KR19980069172A - Residual gas exhaust method of gas supply system - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for exhausting residual gas in a gas supply system, and alternately opens and closes a second air valve provided in a first gas pipe and a fourth air valve provided in a second gas pipe, thereby remaining in the gas pipe. By exhausting the present combustible gas into a small amount of the vacuum exhaust device, it is possible to prevent the vacuum pump from being contaminated by the combustible gas and to burn out the neutralizing device.

Description

Residual gas exhaust method of gas supply system

The present invention relates to a method of exhausting residual gas of a gas supply system, and more particularly, to replace a gas cylinder, a gas for protecting peripheral equipment of a gas supply system by sequentially exhausting combustible gas remaining in a gas pipe. A method for exhausting residual gas in a supply system.

Generally, various types of reaction gases are used in a semiconductor manufacturing apparatus for manufacturing a semiconductor device. Such reaction gases are transferred to a reactor by a pipe connected to a gas cylinder, and a reaction gas of a certain amount or less remains in the gas cylinder. Will replace the gas cylinder.

At this time, according to the replacement of the gas cylinder, the reaction gas cannot be supplied to the reactor for the replacement time of the gas cylinder. As shown in FIG. 1, the automatic replacement that can replace the gas cylinder without stopping the supply of the reaction gas as shown in FIG. Gas cabinets have been developed.

1 is a view schematically showing the structure of a conventional gas supply system.

As illustrated, the gas supply system 100 of the semiconductor manufacturing facility includes a gas cylinder 10 in which a reactive gas is filled with high pressure, a processor chamber 20 for performing a process using the reactive gas, and a gas cylinder 10. And a gas pipe 30 in which the process chamber 20 is in common communication, a purge pipe 40 for supplying purge gas to the gas pipe 30 when the gas cylinder 10 is replaced, and a gas when gas is replaced. The vent pipe 50 for exhausting the gas remaining in the pipe 30 and the vacuum exhaust device 50 which communicates with the vent pipe 50 and discharges the gas to the outside are comprised.

Here, the gas pipe 30 communicates with the first gas pipe 31, which communicates with the gas cylinder 10, the end of the first gas pipe 31, and the processor chamber 20, and communicates with the processor chamber 20. One end of the second gas pipe 32 for supplying the process gas to the first gas pipe 31 and a predetermined region of the first gas pipe 31 communicates with each other, and an end of the second gas pipe 32 communicates with the other end of the vent pipe 50. It is comprised by the 3rd gas piping 33 connected to (). Here, the 1st and 2nd air valve 34a, 34b is provided in the 1st gas piping 31 predetermined area | region, and the gas cylinder 10 is provided between the 1st and 2nd air valve 34a, 34b. A first gas filter 35 is installed to remove the suspended matter of the gas supplied from the gas, and a regulator 36 for measuring the flow rate and oil pressure of the gas is provided above the second air valve 34b. In addition, a third air valve AV3 and a second gas filter LF2 are disposed on an upper side of the first gas pipe 31 based on a portion where the first gas pipe 31 communicates with the second gas pipe 32. In the lower part of the 1st gas piping 31, the 1st check valve 37 which controls so that the 4th air valve 34c and the supplied gas may flow only in one direction is provided. The third gas pipe 33 is provided with a fifth air valve AV5 and a second check valve CV2 on the right side of the second gas pipe 32 on the basis of the second gas pipe 32. 2 A manual valve 38 is provided on the left side of the gas pipe 32.

Further, the purge pipe 40 communicates with the nitrogen purge gas pipe 41 communicating with the first gas pipe 31, and the helium purge gas pipe communicating with a predetermined region of the nitrogen purge gas pipe 41 to supply helium gas. It consists of 43. Here, the air valve 45 is provided in predetermined region of the nitrogen purge gas pipe 41 and the helium purge gas pipe 43.

In addition, the vent pipe 50 is communicated between the end of the third gas pipe 33 and the vacuum exhaust device 60, the vacuum exhaust device 60 is a vacuum pump 61, a vacuum pump 61 for generating a low pressure And a scrubber 63, which is an acid neutralizer, which neutralizes the reaction gas discharged through the < RTI ID = 0.0 >), and < / RTI >

The residual gas venting method of the conventional gas supply system configured as described above is as follows.

When the silane gas (SiH ₄ ) filled in the gas cylinder 10 is consumed in the semiconductor manufacturing process, the empty gas cylinder 10 should be replaced with a new gas cylinder 10 filled with the silane gas.

In order to replace the gas cylinder 10, the 1st air valve 34a provided in the 1st gas piping 31 and the 3rd air valve AV3 provided in the 2nd gas piping 32 are closed, 3 Open the manual valve 38 provided in the gas pipe 33. Thereafter, the air valve 45 provided in the nitrogen purge gas pipe 41 and the helium purge gas pipe 43 is opened to provide nitrogen to the first, second and third gas pipes 31, 32, 33. And when helium gas is supplied, all of the silane gas remaining in the gas pipe 30 is exhausted to the vent pipe 50 by suction of the vacuum pump 61.

Thus, the silane gas exhausted to the vent pipe 50 by the suction of the vacuum pump 61 is exhausted to the outside via the vacuum pump 61, the scrubber 63 and the main exhaust pipe (65).

However, when nitrogen gas and helium gas, which are purge gas, are supplied to the first, second, and third gas pipes in which the silane gas remains, a large amount of silane gas is momentarily purged by the vacuum exhaust device to the silane gas, which is combustible gas. There was a problem that the vacuum pump is contaminated or the neutralizer is burned out.

Accordingly, the present invention provides a method of exhausting residual gas of a gas supply system to prevent the vacuum pump from being contaminated or burned out by a large amount of combustible gas by dividing the exhaust of the combustible gas exhausted toward the vent pipe in multiple stages. It is.

1 is a view schematically showing the structure of a conventional gas supply system.

In order to achieve the above object, the present invention maintains the first air valve installed at the front end of the gas pipe on the basis of the gas cylinder, and closes the second air valve installed at the rear end of the gas pipe. Purging the residual gas, and closing the first air valve and opening the second air valve to discharge the purged residual gas into the vent pipe, thereby completely exhausting the remaining gas in the gas pipe. Characterized in that.

Hereinafter, a method of evacuating a combustible gas according to the present invention will be described with reference to FIG. 1. Here, since the structure of the gas supply system is the same as that shown in FIG. 1, the description of the structure of the gas supply system will be omitted.

The gas exhaust method according to the present invention will be described with reference to FIG. 1.

When the silane gas filled in the gas cylinder 10 is consumed in the semiconductor manufacturing process, the empty gas cylinder 10 should be replaced with a new gas cylinder 10 filled with the silane gas.

In order to replace the gas cylinder 10, the 1st air valve 34a provided in the 1st gas piping 31 and the 3rd air valve AV3 and 4th air provided in the 2nd gas piping 32 are shown. The valve 34c is closed and the manual valve 38 provided in the third gas pipe 33 is opened. Thereafter, when the air valve 45 provided in the nitrogen purge gas pipe 41 and the helium purge gas pipe 43 is opened to supply nitrogen and helium gas to the gas pipe 30, the second air valve 34b is It is open and the 4th air valve 34c is closed, and purge gas is supplied only to the front of 4th air valve 34c. Thereafter, when the second air valve 34b is closed and the fourth air valve 34c is opened, the purge gas and the silane gas remaining between the second air valve 34b and the fourth air valve 34c are vacuum pumped. By the suction force of 61, it is exhausted to the vent pipe 50 side.

Then, when the gas remaining between the second air valve 34b and the fourth air valve 34c is exhausted toward the vent pipe 50, the fourth air valve 34c is closed again and the second air valve 34b is closed. ) Is opened to purge the gas remaining between the first air valve 34a and the second air valve 34b toward the fourth air valve 34c. In this manner, the second air valve 34b and the fourth air valve 34c until all of the silane gas remaining in the first, second and third gas pipes 31, 32 and 33 are exhausted. Open and close alternately.

As described above, when the second air valve 34b and the fourth air valve 34c are alternately opened and closed to exhaust the gas remaining in the gas pipe 30, a small amount of silane gas is continuously transferred to the vacuum exhaust device 60. Exhausted.

As described above, the present invention alternately opens and closes the second air valve provided in the first gas pipe and the fourth air valve provided in the second gas pipe to evacuate a small amount of combustible gas remaining in the gas pipe. By evacuating to the apparatus, the vacuum pump is contaminated by the combustible gas and the neutralizing apparatus can be prevented from being burned out.

Claims (2)

In the case of replacing the gas cylinder in the method of exhausting the gas remaining in the gas pipe to the outside, Opening the first air valve installed at the front end of the gas pipe on the basis of the gas cylinder and closing the second air valve installed at the rear end of the gas pipe to purge residual gas remaining in the gas pipe; Closing the first air valve and opening the second air valve to discharge the purged residual gas into the vent pipe, thereby exhausting the remaining gas in the gas pipe completely. Method of exhausting residual gas. The method of claim 1, wherein the residual gas is a combustible gas.