JPH03183693A - Method and apparatus for cleaning vapor growth device - Google Patents

Abstract

PURPOSE:To clean a vapor growth device with low-cost facilities by feeding a reactive cleaning gas not activated with ions into the reactor of the device and an exhaust pipe connected to the reactor. CONSTITUTION:A reactive cleaning gas 9 not activated with ions is fed into the reactor 1 of a vapor growth device 8 and an exhaust pipe 4 connected to the reactor 1 to remove a reaction product sticking to the insides of the reactor 1 and the pipe 4. HF3, ClF3 or Cl2, etc., may be used as the reactive cleaning gas. Cleaning is carried out without requiring an ion source and the reactive cleaning gas maintains its reactivity and can clean even the inside of the exhaust pipe without hindrance.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method and apparatus for cleaning a vapor phase growth apparatus.

[Prior art] For example, a GaAs thin film or an Al2G film is deposited on a GaAs wafer.
Epitaxial wafers in which aAs thin films are formed by a metal organic chemical deposition method (hereinafter referred to as MOCVD method) have recently attracted attention for use in field effect transistors (FETs) and high electron mobility transistors (HEMTs). Also,
InPn on wafer nP, InGaAs, InGaA
Epitaxial wafers on which thin films such as sP are formed by MOCVD are being used for laser diodes and the like. In the MOCVD method, the temperature in the reactor is 8[)[1℃
Group II organometallic TMIn, i.e. (In (
CH3)3), TMG, ie, (Ga (CH3)3), PH3 and ASH3 of group V are made into gases and flowed to form a film on an InP wafer. At this time, reaction products also adhere to the heated reactor and susceptor, so the reactor, susceptor, etc. are periodically disassembled and cleaned in order to clean the inside of the reactor. In addition, reaction products also adhere to the inner surface of the exhaust pipe connected after the reactor. In the case of the reduced pressure MOCVD method, reaction products also adhere to the inside of the reduced pressure pump. In particular, in processes that use P (phosphorus), the P reacts with oxygen in the air, and when a reactor or the like is disassembled and cleaned, the P ignites, creating a very dangerous situation.

In order to avoid this, a method has been proposed in which cleaning is performed by flowing an ion-activated reactive cleaning gas activated by an ion source into the reactor and exhaust pipe.

[Problems to be Solved by the Invention] However, such an ion-activated reactive cleaning gas activated by an ion source has the problem of requiring an ion source and increasing costs. Furthermore, the ion-activated reactive cleaning gas activated by the ion source has a problem in that it is difficult to clean the exhaust pipe because the ions have a short lifespan.

An object of the present invention is to provide a method and apparatus for cleaning a vapor phase growth apparatus, which allows cleaning to be performed using inexpensive equipment.

[Means to solve the problem] The present invention will now be described in detail to achieve the above objects.

The method for cleaning a vapor-phase growth apparatus according to claim (1) includes flowing a reactive cleaning gas that is not ion-activated into the reactor of the vapor-phase growth apparatus and the exhaust pipe connected to the reactor. and removing reaction products attached to the inner surface of the exhaust pipe.

Examples of reactive cleaning gases that are not ion activated include NF3. C, QF3. CJ22 or the like is used.

The invention according to claim (2) provides a method for cleaning a vapor phase growth apparatus that includes a reactor, an exhaust pipe connected to the reactor, and a raw material gas waste gas treatment section connected to the exhaust pipe. In the apparatus, a reactive cleaning gas supply pipe that supplies a non-ion activated reactive cleaning gas into the reactor via an on-off valve, and a reactive cleaning gas supply pipe that supplies a reactive cleaning gas that is not ion activated into the reactor, and a reactive cleaning gas supply pipe that supplies a reactive cleaning gas that is not ion-activated into the reactor, and a reactive cleaning gas supply pipe that supplies a reactive cleaning gas that is not ion-activated into the reactor, and a reactive cleaning gas supply pipe that supplies a reactive cleaning gas that is not ion-activated into the reactor, and a reactive cleaning gas supply pipe that supplies a reactive cleaning gas that is not ion-activated into the reactor, and a reactive cleaning gas supply pipe that supplies a reactive cleaning gas that is not ion-activated into the reactor, and a reactive cleaning gas waste gas treatment section that is connected via a cleaning gas exhaust pipe and processes the reactive cleaning gas; and the raw material gas waste gas treatment section or the reactive cleaning gas waste gas treatment section. The invention is characterized in that it has a switching valve connected to the exhaust pipe and the reactive cleaning gas exhaust pipe in order to selectively use one of the reactive cleaning gas exhaust pipes.

[Function] Such a reactive cleaning gas that is not ion activated can perform cleaning without requiring an ion source. Further, since this reactive cleaning gas is not ionized and remains reactive, the inside of the exhaust pipe can be cleaned without any problem.

In particular, in claim (2), since the reactive cleaning gas waste gas treatment section is provided separately from the raw material gas waste gas treatment section, the reactive cleaning gas is processed in the raw material gas waste gas treatment section. It is possible to detoxify the reactive cleaning gas while avoiding excessive reaction during processing and the resulting overheating that would otherwise occur.

[Example] Hereinafter, an example of the present invention will be described in detail with reference to the drawings. In the figure, 1 is a reactor with a built-in susceptor (not shown), 2 is a raw material gas supply pipe that supplies raw material gas into the reactor 1, and 3 is a source gas opening and closing provided in the raw material gas supply pipe 2. 4 is an exhaust pipe connected to the reactor 1; 5 is an exhaust opening/closing valve provided in the exhaust pipe 4; 6 is an oil rotary pump connected to the end of the exhaust pipe 4. The suction device 7 is a waste gas treatment section for raw material gas that is connected after the suction device 6 for raw material gas and detoxifies the raw material gas. These 1 to 7 constitute a vapor phase growth apparatus 8.

Further, 9 is a reactive cleaning gas supply pipe for supplying reactive cleaning gas to the reactor 1 or the exhaust pipe 4;
0 is a branched reactive cleaning gas supply pipe that is branched from the reactive cleaning gas supply pipe 9 and supplies reactive cleaning gas into the reactor 1, and 11 is a reactive cleaning gas provided in the branched reactive cleaning gas supply pipe 10. 12 is a branched reactive cleaning gas supply pipe that is branched from the reactive cleaning gas supply pipe 9 and supplies reactive cleaning gas into the pipe 4; 13 is provided in the branched reactive cleaning gas supply pipe 12; This is an on-off valve for reactive cleaning gas.

Reference numeral 14 indicates a reactive cleaning gas exhaust pipe connected to the exhaust pipe 4 on the intake side of the raw material gas suction device 6, and reference numeral 15 indicates a reactive cleaning gas exhaust pipe 16 which is connected in the middle of the reactive cleaning gas exhaust pipe 14 through a bypass reactive cleaning gas exhaust pipe 16. A suction device for reactive cleaning gas consisting of an oil rotary pump or the like connected to a bypass, 17.18 an on-off valve for reactive cleaning gas provided at the inlet and outlet of the bypass reactive cleaning gas exhaust pipe 16, 19 a bypass A reactive cleaning gas opening/closing valve 20 is provided at a portion of the reactive cleaning gas exhaust pipe 14 that is parallel to the reactive cleaning gas exhaust pipe 16, and is connected to the end side of the reactive cleaning gas exhaust pipe 14. This is a waste gas processing unit for reactive cleaning gas that detoxifies the reactive cleaning gas. 21.22 is the raw material gas waste gas processing section 7
This is a switching valve connected to the exhaust pipe 4 and the reactive cleaning gas exhaust pipe ↑4 in order to switch between using the exhaust gas treatment section 20 for reactive cleaning gas and the exhaust gas treatment section 20 for reactive cleaning gas. These 9 to 22 constitute a cleaning device 23 of the vapor phase growth apparatus 8.

Next, a method of cleaning the vapor phase growth apparatus 8 using the cleaning apparatus 23 will be described.

In the case of the low pressure MOCVD method, during the production of epitaxial wafers, valve 3. 5. 21 is opened, all other valves are closed, the raw material gas suction machine 6 is operated, and the reactor 1 is opened.
The waste gas of the raw material gas discharged from the raw material gas is guided to the raw material gas waste gas processing section 7 and is rendered harmless. That is, in this raw material gas waste gas treatment section 7, for example, PH3, AsH3, TMG
, TMI n, etc.

After manufacturing the epitaxial wafer, a purge gas made of nitrogen or Ar is flowed from the source gas supply pipe 2 to the reactor 1 and the exhaust pipe 4 to purge the source gas.

Next, the valve 3 is closed, and the inside of the reactor 1 and the exhaust pipe 4 are evacuated by operating the raw material gas suction device 6.

Then, by opening the valves 11, 22, and 19 and closing the valve 21, the non-activated ions are introduced into the reactor 1 and the exhaust pipe 4 through the reactive cleaning gas supply pipe 9 and the branched reactive cleaning gas supply pipe 10. The inside of the reactor 1 and the exhaust pipe 4 are cleaned by flowing the cleaning gas for several hours. Examples of reactive cleaning gases that are not ion activated include NF3. CJ2F3
Use ゜C12 etc. When such a reactive cleaning gas is used, deposits inside the reactor 1 and the exhaust pipe 4 can be removed by converting them into, for example, C° C.-based compound gas or F-based compound gas. The used reactive cleaning gas is sequentially rendered harmless in the reactive cleaning gas waste gas treatment section 20 and then released into the atmosphere. That is, in the reactive cleaning gas waste gas processing section 20, for example, C° C.-based compounds, F-based compounds, and the like are rendered harmless.

Next, valve 11 is closed, valve 3 is opened, and reactor 1. Exhaust pipe 49 Reactive cleaning gas Purge gas is flowed from raw material gas supply pipe 2 to reactive cleaning gas exhaust pipe 14 to purge the reactive cleaning gas.

Thereafter, valve 19 is closed, valve 17.18 is opened, and reactive cleaning gas suction device 15 is used to pump reactor 1. The pressure inside the exhaust pipe 4 is reduced. This step reduces the concentration of the reactive cleaning gas in the reactor 1 and the exhaust pipe 4.

Next, close the valve 11, open the valve 3, close the valve 22, stop the reactive cleaning gas suction device 15, and open the valve 21 to flow the purge gas into the reactor 1 and the exhaust pipe 4. return to its original state.

In addition to the oil rotary pump, the raw material gas supply device 69 and the reactive cleaning gas suction device 15 include a mechanical booster pump and a dry exhaust pump.

A turbo pump etc. can be used.

Furthermore, when using ClF3 as a reactive cleaning gas, the temperature inside the reactor 1 and exhaust pipe 4 may rise rapidly due to the cleaning reaction, so a temperature sensor should be installed near the reactor 1 and exhaust pipe 4 to constantly monitor it. It is preferable.

Furthermore, the reactor 1 and the susceptor can be cleaned to some extent and then disassembled for cleaning. In this case, since these have been cleaned in advance, ignition of P will not occur, so it is safe. Furthermore, by cleaning the inside of the exhaust pipe 4, it is possible to prevent clogging and impurities from flowing back into the reactor 1 and contaminating the epitaxial wafer.

Furthermore, if there is moisture in the exhaust pipe 4, there is a possibility that HC°C or HF may be formed, so it is preferable to provide a dew point meter in the exhaust pipe 4 and constantly monitor it.

[Effects of the Invention] As explained above, according to the method and apparatus for cleaning a vapor phase growth apparatus according to the present invention, the following effects can be obtained.

In claims (1) and (2), since cleaning is performed using a reactive cleaning gas that is not ion activated,
There is an advantage that cleaning can be performed without requiring an ion source. Further, since this reactive cleaning gas is not ionized and remains reactive, it has the advantage that the inside of the exhaust pipe can be cleaned without any trouble.

In particular, in claim (2), since the reactive cleaning gas waste gas treatment section is provided separately from the raw material gas waste gas treatment section, the reactive cleaning gas is processed in the raw material gas waste gas treatment section. There is an advantage that the reactive cleaning gas can be detoxified while avoiding the excessive progress of the reaction during the treatment and the accompanying overheating that would otherwise occur.

[Brief explanation of drawings]

The drawing is a system diagram of an embodiment of a vapor phase growth apparatus equipped with a cleaning device according to the present invention. 1...reactor, 2...raw material gas supply piping, 3...
・Opening/closing valve, 4...Exhaust pipe, 5...Opening/closing valve,
6... Suction device for raw material gas, 7... Waste gas treatment section for raw material gas, 8... Vapor phase growth device, 9... Reactive cleaning gas supply piping, 10.12... Branch reaction cleaning gas supply piping, 11.13... opening/closing valve,
14...Reactive cleaning gas exhaust pipe, ■5...
Suction device for reactive cleaning gas, 16... bypass reactive cleaning gas exhaust pipe, 17.18... opening/closing valve, 19... opening/closing valve, 20... waste gas treatment section for reactive cleaning gas, 21.22...Switching valve, 23...Cleaning device.

Claims (2)

[Claims] (1) A reactive cleaning gas that is not ion-activated is flowed into the reactor of the vapor phase growth apparatus and the exhaust pipe connected to the reactor to remove reaction products attached to the inner surfaces of the reactor and the exhaust pipe. A method for cleaning a vapor phase growth apparatus, characterized by removing. (2) A cleaning device for a vapor phase growth apparatus comprising a reactor, an exhaust pipe connected to the reactor, and a raw material gas waste gas treatment section connected to the exhaust pipe,
A reactive cleaning gas supply pipe that supplies a non-ion activated reactive cleaning gas into the reactor via an on-off valve, and a reactive cleaning gas exhaust pipe that is separate from the raw material gas waste gas treatment section. A reactive cleaning gas waste gas treatment section that is connected via a pipe and processes the reactive cleaning gas, and either the raw material gas waste gas treatment section or the reactive cleaning gas waste gas treatment section. A cleaning device for a vapor phase growth apparatus, comprising a switching valve connected to the exhaust pipe and the reactive cleaning gas exhaust pipe for selectively using the reactive cleaning gas.