, V, Ti, Pt, Pd, and Fe can be used.

In the present invention, a method for roughening a dielectric window may be a method of hitting a spherical projection material such as a centrifugal projection blasting machine, a dry or wet air blasting machine, a belt blasting machine, and the like. Anything can be used.

The method of heating the substrate in the present invention may be any heating element having a vacuum specification, and more specifically, a winding heater of a sheath heater, a plate heater, an electric resistance heating element such as a ceramic heater, a halogen lamp, A heat radiation lamp heating element such as an infrared lamp, a heating element using a liquid, a gas, or the like as a heating medium and a heat exchange unit may be used. As the surface material of the heating means, metals such as stainless steel, nickel, aluminum, and copper, ceramics, heat-resistant polymer resins, and the like can be used. In addition, other methods can be used, such as providing a heating-only container other than the reaction furnace, heating, and then transporting the substrate in a vacuum in the reaction furnace.

In the present invention, the source gas for the deposited film is, for example, an A-Si (H, X) forming source gas such as silane (SiH ₄ ) or disilane (S ₂ iH ₆ ), germane (GeH ₄ ), or methane (CH ₄ ). And other functional deposited film forming raw material gases or a mixed gas thereof. Hydrogen (H ₂ ), argon (A
r), helium (He) and the like. In addition, as a characteristic improving gas for changing the band gap width of the deposited film, an element containing a nitrogen atom such as nitrogen (N ₂ ) and ammonia (NH ₃ ), oxygen (O ₂ ), nitrogen oxide (NO), and oxide Dinitrogen (N2
O) Elements containing oxygen atoms, such as methane (CH ₄ ) and ethane (C ₂
H _5), ethylene (C ₂ H _4), acetylene (C ₂ H _2), hydrocarbons such as propane (C ₃ H _8), silicon tetrafluoride (SiF _4), disilicon hexafluoride (Si ₂ F _5), germanium tetrafluoride (GeF ₄₎
And a mixed gas thereof.
Further, the present invention is similarly effective when dopant gases such as diborane (B ₂ H ₅ ), boron fluoride (BF ₃ ), and phosphine (PH ₃ ) are simultaneously introduced into the discharge space for doping.

As the base material, for example, stainless steel, Al, Cr, M
Metals such as o, Au, Nb, Te, V, Ti, Pt, Pd, Fe, alloys of these or synthetic resins such as polycarbonates whose surfaces are conductively treated, glass, ceramics, paper, etc. are usually used in the present invention. .

Although the substrate temperature at the time of forming a deposited film in the present invention is effective at any temperature, when depositing A-Si (H, X), it is 20 ° C. or more.
00 ° C or lower, preferably 50 ° C or higher and 450 ° C or lower is preferable because a good effect is exhibited.

Further, the present invention relates to a photoconductor for a copying machine such as a blocking type A-Si (H, X) photoconductor, a high resistance type A-Si (H, X) photoconductor, or a photoconductor for a printer, which has good electrical characteristics. It can be applied to the fabrication of any other device that requires a functional deposited film.

The present invention can be applied to any device using microwaves. In particular, a device having a structure in which a base is provided so as to surround a discharge space and microwaves are introduced from at least one end of the base by a waveguide. Has a great effect on

An example of a procedure for actually forming a deposited film using the apparatus of the present invention as described above is shown in FIGS. 1 (A) and 1 (B), a microwave introduction window, and a second ( A) FIG. 2
(B) Description will be made below using the deposited film forming apparatus shown in the figure.

First, the inside of the reaction furnace 201 is evacuated by a vacuum pump (not shown) through the exhaust pipe 204, and the pressure in the furnace, that is, the internal pressure is adjusted to about 1 × 10 ⁻⁷ Torr or less. Next, all the cylindrical substrates 205 are heated and maintained at a temperature suitable for film deposition by the heater 207. In the case where, for example, an A-Si (H, X) film is formed through a gas introducing means (not shown), the raw material gas such as silane gas (SiH ₄ ) and hydrogen gas (H ₂ ) is supplied. It is introduced into the reactor 201. Simultaneously therewith, a microwave power supply (not shown) generates a microwave having a frequency of 500 MHz or more, preferably 2.45 GHz, and reacts the microwave through a waveguide 203 and a dielectric window 202. It is introduced into the furnace 201. Thus, a plurality of cylindrical substrates 205
In the discharge space 206 formed by being surrounded by, the source gas is excited by microwave energy and dissociated, and a deposited film is formed on the surface of all the cylindrical substrates 205. At this time, by rotating all the cylindrical substrates in the circumferential direction of the substrate, a deposited film is formed on the entire surface of each cylindrical substrate.

In the above, only the deposition film forming apparatus having a cylindrical base has been described in detail, but the formation of the base is not limited to this. It is needless to say that the device can be suitably used, for example, in an apparatus configuration as shown in FIG. That is, in FIG. 3, reference numeral 301 denotes a reaction furnace, 302 denotes a microwave transmission window, 303 denotes an introduction wave tube, 304 denotes an exhaust pipe, 305 denotes a flat base, 306 denotes a discharge space, and 307 denotes a heater (not shown). 308 is a gas introduction tube. The feature of this device is that the substrate is not cylindrical but flat. The deposition film formation by the deposition film forming apparatus shown in FIG. 3 is performed as follows. That is, the pressure inside the reaction furnace is reduced to 1 by an exhaust device (not shown).
Exhaust to about ^10-7 Torr or less. Next, the substrate holder 30
The heater (not shown) built in 7 is energized to heat and maintain the temperature of the planar substrate 305 at a temperature suitable for film deposition.
In the case of forming an amorphous silicon deposition film, for example, a source gas such as a silane gas (SiH ₄ ) or a hydrogen gas (H ₂ ) is introduced into the reaction furnace via the source gas introduction pipe 308. At the same time, power is supplied to a microwave power supply (not shown) to generate microwaves having a frequency of 50 MHz or more, preferably 2.45 GHz, and the microwaves are introduced into the reactor 301 through the waveguide 303 and the dielectric window 302. Introduce wave energy. Thus, the raw material gas in the reaction furnace 301 is excited and dissociated by the energy of the microwave, and a deposited film is formed on the substrate surface.

〔Example〕

Hereinafter, the present invention will be described specifically with reference to Examples and Comparative Examples, but the present invention is not limited thereto.

Example 1 A microwave transmitting window shown in FIG.
(A) Using the deposited film forming apparatus shown in FIG. 2 and FIG.
A Si (H, X) photosensitive drum was created. The surface roughness of the dielectric window was adjusted to 0.5: product of depth D and curvature R: D × R. The preparation method followed the method of the present invention.

As a result, film formation from the microwave transmission window holder and the dielectric window did not occur, and the film formation was completed successfully. Further, the produced A-Si (H, X) photosensitive drum is transferred to a Canon copier N
P-7550 was incorporated into a device modified for experiments and evaluated as follows.

Charging ability: A copying machine is equipped with an aluminum cylinder on which a deposited film is formed, and the surface potential at the center of the drum under a constant charge is measured while rotating the drum. The charging ability of each of the plurality of photosensitive drums formed in one film forming step was determined, and the average was taken.

Sensitivity: Charged in the same manner as above, and measure the surface potential under a constant exposure. The sensitivity of each of the plurality of photosensitive drums formed in one film forming process is obtained. According to the above-described method, a total of six photosensitive drums were measured for one film forming process, and an average was obtained.

Image defect: A black image is displayed on the entire surface, and the number and size of white spots are checked. Judgment of 感光 to × for one photosensitive drum, a total of 6
Average the number of photoreceptors.

Durability of cleaning blade: The copying machine was operated continuously, and the number of copies until a cleaning failure due to damage to the cleaning blade occurred was measured.

Comparative Example 1 The microwave transmission window shown in FIG. 4 and FIG.
Using the deposited film forming apparatus shown in FIG. 2B, an A-Si (H, X) photosensitive drum was prepared under the conditions shown in Table 1. The surface of the dielectric window was blasted with an irregular ceramic projection material. After the film formation, when the surface of the dielectric window was assisted by an optical microscope, a large number of spherical projections were densely formed and a part of the projection was observed. Slight peeling was also observed from the inner projection of the microwave transmission window holder. The photosensitive drum thus manufactured was evaluated in the same manner as in Example 1 using an apparatus obtained by modifying a Canon copier NP-7550 for an experiment.

Table 2 shows the results of Example 1 and Comparative Example 1 together. As shown in the table, good results were obtained in the present invention particularly in "image defects" and "durability of the cleaning blade", and the electric characteristics of the photosensitive drum were also improved by the effect of discharge stability.

Example 2 The microwave transmitting window shown in FIG.
Using the deposition film forming apparatus shown in FIGS. 2A and 2B, an A-Si (H, X) photosensitive drum was prepared under the conditions shown in Table 1. Then, when a comparison was made with Comparative Example 1 in the same manner as in Example 1, the same results as in Example 1 were obtained.

Example 3 The microwave transmitting window shown in FIG.
(A), using the deposited film forming apparatus shown in FIG. 2 (B),
An A-Si (H, X) photosensitive drum was prepared under the conditions shown in Table 1. However, at this time, the surface roughness: D × R was controlled to 0.1 to 1. At this time, the same evaluation as in Example 1 was performed together with the evaluation of the state of the microwave transmission window provided with the film. Table 3 shows the results. From this result, it can be seen that a good photosensitive drum can be obtained when D × R is 0.2 or more.

Example 4 The microwave transmission window shown in FIG.
An experiment similar to that of Example 3 was performed using the deposited film forming apparatus shown in FIG. 2A and FIG. 2B, and a result having no difference from Example 3 was obtained.

Example 5 and Comparative Example 2 Example 5 A-Si under the conditions shown in Table 4 using the microwave transmission window shown in FIG. 1A and the deposited film forming apparatus shown in FIG.
(H, X) film was deposited on an aluminum substrate to prepare a sample. After the film formation, the surface of the sample was observed with an optical microscope, and the number of spherical projections was measured. Further, the electrical characteristics of the obtained sample were evaluated.

Comparative Example 2 The microwave transmission window shown in FIG. 4 and the deposited film forming apparatus shown in FIG.
X) The film was deposited on an aluminum substrate. Then, the same evaluation as in Example 5 was performed.

Table 5 shows the evaluation results of Example 5 and Comparative Example 2 together. In the deposited film using the microwave transmission window according to the present invention, good results were obtained in both the defect and the electrical characteristics of the deposited film.

Example 6 The same experiment as in Example 5 was performed using the microwave transmitting window shown in FIG. 1A and the deposited film forming apparatus shown in FIG. Comparing the results with Comparative Example 2, the same results as in Table 5 were obtained.

[Summary of Effects of the Invention] According to the present invention described above, generation of ducts caused by peeling of a deposited film during film formation is suppressed, and abnormal growth (spherical projections) of the deposited film is reduced, thereby enabling electrophotography. In the photoconductor, image defects are reduced, and the durability of the cleaning blade installed in the copying machine is improved, thereby substantially improving the quality of the electrophotographic photoconductor and increasing the yield of non-defective products. be able to.

[Brief description of the drawings]

1 (A) and 1 (B) are longitudinal sectional views showing a typical example of a microwave transmitting window in the deposited film forming apparatus of the present invention. 2 (A) to 2 (B) and FIG.
It is a figure which shows typically this invention and the typical example of the conventional deposition film formation apparatus. FIG. 4 is a longitudinal sectional view showing a microwave transmission window in a conventional deposited film forming apparatus. FIG. 5 is a graph showing the results obtained in the above-described experiment, on the relationship between the degree of film peeling of the microwave transmitting window and the level of image defects. In the figure, 101, 401... Waveguide outer cylinder 102, 402... Atmospheric side dielectric window 102 ', 403... Reactor side dielectric window 103, 403... O-ring 104 for vacuum sealing , 404: Waveguide inner tube 105, 405: Inside the reactor (microwave plasma space) 106, 406: Microwave 107, 407: Microwave transmission window holder 108, 408: Reactor wall 201, 301 ... reactors 202, 302 ... dielectric windows 203, 303 ... waveguides 204, 304 ... exhaust pipes 205, 305 ... substrates 206, 306 ... inside the reactor (microwave plasma space) 207: Heater 307: Base holder 308: Gas inlet tube 209: Rotating shaft 210: Rotating motor

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) C23C 16/00-16/56 H01L 21/205 H01L 21/3065

Claims (3)

(57) [Claims] 1. A microwave transmission system having a substrate holding means inside a reactor, a source gas supply means and an exhaust means, and allowing a microwave from a microwave power supply to pass into the reactor. An apparatus for forming a functional deposition film by a microwave plasma CVD method, wherein a window forms a part of a wall of the reaction furnace, wherein the microwave transmission window has at least two or more removable dielectric films. A dielectric laminated window having a body laminated thereon, the dielectric laminated window having a surface exposed in the reaction furnace, and the dielectric laminated window being fixed by a fixing member on the side of the reaction furnace; The surface of the dielectric laminated window forms a continuous surface without a step with respect to the exposed surface of the dielectric laminated window, and the exposed surface of the dielectric laminated window and the surface of the fixing member are rough surfaces. By microwave plasma CVD method characterized by Forming apparatus potentially deposited film. 2. The apparatus for forming a functional deposition film by microwave plasma CVD according to claim 1, wherein the rough surfaces of the dielectric laminated window and the fixing member are rough surfaces having irregularities formed by spherical depressions. . 3. The formation of a functional deposition film by a microwave plasma CVD method according to claim 2, wherein the rough surface composed of the irregularities due to the spherical depression is formed by colliding a spherical projection material. apparatus.