KR20220002198A - A Method for Preventing a Back Flow to Protect a Wafer and an Apparatus for the Same - Google Patents

Abstract

The present invention relates to a backflow prevention method for semiconductor wafer protection, and to a device therefor. The backflow prevention method for semiconductor wafer protection includes the steps of: receiving, by a controller, an alarm signal generated from a vacuum pump installed in an exhaust line of a process chamber; and adjusting a gate valve and an isolation valve installed in the exhaust line according to the reception of the alarm signal.

Description

A method for Preventing a Back Flow to Protect a Wafer and an Apparatus for the Same

The present invention relates to a backflow prevention method for protecting a semiconductor wafer and an apparatus therefor, and specifically, semiconductor wafer protection for preventing contamination of the wafer by particles or similar contaminants contained in gas flowing into a process chamber from an exhaust line To provide a backflow prevention method and an apparatus therefor.

The process chamber in which the semiconductor wafer process is performed may be made in a vacuum state by, for example, a vacuum pump (dry pump). In the process of making the process chamber a vacuum state, an operation error may occur in the vacuum pump or the operation of the vacuum pump may be temporarily stopped due to an unexpected situation such as a power failure. And, due to this, a reverse flow may be temporarily generated from the exhaust line connecting the process chamber and the vacuum pump to the vacuum chamber. Various types of particles including polymer particles may be generated in such a backflow, which may contaminate the wafer. Patent Publication No. 2003-0009790 discloses a backstream prevention device in a semiconductor manufacturing facility. In addition, Patent Publication No. 10-2073789 discloses a back stream prevention structure for semiconductor manufacturing equipment that allows a time delay until the moment of closing of a valve to be relatively reduced. The counterflow from the exhaust line to the process chamber may be by way of pressure regulation or blockage of the flow path between the process chamber and the exhaust line. For example, a plurality of valves may be installed in the exhaust line or the inlet line of the process chamber, and the blocking of the flow path by the valve may be performed simultaneously or in a manner capable of adjusting the flow pressure. However, the prior art does not disclose a method for preventing backflow in this way.

The present invention is to solve the problems of the prior art and has the following objects.

Patent Document 1: Patent Publication No. 2003-0009790 (Samsung Electronics Co., Ltd., published on February 5, 2003) Device for preventing particle backstream of semiconductor manufacturing device Patent Document 2: Patent Registration No. 10-2073789 (Kim Tae-Hwa, Announced on February 5, 2020) Backstream prevention structure for semiconductor manufacturing equipment

SUMMARY OF THE INVENTION It is an object of the present invention to provide a backflow prevention method and apparatus for protecting a semiconductor wafer capable of preventing wafer contamination due to a backflow from an exhaust line to a process chamber.

According to a preferred embodiment of the present invention, a backflow prevention method for protecting a semiconductor wafer includes: receiving, by a controller, an alarm signal generated from a vacuum pump installed in an exhaust line of a process chamber; and adjusting the gate valve and the isolation valve installed in the exhaust line according to the reception of the alarm signal.

According to another suitable embodiment of the present invention, the gas final valve is closed while the chamber is interlocked by the controller, and the gate valve and the isolation valve are closed at the same time.

According to another suitable embodiment of the invention, the gate valve or isolation valve is an electronically actuated valve and the regulation is effected by the transmission of an electrical signal.

According to another suitable embodiment of the present invention, a backflow preventing device for protecting a wafer includes a backflow preventing means for receiving a warning signal generated from a vacuum pump installed in an exhaust line of a process chamber; and valve trigger means for closing the gas final valve, the gate valve and the isolation valve in the chamber interlocking process by the non-return means.

According to another suitable embodiment of the present invention, the gate valve is of an electromagnetically actuated valve construction, and the isolation valve is of a pneumatic actuated type.

The backflow prevention method for protecting a semiconductor wafer according to the present invention controls opening and closing of at least two valves disposed at different positions of an exhaust line to prevent backflow to a process chamber. The backflow prevention method according to the present invention effectively prevents backflow by closing the gate valve of the exhaust line and the isolation valve of the turbo pump while simultaneously closing the final valve of the process chamber. The backflow prevention device according to the present invention has the advantage that it is possible to prevent backflow without changing the structure of the process chamber by operating the opening and closing of the gate valve, the isolation valve, or the gate valve in a software manner by means of a chamber interlock means. have

1 illustrates an embodiment of a backflow prevention method for protecting a semiconductor wafer according to the present invention.
Figure 2 shows an embodiment of the backflow prevention device according to the present invention.
Figure 3 shows another embodiment of the backflow prevention structure according to the present invention.

Hereinafter, the present invention will be described in detail with reference to the embodiments shown in the accompanying drawings, but the embodiments are for a clear understanding of the present invention, and the present invention is not limited thereto. In the following description, components having the same reference numerals in different drawings have similar functions, so unless necessary for the understanding of the invention, the description will not be repeated and well-known components will be briefly described or omitted, but the present invention It should not be construed as being excluded from the embodiment of

1 illustrates an embodiment of a backflow prevention method for protecting a semiconductor wafer according to the present invention.

Referring to FIG. 1 , a backflow prevention method for protecting a semiconductor wafer includes receiving, by a controller, an alarm signal generated from a vacuum pump installed in an exhaust line of a process chamber; and adjusting the gate valve and the isolation valve installed in the exhaust line according to the reception of the alarm signal.

The process chamber may be a space in which an etching process for a wafer, a lithography process, or a process related thereto is performed. The process chamber may be filled with plasma or similar gas, or may be evacuated for processing. An exhaust line connected to a device such as a scrubber may be formed in the process chamber to evacuate or depressurize the process chamber. In addition, the process chamber may be made in a vacuum state or a reduced pressure state by a vacuum pump (dry pump) installed in the exhaust line. An error may occur during the operation of the vacuum pump, or the operation may be stopped due to a temporary interruption of power supply. Due to such an operation error, a reverse flow may be generated from the exhaust line to the process chamber, which may contaminate the wafer. Therefore, it is necessary to block the flow of the exhaust line by a valve disposed in the exhaust line. If an operating error occurs in the vacuum pump, an alarm signal is sent, which causes the controller to close the isolation valve arranged in the turbo pump thereby blocking the flow of the exhaust line. can However, while the valve is blocked, a portion of the gas existing between the vacuum chamber and the exhaust line may flow into the process chamber, or a vortex may be generated inside the process chamber. Therefore, it is necessary to control the operation of the valve to effectively prevent the generation of such a reverse flow or vortex of the residual gas. According to one embodiment of the present invention, the operation of at least two valves disposed in the exhaust line may be controlled by detecting a signal generated from the vacuum pump. For example, an isolation valve connected to the turbopump and a gate valve disposed below the process chamber or between the process chamber and the turbopump may be closed. In this way, at least two valves disposed at different positions of the exhaust line may be closed. The two valves may be closed sequentially but preferably both valves may be closed simultaneously. Alternatively, an operation of a gate valve positioned adjacent to the process chamber may be initiated, and then the isolation valve may be immediately closed. A first valve, such as a gate valve, and a second valve, such as an isolation valve disposed at a different location in the exhaust line from the first valve, may be actuated electronically or may be actuated in a pressure regulating manner, such as pneumatically. For example, the first valve may be an electromagnetic on/off valve actuated by an electric signal, and the isolation valve may be a pressure actuated valve such as a pneumatic valve actuated by fluid pressure. The isolation valve may be, for example, a pneumatically actuated valve that closes when the supplied air is shut off and the air filled inside the isolation valve is bypassed. Alternatively, both the first and second valves may have a pneumatic actuation structure.

According to one embodiment of the present invention, the gas final valve may be closed while the chamber is interlocked by the controller, and the gate valve and the isolation valve may be closed at the same time. For example, a gas final valve may be installed in an inlet conduit for introducing gas into the process chamber, and opening and closing of the gas final valve may be controlled according to a state of gas flowing along the inlet conduit. For example, if the flow of gas along the inlet conduit is not suitable for the prescribed conditions, the gas final valve may be interlocked by the controller for operation of the equipment. The first and second valves installed in the exhaust line may be closed based on such a chamber interlock process. For example, when a malfunction signal is generated from the vacuum pump and transmitted to the controller, the controller may close the gas final valve according to the chamber interlock process. It can also be closed by actuating the gate valve and isolating valve. As described above, by adjusting the first and second valves according to the chamber interlock process, it is possible to prevent backflow through a software operation method without the need to separately install parts or devices to prevent backflow. The opening/closing control of the gate valve and the isolation valve may be performed in various ways and is not limited to the presented embodiment.

Figure 2 shows an embodiment of the backflow prevention device according to the present invention.

Referring to FIG. 2 , the backflow preventing device for wafer protection includes a backflow preventing means 24 for receiving a warning signal generated from a vacuum pump 23 installed in an exhaust line of a process chamber 21 ; and valve trigger means 26 for closing the gas final valve 27 , the gate valve 28 and the isolation valve 29 in the chamber interlocking process by the non-return means 24 . Optionally, the gate valve 28 may be of an electromagnetically actuated valve construction, and the isolation valve 29 may be of a pneumatic actuation type.

A vacuum chuck for fixing the wafer in the process chamber 21 may be installed, and a gas final valve 27 may be installed in an inlet conduit for guiding gas into the process chamber 21 . A turbo pump 22 and a vacuum pump 23 are installed in the exhaust line of the process chamber 21 to make the process chamber 21 in a vacuum state or a reduced pressure state. A gate valve 28 may be installed between the process chamber 21 and the turbo pump 22 , and an isolation valve 29 may be installed between the turbo pump 22 and the vacuum pump 23 . By the operation of the turbo pump 22 and the vacuum pump 23 , the interior of the process chamber 21 may be made into a high vacuum state, a low vacuum state, or a reduced pressure state. When an operation error is generated by the operation process of the vacuum pump 23 or other detection sensors, an error signal may be received by the backflow prevention means 24 . The backflow prevention means 24 may be software or hardware capable of detecting or receiving such an error signal, and the received error signal may be transmitted to the controller 25 controlling the operation of the equipment. The controller 25 may transmit a closing signal according to an operation error to the valve trigger 26 , and the valve trigger 26 generates a chamber interlock signal and at the same time closes the gate valve 28 and the isolation valve 29 . can generate a signal for Accordingly, as the gas final valve 27 is closed, the gate valve 28 and the isolation valve 29 are closed, thereby blocking the inflow of gas into the process chamber 21 , thereby preventing contamination of the wafer. In such an operating structure, an operation error signal of the vacuum pump 23 may be a chamber interlock signal, and accordingly, the chamber in the lock occurs while the gate valve 28 and the isolation valve 29 are closed at the same time to close the process chamber. (21) While the internal pressure rise is prevented, the particles of the wafer due to the vortex generated by the turbo pump 22 can be prevented. The chamber interlock can be, for example, but not limited to, an ATM (atmosphere) switch, a 1/2 ATM switch, or a chamber lid opening.

Figure 3 shows another embodiment of the backflow prevention structure according to the present invention.

Referring to FIG. 3 , an error signal generated from the vacuum pump 23 is transmitted to the backflow prevention module 24 , and the opening/closing control unit 31 is operated by the backflow prevention module 24 to operate the gate valve 28 and The isolation valve 29 may be closed. The backflow prevention module 24 may be a part of an equipment controller that controls equipment for process progress, and may be in the form of software or hardware. Alternatively, the backflow prevention module 24 may be an independent module that processes an operation error signal while monitoring the operation state of the vacuum pump 23 . When the backflow prevention module 24 detects an error signal of the vacuum pump 23 , the opening/closing control unit 31 is operated to transmit a closing signal to the gate valve 28 and the isolation valve 29 so that they can be closed at the same time. As described above, the gate valve 28 may have an electronically actuated configuration, and the isolation valve 29 may be of an electronically actuated configuration or a pneumatically actuated configuration. In addition, the opening/closing control unit 31 may be hardware or software capable of generating a signal for opening and closing the valve, and the present invention is not limited thereby.

Although the present invention has been described in detail above with reference to the presented embodiment, those skilled in the art will be able to make various modifications and modified inventions without departing from the technical spirit of the present invention with reference to the presented embodiment. . The present invention is not limited by these variations and modifications, but is limited only by the claims appended hereto.

21: process chamber 22: turbo pump
23: vacuum pump 24: backflow prevention means
25: controller 26: valve trigger means
27: gas final valve 28: gate valve
29: isolation valve

Claims (1)

receiving, by a controller, an alarm signal generated from a vacuum pump installed in an exhaust line of the process chamber; and
Comprising the step of closing the isolation valve installed between the turbo pump and the vacuum pump and the gate valve installed between the process chamber and the turbo pump according to the reception of the alarm signal,
In accordance with the alarm signal received by the controller, a closing signal is transmitted by the controller to cause the isolation valve and the gate valve to close simultaneously during the chamber interlock process in which the gas final valve installed in the inlet conduit for introducing gas into the process chamber is closed,
A method for preventing backflow for protecting a semiconductor wafer, characterized in that the gate valve (28) is of an electromagnetically operated valve structure, and the isolation valve (29) is of a pneumatic operation.

Images