JPS6314371Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for releasing a vacuum in a sample exchange chamber or the like and introducing an inert gas into the chamber in an electron beam exposure apparatus or the like.

For example, in electron beam exposure equipment, it is often necessary to release the vacuum in the sample exchange chamber or exposure chamber due to various requests, but in such cases it is necessary to keep the vacuum released chamber clean and away from moisture. Inert gas such as nitrogen gas is introduced into these chambers until the pressure inside the chambers becomes slightly higher than atmospheric pressure, and then the chambers are sealed.

At this time, in order to improve the operating efficiency of the apparatus, it is preferable that the time required for the above-mentioned gas introduction be short. Therefore, the pressure on the gas supply side is increased, but when the pressure on the gas supply side is increased, the pressure in the chamber on the side where the gas is introduced also decreases as the gas is introduced. The pressure approaches the pressure and eventually becomes the same as the pressure on the gas supply side, so if the lid of such a chamber is unlocked, the lid will open forcefully and cause a shock to the equipment, which is an inconvenience. occurs. Also, if the pressure in the chamber into which the gas is introduced increases, it may damage a vacuum gauge attached to the chamber to measure the very low pressure in the chamber.

The present invention has been made to solve the drawbacks of conventional gas introduction devices such as electron beam devices, and one embodiment of the present invention will be described in detail below with reference to the drawings.

In the drawing, 1 is a nitrogen gas cylinder, and the gas cylinder 1 is connected to a filter 3 via a pressure regulating valve 2. The filter 3 is for removing impurity particles contained in the nitrogen gas supplied from the gas cylinder 1, and the conductance of the filter 3 is small. The filter 3 is connected to an evacuated sample exchange chamber 5 via a first cut valve 4 which is electromagnetically opened and closed. A sub-channel 8 branches off from a branch point 7 in the channel 6 that connects the filter 3 and the first cut valve 4, and at the tip of the sub-channel 8 there is a connection between the branch point 7 and the atmosphere side. A second cut valve 9 is provided for controlling the. Further, between the branch point 7 and the second cut valve 9, the pressure from the branch point side to the atmosphere side is set at a constant value, for example.
A relief valve 10 is provided which automatically opens only when the pressure is 0.1 Kg/cm ² or more.

In such a configuration, in order to shorten the time required for gas introduction, the pressure regulating valve 2 is adjusted to set the gas supply pressure from the gas cylinder 1 to, for example, 0.5 kg/cm ² higher than atmospheric pressure.

When the sample exchange chamber 5 is maintained at a high vacuum, the first and second cut valves 4 and 9 and the relief valve are closed, and therefore, after a relatively long period of time, the pressure at the branch point 7 also decreases to the gas level. The pressure is 0.5Kg/ ^cm2 higher than the atmospheric pressure, which is the supply pressure.

Therefore, when introducing nitrogen gas into the sample exchange chamber 5, the second cut valve 9 and the first cut valve 4 are opened. As a result, from the branch point 7 side to the atmosphere side with respect to the relief valve 10.
Relief valve 1 due to pressure of 0.5Kg/ ^cm2
0 is also in the open state. Therefore, the gas present at the branch point 7 is in a state where it can move to the sample exchange chamber 5 and the atmosphere, but since the pressure in the sample exchange chamber 5 is extremely low compared to the atmospheric pressure, the gas present at the branch point 7 is Most of the gas and the gas supplied through the filter 3 move to the sample exchange chamber 5, and the pressure in the sample exchange chamber 5 increases, and the pressure at the branch point 7 decreases because the conductance of the filter 3 is small. Go. As a result, the pressure in the sample exchange chamber 5 and the pressure at the branch point 7 become the same, but this pressure is approximately the same because the relief valve 10 automatically opens and closes at a pressure 0.1 kg/cm ² higher than atmospheric pressure. The pressure is maintained at 0.1Kg/ ^cm2 higher than atmospheric pressure. Then, by closing the first and second cut valves 4 and 9, the operator can fill the sample exchange chamber 5 with nitrogen gas at a pressure 0.1 kg/cm ² higher than atmospheric pressure.

As mentioned above, according to the present device, even when the pressure on the gas supply side is increased to shorten the time required for gas introduction, the final pressure in the chamber into which gas is introduced can be set to a desired value lower than the pressure on the gas supply side. By selecting this set pressure, it is possible to avoid a situation where the lid of the chamber opens forcefully and gives a shock to the apparatus when the chamber lid is unlocked.

Furthermore, since the valves 9 and 10 are not communicated with the chamber 5 which is kept at a high vacuum when the first cut valve 4 is closed, it is not necessary to use expensive valves for a high vacuum for these valves 9 and 10.

[Brief explanation of the drawing]

The drawings are for illustrating one embodiment of the present invention. 1: Gas cylinder, 2: Pressure adjustment valve, 3: Filter, 4: First cut valve, 5: Exposure chamber, 6: Channel, 7: Branch point, 8: Sub-channel, 9: Second cut valve, 10 :Relief valve.

Claims (1)

[Scope of utility model registration request] In an apparatus equipped with a gas cylinder, a filter for removing impurity particles contained in the gas supplied from the gas cylinder, and a cut valve that is opened when introducing the gas that has passed through the filter into a room maintained in a vacuum, branching the flow path connecting the filter and the cut valve to form a sub-flow path, and providing a second cut valve at the tip of the sub-flow path for controlling communication between the branch point and the atmosphere side; An electron beam device, etc., characterized in that a relief valve is provided between the branch point and the second cut valve, and the relief valve is automatically opened only when the pressure from the branch point side to the atmosphere side is equal to or higher than a certain pressure. gas introduction device.