KR940000209B1 - Gasline Pumping System in Dry Etching Process - Google Patents

Abstract

A gas line pumping system of a dry etching process includes a vacuum generator having an inlet thereof connected onto a gas supply line connected between a gas bomb and an etch chamber for supplying gas used for etching, and an outlet thereof connected between a vacuum pump and a gas cleaning unit to form a tubed path by means of a pipe, so that, if the gas accumulates for a long time after completing the etching, the accumulated gas is exhausted to prevent corrosion or clogging phenomena within the line caused by liquefaction of the gas.

Description

Gasline Pumping System in Dry Etching Process

1 is a view showing a conventional dry etching process gas line.

2 is a view showing a gas line of a dry etching process according to the present invention.

3 is a side sectional view of a vacuum generator according to the present invention.

The present invention relates to a gas line pumping system of a dry etching process, and more particularly, to a gas line pumping system which prevents gas from liquefying when a temperature difference or congestion occurs in the gas line to smooth the flow of the gas. .

Due to miniaturization and high integration of semiconductor processes, most etching processes are performed by dry etching using gas.

There is a process in which liquefied gas is used among the gases used for etching, in which case the gas has a drawback of liquefying and blocking the gas line when there is a temperature difference in the gas line or when the flow of the gas is stagnant.

FIG. 1 is a view showing a gas line of a conventional dry etching process. The gas cylinder 1 is connected to a mass flow controller (MFC) 3 through a pressure regulator 2.

The MFC 3 is in communication with the etching chamber 4, which is connected to the vacuum pump 5 to exhaust the gas introduced therein.

The vacuum pump 5 communicates with the gas scrubber 6 to discharge the gas discharged to the outside.

In the drawing, various types of valves are installed in the gas line, which are installed to inject and discharge the gas or to change the flow direction of the gas.

The conventional gas line thus formed does not expose any problems to the supply of the gas for etching, but when the etching chamber 4 or the like is not used, the supplied gas is present in the line. There is a lot of problems because the means are not considered.

In other words, in the case of liquefied gas, when a temperature difference occurs in the gas line, the gas is liquefied to lose the function of the MFC 3, and the gas line is blocked to cause corrosion of the parts.

The present invention has been invented to solve the problems of the prior art as described above, the object of the present invention is to prevent the blockage of the line and the corrosion of the parts by exhausting the gas in the gas line if it is stagnant for a long time. It is to provide a gasline pumping system that can be prevented.

In order to realize this, the present invention is connected to the gas supply line between the gas cylinder and the etching system, the gas generator pump is connected to the inlet of the vacuum generator, the outlet of the vacuum generator connected to the vacuum pump and the gas cleaner pump Providing a system.

In the pumping system of the present invention thus formed, when the gas needs to be exhausted after the etching process is completed, when the nitrogen gas is blown to the inlet side of the vacuum generator at a predetermined pressure, the pressure difference between the first passage and the second passage is reduced. A vacuum is formed and the etching gas into the gas supply line is exhausted.

Hereinafter, preferred embodiments of the present invention will be described in more detail with reference to the accompanying drawings.

2 is a flow chart of the gas line according to the present invention, from the gas cylinder 1 to the gas cleaner 6 via the pressure regulator 2, the MFC 3, the etching chamber 4, and the vacuum pump 5; The flow diagram flowing into is made in the same way.

The present invention is characterized in that it provides a means for pumping the gas remaining in the gas line, it is connected to the inlet side through the vacuum generator 7 between the pressure regulator 2 and the MFC (3), the outlet side It provides a pumping device connected between the vacuum pump (5) and the gas cleaner (6).

The vacuum generator (7) and the gas cleaner (6) has a structure that is connected by a conduit (8), the valve (11) 12 is provided between the gas supply conduits (9, 10), respectively. .

These are installed in the cylinder box B in which the gas spring vessel 1 is located, and another valve 13 is installed on the pipeline 8 to connect the vacuum pump 5 and the gas purifier 6 to the exhaust pipe 14. Opening and closing operation with) is made.

The inlet and outlet sides of the MFC 3 are provided with valves 15 and 16 which can be turned off at the time of gas supply and closed at the time of exhaust.

In the above-described embodiment, the vacuum generator 7 is positioned in the gas cylinder B. However, the vacuum generator 7 may be installed on the conduit 8 to be positioned outside the gas cylinder B.

3 is a side cross-sectional view of the vacuum generator 7 according to the present invention. The body 17 has a structure in which two venturi tubes 18 and 19 are combined.

The venturi tube 18 includes a flange 21 through which an inlet 20 connected to the gas supply line 9 is drilled, and a first passage 22 integrally formed and extending from the flange 21. Doing.

The first passage 22 has a shape that gradually narrows from the inlet side to the outlet side, and this shape has a function of speeding up the flow velocity of the outlet side.

The venturi pipe 19 positioned and combined on the flange 21 has an inlet 23 connected to the gas supply pipe 10, and a second passage in which the first passage 22 is located inward. It includes (24).

The second passage 24 is inclined in the same manner as the first passage 22 so that the outlet side is narrowed. The inner diameter of the second passage 24 is larger than that of the first passage 22. It consists of a structure in which a space is formed between these passages.

The second passage 24 is formed longer than the first passage 22 so that the end of the first passage 22 is positioned inside the second passage 24 exit.

In the gas line pumping system according to the present invention, the valves 11, 12, 13 are closed, and the valves 15, 16 are opened, and the gas cylinders 1 of the gas supply line 10 are opened. When the valves are opened, the liquefied gases filled in the gas cylinder 1 flow into the etching chamber 4 through the MFC 3 and are etched in the same manner as the conventional method.

When the etching is completed, the valves 15 and 16 are locked. If the valves 15 and 16 are locked and the gas remains in the gas supply line 10, the time until the next process becomes longer. In this case, when the valves 11, 12, 13 are opened and nitrogen gas is introduced through the gas supply line 9 above a certain pressure, the nitrogen gas flows into the vacuum generator 7 through the valve 11. do.

The nitrogen gas flowing into the vacuum generator 7 passes through the first passage 22, as shown in FIG. 3, and the first passage 22 is gradually narrowed because the outlet side is narrowed. The flow rate is faster.

As the flow velocity on the outlet side increases, the pressure on the outlet side decreases, and the liquefaction remaining in the gas supply line 10 due to the communication with the inlet 23 connected to the gas supply line 10. The gas begins to be sucked into the second passage 24.

The gas sucked into the second passage 24 exits the outlet side, enters the exhaust pipe 14 through the pipe line 8, and enters the gas cleaner 6 and is discharged.

When such an action is made for a certain time, the gas supply line 10 is in a vacuum state as the liquefied gas exits.

The above-mentioned exhaust time can be adjusted automatically by attaching a timer, and description thereof will be omitted since it can be easily implemented in the art.

As described above, the gasline pumping system according to the present invention can prevent the corrosion or blockage in the line caused by the gas being liquefied by venting the gas used in the etching process after the etching is stagnated for a long time. have.

Claims (3)

On the gas supply line 10 connected between the gas cylinder 1 and the etching chamber 4 to supply the gas used for etching, the inlet of the vacuum generator 7 is connected and the outlet of the vacuum generator 7 is connected. Gas line pumping system of a dry etching process, characterized in that the connection between the vacuum pump (5) and the gas cleaner (6) in a conduit (8). The venturi tube according to claim 1, wherein the gas generator (7) has an inlet (20) connected to the gas supply line (9), and is formed integrally with the first passage (22) whose outlet side is gradually narrowed. 18 and a second passage 24 located outside the venturi tube 18 and having an inlet 23 connected to the gas supply line 10 and gradually narrowing the outlet side thereof. A gas line pumping system of a dry etching process, characterized in that it comprises another Venturi tube (19) provided. 3. The gasline pumping system according to claim 2, wherein the length of the first passage (22) is shorter than the length of the second passage (24).