JPH0240310Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a vacuum device used in a dry etching device, a low-pressure vapor phase growth device, a metal evaporation device, etc., and in particular improves the evacuation and release of the vacuum. related to vacuum equipment.

[Technical background of the invention and its problems]

Generally, a vacuum device includes a vacuum chamber, a vacuum line that communicates with the vacuum chamber via an on-off valve, and a vacuum release line that similarly communicates via an on-off valve. When evacuation is performed, the on-off valve in the vacuum release line is closed, the on-off valve in the evacuation line is opened, and the air in the vacuum chamber is exhausted by the vacuum pump. On the other hand, when releasing the vacuum, the on-off valve in the evacuation line is closed, the on-off valve in the vacuum release line is opened, and air or inert gas is introduced into the vacuum chamber from the outside.

Conventionally, when performing such evacuation or release of vacuum, it has been done by simply opening and closing the on-off valve without considering the pressure difference between the vacuum chamber and each line.
That is, the conventional vacuum apparatus uses the capacity of the vacuum pump and the vacuum release line to the maximum. However, with such a simple operation, for example, if the on-off valve is suddenly opened at the initial stage when the pressure difference between the vacuum chamber and the vacuum release line is large when releasing the vacuum, a large amount of air or waste may enter from the outside through the vacuum release line. An active gas is introduced. This has the disadvantage that dust from outside or inside the line is introduced into the vacuum chamber.

[Purpose of invention]

The present invention has been made in order to overcome the above-mentioned drawbacks of the prior art, and it is an object of the present invention to provide a vacuum device that can reduce the generation of dust due to the pressure difference between the vacuum chamber and the line.

[Summary of the idea]

In order to achieve the above object, the present invention determines the opening/closing amount of the on-off valve when vacuuming or releasing vacuum according to the pressure difference between the vacuum chamber and the vacuuming line or vacuum releasing line. The present invention provides a vacuum device with

[Example of idea]

Hereinafter, one embodiment of the present invention will be described with reference to the accompanying drawings. The figure is a schematic configuration diagram of a vacuum device according to the same embodiment.

A vacuum line 5 is provided in communication with the vacuum chamber 2, and the other end of this vacuum line 5 is connected to a vacuum pump 3.
is connected to. A throttle valve 6 and a vacuum line valve 7 are provided in the vacuum line 5, and by controlling the amount of opening and closing of both, the displacement of the vacuum line 5 can be controlled. On the other hand, a venting gas line 4 is connected to the vacuum chamber 2, and the amount of venting is controlled by a mass flow controller 1 and a venting line valve 8 provided in the middle of this line 4.

Next, the operation of this device will be explained. First, when vacuuming the vacuum chamber 2, use the slot valve 6.
is fully closed, and the vacuum line valve 7 is released.

Then, the throttle valve 6 is gradually opened to gradually evacuate the vacuum chamber 2. Normally, at the start of evacuation, the vacuum chamber 2 and the vacuum pump 3 side of the evacuation line 5 are at approximately the same pressure, that is, atmospheric pressure, so a pressure sensor (not shown) is installed in the vacuum chamber to detect this state. 2 and the vacuum line 5. Then, the pressure from this pressure sensor is detected, and the opening/closing amount of the throttle valve 6 is controlled according to this pressure difference.

In other words, if the pressure difference between the vacuum chamber 2 and the vacuum line 5 is large at the initial stage of evacuation, the throttle valve 6 is slightly opened to reduce the exhaust volume, and as the evacuation progresses, the pressure difference increases. When the amount becomes small, the throttle valve 6 is fully opened to increase the displacement.

Next, when the vacuum chamber 2 is to be released to the atmosphere, the vent line valve 8 is opened and the mass flow controller 1 is gradually opened. In this way, an inert gas such as nitrogen is introduced into the vacuum chamber 2 through the venting gas line 4, and the vacuum chamber 2 is filled with the inert gas and released to the atmosphere. In this case as well, control according to the pressure difference is given to the mass flow controller 1 based on a signal from a pressure sensor (not shown).

Since the pressure difference between the vacuum chamber 2 and the venting gas line 4 is large at the beginning of the release to the atmosphere, the opening degree of the mass flow controller 1 is made small to reduce the introduction of inert gas. As the introduction of the inert gas progresses and the pressure difference gradually decreases, the opening degree of the mass flow controller 1 is increased to increase the amount of inert gas introduced.

Note that a microcomputer can be used to apply a control amount to the throttle valve 6 and the mass flow controller 1 in accordance with the pressure difference during the evacuation and release of the vacuum. The relationship between the pressure difference between the vacuum chamber 2 and the venting gas line 4 and the control amount given to the mass flow controller 1, and the pressure difference between the vacuum chamber 2 and the evacuation line 5 and the control given to the throttle valve 6 Such control can be easily realized if the relationship with the amount and the like are stored in the microcomputer in advance. Further, in the above embodiment, control according to the pressure difference is realized by the mass flow controller 1 and the throttle valve 6, but the vacuum pump 3 is controlled to rotate gradually from low speed to high speed. Good too. Furthermore, a flow meter or a throttle valve may be provided in the vent gas line 4, and the control amount of the flow meter or throttle valve may be varied.

[Effect of idea]

As mentioned above, in the present invention, the speed at which the vacuum chamber reaches vacuum is controlled according to the pressure difference between the vacuum chamber and the vacuum line or vacuum release line communicating therewith. Thus, a vacuum device that can reduce the amount of dust generated can be obtained.

Particularly, when the apparatus according to the present invention is used in an apparatus such as a dry etching apparatus, a low-pressure vapor phase growth apparatus, a metal evaporation apparatus, or the like, where generation of dust is extremely objectionable, great effects can be achieved.

[Brief explanation of drawings]

The figure is a schematic configuration diagram of a vacuum device showing an embodiment of the present invention. 1... Mass flow controller, 2... Vacuum chamber, 3... Vacuum pump, 4... Vent gas line, 5... Vacuum line, 6... Throttle valve, 7... Vacuum line valve, 8 ...Vent line valve.

Claims (1)

[Claims for Utility Model Registration] 1. In a vacuum device comprising a vacuum chamber, and a vacuum line and a vacuum release line communicating with the vacuum chamber via an on-off valve, opening and closing of the on-off valve during evacuation or release of vacuum 1. A vacuum apparatus comprising: a control means for determining the amount of pressure in accordance with a pressure difference between the vacuum chamber and the evacuation line or the evacuation line. 2. The vacuum apparatus according to claim 1, wherein the control means is a microcomputer.