JPH0530657U - Vacuum exhaust device - Google Patents

Abstract

(57) [Summary] [Purpose] In the vacuum exhaust system, simplify the exhaust pipe,
Prevents dust generation when opening and closing the valve. [Structure] A variable conductance valve 8, a turbo molecular pump 4, and an auxiliary pump 5 are sequentially installed from a vacuum container side in a pipe 2 connected to a vacuum container 1, and the variable so that the intake side of the turbo molecular pump becomes a required pressure or less when exhausted. By adjusting the opening of the conductance valve, the intake side of the turbo molecular pump is maintained at a required pressure or less during exhaust, the turbo molecular pump is operated from normal pressure, and the pressure on the vacuum container side is reduced. The opening of the variable conductance valve is increased as it goes.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a vacuum exhaust device for exhausting a vacuum container in a semiconductor manufacturing apparatus or the like.

[0002]

[Prior Art]

 In a semiconductor manufacturing apparatus for manufacturing a semiconductor element, a wafer, which is an object to be processed, is processed in a vacuum or low pressure reaction gas atmosphere. Therefore, the semiconductor manufacturing apparatus is equipped with a vacuum container and a vacuum exhaust device.

A conventional vacuum exhaust device will be described with reference to FIG.

In the drawing, reference numeral 1 denotes a vacuum container, and a main pipe 2 is connected to the vacuum container 1, and a main pipe valve 3, a turbo molecular pump 4, and an auxiliary pipe are connected to the main pipe 2 from the vacuum container 1 side. A rotary pump 5 is provided, and an upstream side of the main pipe valve 3 of the main pipe 2 and a downstream side of the turbo molecular pump 4 are connected by a bypass pipe 6, and a bypass pipe valve 7 is connected to the bypass pipe 6. It is provided.

In the conventional vacuum exhaust device, when exhausting the vacuum container 1, first, the main pipe valve 3 is closed, the bypass pipe valve 7 is opened, and the rotary pump 5 exhausts the air. When the rotary pump 5 exhausts the gas to a desired pressure, the bypass pipe valve 7 is closed, the main pipe valve 3 is opened, and the turbo molecular pump 4 exhausts the gas.

Here, the reason why the turbo molecular pump 4 is not operated until the pressure is reduced to the required pressure is that the turbo molecular pump 4 has a characteristic that the pressure on the intake side is limited, and damage to the turbo molecular pump 4 is prevented. Because of that.

[0007]

[Problems to be solved by the device]

 However, the conventional device described above has the following problems.

In general, the bypass pipe has a small diameter with respect to the main pipe, so that the exhaust flow rate cannot be large and the required pressure cannot be reduced in a short time.

Since the rotary pump is used as an auxiliary pump, the oil used for lubrication is vaporized and pollutes the inside of the vacuum container.

The presence of the bypass pipe increases the internal surface area of the exhaust pipe and complicates the exhaust system pipeline, increasing the amount of dust that accumulates. Therefore, when the main pipe valve and bypass pipe valve are opened / closed, much dust is generated, which contaminates the inside of the vacuum container.

In view of the above situation, the present invention intends to simplify the exhaust pipe line and prevent dust generation when the valve is opened and closed.

[0012]

[Means for Solving the Problems]

 In the present invention, a variable conductance valve, a turbo molecular pump, and an auxiliary pump are sequentially installed from a vacuum container side in a pipe connected to a vacuum container, and the variable conductance valve is opened so that the intake side of the turbo molecular pump is below a required pressure when exhausting. The feature is that the degree is adjusted.

[0013]

[Action]

 By maintaining the intake side of the turbo molecular pump below the required pressure during exhaust, it is possible to operate the turbo molecular pump from normal pressure, and the variable conductance valve opens as the pressure on the vacuum vessel side decreases. Exhaust efficiency is high as the degree increases.

[0014]

Embodiment An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, the same parts as those shown in FIG. 2 are designated by the same reference numerals.

A main pipe 2 is connected to a vacuum container 1, and a main pipe valve 3, a variable conductance valve 8, a turbo molecular pump 4, and an auxiliary rotary pump 5 are sequentially provided on the main pipe 2 from the vacuum container 1 side. .

A pressure gauge 10 is provided between the variable conductance valve 8 and the turbo molecular pump 4, and a detection result of the pressure gauge 10 is input to a controller 9. The controller 9 controls the pressure gauge 10. The valve opening of the variable conductance valve 8 is controlled based on the detection result of 10.

When exhausting, the main piping valve 3 is fully opened, the variable conductance valve 8 is fully closed, the rotary pump 5 and the turbo-molecular pump 4 are operated, and the vacuum is drawn. When the pressure on the suction side of the turbo molecular pump 4 decreases due to the operation of the rotary pump 5 and the pressure detected by the pressure gauge 10 becomes less than or equal to the required pressure, the control from the controller 9 is performed. The variable conductance valve 8 is opened by a signal, and the opening degree of the variable conductance valve 8 is controlled so that the pressure on the suction side of the turbo molecular pump 4 is maintained below a required pressure.

Thus, the opening degree of the variable conductance valve 8 increases as the exhaust gas progresses, and when the pressure inside the vacuum container 1 becomes equal to or lower than the required pressure, the variable conductance valve 8 is fully opened. Becomes

In this embodiment, since the capacity of the variable conductance valve 8 increases as the pressure decreases, the exhaust speed can be increased. Further, it is not necessary to provide a bypass pipe in the exhaust system.

[0021]

[Effect of the device]

 As described above, according to the present invention, the following excellent effects are exhibited.

The exhaust system is simplified.

Dust generation is reduced.

Contamination of the vacuum vessel by the oil of the auxiliary pump is prevented.

Since the conductance of the exhaust system increases as the pressure on the intake side decreases, the exhaust efficiency is high.

Since the dust generation and the exhaust efficiency are high, the operation rate of the device can be improved by performing the vacuuming on the device which needs to be frequently evacuated.

[Brief description of drawings]

FIG. 1 is an explanatory view showing an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a conventional example.

[Explanation of symbols]

 1 Vacuum container 2 Main piping 3 Main piping valve 4 Turbo molecular pump 5 Rotary pump 8 Variable conductance valve 10 Pressure gauge

Claims (1)

[Scope of utility model registration request] 1. A variable conductance valve, a turbo molecular pump, and an auxiliary pump are sequentially installed from a vacuum container side in a pipe connected to a vacuum container, and the variable conductance valve of the variable molecular conductance valve is set so that an intake side of the turbo molecular pump is below a required pressure when exhausted. A vacuum exhaust device characterized in that the opening is adjusted.