JP2889752B2 - Gas supply system and gas supply device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas supply system and a gas supply apparatus used in an industrial manufacturing apparatus such as a semiconductor manufacturing apparatus, and more particularly to a gas supply system for a residual gas in a chamber for mixing component gases. The present invention relates to a gas supply system and a gas supply device provided with replacement means.

[0002]

2. Description of the Related Art Conventionally, in a semiconductor manufacturing process, corrosive gas, toxic gas, flammable gas and the like have been used as a supply gas for etching of photoresist processing and the like.
Since the photoresist processing (photoresist coating, exposure, development, etching) is repeated a plurality of times in the semiconductor manufacturing process, a gas supply device that supplies a corrosive gas or the like as necessary is used in the actual semiconductor manufacturing process.

At this time, a plurality of types of supply gases or supply gases of the same type but having different concentrations are often used in photoresist processing. In this case, a predetermined supply gas is produced by mixing a plurality of corrosive gases, component gases, and the like in a chamber constituted by a closed space, or a predetermined gas is mixed by mixing an inert gas with a corrosive gas. It has been practiced to make and use a supply gas of a concentration.

On the other hand, in recent years, as the degree of integration and the precision of semiconductors have increased, it has been desired to precisely control the supply amount of supply gas used for etching and the like.
In addition, the demand for timing and speed is becoming more stringent due to the demand for shortening the manufacturing process time.

However, in a corrosive gas supply device, once the corrosive gas or the like is once supplied, the corrosive gas or the like is left in the pipe and left until the next supply of the corrosive gas or the like. The metal or the like inside the pipe is corroded by the remaining corrosive gas or the like, and when the corrosive gas or the like is supplied next, impurities are mixed into the corrosive gas or the like, which may adversely affect the semiconductor.

When a chamber or the like in which a plurality of corrosive gases are mixed is used, if a small amount of corrosive gas or flammable gas remains in the chamber, the components of the supply gas to be used next will be reduced. Will change. This has a significant adverse effect on the photoresist processing depending on the type of the remaining gas and the gas to be supplied next, which may cause deterioration in the quality of the semiconductor product.

Further, if the supply gas used last time remains in the chamber, even if it is a flammable gas, even if it is a small amount, depending on the kind, it is mixed with the next gas and the combustion by the flammable gas or An explosion could occur. Also,
Even if an explosion does not occur, the reaction product may become impurities as particles, which may adversely affect the semiconductor manufacturing process.

Therefore, in a supply device for a supply gas, a predetermined amount of corrosive gas or the like of a plurality of types is mixed in a chamber or the like to produce a supply gas and supplied to a semiconductor process, and then remains in the chamber or the like. It has been practiced to replace the supplied gas with an inert gas such as nitrogen gas. As a conventional method of replacing the remaining supply gas, (1) a method in which the supply gas remaining in the chamber is pulled by a vacuum pump, and (2) a supply in which the inert gas is forcibly introduced and remains in the chamber. A method of extruding gas is known.

[0009]

However, in the above method (1), the vacuum pump is positionally separated from the chamber or the like in which the supply gas remains, and the inside of the chamber or the like is efficiently evacuated. At the same time, one of the supply gases, such as corrosive gas, has strong adhesion to metal, so it is necessary to completely eliminate corrosive gas, etc. remaining in close contact with metal surfaces such as inside the chamber. Could not.

[0010] It is not appropriate to arrange the vacuum pump in the vicinity of the gas supply device due to maintenance management and space problems. Normally, the vacuum pump is located at a position distant from the gas supply device. It is connected by a pipe to a chamber or the like in which a reactive gas or the like remains. In this case, since the piping is long, exhaust resistance is increased, and it is difficult to evacuate the inside of the chamber and the like, and it is not possible to completely remove the remaining supply gas.

In the method (2), it takes too much time to dilute the residual gas. 2kg / cm
^When nitrogen gas is pushed into a chamber or the like at a pressure of ² , it takes about one hour to dilute it to 0.05 ppm or less, which is a tentative reference value that does not adversely affect the next supply gas. Was. For this reason, the time required for the semiconductor manufacturing process is lengthened and the production efficiency is deteriorated.

An object of the present invention is to solve the above problems and provide a gas supply system and a gas supply apparatus which can be used in a semiconductor manufacturing process or the like and have a high efficiency and can supply a gas of high purity. Aim.

[0013]

In order to achieve this object, a gas supply system and a gas supply apparatus according to the present invention are provided.
It has the following configuration. (1) a plurality of carry-in pipes into which a component gas of a supply gas flows,
A chamber for mixing the component gases flowing from the plurality of loading tubes, a plurality of unloading tubes for unloading the mixed supply gas, and blocking the inflow of the component gas into the chamber on the loading tube. A plurality of first on-off valves, a plurality of second on-off valves on the carry-out pipe for blocking outflow of the supply gas from the chamber, and a replacement gas supply means for supplying a replacement gas into the chamber And a pressure reducing means for reducing the supply gas in the chamber, wherein a predetermined supply gas is mixed in the chamber, and a gas supply system for supplying the mixed gas mixture, wherein the first and second gas supply systems are provided. A gas supply system for replacing a supply gas remaining in the chamber with a replacement gas after shutting off a two-way opening / closing valve, comprising: a pressure reducing operation of the supply gas in the chamber by the pressure reducing means; The combination of the operation of supplying the replacement gas into the chamber by performing two or more times.

(2) In the gas supply system described in the above (1), the carry-out pipe and the second on-off valve are each one.

(3) One carry-in pipe into which the supply gas or the like flows, and a chamber into which the supply gas flows through the carry-in pipe.
A plurality of unloading tubes for unloading the supplied gas, a first on-off valve on the unloading tube for blocking the inflow of the supply gas into the chamber, and the chamber on the unloading tube. A gas supply comprising: a plurality of second on-off valves for shutting out the supply gas from the inside; a replacement gas supply means for supplying a replacement gas into the chamber; and a pressure reducing means for reducing the supply gas in the chamber. A gas supply system for replacing a supply gas remaining in the chamber with a replacement gas after shutting off the first and second on-off valves, wherein the supply gas in the chamber is reduced by the pressure reducing means. The combination of the pressure reduction operation and the operation of supplying the replacement gas into the chamber by the replacement gas supply unit is performed twice or more.

(4) A plurality of inlet pipes into which the component gases of the supply gas flow, a chamber for mixing the component gases flowing from the plurality of inlet pipes, and a plurality of outlet pipes for discharging the mixed component gases. A plurality of first on-off valves on the carry-in pipe for blocking inflow of the component gas into the chamber, and a plurality of on-off pipes for blocking outflow of the supply gas from the chamber A second on-off valve, a replacement gas supply unit for supplying a replacement gas into the chamber, and a pressure reducing unit for reducing the pressure of the supply gas in the chamber. And a controller for performing the combination of the decompression of the supply gas and the supply of the replacement gas into the chamber by the replacement gas supply means twice or more.

(5) The gas supply device according to (4), wherein the carry-out pipe and the second on-off valve are each one.

(6) One carry-in pipe into which a supply gas or the like flows, and a chamber into which the supply gas flows through the carry-in pipe;
A plurality of unloading tubes for unloading the supplied gas, a first on-off valve on the unloading tube for blocking the inflow of the supply gas into the chamber, and the chamber on the unloading tube. A gas supply comprising: a plurality of second on-off valves for shutting out the supply gas from the inside; a replacement gas supply means for supplying a replacement gas into the chamber; and a pressure reducing means for reducing the supply gas in the chamber. A control device for performing a combination of the pressure reduction of the supply gas in the chamber by the pressure reducing unit and the supply of the replacement gas into the chamber by the replacement gas supply unit twice or more.

[0019]

The plurality of component gas inlet pipes of the gas supply system and the gas supply device of the present invention having the above-described structure allow the supply gas or the component gas constituting the supply gas to flow into the chamber. Further, the chamber mixes the supply gas or the component gas flowing from the plurality of carry-in pipes to produce a predetermined supply gas. The plurality of discharge pipes discharge the mixed supply gas to the outside of the chamber. Here, in the case where the number of carry-in pipes connected to the chamber is one, supply gas is supplied to the chamber by the carry-in pipe, and distribution is performed to a plurality of carry-out pipes in the chamber.

[0020] Further, the plurality of first on-off valves are located on the carry-in pipe and block the inflow of the supply gas or the component gas into the chamber. The plurality of second on-off valves are located on the discharge pipe and block outflow of the supply gas from inside the chamber. The replacement gas supply means supplies a replacement gas made of an inert gas such as nitrogen gas into the chamber. The pressure reducing means reduces the pressure of the supply gas remaining in the chamber.

The above gas supply system is a gas supply system for mixing component gases of a predetermined supply gas in the chamber and supplying the mixed supply gas, wherein the first and second on-off valves are shut off. After that, the supply gas remaining in the chamber is replaced with a replacement gas composed of an inert gas such as nitrogen gas. At this time, a combination of the operation of reducing the supply gas in the chamber by the pressure reducing unit and the operation of supplying the replacement gas into the chamber by the replacement gas supply unit is performed twice or more.

Accordingly, the gas supply device provided with the residual gas replacement device efficiently inactivates the supply gas such as the residual corrosive gas even when the corrosive gas or the like is repeatedly supplied while being mixed in the chamber. Gas can be replaced, and a supply gas such as a highly pure corrosive gas can be efficiently supplied to the semiconductor manufacturing process.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A gas supply system and a gas supply apparatus according to an embodiment of the present invention will be described below with reference to the drawings. FIG. 2 is a circuit diagram showing a configuration of the gas supply system. FIG. 3 is a perspective view of a main part of an embodiment embodying this circuit diagram.

On one side in the longitudinal direction of the rectangular parallelepiped chamber 27 having the hollow portion 27a, supply gas inlet pipes 1A to 1E for transporting five kinds of corrosive gases and component gases FA to FE are provided in the hollow portion 27a of the chamber 27. It is attached to communicate with. Input valves 3A to 3E, which are solenoid valves serving as first on-off valves, are mounted on the supply gas inlet pipes 1A to 1E.

The supply gas inlet pipes 1A to 1E of the chamber 27
The supply gas O
Supply gas discharge pipes 30A to 30C for discharging A to OC from the chamber 27 are attached. Output valves 31A to 31C, which are electromagnetic valves serving as second on-off valves, are mounted on the supply gas discharge pipes 30A to 30C.

At one end of the chamber 27 in the longitudinal direction, an ejector 41 as a pressure reducing means for discharging the supply gas remaining in the hollow portion 27a of the chamber 27 is attached. Further, a hollow portion 27a of the chamber 27 is provided on an end surface opposite to the end surface where the ejector 41 is attached.
A purge valve 42 for supplying an inert gas N made of nitrogen gas is installed in the inside. The purge valve 42 includes
A nitrogen gas tank (not shown) storing a nitrogen gas as a replacement gas is connected.

The flow rates of the corrosive gas and the component gases FA to FE are measured upstream of the supply gas inlet pipes 1A to 1E to supply predetermined amounts of the corrosive gas and the component gases FA to FC. Control valves 5A to 5E are connected in series.

Next, the structure of the ejector 41 is shown in FIG.
The input port 28 of the ejector 41 is connected to the hollow portion 27 a of the chamber 27. The working fluid input port 27 of the ejector 41 is connected to an inert gas tank.
The working fluid input port 27 is in communication with the valve chamber 26.
A valve seat 23 is provided in the valve chamber 26, and the valve element 21 is in contact with the valve seat 23. The valve element 21 is fitted and fixed to one end of the movable iron core 20. The movable iron core is a return spring 2
2 urges the valve body 21 in the direction in which it comes into contact with the valve body 21.
The movable iron core 20 is fitted in the hollow portion of the coil 19 so as to be able to linearly move.

The central hole of the valve seat 23 is connected to the pressure reducing section 24 via the nozzle 25 and to the discharge section 29. on the other hand,
The input port 28 of the ejector 41 is connected to the pressure reducing unit 24.

Before describing the operation of the entire apparatus, the operation of the ejector 41 having the above configuration will be described. When the coil 19 is excited, the fixed core (not shown) is
0 is moved upward. Thereby, the valve element 21 is separated from the valve seat 23. And the inert gas N which is the working fluid
Flows into the nozzle 25 through the working fluid input port 27, the valve chamber 26, and the valve seat 23. The flow rate is increased by lowering the pressure at the nozzle 25, and the inert gas N is blown out from the pressure reducing unit 24 toward the discharge unit 29 at a high flow rate.

The supply gas OA to OC is generated by the rapid flow of the inert gas N, but the pressure of the supply gas OA to OC is reduced by the negative pressure around the pressure reducing unit 24 and the viscosity of the inert gas N and the supply gas OA to OC. The liquid is mixed with the working fluid and discharged from the discharge unit 29. The discharged gas passes through a pipe and is stored in an exhaust tank. At this time, since the supply gases OA to OC are discharged after their concentration has been reduced by the inert gas N which is a working fluid, the inside of the exhaust pipe or the exhaust tank is less likely to corrode.

Next, the control device used in this embodiment will be described. FIG. 4 is a block diagram showing the configuration of the control device. The ROM 8 which stores the control program of the supply gas system and the gas supply device is temporarily stored in the CPU 8 which controls the entire gas supply device. A RAM 10 for storing data is connected. Also, C
The PU 8 includes a valve control unit 11, a mass flow control unit 12
And the ejector control unit 13 are connected.

The valve control section 11 includes a first opening / closing valve driving section 1 for driving the opening and closing of the input valves 3A to 3E as the first opening / closing valves.
4. The second on-off valve drive section 15 for driving the opening and closing of the output valves 30A to 30C, which is the second on-off valve, and the purge valve drive section 16 for driving the purge valve 42 are connected. The ejector control unit 13 is connected to an ejector driving unit 17 that drives the ejector 41.

Next, the operation of the gas supply device having the above configuration will be described with reference to FIG. First, step 1
Will be described. According to a command from a computer controlling the entire semiconductor manufacturing process, one or two or more of the five types of corrosive gases and their component gases FA to FE are selected by the CPU 8, and the selected corrosive gas is selected. Input valves 3A to 3E corresponding to the first opening / closing valve driving unit 14
Opened by Then, a predetermined corrosive gas or the like is supplied to the hollow portion 27a in the chamber 27 while a predetermined amount is measured by the flow control unit 12 of each of the flow control valves 5A to 5E.

At this time, the second on-off valve driving unit 14
Of the output valves 30A to 30C, only the output valve connected to the supply destination is opened, and the other output valves are closed.
Since each gas flowing into the hollow portion 27a in the chamber 27 has a considerable flow rate, it is discharged from the open output valve while being sufficiently mixed without attaching a special mixing device to the hollow portion 27a. You.

Each of the output valves 31A to 31C is connected to each unit such as an etching apparatus in a semiconductor manufacturing process.
A predetermined amount of supply gas OA to OC is supplied to an etching apparatus or the like. Here, in order to perform the mixing more quickly and more uniformly, a mixing device such as a fixed type axial flow impeller for forcibly mixing the component gases FA to FE flowing into the chamber 27 using the flow velocity may be attached. That is natural.

Next, step 2 will be described. The valve control unit 11 controls the flow rate control unit 12 so that each component gas FA
When 所 定 FE is measured by a predetermined amount, the input valve is closed. here,
The predetermined amount is experimentally determined in consideration of the amount that finally remains in the hollow portion 27a of the chamber 27. Subsequently, the valve control unit 11 closes the output valve that has been opened with a slight time delay. As a result, the chamber 27
The supply gas remains in the hollow portion 27a inside.

Next, step 3 will be described. The ejector control unit 13 opens the ejector valve by the ejector driving unit 17 to excite the ejector 41 to reduce the supply gas pressure. That is, when the ejector 41 is excited, the inert gas N composed of nitrogen gas, which is a working fluid, flows into the ejector 41, depressurizes the supply gas, and is discharged as a mixed gas.

Here, the reason why the inert gas N is used as the working fluid of the ejector 41 is that the inert gas N is piped to the vicinity of the chamber 27 in order to supply it as a replacement gas. Because it is convenient without need.

Next, step 4 will be described. After the drive of the ejector 41 is stopped, the purge valve 42 is opened by the purge valve drive unit 16 and the inert gas N flows into the hollow portion 27 a in the chamber 27.

Step 5 is a repetition of step 3 and step 4 described above. The CPU 8 determines the number of repetitions based on the remaining supply gas and the type of supply gas to be supplied next. Alternatively, when the supply gas is input, the user may input the number of repetitions using an IC card or the like, and control the gas supply system and the gas supply device based on the input number of repetitions.

Here, since the pressure reduction by the ejector 41 and the inflow of the inert gas N by the purge valve 6 are performed alternately, the supply gases OA to OC adsorbed on the wall surface inside the hollow portion 27a of the chamber 27 are formed. Can be reduced by the ejector 41 while blowing off with the inert gas N, it is possible to efficiently remove the remaining supply gas.

FIGS. 5 to 8 show the effect. That is, FIG. 5 shows a case where only the purge replacement with the inert gas N is performed for one minute without reducing the pressure by the ejector 41. The residual concentration of the supply gas after 1 minute is still 10 pp
m, and the time required for the background value of the inert gas N to reach 0.05 ppm also takes about 30 minutes.

FIG. 6 shows a case where the pressure in the ejector 41 in step 3 is reduced for 2 seconds, and the purge replacement with the inert gas N in step 4 is performed for 8 seconds. The residual concentration of the supply gas after 1 minute is still 10 ppm or more, and it takes about 30 minutes for the background value of the inert gas N to reach 0.05 ppm. That is, it can be seen that there is almost no difference from the case where only the purging is performed.

Next, the effect of this embodiment will be described. As shown in FIG. 7, the pressure of the ejector 41 in Step 3 described in this embodiment is alternately reduced 5 times for 2 seconds, and the purge and filling of the inert gas N in Step 4 is repeated 5 times for 8 seconds. The residual concentration of the corrosive gas F after one minute is reduced to about 0.1 ppm or less in a very short time. The time required for the inert gas N to reach the background value of 0.05 ppm is also reduced to about 10 minutes.

FIG. 8 shows a case in which the pressure of the ejector 41 in step 3 described in this embodiment is alternately reduced 10 times for 2 seconds, and the inert gas N is purged and filled in step 4 10 times for 8 seconds. The residual concentration of the corrosive gas F after one minute is reduced to about 0.1 ppm in a very short time. The time required for the inert gas N to reach the background value of 0.05 ppm is also reduced to about 10 minutes. The result is
It can be seen that the number of repetitions N hardly differs between the case of 5 times and the case of 10 times.

As described above, the ejector 41 is connected to the chamber 27.
, And the purge of the inert gas N and the pressure reduction by the ejector 41 are alternately and repeatedly performed, whereby the supply gas remaining in a short time can be efficiently removed, and the efficiency of the semiconductor manufacturing process can be improved. Can be.

In the above embodiment, the case where the purge with the inert gas N and the pressure reduction of the remaining supply gas with the ejector 41 are alternately performed, but the purge and the pressure reduction may be performed simultaneously.

When a vacuum pump is used, if the corrosive gas or the like is first decompressed, the inside of the discharge pipe is exposed to a corrosive gas having a high concentration, and the pipe is corroded. Supply gas O by some inert gas N
Since the concentrations of A to OC are reduced and discharged, it is possible to perform a pressure reducing operation first.

By using an inert gas N consisting of a nitrogen gas as one of the component gases FA to FE, the inert gas N is diluted to a required concentration such as a corrosive gas and supplied to the semiconductor process. It is possible to do.

In the present embodiment, a plurality of component gases are carried into the chamber 27 by a plurality of component gas inlet pipes, and a supply gas is supplied from the chamber 27 to each process of the semiconductor by a plurality of supply gas outlet pipes. Although the gas supply system and the gas supply device for supplying the gas have been described, the present invention can be implemented and the effect of the present invention can be exerted even with only one supply gas discharge pipe 30A. In this case, it is natural that there is also one output valve 31A as the second on-off valve.

The present invention can be implemented and the effects of the present invention can be exhibited even if there are a plurality of supply gas discharge pipes 30A to 30C and only one component gas supply pipe 1A. In this case, the function of the chamber 27 is not to mix the component gases, but simply to distribute the supplied gas to the plurality of supply gas discharge pipes OA to OC. In this case, it is natural that the number of input valves 3A as the first on-off valve is also one.

[0053]

As is apparent from the above description, according to the gas supply system and the gas supply device of the present invention,
In a gas supply system for mixing and supplying a plurality of component gases in a chamber, a combination of a pressure reducing operation of a supply gas in a chamber by a pressure reducing unit and a supply operation of a replacement gas into a chamber by a replacement gas supply unit is performed twice. As described above, the supply gas remaining in the chamber or the like can be efficiently eliminated and replaced with an inert gas, so that the components of the next gas to be supplied are not affected and stable and efficient. A good semiconductor manufacturing process can be realized.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a control method of a gas supply system according to one embodiment of the present invention.

FIG. 2 is a circuit diagram showing a configuration of a gas supply system according to one embodiment of the present invention.

FIG. 3 is a perspective view showing a specific configuration of a main part of the gas supply device.

FIG. 4 is a block diagram illustrating a configuration of a control device of the gas supply device.

FIG. 5 is a data diagram showing a first experimental result of a conventional gas supply system.

FIG. 6 is a data diagram showing a second experiment result of the conventional gas supply system.

FIG. 7 is a data diagram showing a first experimental result of the gas supply system according to one embodiment of the present invention.

FIG. 8 is a data diagram showing a second experimental result of the gas supply system according to one embodiment of the present invention.

FIG. 9 is a cross-sectional view illustrating a configuration of an ejector.

[Explanation of symbols]

 F Corrosive gas or component gas N Inert gas O Supply gas 1 Component gas carry-in pipe 3 Input valve 5 Flow control valve 8 CPU 9 ROM 10 RAM 11 Valve control unit 13 Ejector control unit 14 First open / close valve drive unit 15 Second Opening / closing valve drive section 16 Purge valve drive section 27 Chamber 27a hollow section 30 Supply gas discharge pipe 31 Output valve 41 Ejector 42 Purge valve

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kenichi Goshima 3005 Hayasaki, Hokutoyama, Kodai-shi, Aichi Prefecture Inside Kakei Co., Ltd. In-company (72) Inventor Akihiro Kojima 3005 Hayasaki, Kogaiyama, Kochi-shi, Aichi Prefecture Inside Sakaide Corporation (56) References JP-A-2-21618 (JP, A) (58) Fields investigated . ⁶ , DB name) F17D 1/04

Claims (4)

(57) [Claims] 1. A plurality of carry-in pipes for flowing component gas or the like of a supply gas, a chamber for mixing component gas flowing from the plurality of carry-in pipes, and a plurality of carry-out pipes for carrying out the mixed supply gas. A plurality of first on-off valves on the carry-in pipe to block the flow of the component gas into the chamber;
A plurality of second on-off valves on the carry-out pipe to block outflow of the supply gas from the chamber, a replacement gas supply unit for supplying a replacement gas into the chamber, and a supply gas in the chamber. A gas supply system for mixing a predetermined component gas in the chamber and supplying a mixed supply gas, wherein the first and second on-off valves are shut off, and In a gas supply system for replacing a supply gas remaining in a chamber with a replacement gas, a pressure reducing operation of the supply gas in the chamber by the pressure reducing unit and a supply operation of the replacement gas into the chamber by the replacement gas supply unit are performed. The number of times the combination is performed is stored according to the type of the supply gas remaining in the chamber and the type of the next supply gas supplied after the replacement with the replacement gas.
Storage means, supply gas remaining in the chamber, and the replacement gas.
Depending on the type of the next supply gas supplied after the replacement,
Reading the corresponding number of times from the storage means,
Pressure reducing operation of the supply gas in the chamber by the
Supply of replacement gas into the chamber by replacement gas supply means
CPU that controls to change the number of times to combine with work
Gas supply system characterized in that it has and. 2. The gas supply system according to claim 1, wherein the carry-out pipe and the second on-off valve are each one. 3. A plurality of inlet pipes for flowing component gas of the supply gas, a chamber for mixing component gas flowing from the plurality of inlet pipes, and a plurality of outlet pipes for discharging the mixed supply gas. A plurality of first on-off valves on the carry-in pipe for blocking the inflow of the component gas into the chamber, and a plurality of first on-off valves on the carry-out pipe for blocking the outflow of the supply gas from the chamber; In a gas supply device having a second on-off valve, a replacement gas supply unit for supplying a replacement gas into the chamber, and a pressure reducing unit for reducing the supply gas in the chamber, a supply gas in the chamber by the pressure reduction unit And the number of times the combination of the pressure reduction and the supply of the replacement gas into the chamber by the replacement gas supply means is performed after the replacement gas is replaced with the supply gas remaining in the chamber and the replacement gas. Storing hand respectively stored according to the type of the next feed gas
A step, a supply gas remaining in the chamber, and the replacement gas.
Depending on the type of the next supply gas supplied after the replacement,
Reading the corresponding number of times from the storage means,
Pressure of the supply gas in the chamber due to
Supply of the replacement gas into the chamber by the gas supply means.
And a CPU that controls the number of combinations to be changed.
Gas supply device, characterized in that that. 4. The gas supply device according to claim 3, wherein the carry-out pipe and the second on-off valve are each one.