WO2015162868A1

WO2015162868A1 - Reaction device

Info

Publication number: WO2015162868A1
Application number: PCT/JP2015/001994
Authority: WO
Inventors: 勝志寺岡; 平岩　次郎
Original assignee: 東洋炭素株式会社
Priority date: 2014-04-24
Filing date: 2015-04-09
Publication date: 2015-10-29
Also published as: TW201610209A

Abstract

A CVD device includes a film formation processing unit, a fluorine gas generation unit, an inert gas supply source, and a film forming gas supply source. An object is housed in a chamber of the film formation processing unit during film formation processing, and film forming gas from the film forming gas supply source is supplied into the chamber. The fluorine gas generation unit includes an electrolytic bath, an anode, and a cathode. At least part of the surface of the anode is formed from a conductive carbon material having a diamond structure. Fluorine gas generated by the fluorine gas generation unit is supplied into the chamber when the chamber is cleaned. The film formation processing of the object and the cleaning of the chamber are controlled by one control unit.

Description

Reactor

The present invention relates to a reaction apparatus for forming a predetermined film on the surface of an object.

In a CVD (Chemical Vapor Deposition) apparatus, a film is also formed on the inner surface of a chamber (reaction chamber) during film formation on the surface of an object. When the film attached to the inner surface of the chamber is peeled off from the inner surface, the peeled film is scattered as particles in the chamber, which adversely affects the film forming process. In order to remove the film attached to the inner surface of the chamber at the time of film formation, the chamber is cleaned.

Patent Document 1 describes a plasma CVD apparatus that cleans a reaction chamber using a cleaning gas. This plasma CVD apparatus includes a cleaning gas generator in addition to film forming components such as a reaction chamber, a high-frequency power source, a high-frequency application device, and a plurality of pumps. The cleaning gas generator includes an energy application device and a fluorine gas concentrating / separating / purifying device, and generates fluorine gas as a cleaning gas.

When generating fluorine gas, energy is applied to the fluorine compound by the energy application device in the cleaning gas generator. A plasma generator or the like is used as the energy application device. Thereby, a fluorine gas component and components other than fluorine gas are produced from the fluorine compound. A fluorine gas component and a component other than fluorine gas are separated by a fluorine gas concentrating / separating device, and fluorine gas is generated.

Fluorine gas generated by the cleaning gas generator is supplied into the reaction chamber, and the inside of the reaction chamber is adjusted to a predetermined pressure. In this state, plasma is generated in the reaction chamber. Thereby, the by-product (film adhering to the inner surface of the reaction chamber) in the reaction chamber is gasified. Then, the gas containing a by-product is exhausted.
JP 2004-39740 A

As described above, in the plasma CVD apparatus of Patent Document 1, the cleaning gas generation apparatus for generating fluorine gas is composed of an energy application apparatus and a fluorine gas concentrating / separating / purifying apparatus. In order to generate high energy such as plasma, the energy application device includes components similar to those for film formation such as a reaction chamber, a high-frequency power source, a high-frequency application device, and a pump, and thus is large and expensive. . The cleaning gas generator requires a fluorine gas concentrating / separating / purifying device in addition to such an energy applying device. Therefore, the cleaning gas generator is larger and expensive. Therefore, in the plasma CVD apparatus of Patent Document 1, it is difficult to reduce the size and cost.

An object of the present invention is to provide a reaction apparatus that has a cleaning function and can be reduced in size and cost.

(1) A reaction apparatus according to one aspect of the present invention is a reaction apparatus that forms a predetermined film on the surface of an object by gas reaction in a chamber, and a film forming gas supply system used for gas reaction, A fluorine gas supply device for supplying fluorine gas, which serves as a cleaning gas for the inner wall of the chamber, by electrolysis of an electrolytic bath containing hydrogen fluoride to the chamber, a film forming gas supply system, and a controller for controlling the fluorine gas supply device The fluorine gas supply device has an electrolytic cell, a cathode and an anode provided in the electrolytic cell, and at least a part of the surface of the anode is formed of a conductive carbon material having a diamond structure.

In the reaction apparatus, the control unit controls the film forming gas supply system during film formation. In this case, the film-forming gas is supplied into the chamber by the film-forming gas supply system in a state where the object is accommodated in the chamber. Thereby, a gas reaction occurs in the chamber, and a predetermined film is formed on the surface of the object.

On the other hand, when the chamber is cleaned, the control unit controls the fluorine gas supply device. That is, a control part controls the electrolysis of the electrolytic bath accommodated in the electrolytic cell. Fluorine gas is generated by electrolysis of the electrolytic bath in the electrolytic cell of the fluorine gas supply device. The generated fluorine gas is supplied into the chamber as a cleaning gas. Thereby, the deposit on the inner wall of the chamber is removed.

In the fluorine gas supply device, at least a part of the surface immersed in the electrolytic bath on the surface of the anode is formed of a conductive carbon material having a diamond structure. In this case, it is possible to increase the current density in the electrolytic bath while preventing polarization at the anode. Thereby, a sufficient amount of fluorine gas can be generated in a small electrolytic cell for cleaning the inner wall of the chamber in a short time. Moreover, the fluorine gas generated in the electrolytic cell can be supplied to the chamber without going through the storage facility. Further, the common control unit controls film formation processing by the film forming gas supply system and cleaning of the inner wall of the chamber by the fluorine gas supply device. As a result, a reactor having a cleaning function and capable of being reduced in size and cost is realized.

(2) The fluorine gas supply device may perform electrolysis at an applied current density of 20 A / dm ² or more and 1000 A / dm ² or less during electrolysis of the electrolytic bath.

When the current density in the periphery of the anode in the electrolytic bath is 20 A / dm ² or more, a large amount of fluorine gas can be generated in the small-capacity electrolytic bath. Moreover, deterioration of the anode can be suppressed when the current density in the periphery of the anode in the electrolytic bath is 1000 A / dm ² or less. Accordingly, it is possible to reduce the size and life of the fluorine gas supply device.

(3) The reaction apparatus may be configured such that an inert gas is supplied from one inert gas supply source into the chamber and the electrolytic cell.

In this case, the inert gas can be supplied into the chamber and the electrolytic cell by one inert gas supply source. Thereby, it is not necessary to separately prepare an inert gas supply source for supplying an inert gas into the chamber and the electrolytic cell. Therefore, downsizing and cost reduction are realized.

(4) The control unit may adjust the pressure in the electrolytic cell by controlling an inert gas supply system including an inert gas supply source.

In this case, the pressure in the electrolytic cell is adjusted by the inert gas. Thereby, stable electrolysis can be performed in the electrolytic cell without increasing the size of the reaction apparatus.

In addition, when an electrolytic bath containing hydrogen fluoride is electrolyzed, hydrogen gas is generated together with fluorine gas in the electrolytic cell. As described above, when the pressure in the electrolytic cell is adjusted by the inert gas, the hydrogen gas generated in the electrolytic cell can be diluted with the inert gas used for pressure adjustment. Thereby, since the raise of the hydrogen concentration in an electrolytic vessel can be suppressed, safety is ensured.

(5) The control unit is configured to replace the film forming gas or fluorine gas remaining in the chamber with an inert gas so as to replace the film forming gas or fluorine gas remaining in the chamber after at least one of the film formation and the chamber cleaning with the fluorine gas. You may control the inert gas supply system containing a supply source.

Thereby, after the film forming gas or fluorine gas is supplied into the chamber, the film forming gas or fluorine gas remaining in the chamber is replaced with an inert gas. In this case, the chamber is filled with an inert gas after at least one of the film formation and the chamber cleaning. Thereby, film forming gas or fluorine gas harmful to the human body is prevented from remaining in the chamber. Therefore, safety is ensured when the operator opens the chamber after at least one of the above-described processes. Further, the reaction chamber after film formation or cleaning can be easily returned to atmospheric pressure.

(6) The fluorine gas supply device may include a fluorine gas supply system that guides the fluorine gas generated in the electrolytic cell from the electrolytic cell to the chamber.

In this case, the fluorine gas generated in the electrolytic cell is guided into the chamber by the fluorine gas supply system.

(7) The fluorine gas supply system may include a fluorine gas supply pipe.

In this case, the fluorine gas generated in the electrolytic cell is guided into the chamber through the fluorine gas supply pipe. Thereby, the fluorine gas can be supplied into the chamber with a simple configuration.

(8) The fluorine gas supply system is a fluorine gas supply pipe, and the fluorine gas supply pipe includes one or a plurality of valves, and is configured to supply fluorine gas generated in the electrolytic cell directly into the chamber. Also good.

In this case, the supply path of the fluorine gas from the electrolytic cell to the inside of the chamber is composed of, for example, only a fluorine gas supply pipe including one or more valves. With such a configuration, the fluorine gas generated in the electrolytic cell is directly supplied to the chamber without going through the gas storage facility. Therefore, it is not necessary to provide a gas storage facility between the electrolytic cell and the chamber, so that an increase in the size of the reaction apparatus is suppressed. Further, when the chamber is cleaned, the pressure in the chamber is reduced, and the pressure in the chamber becomes lower than the pressure in the anode chamber. Thereby, the fluorine gas generated in the electrolytic cell is smoothly guided into the chamber through the fluorine gas supply pipe. Therefore, it is not necessary to provide a configuration for pumping fluorine gas from the electrolytic cell to the chamber between the electrolytic cell and the chamber. Therefore, the enlargement of the reaction apparatus is suppressed.

(9) The fluorine gas supply system may include a vacuum generator that sucks fluorine gas from the electrolytic cell by the flow of inert gas and guides the sucked fluorine gas to the chamber together with the inert gas.

In this case, the fluorine gas generated in the electrolytic cell can be introduced into the chamber while being diluted with an inert gas. Thereby, appropriate cleaning can be performed with diluted fluorine gas.

(10) The fluorine gas supply system may include a pumping device that pumps the fluorine gas generated in the electrolytic cell to the chamber.

In this case, the fluorine gas generated in the electrolytic cell is supplied into the chamber while being pressurized. Thereby, pressurized fluorine gas can be supplied into the chamber. Therefore, appropriate cleaning can be performed with fluorine gas having a desired pressure.

(11) The fluorine gas supply system may include a tank for storing fluorine gas generated in the electrolytic cell.

In this case, fluorine gas generated in the electrolytic cell is stored in the tank. Thereby, an amount of fluorine gas necessary for cleaning the chamber can be stored in the tank in advance. Therefore, a sufficient amount of fluorine gas can be supplied into the chamber when the chamber is cleaned.

(12) The fluorine gas supply system may include a tank that stores the fluorine gas generated in the electrolytic cell and a pumping device that pumps the fluorine gas generated in the electrolytic cell to the tank.

In this case, the fluorine gas generated in the electrolytic cell is supplied into the tank while being pressurized by the pressure feeding device. Thereby, since the pressurized fluorine gas can be stored in the tank, the enlargement of the tank can be suppressed. Further, a fluorine gas in an amount necessary for cleaning the chamber can be stored in the tank in advance. Therefore, a sufficient amount of fluorine gas can be supplied into the chamber when the chamber is cleaned.

(13) The fluorine gas supply device may further include a flow rate adjusting device for adjusting the flow rate of the fluorine gas flowing into the chamber through the fluorine gas supply system.

In this case, the flow rate of the fluorine gas introduced into the chamber can be adjusted. Thereby, appropriate cleaning can be performed by supplying fluorine gas to the chamber at a desired flow rate.

(14) The reaction apparatus may further include a housing that houses the chamber and the fluorine gas supply device, and an exhaust device that exhausts the inside of the housing.

In this case, the atmosphere inside the housing is exhausted. This prevents fluorine gas or other gases from leaking out of the housing.

(15) The fluorine gas supply device includes a plurality of electrolytic cells, each electrolytic cell is provided with an anode and a cathode, and the control unit is an electrolyzer accommodated in each electrolytic cell when supplying fluorine gas into the chamber. The fluorine gas supply device may be controlled so that fluorine gas is generated by electrolysis in the bath.

In this case, fluorine gas generated in a plurality of electrolytic cells can be supplied into the chamber when the chamber is cleaned. Thereby, an amount of fluorine gas necessary for cleaning can be supplied into the chamber in a short time.

Further, since the fluorine gas supply device has a plurality of electrolytic cells, for example, when a failure occurs in one electrolytic cell, the fluorine gas generated from the other electrolytic cell is maintained in the chamber while performing maintenance of the one electrolytic cell. Can be supplied to. Therefore, continuous operation of the reaction apparatus becomes possible.

According to the present invention, a reactor having a cleaning function and capable of being reduced in size and cost is realized.

FIG. 1 is a configuration diagram of a CVD apparatus according to the first embodiment. FIG. 2 is a block diagram showing a control system of the CVD apparatus of FIG. FIG. 3 is a configuration diagram showing a part of a CVD apparatus according to the second embodiment. FIG. 4 is a block diagram showing a part of a CVD apparatus according to another embodiment.

A reaction apparatus according to an embodiment of the present invention will be described. In the following description, a CVD apparatus that forms a predetermined film on the surface of an object by CVD (chemical vapor deposition) will be described as an example of a reaction apparatus. The CVD apparatus described below removes the film attached to the inner wall (inner surface) of the chamber by the film formation processing function that forms a predetermined film on the surface of the object in the chamber (reaction chamber) and the film formation processing. Has a cleaning function.

[1] First Embodiment (1) Overall Configuration of CVD Apparatus FIG. 1 is a configuration diagram of a CVD apparatus according to the first embodiment. The CVD apparatus 1 according to the present embodiment is provided in a building BL such as a semiconductor manufacturing factory.

In the example of FIG. 1, the building BL has a first floor part and a second floor part. The first floor portion of the building BL is used as a machine room MR, and the second floor portion of the building BL is used as a clean room CR. A fan filter unit (not shown) is provided on the ceiling of the clean room CR. The floor FL of the clean room CR is composed of, for example, grating. By operating the fan filter unit, a clean air flow from the upper side to the lower side is formed in the clean room CR.

The CVD apparatus 1 mainly includes a film formation processing unit 10, a fluorine gas generation unit 20, a control box 30, a housing 40, a vacuum pump 110, an abatement device 120,

exhaust devices

130 and 140, and an HF (hydrogen fluoride) adsorption tower 150. , HF supply source 160, inert gas supply source 170, film forming gas supply source 180, exhaust equipment 190, a plurality of control valves v1 to v7, and a plurality of pipes p1 to p11.

The film formation processing unit 10, the fluorine gas generation unit 20, the control box 30, and the housing 40 are provided in the clean room CR. On the other hand, the vacuum pump 110, the abatement device 120, the

exhaust devices

130 and 140, the HF adsorption tower 150, the HF supply source 160, the inert gas supply source 170, the film forming gas supply source 180, and the exhaust equipment 190 are machine room MR. Placed inside.

In the clean room CR, the film formation processing unit 10 and the fluorine gas generation unit 20 are further accommodated in a housing 40. An opening 41 is formed on one side wall of the housing 40. A shutter 42 that can open and close the opening 41 and a shutter drive unit 43 that drives the shutter 42 are provided on one side wall.

An exhaust port 44 is formed at the bottom of the housing 40. One end of a pipe p 11 extending into the machine room MR is connected to the exhaust port 44. The other end of the pipe p11 is connected to the exhaust equipment 190. In the machine room MR, an exhaust device 130 and an abatement device 120 are inserted in this order from the upstream to the downstream in the pipe p11.

The exhaust device 130 is, for example, a blower. The atmosphere in the housing 40 is sent to the exhaust facility 190 through the abatement device 120 by the exhaust device 130. Thereby, during the operation of the exhaust device 130, the pressure in the housing 40 becomes lower than the atmospheric pressure. The abatement device 120 is configured to be able to remove HF components and other predetermined harmful components in the gas sent from the exhaust device 130.

In the control box 30, a DC power supply circuit 31, a high frequency power supply circuit 32, and a control unit 33 are provided.

(2) Film Formation Processing Unit The film formation processing unit 10 includes an upper electrode 11, a lower electrode 12, a heater 13, a heater drive unit 14, a chamber 15, a pressure sensor S11, and a temperature sensor S12. The upper electrode 11 and the lower electrode 12 are provided so as to face each other inside the chamber 15. The upper electrode 11 is located above the lower electrode 12 and is electrically connected to the high frequency power supply circuit 32 in the control box 30.

The upper electrode 11 has an upper surface and a lower surface. One opening is formed on the upper surface of the upper electrode 11, and a plurality of openings are formed on the lower surface. Inside the upper electrode 11, a gas supply path 11 i that connects the opening on the upper surface side and the plurality of openings on the lower surface side is formed. One end of the pipe p 1 is connected to the opening on the upper surface side of the upper electrode 11. The other end of the pipe p 1 is located outside the chamber 15 and inside the housing 40. One end of a plurality of (three in this example) pipes p2, p3, and p5 described later is connected to the outer portion of the chamber 15 in the pipe p1. Gas is guided to the pipe p1 through the pipes p2, p3, and p5. The gas guided to the pipe p1 is supplied from one end of the pipe p1 to the space between the upper electrode 11 and the lower electrode 12 through the gas supply path 11i of the upper electrode 11.

The lower electrode 12 has an upper surface and a lower surface. The upper surface of the lower electrode 12 functions as a stage on which an object is placed during the film formation process. A heater 13 is provided inside the lower electrode 12. The heater 13 is electrically connected to a heater driving unit 14 provided outside the chamber 15. The heater driving unit 14 is electrically connected to a DC power supply circuit 31 in the control box 30.

An opening 16 is formed on one side wall of the chamber 15. A shutter 17 that can open and close the opening 16 and a shutter driving unit 18 that drives the shutter 17 are provided on one side wall.

By opening both the shutter 42 provided in the housing 40 and the shutter 17 provided in the chamber 15, an object can be placed on the lower electrode 12 in the chamber 15. In addition, the object can be taken out from the chamber 15. On the other hand, when both the

shutters

42 and 17 are closed, the film forming process and the chamber 15 can be cleaned.

An exhaust port 19 is formed at the bottom of the chamber 15. One end of a pipe p10 extending from the clean room CR to the machine room MR is connected to the exhaust port 19. The other end of the pipe p10 is connected to a part upstream of the abatement device 120 in the pipe p11 (a part between the exhaust device 130 and the abatement device 120 in the example of FIG. 1). Thereby, the abatement apparatus 120 removes the HF component and other predetermined harmful components in the gas sent from the vacuum pump 110.

In the machine room MR, a control valve v7 and a vacuum pump 110 are inserted in this order from the upstream to the downstream of the pipe p10. When the control valve v7 is opened while the shutter 17 of the chamber 15 is closed and the vacuum pump 110 is operating, the atmosphere in the chamber 15 is sent to the exhaust equipment 190 through the exhaust port 19, the pipe p10 and the pipe p11. Thereby, the inside of the chamber 15 is depressurized.

The chamber 15 is provided with a pressure sensor S11 and a temperature sensor S12. The internal pressure of the chamber 15 is detected by the pressure sensor S11, and the temperature of the upper surface of the lower electrode 12 is detected by the temperature sensor S12.

The other end of the pipe p2 is connected to a film forming gas supply source 180 in the machine room MR. A control valve v1 is inserted in the pipe p2. The film forming gas supply source 180 is a gas cylinder in which a film forming gas is stored. As the film forming gas, for example, SiH4 (silane) gas, Si2H6 (disilane) gas, GeH4 (germane) gas, Ge2H4 (digermane) gas, or the like can be used.

The other end of the pipe p3 is connected to one end of the pipe p4. A control valve v2 is inserted in the pipe p3. The other end of the pipe p4 is connected to an inert gas supply source 170. The inert gas supply source 170 is a gas cylinder in which an inert gas is stored, a liquid gas tank, a vaporizer, or the like. As the inert gas, for example, N2 (nitrogen) gas, Ar (argon) gas, He (helium) gas, Xe (xenon) gas, or the like can be used.

One end of the pipe p6 is further connected to one end of the pipe p4. That is, in this example, the other end of the pipe p3, one end of the pipe p4, and one end of the pipe p6 are connected at one point. The other end of the pipe p6 is connected to a cathode chamber 21b of the electrolytic cell 21 described later. A control valve v4 is inserted in the pipe p6.

The other end of the pipe p5 is connected to a gas outlet 26 of the electrolytic cell 21 described later. A control valve v3 is inserted in the pipe p5.

(3) Fluorine Gas Generation Unit The fluorine gas generation unit 20 includes an electrolytic cell 21. The electrolytic cell 21 is made of, for example, a metal or alloy such as Ni (nickel), monel, pure iron, or stainless steel.

An electrolytic bath 22 made of a KF-HF mixed molten salt is formed in the electrolytic bath 21. A partition wall 23 is provided so as to be partially immersed in the electrolytic cell 21. The partition wall 23 is made of, for example, Ni or Monel. In the electrolytic cell 21, an anode chamber 21 a is formed on one side of the partition wall 23, and a cathode chamber 21 b is formed on the other side. The space above the electrolytic bath 22 is blocked by the partition wall 23 between the anode chamber 21a and the cathode chamber 21b.

The anode 24 is disposed so as to contact the electrolytic bath 22 in the anode chamber 21a, and the cathode 25 is disposed so as to contact the electrolytic bath 22 in the cathode chamber 21b. The anode 24 and the cathode 25 are electrically connected to the current supply device 28. The current supply device 28 is further electrically connected to a DC power supply circuit 31 in the control box 30.

When a direct current is passed between the anode 24 and the cathode 25 by the current supply device 28, electrolysis of HF (hydrogen fluoride) in the electrolytic bath 22 is performed. Thereby, fluorine gas is mainly generated in the anode chamber 21a, and hydrogen gas is mainly generated in the cathode chamber 21b.

In the present embodiment, at least a part of the surface of the anode 24 immersed in the electrolytic bath 22 is made of a conductive carbon material having a diamond structure. Specifically, the anode 24 has a configuration in which coating layers made of conductive diamond or conductive diamond-like carbon are formed on both sides of a rectangular conductive substrate. As the conductive substrate, a substrate made of diamond, graphite or amorphous carbon is preferably used. As the conductive substrate, a substrate made of a metal material such as Ni (nickel) may be used. As a material of the cathode 25, for example, Ni is preferably used. Note that the cathode 25 may have the same configuration as the anode 24.

A gas discharge port 26 is provided in the upper part of the anode chamber 21a. As described above, the other end of the pipe p 5 is connected to the gas discharge port 26. When cleaning the chamber 15 to be described later, the gas (mainly fluorine gas) generated in the anode chamber 21a by opening the control valve v3 passes through the gas outlet 26, the pipe p5, the pipe p1, and the gas supply path 11i of the upper electrode 11 to form a film. It is supplied into the chamber 15 of the formation processing unit 10. A mist filter 90 may be inserted in the pipe p5 as shown by a dotted line in FIG. In this case, dust or impurities contained in the gas generated in the anode chamber 21a can be removed. Thereby, high purity fluorine gas can be supplied into the chamber 15 from the anode chamber 21a.

A gas discharge port 27 is provided in the upper part of the cathode chamber 21b. One end of a pipe p8 is connected to the gas discharge port 27. The other end of the pipe p8 is connected to the exhaust equipment 190 of the machine room MR. In the machine room MR, the exhaust device 140 and the HF adsorption tower 150 are inserted in this order from the upstream to the downstream in the pipe p8. The exhaust device 140 is, for example, a vacuum generator. When cleaning the chamber 15, the gas (mainly hydrogen gas) generated in the cathode chamber 21 b by the operation of the exhaust device 140 is sent to the exhaust equipment 190 through the HF adsorption tower 150. The HF adsorption tower 150 is filled with, for example, soda lime as an adsorbent. In the HF adsorption tower 150, HF components in the gas generated in the cathode chamber 21b are removed by soda lime.

One end of a pipe p 7 for supplying HF to the electrolytic bath 22 is connected to the electrolytic cell 21. The other end of the pipe p7 is connected to the HF supply source 160 of the machine room MR. The HF supply source 160 is a storage container in which HF is stored. A control valve v5 is inserted in the pipe p7. By opening the control valve v 5, HF is supplied from the HF supply source 160 into the electrolytic cell 21.

As described above, the other end of the pipe p6 is connected to the cathode chamber 21b. By opening the control valve v4 inserted in the pipe p6, the inert gas is supplied from the inert gas supply source 170 into the cathode chamber 21b through the pipes p4 and p6.

In the machine room MR, a pipe p9 is provided so as to connect the pipe p4 and the pipe p8. A control valve v6 is inserted in the pipe p9. By opening the control valve v6, the inert gas is supplied from the inert gas supply source 170 through the pipes p4 and p9 into the pipe p8.

The electrolytic cell 21 is provided with pressure sensors S21 and S22 and liquid level sensors S23 and S24. The pressure sensor S21 detects the internal pressure of the anode chamber 21a, and the pressure sensor S22 detects the internal pressure of the cathode chamber 21b. Further, the liquid level of the electrolytic bath 22 in the anode chamber 21a is detected by the liquid level sensor S23, and the liquid level of the electrolytic bath 22 in the cathode chamber 21b is detected by the liquid level sensor S24.

(4) Control System The control unit 33 in FIG. 1 includes a CPU (Central Processing Unit) and a memory or a microcomputer, and controls the operation of each component of the CVD apparatus 1.

FIG. 2 is a block diagram showing a control system of the CVD apparatus 1 of FIG. As shown in FIG. 2, the detection results of the pressure sensor S11 and the temperature sensor S12 of the film formation processing unit 10 are given to the control unit 33. The detection results of the pressure sensors S21 and S22 and the liquid level sensors S23 and S24 of the fluorine gas generation unit 20 are given to the control unit 33.

The control unit 33 includes a heater drive unit 14,

shutter drive units

18 and 43, a current supply device 28, a DC power supply circuit 31, a high frequency power supply circuit 32, a vacuum pump 110, an abatement device 120,

exhaust devices

130 and 140, and a control. The operation of the valves v1 to v7 is controlled.

(5) Operation of CVD apparatus (5-1) During film formation process Before the film formation process, the operator opens the shutter 42 of the casing 40 and the shutter 17 of the chamber 15 by operating an operation unit (not shown), An object is placed on the upper surface of the electrode 12. Thereafter, the operator closes the

shutters

17 and 42.

In the initial state of the film forming process, the control valves v1 to v7 are closed. Further, the heater driving unit 14, the current supply device 28, and the exhaust device 140 are not operating. On the other hand, the vacuum pump 110, the abatement device 120, and the exhaust device 130 are operating.

When the film formation process is started, the vacuum pump 110 and the control valve v7 are controlled by the control unit 33 based on the detection result of the pressure sensor S11. Thereby, the pressure in the chamber 15 is adjusted to a predetermined pressure lower than the atmospheric pressure. Further, the DC power supply circuit 31 and the heater driving unit 14 are controlled by the control unit 33 based on the detection result of the temperature sensor S12. Thereby, the heater 13 generates heat, and the temperature of the upper surface of the lower electrode 12 is adjusted to a predetermined temperature.

Next, the control valves v1 and v2 are opened. Thereby, the film forming gas from the film forming gas supply source 180 is supplied into the chamber 15 through the pipes p 2 and p 1 and the gas supply path 11 i of the upper electrode 11. Further, the inert gas from the inert gas supply source 170 is supplied into the chamber 15 through the pipes p4, p3, p1 and the gas supply path 11i of the upper electrode 11. In this case, the film forming gas is diluted with the inert gas in the pipe p1.

Next, the control valves v1, v2, v7 are closed. Alternatively, the control valves v1 and v2 are adjusted so that the opening degree becomes small. In this state, the high frequency power supply circuit 32 is controlled, and a high frequency voltage is applied to the upper electrode 11. Thereby, high frequency plasma is generated between the upper electrode 11 and the lower electrode 12, and a predetermined film is formed on the surface of the object.

Next, the application of the high frequency voltage to the upper electrode 11 is stopped, and the control valves v2 and v7 are opened. Thereby, the inert gas of the inert gas supply source 170 is supplied to the chamber 15 and the atmosphere in the chamber 15 is sent to the exhaust equipment 190 through the exhaust port 19 and the pipes p10 and p11. In this way, the atmosphere in the chamber 15 is replaced with the inert gas from the inert gas supply source 170.

Thereafter, the control valve v7 is closed. Further, the control valve v 2 is held open until the pressure in the chamber 15 reaches atmospheric pressure or the pressure in the housing 40. Finally, the control valve v2 is closed and the shutter 17 of the chamber 15 and the shutter 42 of the housing 40 are opened. In this state, the operator takes out the object after the film formation process from the chamber 15.

(5-2) Cleaning In this embodiment, the chamber 15 is cleaned in a state where no high-frequency plasma is generated in the chamber 15. Before cleaning the chamber 15, the operator closes the shutter 42 of the housing 40 and the shutter 17 of the chamber 15 by operating an operation unit (not shown).

In the initial state of cleaning, the control valves v1 to v7 are closed. Further, the heater driving unit 14, the current supply device 28, and the exhaust device 140 are not operating. On the other hand, the vacuum pump 110, the abatement device 120, and the exhaust device 130 are operating.

When cleaning is started, the control valves v2, v3, v4, v6, v7 are opened. In this state, the current supply device 28 and the DC power supply circuit 31 are controlled by the control unit 33, and a current flows between the anode 24 and the cathode 25 in the electrolytic cell 21. Thereby, the electrolytic bath 22 in the electrolytic cell 21 is electrolyzed, fluorine gas is generated in the anode chamber 21a in the electrolytic cell 21, and hydrogen gas is generated in the cathode chamber 21b.

At this time, the control valve v7 and the vacuum pump 110 are controlled by the control unit 33 based on the detection results of the pressure sensors S11 and S21. Thereby, the pressure in the chamber 15 is adjusted to be lower than the pressure in the anode chamber 21a. In this case, the fluorine gas generated in the anode chamber 21 a is smoothly guided into the chamber 15 through the gas discharge port 26, the pipes p 5 and p 1, and the gas supply path 11 i of the upper electrode 11. Further, the inert gas from the inert gas supply source 170 is introduced into the chamber 15 through the pipes p4, p3, p1 and the gas supply path 11i of the upper electrode 11. In this case, the fluorine gas is diluted with the inert gas in the pipe p1.

As described above, by opening the control valve v4, the inert gas of the inert gas supply source 170 is supplied into the cathode chamber 21b through the pipes p4 and p6. Thereby, the liquid level in the cathode chamber 21b can be controlled by adjusting the amount of the inert gas supplied into the cathode chamber 21b. In the cathode chamber 21b, the generated hydrogen gas is diluted with an inert gas. Thereby, the hydrogen concentration in the cathode chamber 21b is maintained in a state lower than the explosion limit.

The diluted hydrogen gas is sent to the exhaust facility 190 through the gas exhaust port 27 and the pipe p8 by the exhaust device 140. At this time, since the control valve v6 is open, the hydrogen gas sent to the exhaust facility 190 is further diluted with the inert gas in the pipe p8.

When the liquid level of the electrolytic bath 22 detected by the liquid level sensors S23 and S24 is lower than a predetermined value, the control valve v5 is opened. In this state, HF of the HF supply source 160 is supplied into the electrolytic cell 21 through the pipe p7. Thereby, it is prevented that the liquid level of the electrolytic cell 21 becomes lower than a certain height.

In order to perform electrolysis stably in the electrolytic cell 21, the internal pressure of the anode chamber 21a and the internal pressure of the cathode chamber 21b need to be maintained at a constant value equal to each other.

In this example, the opening degree of the control valve v3 is controlled by the control unit 33 based on the detection result of the pressure sensor S21. Thereby, the pressure in the anode chamber 21a is adjusted so as to approach the atmospheric pressure. Further, the opening degree of the control valve v4 is controlled by the control unit 33 based on the detection result of the pressure sensor S22. Thereby, the pressure in the cathode chamber 21b is adjusted so as to approach the atmospheric pressure.

As described above, the internal pressures of the anode chamber 21a and the cathode chamber 21b may be held at atmospheric pressure by controlling the opening degrees of the control valves v3 and v4.

In the chamber 15, diluted fluorine gas is supplied from the gas supply path 11 i of the upper electrode 11, and the atmosphere inside the chamber 15 is exhausted by the vacuum pump 110 through the exhaust port 19. In this way, new fluorine gas is supplied into the chamber 15 and fluorine gas used for cleaning in the chamber 15 is discharged. Thereby, the inside of the chamber 15 is efficiently cleaned with new fluorine gas.

When the predetermined cleaning time has elapsed, the control valves v3, v4, v6 are closed. Further, the operations of the current supply device 28 and the DC power supply circuit 31 are stopped, and the electrolysis is stopped. On the other hand, the control valves v2 and v7 are held open. Thereby, the inert gas of the inert gas supply source 170 is supplied to the chamber 15 and the atmosphere in the chamber 15 is sent to the exhaust equipment 190 through the exhaust port 19 and the pipes p10 and p11. In this way, the atmosphere in the chamber 15 is replaced with the inert gas from the inert gas supply source 170.

Thereafter, the control valve v7 is closed. Further, the control valve v 2 is held open until the pressure in the chamber 15 reaches atmospheric pressure or the pressure in the housing 40. Finally, the control valve v2 is closed and the shutter 17 of the chamber 15 and the shutter 42 of the housing 40 are opened. Thereby, the cleaning of the chamber 15 is completed.

As described above, the anode 24 has a configuration in which coating layers made of conductive diamond or conductive diamond-like carbon are formed on both sides of a rectangular conductive substrate. As a result, it is possible to increase the current density in the electrolytic bath 22 while preventing polarization at the anode 24.

Therefore, in the present embodiment, a direct current is applied between the anode 24 and the cathode 25 so that the current density around the anode 24 in the electrolytic bath 22 is 20 A / dm ² or more and 1000 A / dm ² or less when the chamber 15 is cleaned. Washed away.

When the current density around the anode 24 in the electrolytic bath 22 is 20 A / dm ² or more, a large amount of fluorine gas can be generated in the small-capacity electrolytic bath 22. Thereby, the generated fluorine gas can be supplied to the chamber 15 without going through the storage facility. Further, when the current density around the anode 24 in the electrolytic bath 22 is 1000 A / dm ² or less, the deterioration of the anode 24 can be suppressed. Therefore, the fluorine gas generation unit 20 can be reduced in size and extended in life.

The current density around the anode 24 in the electrolytic bath 22 when the chamber 15 is cleaned is preferably 20 A / dm ² or more and 500 A / dm ² or less, and more preferably 30 A / dm ² or more and 100 A / dm ² or less. More preferred.

(6) Effects (6-1) In the CVD apparatus 1 according to the present embodiment, the film forming gas supply source 180 is housed in the chamber 15 while the object is housed in the chamber 15 during the film forming process. The film forming gas is supplied. Thereby, a predetermined film is formed on the surface of the object.

On the other hand, when the chamber 15 is cleaned, fluorine gas is generated by electrolysis of the electrolytic bath 22 in the electrolytic cell 21 of the fluorine gas generator 20. The generated fluorine gas is supplied into the chamber 15 and the deposits on the inner wall of the chamber 15 are removed.

In the fluorine gas generator 20, at least a part of the surface of the anode 24 immersed in the electrolytic bath 22 is formed of a conductive carbon material having a diamond structure. In this case, the current density in the electrolytic bath 22 can be increased while preventing polarization at the anode 24. Thereby, a sufficient amount of fluorine gas can be generated in the small electrolytic cell 21 for cleaning the inner wall of the chamber 15 in a short time. Moreover, the fluorine gas generated in the electrolytic cell 21 can be supplied to the chamber 15 without going through the storage facility. Further, in the present embodiment, the common control unit 33 controls the film forming process of the object and the cleaning of the inner wall of the chamber 15. As a result, the CVD apparatus 1 that has a cleaning function and can be reduced in size and cost is realized.

(6-2) In this embodiment, the inert gas of the inert gas supply source 170 can be supplied from one inert gas supply source 170 into the chamber 15 and the electrolytic cell 21. In this case, it is not necessary to separately prepare the inert gas supply source 170 for supplying the inert gas into the chamber 15 and the electrolytic cell 21. Therefore, downsizing and cost reduction are realized.

Further, when the common pipe p4 is used for the inert gas supply path from the inert gas supply source 170 to the chamber 15 and the electrolytic cell 21, members for supplying the inert gas to the chamber 15 and the electrolytic cell 21 are provided. Can be reduced. Therefore, size reduction and cost reduction of the CVD apparatus 1 are realized.

(6-3) As described above, when the electrolytic cell 21 and the chamber 15 are connected by the pipes P1 and P5, the fluorine gas generated in the electrolytic cell 21 directly enters the chamber 15 without passing through the gas storage facility. Supplied. Therefore, it is not necessary to provide a gas storage facility between the electrolytic cell 21 and the chamber 15, so that the size of the CVD apparatus 1 is suppressed.

(6-4) When cleaning the chamber 15, the pressure in the chamber 15 is adjusted to be lower than the pressure in the anode chamber 21a by the control valve v7 and the vacuum pump 110. Thereby, the fluorine gas generated in the electrolytic cell 21 is smoothly guided into the chamber 15 through the gas outlet 26 and the pipes p5 and p1. Therefore, it is not necessary to provide a configuration for pumping fluorine gas from the electrolytic cell 21 to the chamber 15 between the electrolytic cell 21 and the chamber 15. Therefore, the enlargement of the CVD apparatus 1 is suppressed.

(6-5) The abatement device 120 removes predetermined harmful components in the gas sent from the vacuum pump 110 during the film formation process, and removes HF components in the gas sent from the vacuum pump 110 during the cleaning of the chamber 15 To do. Thus, in the present embodiment, the harmful components of the exhaust gas can be removed without increasing the size of the CVD apparatus 1 by using the common abatement apparatus 120 for the film formation process and the cleaning of the chamber 15.

(6-6) As described above, the chamber 15 and the fluorine gas generator 20 are accommodated in the housing 40. In addition, the atmosphere inside the housing 40 is exhausted by the exhaust device 130. This prevents the fluorine gas or other gas generated by the fluorine gas generator 20 from leaking outside the housing 40.

(6-7) After forming the film or cleaning the chamber 15, the film forming gas or fluorine gas remaining in the chamber 15 is replaced with an inert gas.

In this case, the chamber 15 is filled with an inert gas after the film formation process and the cleaning of the chamber 15. Thereby, film forming gas or fluorine gas harmful to the human body is prevented from remaining in the chamber 15. Therefore, safety is ensured when the operator opens the chamber 15 after the film forming process and the cleaning of the chamber 15. In addition, the chamber 15 after the film forming process or after the cleaning can be easily returned to the atmospheric pressure.

(6-8) A predetermined amount of inert gas is supplied into the pipe p1 by controlling the control valve v2 during the film formation process and during the cleaning of the chamber 15. Thereby, the film forming gas diluted with the inert gas during the film forming process is supplied into the chamber 15. Further, fluorine gas diluted with an inert gas is supplied into the chamber 15 when the chamber 15 is cleaned. Thus, the concentration of the film forming gas and the fluorine gas used for cleaning can be easily adjusted without increasing the size of the CVD apparatus 1.

(6-9) When the chamber 15 is cleaned, the pressure in the electrolytic cell 21 is adjusted by the inert gas from the inert gas supply source 170. Thereby, stable electrolysis can be performed in the electrolytic cell 21 without increasing the size of the CVD apparatus 1. Further, in the electrolytic cell 21, an inert gas is supplied into the cathode chamber 21b. Thereby, the liquid level in the cathode chamber 21b can be controlled.

(6-10) Also, the hydrogen gas generated in the electrolytic cell 21 is diluted with an inert gas. By diluting the hydrogen gas, the hydrogen concentration in the electrolytic cell 21 can be adjusted to be lower than the explosion limit.

[2] Second Embodiment A CVD apparatus according to the second embodiment will be described while referring to differences from the CVD apparatus 1 according to the first embodiment. The CVD apparatus according to the second embodiment has the following configuration instead of the pipe p5 in FIG. 1 that guides the fluorine gas generated in the electrolytic cell 21 into the chamber 15.

FIG. 3 is a configuration diagram showing a part of the CVD apparatus according to the second embodiment. FIG. 3 shows a configuration in which fluorine gas generated mainly in the electrolytic cell 21 is guided into the chamber 15. As shown in FIG. 3, in the present embodiment, a pipe p20 is connected to the pipe p1 attached to the chamber 15 instead of the pipe p5 of FIG.

The piping p20 is provided with a plurality (four in this example) of piping connection portions. One ends of the pipes p21, p22, p23, and p25 are connected to the plurality of pipe connection portions of the pipe p20, respectively.

The control valve v31 is inserted in the piping p21. One end of the pipe p29 is connected to the other end of the pipe p21. The other end of the pipe p29 is connected to the gas outlet 26 of the electrolytic cell 21. In the pipe p29, a mist filter 90 and a control valve v40 are inserted in this order from upstream to downstream.

The other end of the pipe p22 is connected to the inert gas supply source 170 of FIG. A vacuum generator 61, a mass flow controller (MFC: mass flow control device) 62, and a control valve v32 are interposed in this order from the upstream to the downstream of the pipe p22. One end of a pipe p26 is connected to the vacuum generator 61. The other end of the pipe p26 is connected to one end of the pipe p29. A control valve v33 is inserted in the pipe p26.

A switching valve 72 is provided at the other end of the pipe p23. The switching valve 72 has one inflow port and two outflow ports. The other end of the pipe p23 is connected to one outflow port of the switching valve 72. In the pipe p23, a mass flow controller 73 and a control valve v34 are inserted in this order from upstream to downstream. One end of a pipe p24 is connected to the inflow port of the switching valve 72. The other end of the pipe p24 is connected to one end of the pipe p29. In the pipe p24, a control valve v35 and a pressure feeding device 71 are inserted in this order from upstream to downstream. As the pressure feeding device 71, for example, a bellows pump can be used.

The other end of the pipe p25 is connected to one end of the pipe p29. Thus, in this example, the other ends of the pipes p21, p26, p24, and p25 and one end of the pipe p29 are connected at one point. In the pipe p25, a control valve v38, a tank 81, a control valve v37, a mass flow controller 82, and a control valve v36 are inserted in this order from upstream to downstream. One end of a pipe p27 is connected to the tank 81. The other end of the pipe p27 is connected to the inert gas supply source 170 of FIG. A valve v39 is inserted in the pipe p27. A pipe p28 is provided so as to connect the tank 81 and the other outflow port of the switching valve 72.

The operations of the pressure feeding device 71, the switching valve 72, the control valves v31 to v40, and the

mass flow controllers

62, 73, and 82 in FIG. 3 are controlled by the control unit 33 in FIG. In particular, the opening degree of the control valve v40 is controlled by the control unit 33 based on the detection result of the pressure sensor S21, similarly to the control valve v3 of FIG. Thereby, when fluorine gas is generated in the electrolytic cell 21, the pressure in the anode chamber 21a is adjusted so as to approach the atmospheric pressure.

In the CVD apparatus 1 having the above-described configuration, for example, the control valve v31 is opened and the control valves v32, v33, v34, v35, v36, v37, v38, v39 in a state where fluorine gas is generated in the electrolytic cell 21. Is closed. In this case, when the control valve v40 is opened, the fluorine gas generated in the electrolytic cell 21 is guided into the chamber 15 through the pipes p29, p21, p20, p1 and the gas supply path 11i of the upper electrode 11. Thereby, the chamber 15 can be cleaned with high-purity fluorine gas.

In the state where fluorine gas is generated in the electrolytic cell 21, for example, the control valves v32, v33 are opened, and the control valves v31, v34, v35, v36, v37, v38, v39 are closed. Further, an inert gas is supplied to the pipe p22, and an inert gas flow is formed in the pipe p22. In this case, when the control valve v40 is opened, the fluorine gas generated in the electrolytic cell 21 is sucked into the pipe p22 by the vacuum generator 61 through the pipes p29 and p26. The fluorine gas sucked into the pipe p22 is diluted with an inert gas. The diluted fluorine gas is sent to the pipe p20 through the mass flow controller 62, and is introduced into the chamber 15 through the pipe p1 and the gas supply path 11i of the upper electrode 11.

In the mass flow controller 62, a sufficiently large difference (for example, a difference of 50 kPa or more) is generated between the pressure in the upstream pipe p22 and the pressure in the downstream pipe p22, so that the gas flowing through the pipe p22 The flow rate is adjusted. In this example, when the chamber 15 is cleaned, the pressure inside the chamber 15 is reduced by the vacuum pump 110, so that the pressure on the downstream side of the mass flow controller 62 decreases. At this time, the pressure on the upstream side of the mass flow controller 62 is increased by supplying the inert gas to the pipe p22. Thereby, a sufficiently large difference is ensured between the pressure in the upstream pipe p22 and the pressure in the downstream pipe p22. Therefore, appropriate cleaning can be performed by supplying the fluorine gas diluted at a desired flow rate into the chamber 15.

In the state where fluorine gas is generated in the electrolytic cell 21, for example, the control valves v34 and v35 are opened, and the control valves v31, v32, v33, v36, v37, v38 and v39 are closed. Further, the pressure feeding device 71 operates. Furthermore, the switching valve 72 communicates the internal space of the pipe p24 and the internal space of the pipe p23, and shuts off the internal space of the pipe p24 and the internal space of the pipe p28. In this case, when the control valve v40 is opened, the fluorine gas generated in the electrolytic cell 21 is sucked through the pipes p29 and p24 by the pressure feeding device 71 and supplied to the pipe p23 while being pressurized. The fluorine gas supplied to the pipe p23 is guided into the chamber 15 through the pipes p20 and p1 and the gas supply path 11i of the upper electrode 11.

In the mass flow controller 73, as in the mass flow controller 62, a sufficient difference is generated between the pressure in the upstream pipe p23 and the pressure in the downstream pipe p23, so that the gas flowing through the pipe p23 The flow rate is adjusted. As described above, when the chamber 15 is cleaned, the pressure inside the chamber 15 is reduced by the vacuum pump 110, thereby reducing the pressure on the downstream side of the mass flow controller 73. At this time, the pressure on the upstream side of the mass flow controller 73 is increased by supplying the fluorine gas pressurized by the pressure feeding device 71 to the pipe p23. Thereby, a sufficiently large difference is ensured between the pressure in the upstream pipe p23 and the pressure in the downstream pipe p23. Therefore, appropriate cleaning can be performed by supplying high-purity fluorine gas having a desired pressure into the chamber 15 at a desired flow rate.

Further, in a state where fluorine gas is generated in the electrolytic cell 21, for example, the control valve v38 is opened, and the control valves v31, v32, v33, v34, v35, v36, v37, v39 are closed. In addition, the switching valve 72 communicates the internal space of the pipe p24 and the internal space of the pipe p23, and shuts off the internal space of the pipe p24 and the internal space of the pipe p28.

In this state, when the tank 81 is in a vacuum state, the fluorine gas generated in the electrolytic cell 21 is sucked into the tank 81 through the pipes p29 and p25 by opening the control valve v40. Thereby, an amount of fluorine gas necessary for cleaning the chamber 15 can be stored in the tank 81 in advance.

When the fluorine gas stored in the tank 81 is used for cleaning the chamber 15, for example, the control valves v36, v37 are opened and the control valves v31, v32, v33, v34, v35, v36, v37, v38, v39, Close v40. As a result, the fluorine gas in the tank 81 is guided into the chamber 15 through the pipes p20 and p1 and the gas supply path 11i of the upper electrode 11 when the pressure in the chamber 15 is reduced.

In this case, since an amount of fluorine gas necessary for cleaning the chamber 15 is stored in the tank 81 in advance, a sufficient amount of fluorine gas can be supplied into the chamber 15 when the chamber 15 is cleaned.

Here, in the mass flow controller 82, similarly to the mass flow controller 62, a sufficiently large difference is generated between the pressure in the upstream pipe p 25 and the pressure in the downstream pipe p 25, thereby causing the pipe p 25. The flow rate of the gas flowing through is adjusted. Therefore, only opening the control valves v36 and v37 may not produce a sufficiently large difference between the pressure in the upstream pipe p25 and the pressure in the downstream pipe p25.

Therefore, when supplying the fluorine gas from the tank 81 to the chamber 15, the inert gas may be supplied to the pipe p27 and the control valve v36 may be opened. In this case, the pressure in the tank 81 is increased by supplying the inert gas into the tank 81. In this manner, pressurized fluorine gas can be supplied to the upstream side of the mass flow controller 82. Thereby, a sufficiently large difference is ensured between the pressure in the upstream pipe p25 and the pressure in the downstream pipe p25. In this case, the fluorine gas is diluted with an inert gas in the tank 81. Accordingly, the flow rate of the diluted inert gas is adjusted by the mass flow controller 82. Thereby, the diluted fluorine gas can be supplied into the chamber 15 at a desired flow rate and a desired concentration. As a result, appropriate cleaning can be performed.

As described above, when fluorine gas is stored in the tank 81 in advance, for example, the control valve v35 is opened and the control valves v31, v32, v33, v34, v35 are opened in a state where the fluorine gas is generated in the electrolytic cell 21. , V36, v37, v38, v39 may be closed. Alternatively, the internal space of the pipe p24 and the internal space of the pipe p23 may be blocked by the switching valve 72, and the internal space of the pipe p24 and the internal space of the pipe p28 may be communicated. Further, the pressure feeding device 71 may be operated.

In this case, when the control valve v40 is opened, the fluorine gas generated in the electrolytic cell 21 is supplied to the tank 81 by the pressure feeding device 71 through the pipes p29, p24, and p28. Thereby, since the pressurized fluorine gas can be stored in the tank 81, the enlargement of the tank 81 can be suppressed.

As described above, in the present embodiment, by controlling the operation of the switching valve 72, the control valves v31 to v39, and the

mass flow controllers

62, 73, and 82, the electrolytic cell 21 to the chamber 15 are controlled according to the cleaning conditions of the chamber 15. It is possible to change the supply route of the fluorine gas to.

[3] Other Embodiments (1) In the above embodiment, a film forming process is performed on the surface of an object by CVD in the chamber 15. However, the present invention is not limited to this, and a film forming process may be performed on the surface of the object in the chamber 15 by a method other than CVD. For example, a film formation process by sputtering may be performed in the chamber 15, or a film formation process by PVD (physical vapor deposition) may be performed in the chamber 15. Even in these cases, by cleaning the chamber 15 by the same method as in the above example, it is possible to remove an unnecessary film attached to the inner wall or the like of the chamber 15 during the film forming process.

(2) In the above embodiment, the example in which the single chamber type CVD apparatus 1 includes the fluorine gas generation unit 20 has been described. However, the present invention is not limited to this, and a multi-chamber CVD apparatus may include the above-described fluorine gas generation unit 20. In this case, in the multi-chamber type CVD apparatus, the film formation processing unit 10 includes a plurality of chambers 15. The film formation processing unit 10 and the fluorine gas generation unit 20 are further accommodated in the housing 40. In the housing 40, a fluorine gas supply pipe is provided between the plurality of chambers 15 and the fluorine gas generator 20.

(3) In the above embodiment, the hydrogen gas generated by the fluorine gas generator 20 is diluted with an inert gas and exhausted. Not limited to this, the generated hydrogen gas may be stored in a gas cylinder. In addition, when it is possible to generate a film forming gas using hydrogen gas, the hydrogen gas generated in the cathode chamber 21b may be used for generating the film forming gas. Thus, when it is not necessary to dilute the hydrogen gas in order to reuse the hydrogen gas generated by the fluorine gas generator 20, the inert gas may not be supplied to the cathode chamber 21b. In this case, in order to adjust the pressure in the electrolytic cell 21, an inert gas may be supplied to the anode chamber 21a.

(4) In the above embodiment, the control box 30 is provided outside the housing 40. Not only this but the control box 30 may be provided inside the housing | casing 40 instead of the outer side of the housing | casing 40. FIG.

(5) In the above embodiment, the shutter 42 and the shutter driving unit 43 are provided on one side wall of the housing 40. Not limited to this, the shutter 42 and the shutter driving unit 43 may not be provided on one side wall of the housing 40. In this case, the configuration of the CVD apparatus 1 is simplified.

(6) In the above embodiment, the CVD apparatus 1 includes one electrolytic cell 21, and the control unit 33 controls the electrolysis of the electrolytic bath 22 accommodated in one electrolytic cell 21. Not limited to this, the CVD apparatus 1 may have the following configuration.

FIG. 4 is a block diagram showing a part of a CVD apparatus according to another embodiment. In FIG. 4, the components provided in the housing 40 are shown. Illustration of piping is omitted. The CVD apparatus 1 of FIG. 4 is different from the CVD apparatus 1 of FIG. 1 in that the fluorine gas generation unit 20 of the CVD apparatus 1 includes a plurality (four in this example) of electrolytic cells 21. Each electrolytic cell 21 is provided with an anode 24 and a cathode 25. The control unit 33 of this example controls the electrolysis of the electrolytic baths 22 respectively accommodated in the plurality of electrolytic cells 21.

Thereby, the fluorine gas generated in the four electrolytic cells 21 can be supplied into one chamber 15 when the chamber 15 is cleaned. Accordingly, the fluorine gas necessary for cleaning can be supplied into the chamber 15 in a short time.

Moreover, according to said structure, since the fluorine gas generation | occurrence | production part 20 has the some electrolytic cell 21, when a malfunction arises in one electrolytic cell 21, for example, while performing the maintenance of the one electrolytic cell 21, other Fluorine gas generated from the electrolytic cell 21 can be supplied into the chamber 15. Therefore, continuous operation of the CVD apparatus 1 becomes possible.

(7) In the second embodiment, the supply path including the pipe p21 and the control valve v31, the pipes p22 and p26, and the control valves v32 and v33 as the fluorine gas supply path between the pipe p20 and the pipe p29. And a supply path including the vacuum generator 61, a supply path including the pipes p23 and p24, the control valves v34 and v35, the pressure feeding device 71 and the switching valve 72, and a supply path including the pipe p25, the control valves v36 to v38 and the tank 81. Are provided in parallel, but the present invention is not limited to this. A part of the plurality of supply paths may be provided between the pipe p20 and the pipe p29.

(8) In the CVD apparatus 1 according to the second embodiment, the pipe p21 is not provided with a mass flow controller, but the present invention is not limited to this. For example, when the fluorine gas generated in the electrolytic cell 21 is supplied to the pipe p21 while being pressurized, a mass flow controller may be provided in the pipe p21. Accordingly, appropriate cleaning can be performed by supplying fluorine gas into the chamber 15 at a desired flow rate.

(9) In the above embodiment, the high frequency voltage is not applied to the upper electrode 11 in the chamber 15 when the chamber 15 is cleaned, but the present invention is not limited to this. A high frequency voltage may be applied to the upper electrode 11 from the high frequency power supply circuit 32 when the chamber 15 is cleaned. In this case, high-frequency plasma is generated between the upper electrode 11 and the lower electrode 12. As a result, the fluorine gas is activated, whereby cleaning can be performed more efficiently.

[4] Correspondence relationship between each constituent element of claim and each part of embodiment The following describes an example of the correspondence between each constituent element of the claim and each constituent element of the embodiment. It is not limited to examples.

In the above embodiment, the CVD apparatus 1 is an example of a reaction apparatus, the chamber 15 is an example of a chamber, the film forming gas supply source 180, the pipes p1 and p2, and the control valve v1 are a film forming gas supply system. Fluorine gas generator 20, pipes p1, p5, p20 to p29, control valves v3, v31 to v40, vacuum generator 61, pumping device 71, switching valve 72, tank 81, and

mass flow controllers

62, 73, 82 Is an example of a fluorine gas supply device, an inert gas supply source 170 is an example of an inert gas supply source, an inert gas supply source 170, pipes p1, p3, p4, p6 and control valves v2, v4 are inactive. It is an example of an active gas supply system.

Also, the electrolytic bath 22 is an example of an electrolytic bath, the electrolytic cell 21 is an example of an electrolytic cell, the anode 24 is an example of an anode, and the cathode 25 is an example of a cathode.

The pipes p1, p5, p20 to p26, p28, and p29 are examples of fluorine gas supply pipes, the casing 40 is an example of a casing, the exhaust device 130 is an example of an exhaust device, and the control unit 33 is It is an example of a control part.

The pipes p1, p5, p20 to p29, the control valves v3, v31 to v40, the vacuum generator 61, the pressure feeding device 71, the switching valve 72, and the tank 81 are examples of the fluorine gas supply system, and the vacuum generator 61 is the vacuum generator. For example, the pressure feeding device 71 is an example of a pressure feeding device, the tank 81 is an example of a tank, and the

mass flow controllers

62, 73, and 82 are examples of a flow rate adjusting device.

As each constituent element in the claims, various other constituent elements having configurations or functions described in the claims can be used.

The present invention can be effectively used for a reactor that requires cleaning.

Claims

A reaction apparatus for forming a predetermined film on the surface of an object by gas reaction in a chamber,
A film forming gas supply system used for the gas reaction;
A fluorine gas supply device for supplying fluorine gas, which serves as a cleaning gas for the inner wall of the chamber, by electrolysis of an electrolytic bath containing hydrogen fluoride;
A control unit for controlling the film forming gas supply system and the fluorine gas supply device,
The fluorine gas supply device
An electrolytic cell;
A cathode and an anode provided in the electrolytic cell;
A reactor in which at least a part of the surface of the anode is formed of a conductive carbon material having a diamond structure.
The reaction apparatus according to claim 1, wherein the fluorine gas supply device electrolyzes at an applied current density of 20 A / dm 2 or more and 1000 A / dm 2 or less during electrolysis of the electrolytic bath.
The reaction apparatus according to claim 1 or 2, wherein an inert gas is supplied from one inert gas supply source into the chamber and the electrolytic cell.
The reaction device according to claim 3, wherein the control unit adjusts the pressure in the electrolytic cell by controlling an inert gas supply system including the inert gas supply source.
The controller is configured to replace the film forming gas or fluorine gas remaining in the chamber with an inert gas after at least one of the film formation and the chamber cleaning with fluorine gas. The reaction apparatus of Claim 3 which controls the inert gas supply system containing an active gas supply source.
The reaction apparatus according to any one of claims 1 to 5, wherein the fluorine gas supply device includes a fluorine gas supply system that guides fluorine gas generated in the electrolytic cell from the electrolytic cell to the chamber.
The reaction apparatus according to claim 6, wherein the fluorine gas supply system includes a fluorine gas supply pipe.
The fluorine gas supply system is the fluorine gas supply pipe,
The reaction apparatus according to claim 7, wherein the fluorine gas supply pipe includes one or a plurality of valves, and is configured to supply fluorine gas generated in the electrolytic cell directly into the chamber.
9. The fluorine gas supply system includes a vacuum generator that sucks fluorine gas from the electrolytic cell by an inert gas flow and guides the sucked fluorine gas together with the inert gas to the chamber. The reactor according to the item.
The reaction apparatus according to any one of claims 6 to 9, wherein the fluorine gas supply system includes a pumping device that pumps the fluorine gas generated in the electrolytic cell to the chamber.
The reaction apparatus according to any one of claims 6 to 10, wherein the fluorine gas supply system includes a tank for storing fluorine gas generated in the electrolytic cell.
The fluorine gas supply system is
A tank for storing fluorine gas generated in the electrolytic cell;
The reaction apparatus according to any one of claims 6 to 9, further comprising a pumping device that pumps fluorine gas generated in the electrolytic cell to the tank.
The reaction apparatus according to any one of claims 6 to 12, wherein the fluorine gas supply device further includes a flow rate adjusting device for adjusting a flow rate of the fluorine gas flowing into the chamber through the fluorine gas supply system.
A housing for housing the chamber and the fluorine gas supply device;
The reaction device according to any one of claims 1 to 13, further comprising an exhaust device for exhausting the inside of the housing.
The fluorine gas supply device includes a plurality of the electrolytic cells,
Each electrolytic cell is provided with the anode and the cathode,
The control unit controls the fluorine gas supply device so that fluorine gas is generated by electrolysis in an electrolytic bath accommodated in each electrolytic cell when the fluorine gas is supplied into the chamber. The reaction apparatus according to any one of 14.