KR20010102762A - Vacuum system - Google Patents

Abstract

The present invention relates to a vacuum system for maintaining a vacuum in a process chamber, wherein the process chamber and the first vacuum pump are connected by a first exhaust pipe. In the first exhaust pipe, a first valve is installed at a portion adjacent to the process chamber and a second valve is installed at a portion adjacent to the first vacuum pump. A second exhaust pipe connected with the first exhaust pipe is installed between the first valve and the second valve. The second exhaust pipe is connected to the second vacuum pump, and the second exhaust pipe is provided with a third valve. When the operation of the vacuum pump that exhausts the process chamber is stopped by installing the first and second vacuum pumps, automatic replacement with another vacuum pump can prevent process damage due to the stop of the vacuum pump.

Description

Vacuum system {VACUUM SYSTEM}

The present invention relates to vacuum equipment, and more particularly to a vacuum system for maintaining the vacuum state of the vacuum equipment.

In the process of manufacturing a semiconductor device, a process of forming a thin film or a dry etching process requires a vacuum device because the process is performed in a vacuum state. In such vacuum equipment, a vacuum system is installed to vacuum the inside of a process chamber where a process is performed.

The vacuum system consists of a vacuum pump connected to the process chamber to maintain a vacuum, a plurality of valves installed in an exhaust pipe which is a connection between the process chamber and the vacuum pump, and a vacuum gauge for measuring the degree of vacuum.

A vacuum pump for maintaining the vacuum in the vacuum system consists of a high vacuum pump to create a high vacuum state of the rough pump 10 ^-3 torr or less to make the inside of the process chamber to a low vacuum state of about 760~10 ^-3 torr. According to the degree of vacuum required in the process, a rough pump is used in a process requiring low vacuum, and a rough pump and a high vacuum pump are used together in a process requiring high vacuum. In order to create a high vacuum state, the rough pump is operated first to make the process chamber low vacuum state, and then the high vacuum pump is operated to make the high vacuum state. Mechanical oil rotary pumps are mainly used as rough pumps, and oil diffusion pumps, cryopumps and turbomolecular pumps are used as high vacuum pumps.

Most processes using a vacuum system proceed by loading a semiconductor wafer into a process chamber, vacuuming the process chamber and then supplying a process gas. As the process proceeds, by-products are generated by the reaction of the process gases, which are also produced in powder form. Powders produced in the process chamber enter the vacuum pump through the exhaust pipe. If these impurities are introduced into the vacuum pump, the function of the vacuum pump will be degraded and the degree of vacuum in the process chamber will be reduced. In addition, when a large amount of impurities enter the vacuum pump, the vacuum pump may stop.

The present invention has been proposed to solve the above-mentioned problems, and an object thereof is to provide a vacuum system that allows a separate vacuum pump to operate by replacing a failed vacuum pump when the vacuum pump malfunctions or stops. .

1 is a schematic diagram of a vacuum equipment constructed by an embodiment of the present invention.

* Explanation of symbols for the main parts of the drawings

100: process chamber 104: first exhaust pipe

106: second exhaust pipe 110: first vacuum pump

114: second vacuum pump 120: pressure gauge

122: first valve 126: second valve

128: third valve

(Configuration)

According to the present invention for achieving the above object, a vacuum system for maintaining a vacuum in a process chamber includes a first vacuum pump, a first exhaust pipe connecting the first vacuum pump to the process chamber, and the first exhaust pipe. A first valve disposed adjacent to an exhaust port of the process chamber to determine whether the process chamber is exhausted, a second valve installed adjacent to the first vacuum pump on the first exhaust pipe, the first valve and the first valve; And a second exhaust pipe connected to the first exhaust pipe between the two valves, a second vacuum pump connected to the process chamber by the second exhaust pipe, and a third valve provided on the second exhaust pipe.

Preferably, the second and third valves comprise an air valve, a solenoid for adjusting the air valve, and a control box for giving an electrical signal to the solenoid.

(Example)

Hereinafter, an embodiment of the present invention will be described in detail with reference to FIG. 1.

1 is a schematic diagram illustrating a vacuum equipment including a vacuum system constructed by an embodiment of the present invention.

Referring to FIG. 1, a process chamber 100 is provided for proceeding a process in a vacuum state that is cut off from an external environment. The first exhaust pipe 104 is connected to the bottom of the process chamber 100 so that gases in the process chamber 100 can be exhausted.

The first valve 122 may be installed at a position adjacent to the process chamber 100 in the first exhaust pipe 104 to connect or disconnect the process chamber and the vacuum pumps 110 and 114. A pressure gauge 120 for measuring the pressure in the process chamber 100 is installed between the process chamber 100 and the first valve 122.

The first exhaust pipe 104 is connected to the first vacuum pump 110 for maintaining a vacuum in the process chamber 100. A second vacuum pump 114 separately installed from the first vacuum pump 110, which is a feature of the present invention, is connected to a second exhaust pipe 106 branched from the first exhaust pipe 104. The second exhaust pipe 106 is connected with the first exhaust pipe between the first valve 122 and the second valve 126.

During the process, both the first and second vacuum pumps 110 and 114 are operated. However, since one of them operates in a state of being cut off from the process chamber 100, the exhaust is performed only by the other vacuum pump. As a result, the vacuum system according to the present invention includes an extra vacuum pump in case a problem occurs in the vacuum pump in charge of exhaust.

The first and second vacuum pumps 110 and 114 are composed of rough pumps or a combination of rough pumps and high vacuum pumps depending on the degree of vacuum required for the process. For example, a vacuum equipment for a process requiring a low vacuum of about 10 ^-3 torr is installed by a combination of a mechanical booster pump and a mechanical oil rotary pump. Mechanical booster pumps are pumps that allow the rapid evacuation of large amounts of gas and are used to vacuum the process chamber to about 10 torr. When the process chamber reaches about 10 torr, the mechanical oil rotary pump will run to bring it into a vacuum suitable for the process. In addition, if high vacuum is required, the vacuum pump is composed of a combination of a mechanical oil rotary pump and a turbo molecular pump, or a combination of a mechanical oil rotary pump and a cryo pump. When the process chamber is vacuumed to about 10 ^-3 torr by a mechanical oil rotary pump, the turbomolecular pump or cryo pump is operated to bring it into high vacuum.

A second valve 126 is installed at a portion adjacent to the first vacuum pump 110 in the first exhaust pipe 104 and a third valve (at a portion adjacent to the second vacuum pump 114 in the second exhaust pipe 106). 128) is installed. By the on / off of the second valve 126 or the third valve 128, the first vacuum pump 110 or the second vacuum pump 114 is connected to the process chamber 100 to be responsible for the exhaust. If the second valve 126 is opened and exhausting through the first vacuum pump 110, the third valve 128 is closed.

In this case, when a problem occurs in the vacuum pump that is responsible for the exhaust, the second and third valves 126 and 128 are automatically controlled valves so that another vacuum pump can be connected to the process chamber 100 automatically. Is installed. For example, it is installed as an air valve that controls the opening and closing of the valve by an electrical signal. The air valve is composed of a control box for sending electrical signals and a solenoid for controlling the opening and closing of the air valves in response to electrical signals from the control boxes. Engage the interlock so that the opening and closing can be adjusted automatically when the vacuum pump fails and stops. When a problem occurs in the vacuum pump and the operation is stopped, the current or voltage value of the pump suddenly drops, so that the change is detected and the opening and closing of the second and third valves 126 and 128 are automatically switched. That is, when a problem occurs in the first vacuum pump 110 that was in charge of the exhaust while the second valve 126 is open and the operation is stopped, the second valve 126 is closed and the third valve 128 is opened. Is installed. Then, the exhaust through the second vacuum pump 114 is made instead of the stopped first vacuum pump 110.

In operation of such a vacuum system, first and second vacuum pumps 110 and 114 are first operated. At this time, the first valve 122 and the second valve 126 are simultaneously opened, and the third valve 128 is closed. Exhaust by the first vacuum pump 110 is made through the first exhaust pipe 104, and the second vacuum pump 114 does not participate in the exhaust but keeps operating while the process is in progress. When the process chamber 100 reaches a vacuum state corresponding to the process conditions, the process gas is injected into the process chamber 100 to proceed with the process.

If impurity particles generated during the process are introduced into the first vacuum pump 110 connected to the process chamber 100 while the process is in progress, the first vacuum pump 110 may be stopped due to excessive pressure on the vacuum pump. do. Alternatively, the first vacuum pump 110 that has been operated for other reasons may suddenly stop. When the vacuum pump is stopped, the current or voltage value of the vacuum pump decreases rapidly. Since the interlock with respect to the current or voltage value of the vacuum pump is caught by the second and third valves 126 and 128, when the threshold of the current or voltage due to the operation stop of the first vacuum pump 110 is detected, the second valve 126 ) Is closed and at the same time the third valve 128 is opened. Therefore, since the exhaust through the second vacuum pump 114 which is still in operation is enabled, the vacuum pump can be replaced without affecting the ongoing process.

According to the present invention, a vacuum pump for evacuating the process chamber and an extra vacuum pump that can replace the vacuum chamber are installed so that the vacuum pump can be automatically replaced by another vacuum pump when the vacuum pump is stopped. Therefore, it is possible to reduce the process damage that may occur due to the stop of the vacuum pump, it is possible to replace the broken vacuum pump even during the process can solve the problem of stopping the vacuum equipment to replace the pump.

Claims (2)

A vacuum system for maintaining a vacuum in a process chamber, 1st vacuum pump, A first exhaust pipe connecting the first vacuum pump to the process chamber, A first valve installed on the first exhaust pipe and adjacent to an exhaust port of the process chamber to determine whether the process chamber is exhausted; A second valve installed on the first exhaust pipe and adjacent to the first vacuum pump, A second exhaust pipe connected to the first exhaust pipe between the first valve and the second valve, A second vacuum pump connected with the process chamber by the second exhaust pipe, and And a third valve mounted on said second exhaust pipe. The method of claim 1, And said second and third valves comprise an air valve, a solenoid for regulating said air valve, and a control box for providing an electrical signal to said solenoid.