JP3766760B2 - Valve unit - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a valve unit used in an industrial manufacturing apparatus such as a semiconductor manufacturing apparatus, and more particularly to a valve unit capable of efficiently replacing residual gas staying in a flow path.
[0002]
[Prior art]
In the semiconductor manufacturing process, a process gas such as a corrosive gas, a toxic gas, and a flammable gas has been conventionally used as a supply gas for etching of photoresist processing or the like. Photoresist processing (photoresist application, exposure, development, and etching) is repeated a plurality of times in the semiconductor manufacturing process, where a gas supply device that supplies process gas as needed is used. That is, in photoresist processing, a plurality of types of process gases or process gases having the same concentration but different concentrations may be used. Therefore, a process gas such as a plurality of corrosive gases and component gases may be mixed in a chamber configured with a sealed space, or an inert gas may be mixed with the process gas to obtain a predetermined concentration. Have been supplied.
[0003]
However, corrosive gas among process gases, if left in the pipe after supply, will corrode the metal inside the pipe, etc., so impurities will be mixed in the next gas supply, which will adversely affect the semiconductor. There was to give.
Further, if a corrosive gas remains even in a small amount, the component of the process gas to be used next is changed, which has a great adverse effect on the photoresist processing and causes the quality of the semiconductor product to deteriorate.
In addition, if the process gas used last time is flammable gas, even if it is a small amount, it may be mixed with the next gas depending on the type, and there is a risk of combustion or explosion caused by flammable gas. It was.
Therefore, in the gas supply device, a plurality of types of predetermined amounts of process gas and the like are mixed in the chamber to manufacture the supply gas and supply it to the semiconductor process, and then remain in the chamber and the gas supply device. The gas is replaced with an inert gas such as nitrogen gas.
[0004]
Recently, integration of semiconductor manufacturing apparatuses has progressed, and a valve unit in which a flow path and a control valve constituting a gas supply apparatus are unitized has been adopted. FIG. 3 is a cross-sectional view showing a conventional example of such a valve unit. A valve unit 100 includes a gas supply valve 102 that controls the flow of a process gas to a chamber (not shown), and a gas replacement valve 103 that controls the flow of a purge gas for replacing residual gas, in a manifold 101 in which a flow path is formed. , And check valves 104 for preventing inflow of process gas are aligned in a row and attached integrally. When the process gas is flowed, the gas replacement valve 103 is closed, the gas supply valve 102 is opened, and the process gas is supplied to the chamber side. Therefore, the process gas flows from the process gas inflow passage 111 to the process gas outflow passage 112 via the gas supply valve 102 and is supplied from the discharge passage 113 to a chamber (not shown).
[0005]
On the other hand, when replacing the residual gas, after the gas supply valve 102 is closed and the supply of the process gas is stopped, the gas replacement valve 103 is opened and the purge gas (for example, nitrogen gas) flows at a high pressure (for example, 2 atm). Flowed into the road. The purge gas flows from the check valve 104 through the gas replacement valve 103 to the exhaust gas passage 113 side from the purge gas inflow passage 114 orthogonal to the process gas outflow passage 112 and is supplied at a high pressure. It will also flow into the dead space 120 that continues to the 102 side. Therefore, the residual gas in the dead space 120 is diluted with the purge gas, and flows to the discharge flow path 113 side to be discharged. Therefore, by continuing to flow the purge gas into the process gas outflow path 112, the process gas remaining in the flow path is diluted and gas replacement is completed.
[0006]
[Problems to be solved by the invention]
However, in the conventional valve unit 100 as shown in FIG. 3, it takes time for gas replacement to dilute the residual gas in the flow path to a desired concentration, and the consumption of purge gas increases accordingly. It was. This is because if the gas replacement takes a long time, the cycle time of the semiconductor manufacturing apparatus becomes longer and the production efficiency is lowered, and if the consumption amount of the purge gas is increased, it becomes an obstacle to cost reduction.
[0007]
Accordingly, an object of the present invention is to provide a valve unit that can efficiently replace residual gas in order to solve the above-described problems.
[0008]
[Means for Solving the Problems]
The valve unit according to the present invention is a valve unit in which a plurality of fluid control devices for controlling the flow of fluid flowing through the flow path are integrally attached to a manifold having a flow path formed in a block body. there are, comprises a gas supply valve for controlling the flow of process gas, wherein disposed from a gas supply valve to the downstream side of the flow of the process gas and a gas replacement valve for controlling the flow of purge gas, said manifold, A first connection port connected to a discharge path of the gas supply valve; a process gas flow path communicating the first connection port with a discharge port of the process gas; and a second connection connected to a discharge path of the gas replacement valve. And a purge gas passage for communicating the second connection port with the process gas passage, the process gas passage and the purge gas Confluence with the road, characterized in that between the first connecting port and the second connecting port.
For example, the purge gas channel is formed to be inclined from the second connection port to the first connection port, and the process gas channel is formed to be inclined from the first connection port to the second connection port. The purge gas flow path merges with the inclined portion of the process gas flow path .
Therefore, if the gas supply valve is closed after the process gas is supplied, the gas replacement valve is opened and the purge gas is allowed to flow, the residual gas will be pushed downstream from the purge gas flow path through the confluence of the process gas flow path. Since it is supplied at a high pressure, it flows into the upstream side of the junction where the dead space is closed by the gas supply valve, and the residual gas in the space is diluted and exhausted. At this time, the merge point is located upstream of the gas replacement valve, that is, closer to the closed portion of the gas supply valve. Therefore, the dead space volume is small, that is, the residual amount of process gas is reduced, which is required for gas replacement. Time can be shortened and purge gas consumption can also be reduced.
[0009]
The valve unit according to the present invention is a valve in which a plurality of fluid control devices that control the flow of fluid flowing through the flow path are integrally attached to a manifold having a flow path formed in a block body. a unit has a gas supply valve for controlling the flow of process gas, wherein disposed from a gas supply valve to the downstream side of the flow of the process gas and a gas replacement valve for controlling the flow of purge gas, the manifold It has a first connection port connected to the discharge path of the gas supply valve, and process gas passage for communicating the discharge port of the first connection port, a second connection port connected to the discharge channel of the gas exchange valve the purge gas flow path for communicating the second connection port to the process gas flow path, by which contact with the said first connection port second connection port And having a scan channel.
Therefore, if the gas supply valve is closed after the process gas is supplied, the gas replacement valve is opened and the purge gas is allowed to flow, the residual gas is pushed downstream from the purge gas flow path through the confluence of the process gas flow path, and the bypass flow path. The residual gas in the process gas flow path is forced away from the further upstream side of the confluence through the flow path. Further, since the purge gas is generally supplied at a high pressure, it flows into the upstream side of the process gas flow path entrance which is closed by the gas supply valve and becomes a dead space, and the residual gas in the space is diluted and exhausted. At this time, since the dead space is a slight space in the gas supply valve, the residual amount of process gas is small, the time required for gas replacement can be shortened, and the consumption of purge gas can also be reduced.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Next, an embodiment of a valve unit according to the present invention will be specifically described with reference to the drawings. The valve unit according to the present embodiment constitutes a gas supply device such as a semiconductor manufacturing device as described above. FIG. 1 is a cross-sectional view showing a first embodiment of a valve unit.
A valve unit 10 includes a gas supply valve 2 that controls the flow of a process gas to a chamber (not shown), and a gas replacement valve that controls the flow of a purge gas for replacing residual gas on a manifold 1 in which a flow path is formed. 3 and a check valve 4 for preventing inflow of process gas are arranged in a line and attached integrally. The gas supply valve 2, the gas replacement valve 3, and the check valve 4 are configured integrally with the respective valve blocks 11, 12, and 13, and are attached to the manifold 1 by the valve blocks 11, 12, and 13. The valve blocks 11, 12, 13 are respectively provided with inflow passages 11 A, 12 A, 13 A and outflow passages 11 B, 12 B, 13 B that communicate with the valve portions and open ports on the bottom side that is the mounting surface. Yes.
[0011]
A flow path communicating with the inflow paths 11A, 12A, 13A and the outflow paths 11B, 12B, 13B of the valve blocks 11, 12, 13 is formed in the manifold 1. That is, the process gas inflow passage 21 and the process gas outflow passage 22 communicate with the valve block 11 of the work valve 2 that controls the flow of the process gas. In particular, in the present embodiment, the process gas outflow path 22 has a horizontal portion 22P drilled in the longitudinal direction of the manifold 1, as can be seen in comparison with the conventional example (see FIG. 3). It communicates with the inclined portion 22Q inclined to the downstream side (gas replacement valve 3 side). Therefore, the outflow passage 11B of the valve block 11 is also formed to be inclined in accordance with the inclined portion 22Q of the process gas outflow passage 22.
[0012]
Also in the manifold 1, a purge gas inlet passage 23 for supplying purge gas to the check valve 4, and a communication passage 24 for the flow of purge gas from the check valve 4 to the gas exchange valve 3 are bored. Further, a purge gas supply path 25 is bored in the manifold 1 so as to join from the outflow path 12B of the valve block 12 to the gas replacement valve 3 in the middle of the inclined portion 22Q of the process gas outflow path 22. The purge gas supply path 25 is formed on the upstream side (gas supply valve 2 side) with an inclination similar to that of the inclined portion 22Q of the process gas outflow path 22, and the outflow path 12B of the valve block 12 communicating therewith is also inclined. Is formed.
The process gas outflow path 22 and the purge gas supply path 25 correspond to the process gas flow path and the purge gas flow path described in claim 1, respectively.
[0013]
Therefore, according to such a valve unit 10, gas replacement is performed as follows.
First, the process gas is supplied from the purge gas inflow passage 21 of the manifold 1 to the chamber (not shown) through the purge gas inflow passage 22 with the gas replacement valve 3 being closed and the gas supply valve 2 being opened. When processing such as etching is completed, the gas supply valve 2 is closed, the supply of process gas is stopped, and then gas replacement is performed. That is, following the closing of the gas supply valve 2, the gas replacement valve 3 is opened, and a high-pressure purge gas is pushed into the process gas outflow passage 22. An inert gas such as nitrogen gas is used as the purge gas, and the purge gas is supplied at a pressure of 2 atm or higher.
Accordingly, the purge gas flows from the check valve 4 to the gas replacement valve 3 through the purge gas inflow path 23 and the communication flow path 24 of the manifold 1, and further from the purge gas supply path 25 to the inclined portion 22Q of the process gas outflow path 22. It flows in well.
[0014]
The purge gas that has flowed into the process gas outflow passage 22 is discharged from the discharge passage 26 while pushing the residual gas as it is.
Further, since the purge gas is supplied at a pressure higher than the pressure in the flow path, the inclined portion 22Q flows into the outflow path 11B of the valve block 11, that is, the dead space 28 (illustrated by spots). For this reason, the residual gas in the dead space 28 is diluted with the purge gas, and flows to the discharge flow path 26 side to be discharged. Therefore, by continuing to flow the purge gas into the process gas outflow path 22, the process gas remaining in the flow path is diluted and gas replacement is completed.
[0015]
Here, a test result is compared about the gas displacement characteristic of the valve unit 10 of this Embodiment and the conventional valve unit 100 of FIG. 4 and 5 are graphs showing the test results for the gas replacement characteristics. In this test, gas replacement was performed by purging nitrogen gas in a flow path filled with oxygen instead of corrosive gas. The graph of FIG. 4 shows the comparison of the purge time with respect to the residual oxygen concentration in the valve unit flow path, and the graph of FIG. 5 shows the comparison of the nitrogen gas consumption with respect to the residual oxygen concentration in the valve unit flow path. Yes.
In addition, this test was performed under a replacement gas flow rate of 1 liter per minute at a replacement gas pressure of 0.2 MPa.
In the actual gas replacement, the allowable concentration of the residual gas concentration in the flow path is determined by the gas type, and this test was compared until diluted to 0.5 ppm or less.
[0016]
Therefore, when comparing the valve units 10 and 100 with the purge time until the reference value is substantially reached and the amount of nitrogen gas consumed, the valve unit 10 of this embodiment (shown with a solid line) is clearly more conventional. Compared with the valve unit 100 of FIG.
That is, as shown in FIG. 4, in the case of the conventional valve unit 100, a purge time of about 900 seconds was required until the residual oxygen reached the reference concentration, whereas the present valve unit 10 was about 200 seconds. Further, as shown in FIG. 5, in the case of the conventional valve unit 100, about 15 liters of nitrogen gas was consumed before the residual oxygen reached the reference concentration, whereas in the present valve unit 10, about 3.3 liters were consumed. Liters. Therefore, according to the valve unit 10 of the present embodiment, the consumption of nitrogen gas can be suppressed as the purge time is shortened.
[0017]
This is presumably because the purge gas supply passage 25 that is similarly inclined is joined to the inclined portion 22Q of the process gas outlet passage 22 so that the dead space 28 can be made as small as possible. In that respect, the conventional manifold 101 has a residual gas capacity of 0.71 cc in the dead space 120, whereas the manifold 1 of the present embodiment has a residual gas capacity of 0 in the dead space 28. It was possible to reduce to .13 cc.
From this result, according to the valve unit 10 of the present embodiment, the cycle time of the semiconductor manufacturing apparatus can be shortened, leading to an improvement in manufacturing capability. In addition, the consumption of purge gas used for gas replacement can be reduced, resulting in cost reduction.
[0018]
Next, a second embodiment of the valve unit according to the present invention will be described. FIG. 2 is a cross-sectional view showing a second embodiment of the valve unit. The valve unit 30 of the present embodiment is assembled in the same manner as that of the first embodiment, and constitutes a gas supply apparatus such as a semiconductor manufacturing apparatus. Accordingly, the same components as those of the valve unit 10 (see FIG. 1) will be described with the same reference numerals.
A gas supply valve 2, a gas replacement valve 3, and a check valve 4 are arranged in a line on a manifold 31 in which a flow path is formed, and are integrally attached. These are configured integrally with the respective valve blocks 11, 12, 13 and are attached to the manifold 31 by the valve blocks 11, 12, 13. The valve blocks 11, 12, 13 are respectively provided with inflow passages 11 A, 12 A, 13 A and outflow passages 11 B, 12 B, 13 B that communicate with the valve portions and open ports on the bottom side that is the mounting surface. Yes.
[0019]
A flow path communicating with the inflow paths 11A, 12A, 13A and the outflow paths 11B, 12B, 13B of the valve blocks 11, 12, 13 is formed in the manifold 31. That is, the process gas inflow passage 41 and the process gas outflow passage 42 communicate with the valve block 11 of the work valve 2 that controls the flow of the process gas. The process gas outflow passage 42 communicates with a horizontal portion 42P formed in the longitudinal direction of the manifold 31 by a vertical portion 42Q formed vertically from the upper surface.
The manifold 31 includes a purge gas inlet passage 43 for supplying purge gas to the check valve 4, and the communication passage 44 for the flow of purge gas from the check valve 4 to the gas substitution valve 3 is bored.
The manifold 31 further includes a purge gas supply path 45 that vertically communicates with the horizontal portion 42P of the process gas outflow path 42 from the outflow path 12B of the valve block 12, and the purge gas supply path 45 and the process gas outflow path 42. A V-shaped bypass passage 46 communicating with the upper surface opening is formed.
The process gas outflow path 42 and the purge gas supply path 45 correspond to a process gas flow path and a purge gas flow path described in claim 2, respectively.
[0020]
Therefore, according to such a valve unit 30, gas replacement is performed as follows.
First, the process gas is supplied from the purge gas inflow passage 41 of the manifold 31 to the chamber (not shown) through the purge gas inflow passage 42 while the gas replacement valve 3 is closed and the gas supply valve 2 is opened. When processing such as etching is completed, the gas supply valve 2 is closed, the supply of process gas is stopped, and gas replacement is executed. That is, the gas replacement valve 3 is opened after the gas supply valve 2 is closed, and the high-pressure purge gas is pushed into the process gas outflow passage 42. An inert gas such as nitrogen gas is used as the purge gas, and the purge gas is supplied at a pressure of 2 atm or higher.
Therefore, the purge gas flows from the check valve 4 to the gas replacement valve 3 through the purge gas inflow path 43 and the communication flow path 44 of the manifold 31 and further from the outflow path 12B of the valve block 12 to the purge gas supply path 45 and the bypass flow path 46. And flow in two directions.
[0021]
The purge gas that has flowed into the purge gas supply passage 45 is directly discharged from the discharge passage 26 by pushing away the residual gas in the process gas outlet passage 42. On the other hand, the purge gas that has flowed into the bypass flow path 46 further pushes the residual gas in the process gas outflow path 42 from the upstream side and discharges it to the discharge flow path 26 side. Further, since the purge gas that has flowed into the bypass flow path 46 is supplied at a high pressure, it also flows into the outflow path 11B of the valve block 11 that is a dead space 48 (illustrated with spots).
Therefore, the residual gas in the dead space 48 is diluted with the purge gas and flows to the discharge flow path 26 side to be discharged. Therefore, by continuing the flow of the purge gas, the process gas remaining in the flow path is diluted and the gas replacement is completed.
[0022]
According to the valve unit 30 of the present embodiment, the test result of the gas replacement characteristic is not shown, but the purge time can be further shortened, and the nitrogen gas consumption can be further suppressed accordingly. it can. This is because, as shown in the first embodiment, the improvement in the gas replacement characteristics is considered to be caused by the dead space in the flow path. In this respect, in the present embodiment, since the residual gas in the manifold 31 is completely washed away, the capacity of the residual gas in the dead space 48 is reduced to 0.09 cc in the outflow passage 11B. It was because it was made.
Further, the direction of the purge gas flowing into the dead space 48 can be cited as a basis for improving the gas replacement characteristics. That is, since the purge gas is supplied at a pressure higher than the pressure in the flow path, the purge gas also flows into the dead space. However, since the bypass flow path 46 faces the dead space 48 as in the present embodiment, the purge gas This is because it is considered that the kinetic energy due to the flow of gas effectively works and effectively flows into the dead space.
[0023]
Therefore, according to the valve unit 30 of the present embodiment, the cycle time of the semiconductor manufacturing apparatus can be shortened by improving the gas replacement characteristics, leading to an improvement in manufacturing capability. In addition, the consumption of purge gas used for gas replacement can be reduced, resulting in cost reduction.
[0024]
In addition, this invention is not necessarily limited to the thing of the said embodiment, A various change is possible in the range which does not deviate from the meaning.
For example, in the second embodiment, the bypass flow path 46 is formed in addition to the purge gas supply path 45, but the purge gas may be supplied only by the bypass flow path 46.
[0025]
【The invention's effect】
The present invention provides a valve unit in which a plurality of fluid control devices for controlling the flow of fluid flowing through the flow path are integrally attached to a manifold having a flow path formed in a block body, A gas supply valve that controls a gas flow; and a gas replacement valve that is disposed downstream of the process gas flow from the gas supply valve and controls a flow of a purge gas. The manifold includes the gas supply valve A first connection port connected to the discharge path, a process gas flow path communicating the first connection port with the process gas discharge port, a second connection port connected to the discharge path of the gas replacement valve, the second connection port and a purge gas flow path which communicates with the process gas flow path, the meeting point of the process gas flow path and the purge gas flow path, before Since between the first connection port second connection port, it becomes possible to provide a valve unit capable of performing the substitution of the residual gas efficiently.
[0026]
Further, the present invention is a valve unit in which a plurality of fluid control devices for controlling the flow of fluid flowing through the flow path are integrally attached to a manifold having a flow path formed in a block body. A gas supply valve that controls a flow of the process gas; and a gas replacement valve that is disposed on the downstream side of the flow of the process gas from the gas supply valve to control the flow of the purge gas, and the manifold includes the gas A first connection port connected to the discharge path of the supply valve; a process gas flow path connecting the first connection port to the discharge port; a second connection port connected to the discharge path of the gas replacement valve; structure with a purge gas passage for communicating the connection port to the process gas flow path, and a bypass passage communicating with said first connection port and the second connecting port Since was, it becomes possible to provide a valve unit capable of performing the substitution of the residual gas efficiently.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a first embodiment of a valve unit according to the present invention.
FIG. 2 is a cross-sectional view showing a second embodiment of a valve unit according to the present invention.
FIG. 3 is a cross-sectional view showing a conventional valve unit.
FIG. 4 is a graph showing gas replacement characteristics based on purge time.
FIG. 5 is a graph showing gas replacement characteristics based on purge gas consumption.
[Explanation of symbols]
1,31,101 Manifold 2,102 Gas supply valve 3,103 Gas replacement valve 4,104 Check valve 10,30,100 Valve unit 22,42,112 Process gas outflow passage 25,45,46,114 Purge gas supply passage

Claims (3)

A valve unit in which a plurality of fluid control devices for controlling the flow of fluid flowing through the flow path are integrally attached to a manifold having a flow path formed in a block body,
A gas supply valve for controlling the flow of the process gas, wherein disposed from a gas supply valve to the downstream side of the flow of the process gas and a gas replacement valve for controlling the flow of purge gas,
The manifold is
A first connection port connected to the discharge path of the gas supply valve ;
A process gas flow path for communicating the first connection port with the process gas outlet;
A second connection port connected to the discharge path of the gas replacement valve;
A purge gas flow path communicating the second connection port with the process gas flow path,
The valve unit, wherein a confluence of the process gas flow path and the purge gas flow path is between the first connection port and the second connection port . The valve unit according to claim 1, wherein
The purge gas flow path is formed to be inclined from the second connection port to the first connection port ;
The process gas flow path has an inclined portion formed to be inclined from the first connection port to the second connection port ;
The valve unit , wherein the purge gas flow path joins an inclined portion of the process gas flow path. A valve unit in which a plurality of fluid control devices for controlling the flow of fluid flowing through the flow path are integrally attached to a manifold having a flow path formed in a block body,
A gas supply valve for controlling the flow of the process gas, wherein disposed from a gas supply valve to the downstream side of the flow of the process gas and a gas replacement valve for controlling the flow of purge gas,
The manifold is
A first connection port connected to the discharge path of the gas supply valve ;
A process gas flow path for communicating the first connection port with the discharge port;
A second connection port connected to the discharge path of the gas replacement valve;
A purge gas flow path for communicating the second connection port with the process gas flow path;
A valve unit comprising a bypass flow path connecting the first connection port and the second connection port .

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