JPH03211281A - Gas piping device of cylinder box - Google Patents

Abstract

PURPOSE:To execute the switching of gas cylinders in a short period of time and to prevent the degradation in the working rate of a CVD device by disposing two pieces of the cylinders for reactive gases to be supplied to the CVD device, etc., executing the switching of the gases only by the switching of valves at the time of switching and providing a rotary pump for vacuum in the purge line for residual gases. CONSTITUTION:Two pieces of the cylinders 1, 1a for reactive gases to be used in the CVD device are provided and the gas of the cylinder 1 is supplied to the CVD device. The film formation by CVD is then executed. A reducing valve 2a and a raw gas outlet valve 3a of another cylinder 1a are opened and the outlet valve 3 of the cylinder 1 is closed to continuously supply the reactive gases to the CVD device when the pressure of the cylinder 1 drops to a specified value or below. The CVD film forming treatment is thus continued. The rotary pump 8 provided in the purge line is then operated and a stop valve 9 is opened to supply gaseous N2 and to release the residual gases in the valve 3, purge valve 4 and N2 purge valve 5 of the gas cylinder 1 to a rotary pump side. The purge effect in the piping on cylinder 1 side is thus improved.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a gas piping system for a cylinder box that houses semiconductor gas cylinders such as silane and phosphine.

2. Description of the Related Art A conventional gas piping system in a cylinder box will be described below.

Figure 2 is a diagram of the gas piping system inside a conventional cylinder box, where 1 is the gas cylinder, 2 is the pressure reducing valve, 3 (1) is the raw gas outlet valve, 4 is the vent valve, 5 is the nitrogen purge valve, and 6 is the raw gas outlet valve.
is a check valve, and 7 is a flow meter.

As can be seen from Figure 2, the semiconductor gases used in conventional semiconductor manufacturing equipment such as CVD and dry etching are
The gas is supplied from each gas cylinder 1 housed in a cylinder box.

When replacing these gas cylinders 1 using the conventional gas piping inside the cylinder box, first replace the gas cylinders 1.
After closing the main valve and releasing the residual gas in the piping to the equipment side, perform batch purging and continuous purging to the equipment side with nitrogen gas, then replace gas cylinder 1, perform a high pressure leak check, and perform the same procedure using nitrogen gas. The method used was to open the valve of the new gas cylinder 1 only after purging and confirming that there were no leaks.

Problems to be Solved by the Invention However, in the conventional cylinder box gas piping described above, when replacing the gas cylinder, all residual gas release and nitrogen gas purge are performed through the semiconductor device side. The equipment was unable to operate inside. In addition, in normal pressure CVD equipment,
Since the exit side of the device is at atmospheric pressure, the efficiency of nitrogen gas purging is poor, and this poses a problem in that purges must be performed many times or the purge time must be lengthened.

The present invention solves the above-mentioned conventional problems, and aims to provide a gas piping device for a cylinder box that enables operation of semiconductor manufacturing equipment when replacing gas cylinders and also improves purge efficiency. .

Means for Solving the Problems The present invention is characterized in that it has two gas pipes that can be installed in the cylinder box to the same gas cylinder, and that the purge line can be evacuated by a rotary pump. It is said that

By using gas piping that allows two gas cylinders of the same type to be installed in the working cylinder box, it is possible to switch gases by simply switching the valve when replacing gas cylinders. Therefore, there is no need to stop the operation of the semiconductor manufacturing equipment. Furthermore, by evacuating the purge line with a rotary pump, it is possible to increase the pressure difference within the gas piping during purging, thereby increasing the efficiency of purging within the gas piping.

EXAMPLE Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 shows a diagram of gas piping inside a cylinder box in one embodiment of the present invention.

In Figure 1, 1.1a is the same type of gas cylinder, 2
, 2a is a pressure reducing valve, 3, 3a is a raw gas outlet valve, 4, 4a is a vent (purge) valve, 5, 5a is a nitrogen purge valve, 6, 6
a is a check valve, 7 is a flow meter, 8 is a rotary pump, and 9 is a stop valve.

A case will be described in which gas cylinders are replaced using the gas piping of this embodiment configured as described above.

First, in a gas system in which gas cylinders 1 and 1a of the same type and gas piping of the same configuration are installed in parallel, it is assumed that the line for cylinder 1 is used. When the next suppression pressure becomes less than the specified value, open the source valve of the unused gas cylinder 13 and the raw gas outlet valve 3a.Then, close the gas cylinder 1 and the raw gas outlet valve 3.

Through the above operations, gas is continuously supplied to the device.

Next, the rotary pump 8 installed in the purge line is operated, the stop valve 9 is opened, and nitrogen gas is allowed to flow through the flow meter 7 to the rotary pump.

In this state, the residual gas in the pipe between the valves 3° and 4.5 in the line of the gas cylinder 1 is discharged to the rotary pump 8gs, and then batch purging and continuous purging with nitrogen gas are performed.

Next, replace the gas cylinder.

After performing a high-pressure leak check and a similar purge with nitrogen gas to confirm that there are no leaks, open the cylinder 1, adjust the secondary pressure with the pressure reducing valve 2, and then close the cylinder 1. Further, after the rotary pump is stopped, the purge line is pressurized with nitrogen by closing the stop valve 9.

As described above, according to this embodiment, when replacing a gas cylinder, it is possible to switch the gas by simply switching the valve. Furthermore, gas cylinders can be replaced while other gas cylinders are in use.In particular, by installing the rotary pump 8 in the purge line, the purge efficiency is increased and the purge time in the normal pressure CVD apparatus can be shortened.

Effects of the Invention The present invention provides a cylinder in which two gas cylinders of the same type can be installed, and by using a low-replacement pump in the purge line, it is possible to exchange other gas cylinders even while gas is in use, and it is possible to perform gas purge with high purge efficiency. This makes it possible to realize box gas piping.

[Brief explanation of drawings]

FIG. 1 is a gas piping diagram of a cylinder box according to an embodiment of the present invention, and FIG. 2 is a gas piping diagram of a conventional cylinder box. 1.1a...Gas cylinder, 2,2a...
・Pressure reducing valve, 3, 3a... Raw gas outlet valve, 4, 4
a... Vent (purge) valve, 5, 5a old...
Nitrogen purge valve, 6.6a... Check valve, 7...
...Flowmeter, 8...Rotary pump, 9.
...stop valve.

Claims (2)

[Claims] (1) A gas piping device for a cylinder box, characterized in that two gas cylinders of the same type are installed in the cylinder box. (2) A gas piping system for a cylinder box according to claim 1, characterized in that a vacuum rotary pump is installed in the purge line.