JPH059002A - Automatic cleaning method of gaseous diborane supply system and device therefor - Google Patents

Abstract

PURPOSE:To provide the method for automatically cleaning reducing valves which are out of order without removing the reducing valves of the gaseous diborane supply system formed in parallel with plural reducing valve lines and the device therefor. CONSTITUTION:A cleaning gas supply path (13) is connected to the upstream side of the reducing valves (3) in the respective reducing valve lines (2) and a evacuating path (14) is led out of the downstream side of the reducing valves (3). A high-pressure nitrogen introducing path (15) is selectively communicatably connected to a nitrogen introducing path (6) for purging piped to the upstream side of the reducing valves (3) in the respective reducing valve lines (2). Flow passage stop valves (4), (5) disposed in the reducing valve lines (2) and the respective valves disposed in the cleaning gas supply line (13), the evacuating path (14), the nitrogen introducing path (6) for purging, and the high-pressure nitrogen introducing path (15) are controlled to be opened and closed in accordance with the pressure detection operations in pressure sensors (21) disposed in the state of holding the reducing valves (3).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cleaning method for a diborane gas supply system used in the field of semiconductor manufacturing and a cleaning device used for the cleaning method.

[0002]

_2. Description of the Related Art Generally, in a semiconductor manufacturing line using diborane (B ₂ H ₆ ), a pressure reducing valve is arranged in a gas supply passage so as to reduce the pressure to a predetermined supply pressure and supply it to the equipment used. By the way, diborane is thermally decomposed even at room temperature to form higher-order borane. Since the high-order borane has high viscosity, the high-order borane adheres to the valve element and the valve seat portion, and the pressure reducing valve becomes inoperable and the pressure adjusting function deteriorates. Therefore, as shown in FIG. 2, a conventional diborane gas supply line is provided with a plurality of pressure reducing valve lines (51) and (52) each having a pressure reducing valve (50) arranged in parallel to connect the diborane gas from a diborane gas supply source. A gas supply path (53) to the equipment used is formed, and the flow path opening / closing valves (54) (55) are respectively provided on the upstream side and the downstream side of the pressure reducing valve (50) in each pressure reducing valve line (51) (52). ),
Upstream side on-off valve (54) and pressure reducing valve in each pressure reducing valve line (51) (52)
A nitrogen introducing passage (56) for purging is connected between (50) and each pressure reducing valve line (51) (52) is configured to be used selectively,
The pressure reducing valve (50), which had malfunctioned while using another pressure reducing valve line, was to be replaced.

[0003]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention In a conventional diborane supply system, a pressure reducing valve (5
(0) is removed from the pressure reducing valve line (51) (52) and replaced, but this replacement work must be performed frequently with a short period (for example, 2 weeks) as a cycle, and maintenance is troublesome. There was a problem. Also, in the semiconductor manufacturing equipment that uses diborane gas, the entire equipment is maintained in a high vacuum, but if the pressure reducing valve (50) is removed from the pressure reducing valve lines (51) (52) for replacement, the pressure is reduced. Valve line (51) (5
Since the vacuum state in 2) is broken, there is a problem that it is troublesome to form the pressure reducing valve line (51) again into a high vacuum state after the pressure reducing valve is replaced. The present invention has been made in view of such a point, and an object thereof is to provide a method and an apparatus for automatically cleaning a malfunctioning pressure reducing valve without removing the pressure reducing valve.

[0004]

In order to achieve the above object, the present invention connects a cleaning gas supply passage between a pressure reducing valve and an upstream side opening / closing valve in each pressure reducing valve line, and further reduces each pressure reducing pressure. A vacuum evacuation path is branched out from between the valve and the downstream opening / closing valve, a high-pressure nitrogen introduction path is connected to the purging nitrogen introduction path, and pressure sensors are arranged on the upstream side and the downstream side of each pressure reducing valve, The pressure signal detected by this pressure sensor can be input to the control device, and the output signal from this control device can be used to control the switching of the on-off valve interposed in the pressure reducing valve line and the cleaning gas supply path. The pressure sensor detects pressure abnormalities at the pressure reducing valve in use by using a device configured to switch and control the flow path opening / closing valve respectively installed in the vacuum evacuation path, the nitrogen introducing path for purging, and the high pressure nitrogen introducing path. What to do Based on this, the pressure reducing valve line to be used is closed and the pressure reducing valve line in the standby state is made conductive, and cleaning gas is supplied from the cleaning gas supply path to the closed pressure reducing valve line to clean the pressure reducing valve, and then purged. Supply nitrogen gas to purge the cleaning gas, and then inject high-pressure nitrogen from the high-pressure nitrogen introduction path into the purge nitrogen gas introduction path to check the operation of the pressure reducing valve and maintain the pressure reducing valve line in the standby state. It is characterized by being configured.

[0005]

In the present invention, the cleaning gas supply path is connected between the pressure reducing valve and the upstream side opening / closing valve in each pressure reducing valve line, and the vacuum suction path is branched from between each pressure reducing valve and the downstream side opening / closing valve. Derived, connected the high-pressure nitrogen introduction path to the purge nitrogen introduction path, arranged pressure sensors on the upstream side and the downstream side of each pressure reducing valve, and can input the pressure signal detected by this pressure sensor to the control device This control device is configured to be capable of switching control of the open / close valve interposed in the pressure reducing valve line by an output signal from this control device, and also to a cleaning gas supply path,
Since it is possible to switch and control the flow path on / off valves respectively installed in the vacuum evacuation path, the nitrogen introduction path for purging, and the high-pressure nitrogen introduction path, it is possible to confirm that the pressure reducing valve is in the malfunction state on the upstream side And a pressure sensor placed downstream,
Based on the detection operation, the pressure reducing valve line is automatically switched, and at the same time, the cleaning gas, the purging gas, and the operation checking high-pressure gas are sequentially supplied to the pressure reducing valve line in which the malfunction has occurred to restore them.

[0006]

1 is a piping diagram of a diborane gas supply system showing an embodiment of the present invention. This diborane gas supply path (1)
Is for supplying diborane gas from a diborane gas supply source (not shown) to a device using diborane gas (not shown) such as a semiconductor manufacturing device, and is configured by arranging two pressure reducing valve lines (2) in parallel on the way. I am doing it. Each pressure reducing valve line (2) has a pressure reducing valve (3) sandwiched between them.
Channel opening / closing valves (4) and (5) on the upstream side and the downstream side of (3), respectively.
Are arranged, and the pressure reducing valve lines (2) of the two systems can be selectively used by selectively opening and closing the flow path opening / closing valves (4) and (5).

Further, the pressure reducing valve (3) in each pressure reducing valve line (2)
And the upstream side flow path on-off valve (4)
(6) is connected, and the pressure reducing valve (3) and the downstream flow passage opening / closing valve
The exhaust path (7) is led out from between (5). A check valve (8) and a flow passage opening / closing valve (9) are arranged in parallel pipe portions in each purging nitrogen introducing passage (6). Further, a flow passage opening / closing valve (10) is arranged in the exhaust passage (7). Then, the check valve (1) is provided on the upstream side of the branch portion of the purging nitrogen introducing passage (6).
1) and the purge gas supply switching valve (12) are arranged in order from the upstream side in the gas flow direction.

In the diborane gas supply system having such a structure, the present invention is characterized by adding the following structure. That is, the purging nitrogen introducing passage (6) and the cleaning gas supply passage (1) are provided between the pressure reducing valve (3) and the upstream flow passage opening / closing valve (4) in each pressure reducing valve line (2).
3) is connected, and a vacuum evacuation path (14) is led out together with the exhaust path (7) from between the pressure reducing valve (3) and the downstream side flow path opening / closing valve (5). Then, a high-pressure nitrogen introduction path is provided in the purging nitrogen introduction path (6).
(15) is connected.

A check valve (16) and a supply control valve are provided in each cleaning gas supply passage (13) in order from the upstream side in the gas flow direction.
(17) is arranged, and a flow path opening / closing valve (18) is arranged in each vacuum evacuation path (14). In addition, the high pressure nitrogen introduction path (1
A check valve (19) and a supply switching valve (20) are arranged in sequence 5) from the upstream side in the gas flow direction. In addition, pressure sensors (21) are respectively arranged on the upstream side and the downstream side of the pressure reducing valve (3) in each pressure reducing valve line (2), and the detection signal detected by the pressure sensor (21) is applied to the control device (22). ).

This control device (22) is a pressure reducing valve line in use.
Based on the detection signals from both pressure sensors (21) in (2), the pressure difference between the upstream side and the downstream side of the pressure reducing valve (2) is calculated, and when this pressure difference falls within the allowable pressure range, the control device ( 22) output from each pressure reducing valve line (2), each purge nitrogen introduction path
(6), each exhaust passage (7), each cleaning gas supply passage (13),
Open / close of each valve (4) (5) (9) (10) (12) (17) (18) (20) arranged in each vacuum evacuation path (14) and high pressure nitrogen introduction path (15). It is configured to control.

That is, when the pressure difference between the upstream pressure and the downstream pressure of the pressure reducing valve (3) becomes less than a predetermined value, both the on-off valves (4) and (5) of the pressure reducing valve line (2) in use are closed. The valves are operated, and the open / close valves (4) and (5) of the other pressure reducing valve line (2) in the standby state are opened to continue the supply of diborane gas to the equipment using diborane. Then, the cleaning gas supply path connected to the pressure reducing valve line (2) which has been discontinued
Open the supply control valve (17) of (13) and connect the vacuum line connected to the pressure reducing valve line (2) that is no longer used.
Open the flow path on-off valve (18) of (14), apply a cleaning gas such as chlorine trifluoride to the pressure reducing valve (3) that has malfunctioned, and attach it to the pressure reducing valve (2). Borane is decomposed and removed.

When the cleaning is completed, the supply control valve (17) of the cleaning gas supply passageway (13) and the passage opening / closing valve (18) of the vacuum suction passageway (14) are closed, and the purging nitrogen introducing passageway (6) ) Purge gas supply switching valve (12) and flow path opening / closing valve
(9) and the flow path opening / closing valve (10) of the exhaust path (7) are opened to purge the inside of the pressure reducing valve line (2) with nitrogen for a certain period of time, and after a predetermined time has passed, a nitrogen introducing path for purging (6 ) Purge gas supply switching valve
(12) is closed and the supply switching valve (20) of the high-pressure nitrogen introduction path (15) is closed to reduce the high-pressure nitrogen gas pressure reducing valve line (2).
To check the operation of the pressure reducing valve (3), and then supply switching valve (20) in the high-pressure nitrogen introduction path (15) and nitrogen introduction path for purging.
The flow passage opening / closing valve (9) of (6) and the flow passage opening / closing valve (10) of the exhaust passage (7) are closed, and the passage opening / closing valve (18) of the vacuum suction passage (14)
To open the pressure reducing valve line (2) to a predetermined vacuum state, and then close the flow path opening / closing valve (18) of the vacuum suction line (14) to close the pressure reducing valve line (2). A standby state is maintained while maintaining a vacuum atmosphere.

[0013]

According to the present invention, the cleaning gas supply path is connected between the pressure reducing valve and the upstream side opening / closing valve in each pressure reducing valve line, and the vacuum drawing path is provided between each pressure reducing valve and the downstream side opening / closing valve. The high-pressure nitrogen introduction path is connected to the purging nitrogen introduction path, pressure sensors are arranged on the upstream side and the downstream side of each pressure reducing valve, and the pressure signal detected by this pressure sensor is input to the control device. It is possible to control the switching valve of the on-off valve interposed in the pressure reducing valve line by the output signal from this control device, and the cleaning gas supply passage, the vacuum suction passage, the purge nitrogen introduction passage, the high pressure nitrogen Since it is configured to be able to switch and control the flow path opening and closing valves respectively inserted in the introduction path, it is detected that the pressure reducing valve is in a malfunctioning state by pressure sensors arranged on the upstream side and the downstream side of the pressure reducing valve, The detection work With basis, automatically switching the pressure reducing valve line, a cleaning gas, purge gas,
High-pressure gas for operation check can be sequentially supplied to the pressure-reducing valve line in which the operation failure has occurred, and automatically restored.
Thereby, it is possible to easily deal with the malfunction of the pressure reducing valve and improve the workability.

[Brief description of drawings]

FIG. 1 is a piping diagram of a diborane gas supply system.

FIG. 2 is a piping diagram of a diborane gas supply system according to a conventional technique.

[Explanation of symbols]

1 ... Gas supply path, 2 ... Pressure reducing valve line, 3 ... Pressure reducing valve, 4 ... Upstream side opening / closing valve, 5 ... Downstream side opening / closing valve, 6 ... Purge nitrogen introducing path,
13 ... Cleaning gas supply passage, 14 ... Vacuum passage, 15 ... High pressure nitrogen introduction passage, 17/18/20 ... Flow passage opening / closing valve, 21 ... Pressure sensor, 22 ... Control device.

Claims (2)

[Claims] 1. A plurality of pressure reducing valve lines (2) each having a pressure reducing valve (3) arranged in parallel to form a gas supply path (1) from a diborane gas supply source to a device using diborane gas,
The flow path opening / closing valves (4) and (5) are arranged on the upstream side and the downstream side of the pressure reducing valve (3) in each pressure reducing valve line (2) to open and close the upstream side in each pressure reducing valve line (2). A nitrogen introducing passage (6) for purging is connected between the valve (4) and the pressure reducing valve (3), and each pressure reducing valve line is connected.
In the diborane gas supply system configured to selectively use (2), the pressure reducing valve (3) and the upstream side on-off valve (4) in each pressure reducing valve line (2)
And a cleaning gas supply path (13) are connected between them, and a vacuum evacuation path (14) is branched from between each pressure reducing valve (3) and the downstream opening / closing valve (5) to introduce each purge nitrogen. The high pressure nitrogen introduction path (15) is connected to the path (6), the pressure sensor (21) is arranged on the upstream side and the downstream side of each pressure reducing valve (3), and the pressure reducing valve (3) in use is When the pressure sensor (21) detects an abnormal pressure, the pressure reducing valve line (2) used is closed, and the pressure reducing valve line (2) in the standby state is connected so that the pressure reducing valve line (2) is closed. ) To the cleaning gas supply passage (13) to clean the pressure reducing valve (3), and then purge nitrogen gas is supplied to purge the cleaning gas, and then the purge nitrogen gas introduction passage (6) Inject high-pressure nitrogen into the high-pressure nitrogen introduction path (15) to check the operation of the pressure reducing valve (3). Cleaning method in a diborane gas supply system characterized by being configured to maintain valve line (2) to a standby state. 2. A plurality of pressure reducing valve lines (2) each having a pressure reducing valve (3) arranged in parallel to form a gas supply path (1) from a diborane gas supply source to a device using diborane gas,
The flow path opening / closing valves (4) and (5) are arranged on the upstream side and the downstream side of the pressure reducing valve (3) in each pressure reducing valve line (2) to open and close the upstream side in each pressure reducing valve line (2). A nitrogen introducing passage (6) for purging is connected between the valve (4) and the pressure reducing valve (3), and each pressure reducing valve line is connected.
In the diborane gas supply system configured to selectively use (2), the pressure reducing valve (3) and the upstream side on-off valve (4) in each pressure reducing valve line (2)
A cleaning gas supply path (13) is connected between the pressure reducing valve (3) and the downstream side on-off valve (5), and a vacuum evacuation path (14) is branched from the pressure reducing valve (3) to a nitrogen introducing path for purging. A high-pressure nitrogen introduction path (15) is connected to (6), pressure sensors (21) are arranged on the upstream side and the downstream side of each pressure reducing valve (3), and the pressure signal detected by this pressure sensor (21) Is configured to be input to the control device (22), and the on-off valves (4) and (5) interposed in the pressure reducing valve line (2) can be switch-controlled by an output signal from the control device (22). The cleaning gas supply path (1
3), the vacuum evacuation path (14), the purging nitrogen introducing path (6), and the high pressure nitrogen introducing path (15) respectively, and the passage opening / closing valves (17) (18) (2)
A cleaning device in a diborane gas supply system, characterized in that it is configured so that 0) can be switched and controlled.