Device and method for exhaust gas treatment on CVD reactor

Patent metadata

Field	Value
Publication number	US-10329668-B2
Application number	US-201514686615-A
Country	US
Kind code	B2
Filing date	Apr 14, 2015
Priority date	Apr 14, 2014
Publication date	Jun 25, 2019
Grant date	Jun 25, 2019

Abstract

A first and second process gas is fed into a device during a first and second process step, respectively. The device has an exhaust gas line through which a first and second exhaust gas is conveyed out of the device in the first and second process step, respectively. A first and second exhaust gas device is connected by means of a valve arrangement optionally to the exhaust gas line in a fluidly communicable and separable manner, with a first and second treatment member for treating an exhaust gas produced in the first and second process step, respectively. A gas feed device is arranged between the valve arrangement and the respective treatment members. A control device is provided whose control variable is the pressure difference between the total pressure in the respective exhaust gas devices and is configured to minimize the pressure difference during switching of the valve arrangement.

First claim

What is claimed is:

1. A method, comprising:
in a first process step:
feeding a first process gas into a reactor ( 3 );
conveying a first exhaust gas out of the reactor ( 3 ) through an exhaust gas line ( 5 );
conveying the first exhaust gas from the exhaust gas line ( 5 ) through a valve arrangement ( 11 , 21 ) to a first exhaust gas device ( 10 ) with a first treatment member ( 18 );
treating the first exhaust gas with the first treatment member ( 18 );
feeding a first equalizing gas by means of a first gas feed device ( 12 ) into a gas conduit disposed between the valve arrangement ( 11 , 21 ) and the first treatment member ( 18 ), wherein the first gas feed device ( 12 ) includes a first mass flow controller ( 12 ′); and
determining a total pressure (P F ) in the first exhaust gas device ( 10 ) with a first pressure sensor ( 13 ); and

in a second process step:
feeding a second process gas into the reactor ( 3 );
conveying a second exhaust gas out of the reactor ( 3 ) through the exhaust gas line ( 5 );
conveying the second exhaust gas from the exhaust gas line ( 5 ) through the valve arrangement ( 11 , 21 ) to a second exhaust gas device ( 20 ) with a second treatment member ( 28 );
treating the second exhaust gas with the second treatment member ( 28 );
feeding a second equalizing gas by means of a second gas feed device ( 22 ) into a gas conduit disposed between the valve arrangement ( 11 , 21 ) and the second treatment member ( 28 ), wherein the second gas feed device ( 22 ) includes a second mass flow controller ( 22 ′); and
determining a total pressure (P T ) in the second exhaust gas device ( 20 ) with a second pressure sensor ( 23 ); and

regulating a difference between the total pressure (P F ) in the first exhaust gas device ( 10 ) and the total pressure (P T ) in the second exhaust gas device ( 20 ) by means of a control device ( 9 ) toward zero at least during switching of the valve arrangement while the first and second exhaust gas devices ( 10 , 20 ) are both fluidly coupled to the exhaust gas line ( 5 ) so as to prevent the first exhaust gas from flowing into the second exhaust gas device ( 20 ) and prevent the second exhaust gas from flowing into the first exhaust gas device ( 10 ).

2. The method of claim 1 , wherein actuating elements of the control device ( 9 ) comprise the first and second mass flow controllers ( 12 ′, 22 ′) and/or one or more throttle valves ( 16 , 26 ) arranged upstream from a pump ( 16 , 26 ).

3. The method of claim 1 , further comprising:
during the first process step, maintaining a pressure (P R ) of the reactor ( 3 ) determined by a third pressure sensor ( 4 ) at a first value by the control device ( 9 ) by varying a position of a first throttle valve ( 15 );
before switching from the first process step to the second process step, regulating the total pressure (P F ) of the first exhaust gas device ( 10 ) and the total pressure (P T ) of the second exhaust gas device ( 20 ) both to a second value;
after a stabilization of the total pressures (P F , P T ) in the two exhaust gas devices ( 10 , 20 ), opening a check valve ( 21 ) of the valve arrangement connecting the second exhaust gas device ( 20 ) to the exhaust gas line ( 5 ) and then closing a check valve ( 11 ) of the valve arrangement connecting the first exhaust gas device ( 10 ) to the exhaust gas line ( 5 ); and
thereafter, regulating by the control device ( 9 ) the reactor pressure (P R ) determined by the third pressure sensor ( 4 ) to a third value by varying a position of a second throttle valve ( 25 ).

4. A method for operating a system, the system comprising (i) a reactor with an exhaust gas line, (ii) a first exhaust gas device with a first treatment member, (iii) a first check valve for controlling whether an exhaust gas flows from the exhaust gas line into the first exhaust gas device, (iv) a second exhaust gas device with a second treatment member, (v) a second check valve for controlling whether the exhaust gas flows from the exhaust gas line into the second exhaust gas device, (vi) a first gas feed device configured to feed a first equalizing gas into a gas conduit disposed between the first exhaust gas device and the first check valve, and (vii) a second gas feed device configured to feed a second equalizing gas into a gas conduit disposed between the second exhaust gas device and the second check valve, the method comprising:
performing a first process step during which the exhaust gas flows from the exhaust gas line through the first check valve and into the first exhaust gas device;
at a beginning of a switching phase that switches from the first process step to a second process step, setting a mass flow of the second equalizing gas equal to a value that corresponds to a mass flow that is flowing through the first exhaust gas device so as to equalize a total pressure in the first exhaust gas device and a total pressure in the second exhaust gas device;
as soon as the total pressure in the first exhaust gas device equals the total pressure in the second exhaust gas device, opening the second check valve, causing the first exhaust gas device and the second exhaust gas device to both be fluidly coupled to the exhaust gas line, wherein by flowing the second equalizing gas through the second exhaust gas device, the exhaust gas is prevented from flowing into the second exhaust gas device while the first exhaust gas device and the second exhaust gas device are both fluidly coupled to the exhaust gas line; and
after the opening of the second check valve, closing the first check valve and reducing the mass flow of the second equalizing gas, thereby directing the exhaust gas to flow from the exhaust gas line through the second check valve and into the second exhaust gas device.

Assignees

• Aixtron Se

Inventors

• Franken Patrick
• Deufel Markus

Classifications

• C23C16/4412 Primary

  Details relating to the exhausts, e.g. pumps, filters, scrubbers, particle traps · CPC title

• Y02C20/30

  of perfluorocarbons [PFC], hydrofluorocarbons [HFC] or sulfur hexafluoride [SF6] · CPC title

• Y02P70/605

  Cross-Sectional Technologies · mapped topic

• Y02P70/50

  Manufacturing or production processes characterised by the final manufactured product · CPC title