WO2012008455A1

WO2012008455A1 - Film-forming apparatus and method for cleaning film-forming apparatus

Info

Publication number: WO2012008455A1
Application number: PCT/JP2011/065896
Authority: WO
Inventors: 真典飛田; 小田木　秀幸; 鉄也島田
Original assignee: 株式会社アルバック
Priority date: 2010-07-13
Filing date: 2011-07-12
Publication date: 2012-01-19
Also published as: JPWO2012008455A1; JP5553898B2

Abstract

Provided is a film-forming apparatus which is safe for a cleaning worker and which makes it possible for attached matter inside a vacuum chamber to be cleaned within a shorter period of time and at a lower cost than with a conventional apparatus, and also provided is a method for cleaning the film-forming apparatus. A hollow tank (19) formed of a material that does not dissolve in a cleaning solution which can dissolve film-forming particles is connected to a vacuum chamber (11) of a film-forming apparatus (10a), and a drainage outlet (15) is disposed in the bottom surface of the vacuum chamber (11). After a substrate (21) is carried out of the vacuum chamber (11), the cleaning solution is introduced from the tank (19) into the vacuum chamber (11), the film-forming particles attached inside the vacuum chamber (11) come into contact with the cleaning solution, a film-forming material is dissolved in the cleaning solution, and the cleaning solution is discharged from the drainage outlet (15) to outside of the vacuum chamber (11).

Description

Film forming apparatus and method for cleaning film forming apparatus

The present invention relates to a film forming apparatus and a cleaning method for the film forming apparatus.

Lithium batteries are characterized by high energy density, excellent discharge stability, and a wide operating temperature range compared to other batteries, and are currently used in a variety of electronic devices such as personal digital assistants and security sensors. Yes. Metal lithium (Li) is used for the negative electrode of the lithium battery.
FIG. 4 shows an internal configuration diagram of a conventional Li film deposition apparatus.
The vapor deposition apparatus 100 includes a vacuum chamber 111, a material holding unit 132, and a substrate holding unit 122.
The material holding part 132 is a boat for resistance heating, and is arranged in the vacuum chamber 111 so that the vapor deposition material (Li) can be held inside.
The substrate holding unit 122 is disposed above the material holding unit 132, and a plurality of substrates 121 are attached to a portion of the substrate holding unit 122 that faces the material holding unit 132.
A power supply device 133 is electrically connected to the material holding unit 132.

When a DC voltage is applied from the power supply device 133 to the material holding unit 132, the material holding unit 132 generates heat due to resistance heating, heats the vapor deposition material in the material holding unit 132, and releases film formation particles from the vapor deposition material. . Part of the film formation particles released from the vapor deposition material is incident on the substrate 121 held by the substrate holding unit 122, and a Li thin film is formed on the surface of the substrate 121.
Outside the film formation space between the material holding unit 132 and the substrate holding unit 122, the deposition preventing plate 141 is disposed at a position where the film formation particles emitted from the film formation material are incident and emitted from the vapor deposition material. The deposited particles are prevented from adhering to the wall surface of the vacuum chamber 111.
Film deposition particles adhere to and deposit on the adhesion preventing plate 141. When film-forming particles (hereinafter referred to as deposits) adhering from the deposition preventive plate 141 peel and adhere to the surface of the substrate 121, they become impurities. Therefore, before the peeling occurs, it is necessary to clean the adhesion preventing plate 141 and remove the deposits.

In the conventional method for cleaning a film forming apparatus, the inside of the vacuum chamber 111 is opened to the atmosphere, and the deposition plate 141 is taken out of the vacuum chamber 111, and then the deposition plate 141 is made of pure water or a chemical solution in the atmosphere. It was immersed in the cleaning solution, and the deposits were dissolved and removed in the cleaning solution.
However, when the deposition preventive plate 141 to which adhered Li is attached is exposed to the atmosphere, Li reacts with nitrogen (N ₂ ) gas in the atmosphere to generate lithium nitride (LiN). When the deposition preventing plate 141 is immersed in the cleaning liquid, LiN reacts with H ₂ O contained in the cleaning liquid to generate ammonia (NH ₃ ) gas.
LiN + H ₂ O → LiOH + NH ₃
NH ₃ gas is toxic to the human body, and there is a risk that the cleaning operator is exposed to danger. For this reason, there has been a problem that a large cost is required for safety measures such as protective equipment and abatement equipment for the cleaning operator.
Further, since the inside of the vacuum chamber is opened to the atmosphere during the cleaning operation, there is a disadvantage that much time and labor are required to restart the film forming operation.

JP 2010-40458 A

The present invention was created to solve the above-mentioned disadvantages of the prior art, and its purpose is to be safe for a cleaning operator, and to clean the deposits in the vacuum chamber in a shorter time and at a lower cost. An object of the present invention is to provide a film apparatus and a cleaning method for the film forming apparatus.

In order to solve the above problems, the present invention provides a vacuum chamber having an exhaust port on a wall surface, a vacuum exhaust unit connected to the exhaust port and evacuating the vacuum chamber, and disposed in the vacuum chamber. A material holding unit for holding a film material; a discharge means for releasing film forming particles that are particles of the film forming material from the film forming material held in the material holding unit; and a position at which the film forming particles are incident And a substrate holding part that holds the substrate, and has a hollow tank formed of a material that does not dissolve in a cleaning solution that can dissolve the film-forming particles, The film forming apparatus is connected to the inside of the vacuum chamber and is provided with a drain port on the bottom surface of the vacuum chamber.
The present invention includes a vacuum chamber having an exhaust port on a wall surface, a vacuum exhaust unit that is connected to the exhaust port and evacuates the vacuum chamber, and a gas introduction unit that introduces a plurality of source gases into the vacuum chamber. A reaction means that chemically reacts the source gas introduced into the vacuum chamber to generate film-forming particles; and a substrate holding unit that is disposed at a position where the film-forming particles are incident and holds a substrate. A film forming apparatus, comprising a hollow tank formed of a material that does not dissolve in a cleaning solution capable of dissolving the film forming particles, the inside of the tank being connected to the inside of the vacuum chamber, and the bottom of the vacuum chamber Is a film forming apparatus provided with a drain port.
The present invention is a film forming apparatus, wherein the film forming particles are either Li or Li ₃ PO ₄ , and the cleaning liquid contains H ₂ O.
This invention is a film-forming apparatus, Comprising: It is a film-forming apparatus which has a drying means which is arrange | positioned in the said vacuum chamber and dries the inside of the said vacuum chamber.
The present invention is a film forming apparatus having a detection unit that is connected to the drainage port and detects a hydrogen ion index of the cleaning liquid.
The present invention is a film forming apparatus having an inert gas introduction part for introducing an inert gas that does not react with the film forming particles into the vacuum chamber.
The present invention is a film forming apparatus cleaning method for forming a thin film of the film-forming particles on the substrate by causing the film-forming particles to enter the substrate in a vacuum evacuated vacuum tank. After unloading the substrate, a cleaning liquid capable of dissolving the film-forming particles is introduced into the vacuum chamber, the cleaning liquid is brought into contact with the film-forming particles attached to the inside of the vacuum tank, and the film-forming material is used as the cleaning liquid. A film forming apparatus cleaning method including a cleaning step of dissolving and discharging the cleaning liquid from the vacuum chamber.
The present invention is a film forming apparatus cleaning method, wherein a hydrogen ion index of the cleaning liquid discharged from the vacuum chamber is detected, and the cleaning process is repeated or the cleaning process is ended based on a detection result. This is a film-forming apparatus cleaning method that is determined as one of these.
The present invention relates to a method for cleaning a film forming apparatus, wherein an inert gas that does not react with the film forming particles is introduced into the vacuum chamber before the cleaning liquid is introduced into the vacuum chamber. An inert gas introduction step for setting the pressure to be equal to or higher than the pressure outside the vacuum chamber, and in the cleaning step, the introduction of the inert gas is continued and the pressure inside the vacuum chamber is changed to the pressure outside the vacuum chamber. In this method, the cleaning liquid is injected into the vacuum chamber while maintaining the above, and the gas in the vacuum chamber is discharged to the outside of the vacuum chamber.
The present invention is a method for cleaning a film forming apparatus, and includes a drying process for drying the inside of the vacuum chamber after the cleaning process is completed.
The present invention is a cleaning method for a film forming apparatus, wherein the film forming particles are either Li or Li ₃ PO ₄ , and the cleaning liquid contains H ₂ O.

Since NH ₃ gas is not generated, it is safe. Further, since the H ₂ gas generated during the cleaning operation is exhausted directly from the vacuum chamber to the exhaust facility, the cleaning operator is not exposed to the generated gas. Accordingly, the cost of safety measures such as the protective equipment of the worker and the abatement equipment is not required.
Since the vacuum chamber is not opened to the atmosphere during the cleaning operation, the film forming operation can be resumed in a short time after the cleaning operation, and the downtime can be shortened.
Li that has not been used for film formation can be recovered, and the cost of the film formation material can be saved.

The internal block diagram of the film-forming apparatus which is the vacuum evaporation system of this invention Internal configuration diagram of a film forming apparatus which is a sputtering apparatus of the present invention Internal configuration diagram of a film forming apparatus which is a CVD apparatus of the present invention Internal configuration diagram of conventional film deposition system

<Structure of deposition system>
The structure of the film forming apparatus of the present invention will be described by taking a vacuum deposition apparatus as an example.
FIG. 1 shows an internal configuration diagram of a film forming apparatus 10a which is a vacuum evaporation apparatus.
The film forming apparatus 10a is disposed in a vacuum chamber 11 having an exhaust port 16 on a wall surface, a vacuum exhaust unit 12 connected to the exhaust port 16 and evacuating the inside of the vacuum chamber 11, and a film forming material. A material holding part 32a for holding the film, a release means 30a for releasing film forming particles that are particles of the film forming material from the film forming material held in the material holding part 32a, and a position where the film forming particles are incident, And a substrate holding part 22a for holding the substrate 21.
The exhaust port 16 is provided on the wall surface of the vacuum chamber 11 at a position higher than the upper end of a deposition prevention plate 41 described later.

A main exhaust pipe 45 is hermetically connected to the exhaust port 16, and the vacuum exhaust unit 12 is connected to the main exhaust pipe 45 via a main exhaust valve 46. When the main exhaust valve 46 is opened, the evacuation unit 12 can evacuate the vacuum chamber 11.
Here, the material holding portion 32a is a resistance heating boat, and is configured to hold the film forming material inside the boat. The film forming material is, for example, either Li or Li ₃ PO ₄ .
The substrate holding part 22a is arranged above the material holding part 32a, and is configured to hold a plurality of substrates 21 in a portion facing the material holding part 32a.

The discharge means 30 a has a power supply device 33. The power supply device 33 is electrically connected to the material holding part 32a. When a DC voltage is applied from the power supply device 33 to the material holding unit 32a, the material holding unit 32a generates heat by resistance heating, and heats the film forming material held in the material holding unit 32a to form a film from the film forming material. The film-forming particles, which are material particles, are released.
The part of the film forming apparatus 10a in which the film forming particles are incident on the substrate 21 in the vacuum chamber 11 is called a film forming part 50a. Here, the film forming part 50a includes the substrate holding part 22a, the material holding part 32a, and the release. And means 30a.
An adhesion preventing plate 41 is disposed outside the discharge space, which is a space between the material holding part 32a and the substrate holding part 22a, at a position where the film forming particles emitted from the film forming material are incident.
The deposition preventing plate 41 is formed in a cylindrical shape and is disposed so as to surround the discharge space, and prevents film formation particles released from the film formation material from adhering to the wall surface of the vacuum chamber 11.

A hollow tank 19 made of a material that does not dissolve in a cleaning solution that can dissolve film-forming particles is disposed outside the vacuum chamber 11. The cleaning liquid is a liquid containing, for example, H ₂ O. The inside (hollow part) of the tank 19 is connected to the inside of the vacuum chamber 11 via a liquid supply valve 43.
When the cleaning liquid is stored in the tank 19 and the liquid supply valve 43 is opened, the cleaning liquid is introduced into the vacuum chamber 11.
A drainage port 15 is provided on the bottom surface of the vacuum chamber 11, and the drainage port 15 is connected to a drainage facility 61 disposed outside the vacuum chamber 11 via a drainage valve 44.
When the cleaning liquid is introduced into the vacuum chamber 11 with the drain valve 44 closed, the cleaning liquid is gradually accumulated from the bottom of the vacuum chamber 11 toward the ceiling. The cleaning liquid stored in the tank 11 is discharged from the liquid discharge port 15 to the drainage equipment 61 outside the vacuum tank 11.

In the present embodiment, the drainage facility 61 is configured to recover the element of the film forming material from the discharged cleaning liquid.
The drain port 15 is connected to a detection unit 17 that detects a hydrogen ion index (pH) so that the pH of the cleaning liquid discharged from the drain port 15 can be detected.
The detection unit 17 of the film forming apparatus 10a of the present invention is not limited to the structure connected to the liquid discharge port 15, and may be disposed in the vacuum chamber 11, but is connected to the liquid discharge port 15. However, it is preferable because the structure of the apparatus is simple and the pH of the cleaning liquid can be detected regardless of the concentration of the cleaning liquid in the vacuum chamber 11.

A drying means 34 for drying the inside of the vacuum chamber 11 is disposed in the vacuum chamber 11.
The drying means 34 is a sheath heater here, and is disposed along the inner wall surface of the vacuum chamber 11. The drying means 34 may be further disposed along the back surface of the deposition preventing plate 41 (the surface facing the inner wall surface of the vacuum chamber 11).
The drying means 34 is electrically connected to the power supply device 33. When a DC voltage is applied from the power supply device 33 to the drying unit 34, the drying unit 34 generates heat, and the moisture of the cleaning liquid adhering to the inner wall surface of the vacuum chamber 11 or the surface of the deposition preventing plate 41 is evaporated. ing.
An air supply port 13 is provided at a position higher than the upper end of the deposition preventing plate 41 in the wall surface of the vacuum chamber 11.
Outside the vacuum chamber 11, an inert gas introduction unit 18 for introducing an inert gas that does not react with the film forming particles is disposed in the vacuum chamber 11. The inert gas is, for example, Ar gas. The inert gas introduction unit 18 is connected to the air supply port 13 via the air supply valve 49, and when the air supply valve 49 is opened, the inert gas is introduced into the vacuum chamber 11 from the air supply port 13. ing.

Outside the vacuum chamber 11, an exhaust facility 62 that is set to atmospheric pressure is disposed.
One end of a sub exhaust pipe 47 is connected to the main exhaust pipe 45, and the other end of the sub exhaust pipe 47 is connected to an exhaust facility 62 via a sub exhaust valve 48.
When the main exhaust valve 46, the sub exhaust valve 48, the air supply valve 49, the liquid supply valve 43, and the liquid discharge valve 44 are all closed, the inside of the vacuum chamber 11 is insulated from the atmosphere outside the vacuum chamber 11. Yes.
When the main exhaust valve 46 is closed and the pressure in the vacuum chamber 11 is higher than the pressure outside the vacuum chamber 11, if the sub exhaust valve 48 is opened, the gas in the vacuum chamber 11 is discharged from the exhaust port 16 and the sub exhaust. The gas is discharged through the pipe 47 to the exhaust facility 62 placed at the atmospheric pressure outside the vacuum chamber 11.
The film forming apparatus of the present invention is not limited to the vacuum vapor deposition apparatus as described above, and other physical vapor deposition apparatuses such as a sputtering apparatus are also included in the present invention.

The structure of the film forming apparatus of the present invention will be described using a sputtering apparatus as an example.
FIG. 2 shows an internal configuration diagram of the film forming apparatus 10b which is a sputtering apparatus. Of the configuration of the film forming apparatus 10b, the same portions as those of the film forming apparatus 10a are denoted by the same reference numerals.
Reference numeral 50b denotes a film forming unit of the film forming apparatus 10b.
The configuration of the film forming unit 50b is different from the configuration of the film forming unit 50a of the film forming apparatus 10a, but the configuration of the other parts is the same as that of the film forming apparatus 10a. A description of the same parts as those of the film forming apparatus 10a will be omitted.
The film forming unit 50 b is disposed in the vacuum chamber 11, and a material holding unit 32 b that holds the film forming material 31 and a film that is particles of the film forming material 31 from the film forming material 31 held in the material holding unit 32 b. It has a discharge means 30b for discharging the particles, and a substrate holding portion 22b that is arranged at a position where the film forming particles are incident and holds the substrate 21.

The material holding part 32b is a backing plate, and the film forming material 31 is attached in close contact with the surface of the backing plate. The film forming material 31 is, for example, one of Li and Li ₃ PO ₄ .
The substrate holding part 22 b is formed in a flat plate shape, and is disposed in parallel with the film forming material 31 at a position facing the film forming material 31. The substrate holding part 22 b is configured to hold the substrate 21 on the surface facing the film forming material 31.

The discharge means 30 b has a sputtering gas introduction part 51 and a power supply device 33. The sputter gas introduction unit 51 is connected to the vacuum chamber 11 and is configured so that the sputter gas can be introduced into the vacuum chamber 11. The sputtering gas is, for example, Ar gas. The power supply device 33 is electrically connected to the material holding unit 32b and the substrate holding unit 22b.
After the vacuum chamber 11 is evacuated, a sputtering gas is introduced into the vacuum chamber 11 from the sputtering gas introduction unit 51, and a DC voltage or an AC voltage is applied from the power supply device 33 between the material holding unit 32 b and the substrate holding unit 22 b. When applied, discharge occurs between the film forming material 31 and the substrate 21, and the sputtering gas is turned into plasma. The ions of the sputtering gas are incident on the film forming material 31 having a negative potential, the film forming material 31 is sputtered, and the film forming particles are released from the film forming material 31.

In FIG. 2, the substrate holding part 22b is arranged above the material holding part 32b. However, if the film forming material 31 and the substrate 21 are arranged to face each other, the present invention is not limited to this configuration. The substrate holding part 22b may be arranged below the holding part 32b, or the material holding part 32b and the substrate holding part 22b may be arranged side by side in a state where they are vertically set up to face each other. .
The film forming apparatus of the present invention is not limited to the physical vapor deposition apparatus such as the vacuum vapor deposition apparatus and the sputtering apparatus described above, and a chemical vapor deposition apparatus (CVD apparatus) is also included in the present invention.

The structure of the film forming apparatus of the present invention will be described using a CVD apparatus as an example.
FIG. 3 shows an internal configuration diagram of a film forming apparatus 10c which is a CVD apparatus. Of the configuration of the film forming apparatus 10c, the same portions as those of the

film forming apparatuses

10a and 10b are denoted by the same reference numerals.
Reference numeral 50c denotes a film forming unit of the film forming apparatus 10c.
The configuration of the film forming unit 50c is different from the configuration of the

film forming units

50a and 50b of the

film forming apparatus

10a and 10b, but the configuration of the other parts is the same as that of the

film forming apparatus

10a and 10b. The description of the same parts as those of the film forming apparatus denoted by

reference numerals

10a and 10b is omitted.
The film forming unit 50c includes a gas introducing unit 30c ₁ that introduces a plurality of source gases into the vacuum chamber 11, and a reaction unit 30c ₂ that generates film forming particles by chemically reacting the source gases introduced into the vacuum chamber. have.

The gas introduction part 30c ₁ has a hollow discharge container 52 provided with a plurality of discharge holes on one surface, and a source gas discharge part 53 that discharges a plurality of source gases. The discharge container 52 is disposed in the vacuum chamber 11. The source gas discharge unit 53 is disposed outside the vacuum chamber 11 and is connected to the discharge container 52 via a pipe 54 that hermetically penetrates the side wall of the vacuum chamber 11.
The substrate holding part 22c is formed in a flat plate shape, and is disposed in a position facing a surface (hereinafter referred to as a discharge surface) provided with a discharge hole of the discharge container 52 so as to face the discharge surface. It is comprised so that the board | substrate 21 can be hold | maintained on the surface to perform.
The reaction means 39c ₂ includes an electric heater 23 and a power supply device 33. The electric heater 23 is attached to the substrate holding part 22 c, and the power supply device 33 is electrically connected to the electric heater 23.

When the raw material gas is introduced into the discharge container 52 from the raw material gas discharge unit 53, the raw material gas is discharged toward the substrate 21 from the discharge hole of the discharge container 52. When a DC voltage is applied from the power supply device 33 to the electric heater 23, the electric heater 23 generates heat, the substrate 21 held by the substrate holding portion 22c is heated, and the source gas on the substrate 21 undergoes a chemical reaction due to the heat of the substrate 21. Thus, film-forming particles are generated.

In FIG. 3, the substrate holding portion 22c is disposed below the discharge surface of the discharge container 52. However, the present invention is limited to this configuration as long as the discharge surface of the discharge container 52 and the substrate 21 are disposed to face each other. Alternatively, the substrate holding portion 22c may be disposed above the discharge surface of the discharge container 52, or the discharge surface of the discharge container 52 and the substrate holding portion 22c are arranged side by side in a state where the discharge surface is vertically set. May be arranged.

<Film Forming Method Using Film Forming Apparatus>
With reference to FIG. 1, the film-forming method using the film-forming apparatus 10a which is a vacuum evaporation system is demonstrated.
The liquid supply valve 43, the drain valve 44, the air supply valve 49, and the sub exhaust valve 48 are closed to insulate the vacuum chamber 11 from the atmosphere outside the vacuum chamber 11.
The main exhaust valve 46 is opened, and the vacuum chamber 11 is evacuated by the vacuum exhaust unit 12. Thereafter, evacuation is continued and the vacuum atmosphere in the vacuum chamber 11 is maintained.
With a transfer robot (not shown), while maintaining the vacuum atmosphere in the vacuum chamber 11, either Li or Li ₃ PO ₄ here is carried into the vacuum chamber 11 as a film forming material, and the material holding portion 32 a is loaded. Deploy.
A substrate 21 is carried into the vacuum chamber 11 by a transfer robot (not shown) while maintaining the vacuum atmosphere in the vacuum chamber 11 and is held by the substrate holder 22a.

A DC voltage is applied from the power supply device 33 to the material holding unit 32a to cause the material holding unit 32a to generate heat, and the film forming material in the material holding unit 32a is evaporated.
Part of the film formation particles released from the film formation material is incident on the substrate 21, and a thin film of film formation particles is formed on the substrate 21. The other film forming particles enter the deposition preventing plate 41 and the material holding unit 32a and adhere to the deposition preventing plate 41 and the material holding unit 32a. The film-forming particles attached to the material holding part 32 a are evaporated again, but the film-forming particles attached to the adhesion preventing plate 41 are deposited on the adhesion preventing plate 41.
After a thin film having a predetermined thickness is formed on the surface of the substrate 21, the voltage application from the power supply device 33 to the material holding unit 32a is stopped.
The substrate 21 on which the film has been formed is carried out of the vacuum chamber 11 while the vacuum atmosphere in the vacuum chamber 11 is maintained by a transfer robot (not shown).
Next, a substrate 21 different from the substrate 21 on which the film is formed is carried into the vacuum chamber 11 by a transfer robot (not shown) while maintaining the vacuum atmosphere in the vacuum chamber 11, and the above-described film forming operation is repeated.

With reference to FIG. 2, the film-forming method using the film-forming apparatus 10b which is a sputtering device is demonstrated.
The liquid supply valve 43, the drain valve 44, the air supply valve 49, and the sub exhaust valve 48 are closed to insulate the vacuum chamber 11 from the atmosphere outside the vacuum chamber 11.
The main exhaust valve 46 is opened, and the vacuum chamber 11 is evacuated by the vacuum exhaust unit 12. Thereafter, evacuation is continued and the vacuum atmosphere in the vacuum chamber 11 is maintained.
Either Li or Li ₃ PO _{4 as} the film forming material 31 is attached to the material holding portion 32b in advance.
A substrate 21 is carried into the vacuum chamber 11 and held by the substrate holding unit 22b while the vacuum atmosphere in the vacuum chamber 11 is maintained by a transfer robot (not shown).
Here, Ar gas is introduced as a sputtering gas into the vacuum chamber 11 from the sputtering gas introduction unit 51, and a DC voltage or an AC voltage is applied from the power supply device 33 between the material holding unit 32b and the substrate holding unit 22b. The formed sputtering gas is turned into plasma, and the film forming material 31 is sputtered.

Part of the film formation particles emitted from the film formation material 31 is incident on the substrate 21, and a thin film of film formation particles is formed on the substrate 21. Other film forming particles are incident on and adhere to the deposition preventing plate 41 and the film forming material 31. The film forming particles adhering to the film forming material 31 are sputtered again, but the film forming particles adhering to the deposition preventing plate 41 are deposited on the deposition preventing plate 41.
After a thin film having a predetermined thickness is formed on the surface of the substrate 21, the voltage application from the power supply device 33 to the substrate holding unit 22 b and the material holding unit 32 b is stopped, and the introduction of the sputtering gas from the sputtering gas introduction unit 51 is stopped. .
The substrate 21 on which the film has been formed is carried out of the vacuum chamber 11 while the vacuum atmosphere in the vacuum chamber 11 is maintained by a transfer robot (not shown).
Next, a substrate 21 different from the substrate 21 on which the film is formed is carried into the vacuum chamber 11 by a transfer robot (not shown) while maintaining the vacuum atmosphere in the vacuum chamber 11, and the above-described film forming operation is repeated.

With reference to FIG. 3, the film-forming method using the film-forming apparatus 10c which is a CVD apparatus is demonstrated.
The liquid supply valve 43, the drain valve 44, the air supply valve 49, and the sub exhaust valve 48 are closed to insulate the vacuum chamber 11 from the atmosphere outside the vacuum chamber 11.
The main exhaust valve 46 is opened, and the vacuum chamber 11 is evacuated by the vacuum exhaust unit 12. Thereafter, evacuation is continued and the vacuum atmosphere in the vacuum chamber 11 is maintained.
A substrate 21 is carried into the vacuum chamber 11 and held by the substrate holding unit 22c while the vacuum atmosphere in the vacuum chamber 11 is maintained by a transfer robot (not shown).
A DC voltage is applied from the power supply device 33 to the electric heater 23 to heat the substrate 21.
A source gas is introduced into the discharge container 52 from the source gas discharge unit 53, and the source gas is discharged from the discharge hole of the discharge container 52 toward the substrate 21.
The source gas chemically reacts with the heat of the substrate 21 to generate film-forming particles. Part of the generated film formation particles adheres to the substrate 21, and a thin film of film formation particles is formed on the substrate 21. Other film forming particles adhere to the deposition preventing plate 41 and are deposited.

After a thin film having a predetermined thickness is formed on the surface of the substrate 21, the supply of the source gas from the source gas discharge unit 53 is stopped, and the voltage application from the power supply device 33 to the electric heater 23 is stopped.
The substrate 21 on which the film has been formed is carried out of the vacuum chamber 11 while the vacuum atmosphere in the vacuum chamber 11 is maintained by a transfer robot (not shown).
Next, a substrate 21 different from the substrate 21 on which the film has been formed is carried into the vacuum chamber 11 while maintaining the vacuum atmosphere in the vacuum chamber 11 by a transfer robot (not shown), and the above-described film forming operation is repeated.
In any of the film forming apparatuses denoted by reference numerals 10a to 10c, as the film forming operation is repeated, the film thickness of the film forming particles attached to the deposition preventing plate 41 increases. When the film-forming particles attached from the deposition preventing plate 41 are peeled off and attached to the substrate 21, they become impurities. Therefore, before the film forming particles attached from the deposition preventing plate 41 are peeled off, the film forming particles attached from the deposition preventing plate 41 are removed by a cleaning method described later.

<Cleaning method for film forming apparatus>
A cleaning method for the film forming apparatuses 10a to 10c of the present invention will be described.
With reference to FIGS. 1 to 3, a cleaning liquid capable of dissolving the film-forming particles is stored in the tank 19 in advance. Here, pure water or a liquid containing H ₂ O is used as the cleaning liquid.
The length of time for immersing the adhesion region, which is a portion where the film-forming particles adhere inside the vacuum chamber 11, in the cleaning liquid and the pH threshold value of the cleaning liquid when the cleaning process is finished are determined in advance by tests and simulations.

When the substrate 21 is disposed in the vacuum chamber 11, the substrate 21 is unloaded from the vacuum chamber 11 while maintaining the vacuum atmosphere in the vacuum chamber 11 by a transfer robot (not shown).
The main exhaust valve 46 is closed and the vacuum exhaust in the vacuum chamber 11 is stopped. The liquid supply valve 43, the drain valve 44, the air supply valve 49, and the sub exhaust valve 48 are closed in advance, and the inside of the vacuum chamber 11 is insulated from the atmosphere outside the vacuum chamber 11.

First, as an inert gas introduction process, an air supply valve 49 is opened, an inert gas that does not react with film-forming particles is introduced into the vacuum chamber 11 from the inert gas introduction unit 18 through the air supply port 13, and vacuum is applied. The pressure in the tank 11 is set to a magnitude equal to or greater than the pressure outside the vacuum tank 11. Here, Ar gas is used as the inert gas.
The sub exhaust valve 48 is opened, and the inert gas in the vacuum chamber 11 is discharged to the outside of the vacuum chamber 11 through the exhaust port 16.
Thereafter, the introduction of the inert gas from the inert gas introduction unit 18 is continued so that the pressure in the vacuum chamber 11 is maintained at a level equal to or greater than the pressure outside the vacuum chamber 11.

Next, as a cleaning process, the liquid supply valve 43 is opened, and the cleaning liquid is introduced from the tank 19 into the vacuum chamber 11.
When the cleaning liquid comes into contact with the film-forming particles attached to the attachment region in the vacuum chamber 11,
Li + H ₂ O → LiOH + H ₂
Through the chemical reaction, the film-forming particles are dissolved in the cleaning liquid, and H ₂ gas is generated. The hydrogen ion index (pH) of the cleaning liquid in which the film-forming particles are dissolved is larger than that before the film-forming particles are dissolved.
The generated H ₂ gas is carried out together with the inert gas to the outside of the vacuum chamber 11 through the exhaust port 16 and the sub exhaust pipe 47. Unlike the prior art, NH ₃ gas is not generated, and it is safe for the cleaning operator. Also, the cleaning operator is not exposed to the generated H ₂ gas and is safe.

The cleaning liquid is introduced into the vacuum chamber 11 until the water level of the cleaning liquid is higher than the upper end of the deposition preventing plate 41 so that the cleaning liquid contacts the entire portion of the vacuum chamber 11 where the film-forming particles are adhered. The liquid valve 43 is closed and the introduction of the cleaning liquid is stopped.
The exhaust port 16 and the air supply port 13 are arranged at a position higher than the upper end of the deposition preventing plate 41, and the cleaning liquid does not enter the exhaust port 16 and the air supply port 13. The introduction of the inert gas from 13 and the exhaust of the gas from the exhaust port 16 can be continued.
After immersing the adhering region in the cleaning liquid for a predetermined time, the drain valve 44 is opened to discharge the cleaning liquid from the vacuum chamber 11.

The detection unit 17 detects the pH of the cleaning liquid discharged from the vacuum chamber 11. When the cleaning liquid is completely discharged, the drain valve 44 is closed.
If the detection result of the detection unit 17 is larger than a predetermined threshold value, the above-described inert gas introduction process and cleaning process are repeated.
If the detection result of the detection unit 17 is equal to or less than the threshold value, the cleaning process is terminated.
After finishing the cleaning process, as a drying process, water droplets of the cleaning liquid adhering to the inside of the vacuum chamber 11 are evaporated by the drying means 34 to dry the inside of the vacuum chamber 11. The water vapor of the cleaning liquid is carried out of the vacuum chamber 11 through the exhaust port 16 and the sub exhaust pipe 47 together with the inert gas.

Next, the air supply valve 49 is closed to stop the introduction of the inert gas into the vacuum chamber 11. The sub exhaust valve 48 is closed to insulate the inside of the vacuum chamber 11 from the atmosphere outside the vacuum chamber 11.
The main exhaust valve 46 is opened, and the vacuum chamber 11 is evacuated by the vacuum exhaust unit 12. Since the cleaning operation is performed without opening the inside of the vacuum chamber 11 to the atmosphere, the time required from the end of the cleaning operation to the evacuation is shortened compared to the conventional case.
The evacuated vacuum chamber 11 is dried again by the drying means 34. The water vapor of the cleaning liquid is evacuated by the evacuation unit 12.
While the vacuum atmosphere in the vacuum chamber 11 is maintained, an undeposited substrate 21 is carried into the vacuum chamber 11 by a transfer robot (not shown), and the above-described film forming operation is resumed.

In the above description, the deposition plate 41 is immersed in the cleaning liquid, and the film forming particles adhering to the deposition plate 41 are dissolved in the cleaning liquid. However, the cleaning method of the film forming apparatus of the present invention is performed in the vacuum chamber 11. The present invention is not limited to this method as long as the film-forming particles attached to the plate 41 can be removed by dissolving in the cleaning liquid. It may be dissolved in

The cleaning method of the film forming apparatus of the present invention is not limited to the method of introducing the inert gas before introducing the cleaning liquid into the vacuum chamber 11 that has been evacuated as described above, and the inside of the vacuum chamber 11 that has been evacuated. Alternatively, the cleaning liquid may be introduced into the vacuum chamber 11 without introducing the inert gas, and the generated gas may be discharged to the outside of the vacuum chamber 11 by the vacuum exhaust unit 12. However, since introduction of the cleaning liquid into the vacuum atmosphere may cause an unexpected problem, it is preferable to introduce the cleaning liquid after introducing the inert gas.

10a, 10b, 10c ... Film forming apparatus 11 ... Vacuum chamber 12 ... Vacuum exhaust part 15 ... Drainage port 17 ... Detection part 18 ... Inert gas introduction part 19 ... Tank 21 ...

Substrate

22a, 22b, 22c ...

Substrate holder

30a, 30b ... Discharge means 30c ₁ ... Gas introduction part 30c ₂ ... Reaction means 31 ...

Deposition material

32a, 32b, 32c ... Material holder 34 ... Dry means

Claims

A vacuum chamber having an exhaust port on the wall;
A vacuum exhaust unit connected to the exhaust port for evacuating the vacuum chamber;
A material holding unit arranged in the vacuum chamber and holding a film forming material;
Release means for releasing film forming particles, which are particles of the film forming material, from the film forming material held in the material holding unit;
A substrate holding part that is disposed at a position where the film-forming particles are incident and holds a substrate;
A film forming apparatus comprising:
A hollow tank formed of a material that does not dissolve in a cleaning solution capable of dissolving the film-forming particles;
The inside of the tank is connected to the inside of the vacuum chamber,
A film forming apparatus in which a drainage port is provided on a bottom surface of the vacuum chamber.
A vacuum chamber having an exhaust port on the wall;
A vacuum exhaust unit connected to the exhaust port for evacuating the vacuum chamber;
A gas introduction part for introducing a plurality of source gases into the vacuum chamber;
A reaction means for chemically forming the source gas introduced into the vacuum chamber to generate film-forming particles;
A substrate holding part that is disposed at a position where the film-forming particles are incident and holds a substrate;
A film forming apparatus comprising:
A hollow tank formed of a material that does not dissolve in a cleaning solution capable of dissolving the film-forming particles;
The inside of the tank is connected to the inside of the vacuum chamber,
A film forming apparatus in which a drainage port is provided on a bottom surface of the vacuum chamber.
The film forming apparatus according to claim 1, wherein the film forming particles are either Li or Li 3 PO 4 , and the cleaning liquid contains H 2 O.
The film forming apparatus according to any one of claims 1 to 3, further comprising a drying unit that is disposed in the vacuum chamber and dries the inside of the vacuum chamber.
The film forming apparatus according to any one of claims 1 to 4, further comprising a detection unit that is connected to the drainage port and detects a hydrogen ion index of the cleaning liquid.
The film forming apparatus according to any one of claims 1 to 5, further comprising an inert gas introduction unit that introduces an inert gas that does not react with the film forming particles into the vacuum chamber.
In a vacuum evacuated vacuum chamber, a method for cleaning a film forming apparatus in which film forming particles are incident on a substrate and a thin film of the film forming particles is formed on the substrate,
After unloading the substrate from the vacuum chamber, a cleaning solution capable of dissolving the film-forming particles is introduced into the vacuum chamber, the cleaning solution is brought into contact with the film-forming particles attached to the inside of the vacuum chamber, and A method for cleaning a film forming apparatus, comprising: a cleaning step of dissolving a film material in the cleaning liquid and discharging the cleaning liquid from the vacuum chamber.
The hydrogen ion index of the cleaning liquid discharged from the vacuum chamber is detected, and based on the detection result, either the cleaning process is repeated or the cleaning process is terminated. A method for cleaning a film forming apparatus.
Before introducing the cleaning liquid into the vacuum chamber, an inert gas that does not react with the film-forming particles is introduced into the vacuum chamber so that the pressure in the vacuum chamber is equal to or higher than the pressure outside the vacuum chamber. Having an active gas introduction step,
In the cleaning step, the introduction of the inert gas is continued and the pressure in the vacuum chamber is maintained at a pressure equal to or higher than the pressure outside the vacuum chamber, and the cleaning liquid is injected into the vacuum chamber, The film-forming apparatus cleaning method according to claim 7, wherein the gas is discharged to the outside of the vacuum chamber.
The film-forming apparatus cleaning method according to any one of claims 7 to 9, further comprising a drying step of drying the vacuum chamber after the cleaning step.
The film-forming apparatus cleaning method according to claim 7, wherein the film-forming particles are either Li or Li 3 PO 4 , and the cleaning liquid contains H 2 O.