JPH0738932B2 - Gas piping for semiconductor manufacturing equipment - Google Patents

Description

The present invention relates to a gas pipe of a semiconductor manufacturing apparatus, and more particularly to a gas pipe capable of supplying a high-purity gas to a wafer processing tank.

[Prior Art] In the gas pipe in the conventional semiconductor manufacturing apparatus, as shown in the piping diagram of FIG. 3, the gas supplied from the Ar cylinder 1 is adjusted to an appropriate pressure by the pressure reducing valve 21, and then the adsorbent is supplied. 5, it is directly led to the sputtering tank 12 which is a processing tank through the stop valve 10 and the flow rate controller 11. FIG. 3 shows an example of a conventional gas pipe in the sputtering apparatus. With this structure, the gas flow rate is the same everywhere in the pipe, from the cylinder to the processing tank.

[Problems to be Solved by the Invention]

In the conventional gas pipe described above, the gas flow rate is the same anywhere in the pipe from the cylinder to the treatment tank.Therefore, the flow rate in the pipe greatly varies depending on the gas flow rate introduced into the treatment tank, and the gas flow rate changes when the treatment is stopped. It becomes zero. It is known that when the gas flow rate becomes zero, the gas in the pipe is contaminated with the impurity gas released from the inner wall of the pipe over time. Also, the smaller the gas flow rate, the more easily the gas purity is affected by the gas released from the inner wall of the pipe, which leads to a decrease in the purity. Therefore, the effect of the adsorbent for impurities in the gas in the middle of the pipe is also small.

As described above, in the conventional gas pipe, since the gas flow rate of the entire pipe depends on the gas flow rate introduced into the processing tank, the gas flow rate in the pipe cannot be sufficiently controlled to maintain the purity, There is a drawback that the gas purity varies depending on the flow rate of the gas introduced into the processing tank.

In contrast to the conventional gas pipe described above, the present invention provides a sufficient amount of gas for maintaining the gas purity in the annular pipe having an in-gas impurity component adsorbent as a gas required in the treatment tank. Always circulate a fixed amount regardless of the flow rate,
A gas pipe is branched into the processing tank from the annular pipe by a necessary amount and taken out.

[Means for Solving the Problems]

The present invention, in a gas pipe of a semiconductor manufacturing apparatus for performing wafer processing using a high-purity gas, an annular pipe is provided in the middle of a pipe path from a gas supply source to a processing tank, and the gas is supplied at a constant flow rate in the annular pipe. A mechanism that circulates, a mechanism that detects the pressure in the annular pipe to supplement gas, a mechanism that branches a part of the circulating gas from the annular pipe and introduces a desired flow rate into the processing tank, and the annular It is a gas pipe of a semiconductor manufacturing apparatus provided with a mechanism for adsorbing and removing an impurity component in gas in the middle of the pipe.

〔Example〕

 Next, the present invention will be described with reference to the drawings.

FIG. 1 is a piping diagram of an embodiment in which the present invention is applied to a sputtering device.

Gas is gas replenishment point 4, adsorbent 5, gas branch point 9, circulation pump
6, the flow rate detector 7, and the check valve 8 are circulated in this order. The circulation is performed by the circulation pump 6. As the pump, a diaphragm type pump that can obtain a flow rate of 1 / min was selected. Sputtering tank 12
The gas is introduced to the stop valve 10 from the gas branch point 9,
It is performed via the flow controller 11, and the flow rate is selected in the range of 0 to 1000 sccm depending on the flow rate required for processing.

Further, the flow rate of the gas circulated in the annular pipe is measured by the flow rate detecting unit 7, and the signal is sent to the pressure control valve controller 3. The pressure control valve controller 3 adjusts the pressure control valve 2 so that the gas flow rate measured by the flow rate detection unit 7 becomes constant, and controls the amount of gas flowing from the Ar cylinder 1 to the gas replenishment point 4.

Thus, in this gas pipe, the gas flow rate in the annular pipe containing the adsorbent can be kept constant regardless of the amount of gas used in the sputtering tank 12. Therefore, the decrease in gas purity due to the gas released from the inner wall of the pipe when gas is stopped or when the flow rate is low, as seen in conventional gas pipes, does not occur in the annular pipe, and a gas of high purity is always used as the gas branch point. Up to 9 are supplied. On the other hand, the flow controller 11 and the stop valve 10 can be installed very close to the sputtering tank, and the pipe length from the gas branch point 9 to the sputtering tank 12 can be minimized to minimize the deterioration of purity in the pipe. it can.

That is, in the conventional gas pipe, the gas purity was lowered due to the gas released from the entire pipe, whereas in the present invention, only the effect of the gas released from the extremely short pipe from the gas branch point 9 to the sputtering tank 12 was obtained. A dramatic improvement in gas purity can be realized. As the adsorbent, Ti is 900 ° C.
After heating, a spiral coil-shaped pipe that lowers the gas temperature was used. The flow rate of the circulating gas was 1 / min.

FIG. 2 is a piping diagram of an application example of the present invention. This application example is a gas pipe when there are three processing tanks.

The configuration from the Ar cylinder 1 to the annular pipe is the same as that of the above-mentioned embodiment, and three combinations of gas branch points 9, 13, 17 and sputtering tanks 12, 16, 20 are provided. Each stop valve 10,14,18 and flow controller 1 as in the previous embodiment
1, 15 and 19 are installed very close to the corresponding sputtering tank.

In this application example, there is an advantage that high-purity gas can be supplied to all the sputtering tanks by one set of the annular piping and the cylinder by separating the annular piping according to the arrangement of each sputtering tank.

〔The invention's effect〕

As described above, the present invention configures the gas pipe in an annular shape, circulates the gas while passing the adsorbent at a constant flow rate, and extracts only the flow rate necessary for processing by branching from the annular pipe, There is an effect that a high-purity gas can be supplied to the processing tank without fluctuations in the purity of the gas due to changes in the flow rate.

[Brief description of drawings]

FIG. 1 is a piping diagram of an embodiment of the present invention, FIG. 2 is a piping diagram of an application example of the present invention, and FIG. 3 is a piping diagram showing an example of piping in a conventional semiconductor manufacturing apparatus. 1 ... Ar cylinder, 2 ... Pressure control valve, 3 ... Pressure control valve controller, 4 ... Gas replenishment point, 5 ... Adsorbent, 6 ... Circulation pump, 7 ... Flow rate detector, 8 ... Check valve, 9 ... Gas branch point, 10 ... Stop valve, 11 ...
... Flow controller, 12 ... Sputtering tank, 13 ...
… Gas branch point 2, 14 …… Stop valve 2, 15 …… Flow controller 2, 16 …… Sputtering tank 2, 17 ……
Gas branch point 3,18 …… Stop valve 3,19 …… Flow controller 3,20 …… Sputtering tank 3,21 …… Decompression valve.

Claims (1)

[Claims] 1. In a gas pipe of a semiconductor manufacturing apparatus for performing wafer processing using a high-purity gas, an annular pipe is provided in the middle of a pipe path from a gas supply source to a processing tank, and a constant flow rate is provided in the annular pipe. A mechanism for circulating a gas, a mechanism for replenishing the gas by detecting the pressure in the annular pipe, a mechanism for branching a part of the circulating gas from the annular pipe and introducing a desired flow rate into the processing tank, A gas pipe for a semiconductor manufacturing apparatus, wherein a mechanism for adsorbing and removing an impurity component in a gas is provided in the middle of the annular pipe.