JPH01309982A - Method for cleaning device for forming deposited film - Google Patents

Abstract

PURPOSE:To accurately detect the end of removal of reaction residue sticking to the inner wall of a vacuum reaction vessel and to shorten the time required to clean the inner wall by monitoring the intensity of light emitted during cleaning by dry etching. CONSTITUTION:When the inner wall of the vacuum reaction vessel 21 of a device for forming a deposited film by a vapor phase method with a flowing film forming gas is cleaned by dry etching, a light emitting phenomenon occurs. This light emitting state is monitored with an emission intensity monitor 32 and the degree of cleaning by dry etching is detected.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for cleaning a conjunctiva forming device using a dry etching method.

[Prior Art] Conventionally, a silicon-based deposit y1121 (
The technique of forming a deposited film (hereinafter abbreviated as a deposited film) is widely used when forming a photoconductive member on a cylindrical substrate in electrophotography, or when forming a light-receiving member on a flat substrate in a solar cell. ing. However, it is difficult to deposit by such a vapor phase method! During film formation, it is unavoidable that a part of the reaction product adheres as a film or powder to parts other than the target substrate, i.e., the inner walls of the vacuum reaction tank, exhaust pipe, etc. of the deposited film forming apparatus. These coatings or powders are easily separated, and the peeled off pieces and powders fly in the vacuum reaction tank and become the substrate on which the functional deposited film is to be formed.
This adhesion is one of the causes of film defects such as pinholes in the deposited film.

Therefore, before forming a monofunctional deposited film pattern, it is important to remove these films or powders and purify the vacuum reactor both physically and electrically, in order to repeatedly form functional deposited films. It is necessary.

As a deposited film formed by a vapor phase method, for example, there is a salt m film of a photoconductive member whose main component is silicon atoms, which is formed by a plasma reaction using a silane compound. After the deposited film is formed, a heavy composite of silane (called polysilane) is produced as a by-product in areas other than the substrate in the reaction tank. As a method of washing and removing this, for example, Japanese Patent Application Laid-Open No. 59-142839, Japanese Patent Publication No. 59-4
A cleaning method using a plasma reaction using a mixed gas of CFs and 02 is known, as disclosed in Japanese Patent No. 4770. By performing a cycle of deposited film formation and cleaning using this method, the occurrence of the above-mentioned pinholes can be reduced.

[Problems to be Solved by the Invention] However, in this method, the time required for cleaning often varies, and until now there has been no suitable means for accurately detecting the end of cleaning. Therefore, when giving priority to the quality of the deposited film, it is necessary to take measures such as allowing extra time for cleaning, and as a result, the time required for a unit cycle of film formation becomes long, which limits the improvement in production efficiency.

Furthermore, when an attempt is made to improve production efficiency by shortening the cleaning time, poor etching results in a decrease in product yield, making it difficult to improve productivity.

Therefore, one object of the present invention is to accurately detect the completion of cleaning by dry etching in the vacuum reaction tank and exhaust pipe of a deposited film forming apparatus, that is, the completion of removal of reaction residues, thereby preventing the formation of a deposited film. An object of the present invention is to provide a method for cleaning a deposited film forming apparatus, which can improve the yield of products and also improve productivity by shortening cleaning time.

[Means for Solving the Problems] To solve the above problems, in a method for cleaning a deposited film forming apparatus that forms a deposited film by a vapor phase method, a gas circulation space for forming a deposited film in the deposited film forming apparatus is provided. There is provided a method for cleaning a deposited film forming apparatus, which comprises detecting the degree of cleaning by monitoring the state of light emission caused by the dry etching action when cleaning the inner wall forming the deposited film using a dry etching method. Ru.

When cleaning gases such as C1 and F' y chemically react with reaction residues (silane heavy complexes), they are accompanied by a light emission phenomenon, so etching can be detected by monitoring the intensity of light emission within the vacuum reaction layer and analyzing its changes. Based on the above-mentioned knowledge, the present invention has obtained the knowledge that it is possible to know the degree of progress of etching.Based on the above-mentioned knowledge, the present invention makes it possible to detect the completion of etching in the vacuum reaction tank by, for example, providing a means for detecting the luminescence intensity in the vacuum reaction tank. Since it is possible to accurately determine the quality of the deposited lIt film, it is possible to substantially reduce cleaning time and improve productivity while ensuring a high level of quality.

Is it used in the present invention according to the F drawings? T! and the method of the present invention will be specifically explained. FIG. 1 is a cross-sectional view of a cleaning device for a deposited film forming apparatus according to the present invention, and is also a cross-sectional view of a silicon-based deposited film forming apparatus used in the present invention.
In the figure, 1 is the main body of the vacuum reaction tank, and the vacuum reaction tank is composed of high frequency electrodes 2 and 1, mounting 7.8, and lower cover bottom plates 3 and 4. The high-frequency electrode 2 is connected to a high-frequency power source (not shown), and the 11-
・It is also a department.゛Gas for forming deposited film used in the present invention (
Film-forming gas) and cleaning gas (etching gas) are introduced into the vacuum reaction tank l through the introduction pipes 11 and 9 and the introduction hole 10, and are then introduced from the exhaust pipe 13 by a vacuum evacuation device 21t17 such as an oil rotary pump or a mechanical booster pump. In the present invention, for example, a means for detecting luminescence intensity is provided in the vacuum reaction tank l, and in FIG. 1, a luminescence intensity detector 15 and a luminescence An intensity monitor 16 is provided. 6 is a base of a photoconductive member for an electrophotographic photoreceptor that can be used in the present invention, 5 is a pedestal for the base 6, and 14 is a heating resistance heater for heating the base 6. 18 is an outflow valve, and 19 is an inflow valve.

FIG. 5 is a sectional view showing an example of a photoconductive member for an electrophotographic photoreceptor that can be formed using the apparatus shown in FIG. In Figure 5, lot is a guide made up of A1 rods.
102 is a heavy implantation blocking layer containing silicon as one component, 103 is a photoconductive layer containing silicon as a main component, and 104 is a surface layer containing silicon and carbon as main components.

Taking as an example the case where the photoconductive member for an electrophotographic photoreceptor shown in FIG. 5 is formed using the apparatus shown in FIG. 1, the procedure for carrying out the method of the present invention will be briefly explained below.

First, the conductive base 6 made of A1 or the like is placed on the base pedestal 5, and the upper lid 7.8. The inflow valve 19 is closed, the outflow valve 18 is opened, and the inside of the vacuum reaction tank 1 is vacuum-exhausted.
At step 17, the vacuum is evacuated to about I x 10-3 Torr, and the substrate 6 is heated to a predetermined temperature by the heating resistor 14. Next, the inflow valve 19 is opened to form a photoconductive member for an electrophotographic photoreceptor. A film-forming gas is introduced into the vacuum reaction chamber 1, and the rotational speed of a mass flow controller (not shown) and a mechanical booster pump are adjusted to achieve predetermined film-forming conditions. 2, a glow discharge is generated in the vacuum reaction chamber 1, and a desired silicon-based deposited film is formed on the conductive substrate 6. When the desired silicon-based deposited film has been formed, the high-frequency power from the high-frequency power supply is cut off, the inflow valve 19 is closed, and the introduction of the film-forming gas is stopped.
Next, close the outflow valve 18 and open the inflow valve 19 to introduce Ar gas into the vacuum reaction tank 1 to leak the vacuum reaction tank 1, and then remove the vacuum from the vacuum reaction tank 1. Remove heavy components.

Inside the vacuum reaction tank 1 after forming the deposited film in this way,
Specifically, the inner wall 2 introduction tube 9 of the high frequency electrode 2, the upper lid 7,
8 and the inner wall of the lower lid bottom plate 3.4, reaction residues (silane heavy compound) are deposited and deposited.

Next, a procedure for etching this silane composite using the Stl shown in FIG. 1 and cleaning the apparatus will be described below.

First, place a dummy cylindrical conductive substrate by δ on the pedestal 5.
7.8 and the inflow valve 19 are closed, and the outflow valve 18 is opened. When the inside of the vacuum reaction tank 1 is evacuated to about I x 101 Tarr, the inflow valve 19 is opened to supply cleaning gas (etching gas) to the vacuum reaction tank 1. The rotational speed of the mass flow controller and mechanical booster pump (not shown) was set to 7 to achieve the specified etching conditions.
A glow discharge is generated in the vacuum reactor 1 to etch the silane compound deposited on the inner wall of the vacuum reactor 1. When etching is finished by the method described later, the inflow valve 19 is closed to stop the introduction of etching gas, and the inside of the vacuum reactor 1 is again evacuated to about 1 x 1 O-3 Torr.Next, the outflow valve 18 is closed and the inflow valve 19 Open A and introduce gas into the vacuum reaction tank 1 to leak the vacuum reaction tank 1, and take out the dummy cylindrical conductive substrate.

In the present invention, according to the above procedure, a silicon-based deposited film is formed and the deposited film shape r! A cycle of cleaning the equipment is performed, but the salt 8! Depending on the type of film, the salt 81 film may be formed and deposited using procedures other than those described above. ! A cycle of forming and washing may be performed.

The cleaning gas used in the present invention is preferably chlorine trifluoride (ClF3).1 For example, ClF3 gas does not need to be in a plasma state unlike conventional cleaning gases, such as mixed gases of CF4 and 02, and thus does not require release. When cleaning the deposited film forming apparatus with ClF3 gas, which does not require electrician energy, Clh gas alone may be used, but Ar,)! e, Me, To, N2. It may be used in combination with a diluent gas such as H2 gas, or C1h alone or a mixed gas may be heated in an electric furnace or the like depending on the type of deposited film to be etched.

In addition, when cleaning a deposition IJt device with the above CIF+ gas alone or a mixed gas, it may be used while evacuating with a vacuum evacuation device, etc., or it may be enclosed within the deposited film forming device. Furthermore, ClF3 gas has the 4'r characteristic of having a faster etching rate than conventional etching gases (for example, a mixture of CF4 and 02), and allows efficient etching. When adjusting the etching speed, Ar, He, Ne, 02. It may be used in combination with a diluent gas such as N2 or H2 gas.

Depending on the case, ClF37t1 gas or mixed gas may be heated in an electric furnace or the like.

The structure and operation of the present invention will be further explained in JL format using experimental examples below.

(Experimental Example 1) A photoconductive member for an electrophotographic photoreceptor shown in FIG. 5 was formed using the apparatus shown in FIG. 1 according to the procedure described above under the film forming conditions shown in Table 1.

Table 1 When the above photoconductive member for an electrophotographic photoreceptor was formed, a heavy composite of silane was deposited inside the vacuum reaction tank 1. The photoconductive member was removed from the apparatus of FIG. 1 and the silane composite was etched with a mixture of ClF3 and Ar using the procedure described above. The etching conditions are shown below.

Etching conditions-1 CIF Ti performance 100s1005c Flow rate 900sccm Internal pressure 10.0Torr When a mixed gas of CIF+ and ^' is introduced into the vacuum reaction tank 1 shown in Figure 3, a chemical reaction of a heavy complex of ClF3 and silane immediately occurs and etching begins. At this time, the relationship between the luminescence intensity CI) in the vacuum reaction tank indicated by the light intensity detector 15 and the etching time (T) is shown in Figure 2. The luminescence intensity I increases by 1
After time T1 elapses, 1 emission intensity becomes 11 and time T2
The luminescence intensity I rapidly decreased from 0 time T2, which remained almost constant until time T3, and when the luminescence gas intensity became 0, the inflow valve 19 was closed and the supply of the mixed gas of CIh and Ar was stopped. When the inside of the vacuum reactor shown in FIG. 1 was leaked, no heavy compound of silane was deposited inside the vacuum reactor 1, and etching of the vacuum reactor 1 was completed.

Next, according to the same procedure as above, the etching time T is
2 (that is, the supply of ClF3 and Ar was stopped when the luminescence intensity (1) began to decrease), and a silane overlapping compound remained in the vacuum reaction tank.

From the two experiments described in Section L, it was found that in order to completely and efficiently etch the inside of the vacuum reactor, it is sufficient to stop the supply of etching gas when the luminescence intensity reaches O.

When an experiment similar to Experimental Example 1 was carried out using the same apparatus as Experimental Example 1 and only the etching conditions (etching gas flow, internal pressure) were varied, the luminescence intensity in the vacuum reaction chamber 1 was as follows. The results were similar to those shown in FIG. 2, and it was found that the relationship shown in FIG. 2 was uniform regardless of the etching conditions.

Hereinafter, an experimental example in which the type of diluent gas and the cleaning device were changed will be shown.

(Experiment Example 2) Figure 3 is a cross-sectional view of a silicon-based deposited film forming device that can be used in the present invention, and is also a cleaning device for deposited film forming according to the present invention. The container, 25 is a high frequency power source, 22 is a high frequency electrode connected to this high frequency power source, 21 is grounded by the other high frequency electrode, and is also part of the vacuum reaction tank container according to the present invention. The gas for forming the compost and I and the cleaning gas to be used are introduced into the vacuum reaction tank 20 through the introduction pipe 29, and are passed through the exhaust pipe 30 by an exhaust system 2134 such as an oil rotary pump or a mechanical booster pump to a scarlet gas treatment device (not shown). is exhausted. In FIG. 3, the vacuum reactor container 21 is provided with means for detecting the luminescence intensity, that is, a luminescence intensity detector 32 and a luminescence intensity monitor 33 connected thereto. 27 is a base of a light-receiving member for a solar cell that can be used in the present invention, 23 is a pedestal for the base 27, and 26 is a heating resistor for heating the base 27. 2
4 is a shield, 28 is an inflow valve, and 31 is an outflow valve.

FIG. 6 is a sectional view showing an example of a light-receiving member for a solar cell that can be formed using the apparatus shown in FIG. 3. In FIG. 6, 201 is a conductive substrate made of stainless steel or the like, 202 is a layer containing silicon as the main component and exhibiting P-type conductivity, and 203 is an intrinsic photoreceptive layer containing silicon as the main component. 204 is a layer mainly composed of silicon and exhibiting N-type conductivity.

The sixth experiment was carried out in the same manner as in Experimental Example 1 using the equipment shown in Figure 3.
The light-receiving member for a solar cell shown in the figure was formed under the film-forming conditions shown in Table 2.

In Table 2, the conductive substrate 27 made of stainless steel or the like is placed on the substrate pedestal 23, the inflow valve 28 is closed and the outflow valve 31 is opened, and the inside of the vacuum reaction tank 20 is evacuated using the evacuation device 34. After evacuation to 1X10 to 3 Torr and heating the substrate 27 to a predetermined temperature using the heating resistor 26, the inflow valve 28 is opened and a film-forming gas for forming a light-receiving member for a solar cell is placed in the vacuum reaction tank 20. High-frequency power is supplied to the high-frequency electrode 22 from the zero-order high-frequency power supply 25, which has adjusted the rotational speed of a mass flow controller (not shown) and a mechanical booster pump to achieve predetermined film-forming conditions, and a glow is generated in the vacuum reaction tank 2o. A discharge was generated to form a silicon-based deposited film shown in Table 2 on the conductive substrate 27. After forming the desired silicon-based deposited film, turn off the high frequency power from the high frequency power supply and close the inflow valve 2.
8, the introduction of the film forming gas was stopped, and the inside of the vacuum reaction tank 20 was again evacuated to about I x 1O-3 Torr. 8. Next, the outflow valve 31 was closed, and the inflow valve 28 was opened to remove Ar scum from the vacuum reaction tank 20. J' was passed through the empty reaction tank 2o, and the light-receiving member for solar cells was taken out.

Inside the vacuum reaction tank 20, specifically, on the high frequency electrode 22, the inner wall of the vacuum reaction tank container 21, and the pedestal 23, a heavy composite of silane was deposited.

Next, using the apparatus shown in FIG. 3, the procedure for etching this silane composite with a mixed gas of CIFp gas and N2 gas and cleaning the apparatus will be described below.

First, a dummy flat conductive substrate is placed on the pedestal 23, the inflow valve 28 is closed, and the outflow valve 31 is opened.After the inside of the vacuum reaction tank 20 has been evacuated to about I x 1O-3 Torr, the inflow valve 28 is opened. A mixed gas of Clh gas and N2 gas is introduced into the vacuum reaction tank 20, and the rotational speed of the mass flow controller and mechanical booster pump (not shown) are adjusted so that the following etching conditions are met.
Etching was carried out with the high frequency power supply 25 turned off.

Etching conditions-2 CIF3R, til 10se105e flow, f990sccm Internal pressure 10.0 Torr When a mixed gas of CIF3 and N2 is introduced into the vacuum reaction tank 20 shown in Fig. 3, a chemical reaction of a heavy complex of ClF3 and silane immediately occurs and etching begins. Ta. FIG. 4 shows the relationship between the luminescence intensity (1) in the vacuum reactor and the etching time (T) indicated by the luminescence intensity detector 32 at this time. The luminescence intensity I in the vacuum reactor increases from the start of etching (T=O), and after time TI, the luminescence intensity I becomes 1 and remains almost constant until time T2.
rapidly decreases, and when the luminescence intensity reaches O at time T1, the inflow valve 28 is closed and ClF3 and N? The supply of mixed gas was stopped. When the vacuum reactor shown in FIG. 1 was leaked, no heavy compound of silane was deposited inside the vacuum reactor 20, and etching of the vacuum reactor 20 was completed when etching was started.

Next, according to the same procedure as in L, when etching +11I
When T was changed to T2 (that is, the supply of ClF3 and N2 was stopped when the luminescence intensity I began to decrease), a silane overlapping compound remained in the vacuum reactor.

From the above two experiments, it was found that in order to completely and efficiently etch the inside of the vacuum reactor, it is sufficient to stop the supply of etching gas when the luminescence intensity I becomes 0.

An experiment similar to Experimental Example 2 was conducted using the same apparatus as Experimental Example 2, but only by varying the etching conditions (etching gas flow rate, internal pressure?).

The luminescence intensity within the vacuum reaction chamber 20 was found to be similar to that shown in FIG. 4, and it was found that the relationship shown in FIG. 4 is universal regardless of the etching conditions.

Above is Experimental Example 1. As seen in Experimental Example 2, the luminescence intensity in the vacuum reactor and the progress of etching depend on the etching conditions (
It was found that the problem is independent of the etching gas flow rate, internal pressure, etc.), the type of diluent gas, and the cleaning device.

[Example 1] Specific examples for demonstrating the effects of the present invention will be described below, but the present invention is not limited thereto.

(Example g41) A high frequency power source (not shown) was connected to the apparatus shown in FIG. 1, and a photoconductive member for an electrophotographic photoreceptor was formed under the same conditions as in Experimental Example 1. Etching conditions-1 and etching time T = T3 shown in
When the cycle of vacuum reaction 4e10 etching was repeated 50 times under the condition that the introduction of etching gas was stopped when the total light intensity If I became 0, there was no gas in the vacuum reaction tank 1. There were no cases where a heavy compound of silane remained (poor etching). The etching time in one cycle varied from 45 minutes to 62 minutes, with 55 minutes being the most common. The total etching time after 50 repeated operations was 2620 minutes.
7550 and evaluated the image characteristics, all images were of excellent quality with no image defects.

(Comparative Example 1-■) Example 1 except that the etching time was fixed at T = 55 minutes.
The cycle of forming a photoconductive member for an electrophotographic photoreceptor and etching the vacuum reaction tank 1 was repeated 50 times under the same conditions as above.
When the test was repeated 5 times, the silane composite remained in the vacuum reaction tank 1 5 times. When the image characteristics of the photoconductive members for electrophotographic photoreceptors formed by the subsequent film formation when a heavy composite of silane remained in the vacuum reaction tank 1 were evaluated in the same manner as in Example 1, it was found that all of them had image defects. It was of poor quality. The total etching time after 50 repeated runs was 2750 minutes.

(Comparative Example 1-2) Example 1 except that the etching time was fixed at T = 62 minutes.
The cycle of forming a photoconductive member for an electrophotographic photoreceptor and etching the vacuum reaction tank 1 was repeated 50 times under the same conditions as above.
When the process was repeated several times, there was no case that a heavy composite of silane remained in the vacuum reaction tank 1. When the properties were evaluated, all of them were of excellent quality with no image defects, but the total etching time after 50 repeated operations was as long as 3100 minutes.

Considering both the deterioration of image characteristics due to poor etching and the total etching time as seen in Example 1, Comparative Example 1-1, and Comparative Example 1-2, Comparative Example 1-1 and Comparative Example 1-2
It was recognized that Example 1 was superior overall.

(Example 2) A light-receiving member for a solar cell was formed using the apparatus shown in FIG. etching time T = T], that is, the emission intensity is O
When the cycle of etching the vacuum reaction tank 20 was repeated 50 times under the condition that the introduction of the etching gas was stopped at this point, a heavy compound of silane remained in the vacuum reaction tank 20 ( There were no etching defects. The etching time in one cycle varied from 15 minutes to 21 minutes, with 18 minutes being the most common. The total etching time after 50 repeated operations was 870 minutes. When the prepared photoreceptive materials for large FIIJMl ponds were evaluated, they were all of excellent quality with no short circuits due to pinholes.

(Comparative Example 2-1) Example 2 except that the etching time was fixed at T = 18 minutes.
When the cycle of forming a light-receiving member for a solar cell and etching the vacuum reaction tank 20 was repeated 50 times under the same conditions as above, the number of times that a heavy compound of silane remained in the vacuum reaction tank 20 was 6. It was times. Vacuum reaction tank 20
When the light-receiving members for solar cells were evaluated in the same manner as in Example 2 after the subsequent film formation when the silane heavy composite remained in the film, all of them were of poor quality with m-interference caused by pinholes. . The total etching time after 50 repeat operations was 900 minutes.

(Comparative Example 2-2) Example 2 except that the etching time was fixed at T = 21 minutes.
When the cycle of forming a light-receiving member for a solar cell and etching the vacuum reaction tank 20 was repeated 50 times under the same conditions as above, the number of times that a heavy compound of silane remained in the vacuum reaction tank 20 was as follows. Not even once. When the formed light-receiving members for solar cells were evaluated in the same manner as in Example 2, they were all of excellent quality with no short circuits due to pinholes, but the total etching time after 50 repeated operations was 1050 minutes. It took time.

Considering both the short circuit of the member due to poor etching and the total etching time as seen in Example 2, Comparative Example 2-1, and Comparative Example 2-2, the etching process was better than Comparative Example 2-1 and Comparative Example 2-2. It was recognized that Example 2 was superior overall.

The effects of the present invention are achieved regardless of the type of diluent gas, their mixing ratio and flow rate, the etching conditions such as the internal pressure of the vacuum reaction tank, the type of deposited film to be cleaned and removed, the formation method, the formation apparatus, etc. ], and is not limited to the two embodiments.

[Effects of the Invention] According to the present invention, it is possible to accurately detect the end of cleaning by dry etching in the vacuum reaction tank of the deposited film forming device a, that is, the completion of the removal of reaction residues. Productivity can be improved by improving water retention in formed products and shortening cleaning time.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a specific example of an apparatus for cleaning a deposited film forming apparatus that can be used in the present invention. In Fig. 1, 1... Vacuum reaction tank, 2... High frequency electrode, 3, 4... Bottom cover bottom plate, 5... Substrate holder is a stand, 6
...Cylindrical conductive base, 7.8...Top lid, 9.
...Gas inlet pipe, 10...Gas inlet hole, 11...Gas inlet pipe, 13...Gas exhaust pipe, 14...Heating resistor, 15...Emission intensity detector, 16...・Emission intensity monitor, 17... Vacuum exhaust device, 18... Outflow valve, 19... Inflow valve: 52 Figure shows the etching time (T) and the emission intensity CI) in the vacuum reaction tank in Experimental Example 1. It is a diagram showing a relationship. FIG. 3 is a diagram showing a specific example of a device for cleaning a deposited film forming apparatus that can be used in the present invention. In FIG. 3, 20...Vacuum reaction tank, 21...Vacuum reaction tank container, 22...High frequency electrode, 23...Substrate support is stand, 24...Shield, 25...High frequency power source . 26... Heating resistor, 27... Substrate, 28... Inflow valve, 29...
...Filming gas or etching gas, 30...Exhaust pipe, 31...Outflow valve, 32...Emission intensity detector, 33...Emission intensity monitor, 34...Evacuation device. FIG. 4 is a diagram showing the relationship between the etching time (T) and the luminescence intensity CI) in the vacuum reaction chamber in Experimental Example 2. FIG. 5 is a diagram showing the layer structure of a photoconductive member for electrophotography used in the present invention. In FIG. 5, 101... conductive substrate, 102...
・Charge injection blocking layer. 103...Photoconductive layer, 104...-Surface layer. FIG. 6 is a diagram showing the layer structure of a light-receiving member for a large wA battery used in the present invention. In FIG. 6, 201... conductive substrate, 202...
- P-type layer, 203... ■-type photoreceptive layer, 204... N-type layer. Agent Patent Attorney Seki Yamashita Figure 1 Day Figure 2 1.7 Ching°8! I open (T) Figure 3 Figure 4 F+NG ° Time (T) Figure 5 Figure N6

Claims (1)

[Claims] 1. In a method for cleaning a deposited film forming apparatus that forms a deposited film by a vapor phase method, an inner wall forming a gas circulation space for forming a deposited film in the deposited film forming apparatus is dry etched. 1. A method for cleaning a deposited film forming apparatus, characterized in that the degree of cleaning is detected by monitoring the state of light emitted by dry etching during cleaning. 2. The method for cleaning a deposited film forming apparatus according to claim 1, wherein the gas used for cleaning is ClF_3.