JPH0774113A - Gas supply system - Google Patents

Abstract

PURPOSE:To provide a gas supply system for feeding process gas, which is likely to liquefy at normal temperature under normal pressure, precisely at a predetermined flow rate while heating it. CONSTITUTION:A gas supply system for feeding dichlorosilane F, which is likely to liquefy at normal temperature under normal pressure, comprises a solenoid valve 53 provided with a mass flow meter to measure the mass flow of dichlorosilane F and pass it at a predetermined flow rate; an input block 10 connected with the input port of the solenoid valve 53; an input switch valve 52 provided on the input block 10; an output block 11 connected with the output port of the solenoid valve 53; an output switch valve 54 provided with the output block 11; and rod heaters 14 and 15 embedded in the input and output blocks 10 and 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas supply device used in a semiconductor manufacturing apparatus or the like, and more specifically, it has a high vaporization temperature and is easily liquefied unless external heat is applied at room temperature. The present invention relates to a gas supply device that supplies a process gas such as WF6 and HBr with high accuracy without liquefying the process gas.

[0002]

2. Description of the Related Art Conventionally, a vapor-phase deposited silicon oxide thin film has been widely used as an insulating film in a semiconductor integrated circuit. Such vapor phase film formation of silicon oxide or the like is usually performed by a chemical vapor deposition film forming method on a wafer placed in a film forming tank. As a silicon supply source for that purpose, not only a gas such as monosilane SiH ₄ which is a gas at room temperature and an atmospheric pressure, but also a material which is liquid at a room temperature and an atmospheric pressure such as dichlorosilane are often used.

When a process gas such as dichlorosilane that is easily liquefied is supplied, it is necessary to heat a high pressure cylinder, a pipe, a mass flow controller, a reaction chamber and the like which are process gas supply routes. The reason is that if dichlorsilane is liquefied in the middle of the supply route, the flow rate cannot be measured accurately, and the performance of the manufactured semiconductor integrated circuit or the like is deteriorated. There is also a problem that liquefied dichlorsilane or the like blocks the thin tube of the solenoid valve with a mass flow meter, resulting in inaccurate flow rate measurement. In order to prevent the liquefaction of the process gas such as dichlorosilane, in the conventional gas supply device, as shown in FIG.
By winding 1 around the outside of the pipes, joints, gas valves 52, 54, etc., the temperature of the dichlorosilane and the like was kept warm so that the vaporization temperature was exceeded. Further, as shown in FIGS. 9 and 10, the stainless steel body portion 53a of the mass flowmeter-equipped solenoid valve 53, which serves as a flow path for the process gas, is attached with silicon rubber heaters 56 from both sides, and is fixed with a heat insulating plate. By doing so, the solenoid valve 53 with a mass flowmeter is heated and kept warm.

[0004]

However, the conventional gas supply device has the following problems. (1) As shown in FIG. 8, the gas supply device is composed of a plurality of gas valves 52, 54 having different shapes, a joint, a solenoid valve 53 with a mass flowmeter, etc. Skill has been required to wind the tape-shaped heater 51 evenly and tightly around the surfaces of the gas valves 52, 54, the joint and the solenoid valve 53 with a mass flowmeter. In particular, since the thicknesses of the outer walls of the gas valves 52 and 54, the joint and the solenoid valve 53 with the mass flowmeter are different, the process of passing through the gas valves 52, 54, the joint and the solenoid valve 53 with the mass flowmeter and easily liquefied The operator's experience and intuition depended on how to wind the tape-shaped heater 51 in order to heat and keep the gas warm and prevent liquefaction.

On the other hand, if the temperature of the supplied process gas greatly changes, the measurement of the mass flow rate of the solenoid valve 53 with a mass flow meter becomes inaccurate and the semiconductor manufacturing process is adversely affected. Therefore, the process gas is controlled at a constant temperature as much as possible. There is a need to. However, with the conventional method using the tape-shaped heater 51, it is difficult to keep the temperature of the process gas at a constant temperature because the experience of the operator must be relied upon. Further, the mass flowmeter-equipped solenoid valve 53 uses a thin conduit for measurement, but the pipe may be clogged, and the mass flowmeter-equipped solenoid valve 53 may be removed for maintenance. However, removing the wound tape-shaped heater 51, servicing the solenoid valve 53 with a mass flowmeter, and winding the tape-shaped heater 51 again,
It was extremely complicated. Further, since the winding method of the tape-shaped heater 51 cannot be accurately reproduced, there are cases in which the process conditions after maintenance change and the semiconductor manufacturing process is adversely affected.

(2) In a conventional solenoid valve with a mass flow meter, in order to improve the responsiveness of the valve body when the coil is energized, a certain amount of bias current is supplied even when the valve body is not operated. Was there. The present inventors have conceived to utilize this bias current for heating a solenoid valve with a mass flow meter. However, in the conventional solenoid valve with mass flow meter, the mass flow meter and the solenoid valve were connected in series, so if a bias current was applied to the coil to heat and keep the mass flow meter warm, The temperature near the coil of the conduit becomes higher. Further, since the temperature of the conduit differs under conditions other than the flow of the fluid, there is a problem that the mass flow rate cannot be accurately measured. In addition, the zero adjustment was wrong, and there was a case where the output was flowing even though the fluid was not flowing. If the measurement by the mass flow meter becomes inaccurate, the mass flow rate of the supplied process gas changes, which adversely affects the semiconductor manufacturing process and deteriorates the semiconductor yield.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above problems of the prior art and to provide a gas supply device for accurately supplying a predetermined amount of a process gas which is likely to be liquefied at room temperature and atmospheric pressure while heating and maintaining the temperature. And

[0008]

In order to achieve this object, a gas supply device of the present invention is a gas supply device for supplying a gas that is easily liquefied at room temperature and atmospheric pressure, and the mass flow rate of the supplied gas is Solenoid valve with mass flow meter that allows passage of gas at a specified mass flow rate while measuring, input block connected to input port of solenoid valve with mass flow meter, input on-off valve attached to input block, and mass flow rate It has an output block connected to the output port of the metered solenoid valve, an output on-off valve attached to the output block, and a rod-shaped heater embedded in the input block and the output block.

Further, the solenoid valve with mass flowmeter of the gas supply apparatus of the present invention is independently wound around the inside of a conduit through which a gas that easily liquefies at room temperature and normal pressure flows, and is dependent on the temperature of the gas. A mass flow meter that measures the mass flow rate of gas flowing through the conduit based on the value of the current flowing through the two resistors whose resistance values change, a coil formed by winding a wire around the outer circumference of the coil bobbin, and fixed to the coil bobbin hole. A solenoid valve with a mass flowmeter, comprising: a solenoid having a fixed iron core; a movable iron core that is attracted to the fixed iron core when a coil is energized; and a valve seat that is opened and closed by driving the movable iron core to switch communication between ports. In order to prevent the gas from being liquefied, the coil has a control means for always supplying a bias current. Further, the solenoid valve with a mass flowmeter is characterized in that the inlet and outlet of the conduit are separated on both sides of the coil.

[0010]

The gas supply device of the present invention having the above-mentioned structure,
Supply a gas that easily liquefies at room temperature and pressure. The solenoid valve with a mass flow meter allows a gas having a predetermined mass flow rate to pass while measuring the mass flow rate of the supplied gas. Further, the rod-shaped heater embedded in the input block heats and keeps the input block connected to the input port of the solenoid valve with a mass flow meter heated to keep a gas that is easily liquefied at a predetermined temperature equal to or higher than the vaporization temperature. Further, the rod-shaped heater embedded in the output block heats and keeps the output block connected to the output port of the solenoid valve with a mass flow meter, and keeps a gas that is easily liquefied at a predetermined temperature equal to or higher than the vaporization temperature.

Further, the mass flowmeter of the solenoid valve with a mass flowmeter is independently wound around the inside of a conduit through which a gas that easily liquefies at room temperature and pressure flows, and has a resistance value depending on the temperature of the gas. The mass flow rate of the gas flowing through the conduit is measured from the value of the current flowing through the two changing resistors. Further, the solenoid attracts the movable iron core to the fixed iron core when the coil is energized.
The valve body is opened and closed by driving the movable iron core to switch communication between ports of the valve seat. The control means always applies a bias current to the coil to prevent the gas from liquefying.
At this time, since the inlet and outlet of the conduit are separated on both sides of the coil, the heat generated in the coil heats the conduit uniformly, so that the conduit is maintained at a uniform temperature, and the mass flowmeter accurately operates. The mass flow rate can be measured.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A gas supply device and a solenoid valve with a mass flow meter, which are embodiments of the present invention, will be described in detail below with reference to the drawings. FIG. 1 is a conceptual diagram showing the overall configuration of the gas supply device, and FIG. 2 is a perspective view thereof. The input block of the solenoid valve with mass flowmeter 53 has a coupling block 2
An input block 10 is attached via 4. An input opening / closing valve 52 and a purge valve 12 are attached to the upper surface of the input block 10. Further, a heater hole 10a is formed on the left side surface of the input block 10. Heater hole 1
A rod-shaped heater 15 is attached to 0a and is fixed by a set screw 23. The output block 11 is attached to the output port of the mass flowmeter-equipped solenoid valve 53 via the joint block 25. An output opening / closing valve 54 and a purge output valve 55 are attached to the upper surface of the output block 11. A heater hole 11a is formed on the right side surface of the output block 11. A rod-shaped heater 14 is attached to the heater hole 11 a and is fixed by a set screw 23.

Further, in the input block 10, the communication passage 16 connected to the input port of the input on-off valve 52, the output port of the input on-off valve 52 and the solenoid valve 53 with a mass flowmeter are connected through the communication passage of the joint block 24. A communication passage 18 that connects the input port and the output port of the purge valve 12, and the purge valve 12
And a communication passage 17 connected to the input port of. The communication passage 16 communicates with a supply source of dichlorosilane. In addition, the communication passage 17 communicates with a nitrogen gas supply source for purging via a communication passage formed in the transverse block 117 that transversely connects the input blocks 10. In the output block 11, the output on-off valve 54 is connected via the communication passage 20 connected to the output port of the output on-off valve 54, the communication passage 26 connected to the output port of the purge output valve 55, and the communication passage of the joint block 25. Of the purge output valve 55 and the output port of the solenoid valve 53 with a mass flowmeter are provided in the communication passage 19.

The communication passage 20 communicates with a supply destination using dichlorosilane F in the semiconductor process. Communication passage 26
Is connected to a tank for discarding residual dichlorosilane F through a communication passage formed in a transverse block 126 that transversely connects the output block 11. Further, the output block 11 is provided with a sensor hole 11 b for embedding the temperature sensor 13 separately from the communication passage 20. In addition, the rod-shaped heaters 14 and 15 and the temperature sensor 1
3 is connected to the control device 21 of the gas supply device. The control device 21 is a microcomputer (not shown), RO
The temperature sensor 1 is composed of M, RAM, etc.
A temperature adjustment program for supplying a predetermined current to the rod-shaped heater is stored in order to maintain the input block 10 and the output block 11 at a constant temperature by receiving the output of No. 3.

Next, FIG. 3 is a sectional view showing the structure of a normally closed type solenoid valve with a mass flowmeter, which is an embodiment of the solenoid valve 53 with a mass flowmeter. The mass flowmeter-equipped solenoid valve is composed of an upper mass flowmeter section 32 and a lower solenoid valve section 31. At the center of the solenoid valve portion 31 is a coil 38 in which a copper wire is wound around the body of a hollow cylindrical coil bobbin 39. Further, the fixed iron core 3 is provided in the hollow portion of the coil bobbin 39.
4 is fixed to the inner wall of the coil bobbin 39 with a predetermined gap. Therefore, a gap 45 is formed by the outer wall of the fixed iron core 34 and the inner wall of the coil bobbin 39. An input port 42 is opened on the left side of the fixed iron core 34. A leaf spring 40a having a through hole on the right side of the fixed iron core 34 is fixed to the inner wall surface around the periphery thereof, and the valve body 40 in which the main body is movable is held. An output port 43 is formed on the right side of the valve body 40. Further, a valve seat 41 that connects the input port and the output port is provided at a position where the valve body 40 faces each other. In addition, the coil bobbin 3 is separated on both sides of the coil 38.
An inflow port 33a and an outflow port 33b are opened on the inner wall of 9, and a conduit 33 is attached.

In order to accurately measure the mass flow rate in the conduit 33 with good responsiveness, it is necessary to accurately flow the fluid at a constant ratio with respect to the total mass flow rate of the fluid. Therefore, it is necessary to keep the fluid flowing through the main channel and the conduit in a laminar flow state. The mass flowmeter unit 32 is composed of this conduit 33, and thermosensitive coils R1 and R2 around which a pair of self-heating temperature measuring elements each having a large temperature coefficient are wound on the upstream side and the downstream side of the conduit 33 through which the fluid flows. Has been done. Here, inside the conduit 33, the fluid F
Is flowing in the direction indicated by the arrow. Conduit 33 has an inner diameter of 0.5
It is a tube made of SUS316 having a length of 20 mm and a length of 20 mm.

A diameter of 25 is provided upstream and downstream of the conduit 33.
Two heat sensitive coils R1 and R2 are formed by winding 70 μm heat sensitive resistance wires. The heat-sensitive resistance wire is iron,
It is made of a material with a large temperature coefficient such as nickel alloy. The heat sensitive coils R1 and R2 are bonded to the conduit 33 with UV curable resin or the like to form the sensor unit 32. A bridge circuit is formed by the heat sensitive coils R1 and R2, the temperature of the heat sensitive coils R1 and R2 is controlled to a constant value, and the mass flow rate of the fluid is calculated from the potential difference between the bridge circuits.

Next, the operation of the gas supply apparatus and the solenoid valve with a mass flowmeter having the above-mentioned construction will be described. First, the overall operation of the gas supply device of this embodiment will be described. The operation when the supply of dichlorosilane F is completed will be described. In order to cut off the supply of dichlorosilane F to the semiconductor manufacturing process, the solenoid valve 53 with a mass flow meter is de-energized and the solenoid valve 53 with a mass flow meter is closed. Next, the output on-off valve 54 is closed and the purge output valve 55 is opened to connect the input port and the communication passage 26. Also, the input on-off valve 5
2 is closed to block the flow of dichlorosilane F. Next, after fully opening the solenoid valve 53 with a mass flowmeter, the purge valve 1
2 is opened to allow nitrogen gas to flow in, so that the communication passage 1
8. Dichlorosilane remaining in the mass flow meter solenoid valve 53 and the communication passage 19 is exhausted to the tank from the purge output valve 55. Then, after a predetermined time, the purge valve 12 is shut off to stop the inflow of nitrogen. This is because if the dichlorosilane F is left in the conduit 33 of the mass flowmeter-equipped solenoid valve 53 for a long time, the conduit 33 becomes clogged and the measurement of the mass flow rate becomes inaccurate. is there.

Next, the case of supplying dichlorosilane F will be described. After closing the solenoid valve 53 with a mass flowmeter, the input on-off valve 52 is opened, and the purge output valve 55 is closed and the output on-off valve 54 is opened to connect the input port and the communication passage 20. Then, the solenoid valve with mass flowmeter 53 is operated. The operation of the solenoid valve 53 with a mass flowmeter will be described in detail. FIG. 3 shows a normally closed type solenoid valve 53 with a mass flowmeter. When the coil 38 is not energized, as shown in FIG. 3, the valve element 40 contacts the valve seat 41, and the input port 42 and the output It does not communicate with the port 43. Here, a plurality of through holes are opened in the leaf spring 40a, and the left and right spaces of the leaf spring 40a communicate with each other.

When the coil 38 is energized, a magnetic field is formed through the fixed iron core 34 so that the valve body 40 is fixed to the fixed iron core 3.
4, and moves toward the fixed iron core 34. And
When the valve body 40 and the valve seat 41 are separated from each other, the input port 42 and the output port 43 communicate with each other, and the fluid gas passes from the input port 42 through the gap 45 and the valve seat 41 to the output port 4
It flows to 3. Here, the solenoid valve control circuit compares the measured value of the mass flow rate of the fluid input from the mass flow rate measurement circuit with the command value input from the central control device, so that the actual mass flow rate approaches the command value. Then, the value of the current flowing through the coil 38 is adjusted. Then, the solenoid excites when a current is applied to the coil 38 and attracts the valve element 40, which is a movable iron core, to the fixed iron core 34. And the valve seat 41 is the valve body 40.
It is opened and closed by driving.

At this time, the amount of movement of the valve element 40 changes in proportion to the value of the current applied to the coil 38, the opening area formed by the valve element 40 and the valve seat 41 is adjusted, and the mass flow rate is Adjusted. Then, when the predetermined flow rate is completed, the power supply to the coil 38 is stopped. Then, the valve body 40 returns to the position where it abuts the valve seat 41 by the leaf spring, and the communication between the input port 42 and the output port 43 is cut off.

Next, the operation of the mass flow meter will be described. Conduit 3
Dichlorosilane F flows in the inside of 3 in the direction indicated by the arrow. The heat sensitive coils R1 and R2 are each connected to a constant temperature control circuit, and are controlled so that the temperatures of the heat sensitive coils R1 and R2 are always equal and constant. That is, when dichlorosilane F is flown in the pipe of the conduit 33 in the direction of the arrow, the heat sensitive coil R1 wound on the upstream side of the conduit 33.
, The temperature is lowered because the heat is taken by the dichlorosilane F. In order to make it higher, the output voltage becomes higher than the output voltage when dichlorosilane F is not flowing. Further, the heat sensitive coil R2 wound on the downstream side of the conduit 33.
Is heated by the dichlorosilane F heated by the heat-sensitive coil R1, so that the temperature rises. In order to lower it, the output voltage becomes smaller than the output voltage when dichlorosilane F is not flowing. Therefore, the voltage output from the constant temperature control circuit is proportional to the amount of energy required to maintain the thermosensitive coils R1 and R2 at the constant temperature in each constant temperature control circuit. Here, the voltage difference is proportional to the mass flow rate of the dichlorosilane F, and the mass flow rate can be measured by measuring the voltage difference. Thereby, the required mass flow rate of dichlorosilane F can be accurately fed.

Although the normal operation has been described above, in order to accurately measure the mass flow rate, it is necessary to heat and heat the dichlorosilane F, which is a gas that is easily liquefied at room temperature and normal pressure, so as not to be liquefied. Furthermore, it is a condition that the temperature of the conduit is not changed by external factors other than the flow of dichlorosilane. Therefore, in this example, the dichlorosilane F is always heated and held at 55 degrees Celsius or higher.

Next, the heating and heat retaining method of the gas supply device, which is the main part of the present invention, will be described. Input block 10
Is heated and kept warm by the rod heater 15. Since the rod-shaped heater 15 is pressed against the inner wall of the heater hole 10a by the set screw 23 and is in close contact with it, the heat of the rod-shaped heater 15 is efficiently transmitted to the input block 10, and the input block 10 has a uniform temperature. The output block 11 is heated and kept warm by the rod-shaped heater 14. Bar heater 14
Is pressed against the inner wall of the heater hole 11a by the set screw 23 and is in close contact with the inner wall of the heater hole 11a. Therefore, the heat of the rod-shaped heater 14 is efficiently transmitted to the output block 11, and the output block 11 has a uniform temperature. Further, the temperature sensor 13 mounted in the sensor hole 11b of the output block 11 is pressed against the inner wall of the sensor hole 11b by the set screw 23 and is in close contact therewith, so that the temperature of the output block 11 can be accurately measured. .

Further, the solenoid valve 53 with a mass flowmeter of the present embodiment.
FIG. 6 shows the relationship between the coil applied current applied to the coil and the flow rate. As shown in the figure, the coil applied current is 300m
Since the valve body 40 is driven only when the voltage becomes V or more, 30
A bias current of 0 mV or less can be applied. FIG. 7 shows experimental data on the relationship between the coil applied current and the coil temperature rise value. In order to keep the temperature of the dichlorosilane F at 55 degrees or higher, the temperature of the fixed iron core 34, which is the passage of the dichlorosilane F, is kept at 55 degrees or higher. For that purpose, it is required by experiments that the coil temperature is kept at 60 degrees. Therefore, as shown in FIG. 7, a coil application current of 250 mV is applied to the coil as a bias current. When the bias current is applied, since the inlet 33a and the outlet 33b of the conduit 33 are separately arranged on both sides of the coil 38, the conduit 33 is evenly affected by the heat generation of the coil 38, so The mass flow rate of dichlorosilane can be measured.

Next, FIGS. 4 and 5 show measurement data of each part of the gas supply device in the state where the rod-shaped heaters 14 and 15 and the bias current are applied. 4 a to i indicate measurement points of the gas supply device, and FIG. 5 shows temperatures measured at the measurement points a to i. The measurement points a to i are all points at which the surface temperature of the dichlorosilane F passage is measured. These temperatures are data measured when the temperature is saturated for a certain period of time or more while keeping the heat-retention state.
As shown in FIG. 5, it can be seen that the surface temperature of the dichlorosilane F passage is maintained between 55 and 58 degrees.
Therefore, the temperature of the dichlorosilane F can always be heated and maintained within a small variation range of 55 degrees or more, and the dichlorosilane F can be prevented from liquefying. Further, since the temperature change of the dichlorosilane F caused by the disturbance can be reduced, the influence on the mass flow meter can be reduced and the mass flow rate can be accurately measured.

As described in detail above, according to the gas supply system of this embodiment, the rod heaters 15 and 14 embedded in the input block 10 and the output block 11 are provided. Since the fluid passage can be heated and kept at a predetermined temperature, even when a gas such as dichlorosilane that is easily liquefied is supplied, the dichlorsilane or the like can be reliably supplied without liquefying. Further, unlike the tape-shaped heater 51, even when the mass flow meter solenoid valve 53 is removed and reassembled for maintenance of the mass flow meter, the state before the removal can be reliably reproduced.

According to the gas supply system of this embodiment,
In order to prevent the gas from being liquefied, a control means for constantly applying a bias current to the coil 38 of the mass flowmeter-equipped solenoid valve 53 is provided, so that the fluid passage of the mass flowmeter-equipped solenoid valve 53 is directly heated and kept warm. Therefore, even when a gas such as dichlorosilane that is easily liquefied is supplied, the dichlorsilane or the like can be reliably supplied without liquefying. Further, unlike the tape-shaped heater 51, even when the mass flow meter solenoid valve 53 is removed and reassembled for maintenance of the mass flow meter, the state before the removal can be reliably reproduced. Further, according to the gas supply device of the present embodiment, the conduit 33
Since the inflow port 33a and the outflow port 33b are separated on both sides of the coil 38, even if a bias current is passed through the coil 38, the conduit 33 is uniformly heated, which causes an error in the mass flow rate measurement. It is possible to accurately supply a gas that is easily liquefied, such as dichlorosilane.

The above-mentioned embodiments do not limit the present invention at all, and it goes without saying that various modifications and improvements can be made without departing from the scope of the invention. For example, in this embodiment, each of the input block 10 and the output block 11 is provided with one rod-shaped heater 14, 15, but each may be provided with two or more rod-shaped heaters. Further, in the present embodiment, the temperature sensor is provided only on the output block side to control the entire temperature, but a temperature sensor is also provided on the input block side to control each rod-shaped heater by the output of each temperature sensor. You may. Also,
In this embodiment, the temperature control is not provided in the solenoid valve with the mass flow meter, and the open control is performed by the experimental data.
A temperature sensor may be attached to the gas passage of the solenoid valve with a mass flowmeter for feedback control.

[0030]

As is apparent from the above description, according to the gas supply device of the present invention, since the rod-shaped heaters are embedded in the input block and the output block, the fluid passage near the gas valve is provided. Since it can be heated and kept warm to a predetermined temperature,
Even when a gas such as dichlorosilane that is easily liquefied is supplied, the required amount can be surely supplied without liquefying dichlorosilane and the like, and the yield of semiconductors can be improved. Further, unlike the tape-shaped heater, even when the mass flow meter equipped solenoid valve is removed and reassembled for maintenance of the mass flow meter, the state before the removal can be reliably reproduced.

Further, according to the gas supply apparatus of the present invention, in order to prevent the gas from being liquefied, the gas supply apparatus has a control means for constantly applying a bias current to the coil of the solenoid valve with a mass flow meter. Since the fluid passage of the solenoid valve with a flow meter can be directly heated and kept warm, it is possible to reliably supply the required amount without liquefying dichlorosilane etc. even when supplying a gas that is easily liquefied such as dichlorosilane. The yield of semiconductors can be improved. Further, unlike the tape-shaped heater, even when the mass flow meter equipped solenoid valve is removed and reassembled for maintenance of the mass flow meter, the state before the removal can be reliably reproduced.

Further, according to the gas supply device of the present invention, since the inlet and outlet of the conduit are separated on both sides of the coil, the conduit is uniformly heated even when a bias current is applied to the coil. Therefore, an error is not generated in the measurement of the mass flow rate, and a gas such as dichlorosilane that is easily liquefied can be accurately supplied.

[Brief description of drawings]

FIG. 1 is a conceptual diagram showing a configuration of a gas supply device that is an embodiment of the present invention.

FIG. 2 is a perspective view of a gas supply device.

FIG. 3 is a cross-sectional view showing the configuration of a solenoid valve with a mass flowmeter that is an embodiment of the present invention.

FIG. 4 is a conceptual diagram showing an experimental method of a gas supply device.

FIG. 5 is a data diagram showing an experimental result of the gas supply device.

FIG. 6 is a data diagram showing a relationship between a coil applied current and a gas flow rate of a solenoid valve with a mass flowmeter.

FIG. 7 is a data diagram showing a relationship between a coil applied current and a coil temperature rise value.

FIG. 8 is an external view showing a configuration of a conventional gas supply device.

FIG. 9 is an external view showing the configuration of another conventional gas supply device.

FIG. 10 is an external view showing a conventional heat retention method for a solenoid valve with a mass flowmeter.

[Explanation of symbols]

 10 Input Block 11 Output Block 12 Purge Valve 13 Temperature Sensor 14,15 Rod Heater 33 Conduit 38 Coil 40 Valve Body 41 Valve Seat 52 Input Open / Close Valve 53 Mass Flowmeter Solenoid Valve 54 Output Open / Close Valve 55 Purge Output Valve F Dichlorsilane R1, R2 heat sensitive coil

Claims (3)

[Claims] 1. A gas supply device for supplying a gas that is easily liquefied at room temperature and atmospheric pressure, and a solenoid valve with a mass flow meter, which allows a gas having a predetermined mass flow rate to pass while measuring the mass flow rate of the supplied gas. An input block connected to an input port of the solenoid valve with a mass flow meter, an input opening / closing valve attached to the input block, an output block connected to an output port of the solenoid valve with a mass flow meter, the output block And a rod-shaped heater embedded in the input block and the output block. 2. A current value flowing through two resistors, which are independently wound around a conduit through which a gas that easily liquefies at room temperature and atmospheric pressure flows, and whose resistance value changes according to the temperature of the gas, A mass flow meter for measuring the mass flow rate of gas flowing through the conduit, a coil in which a wire is wound around the outer circumference of a coil bobbin, a fixed iron core fixed to the coil bobbin hole, and a movable iron core attracted to the fixed iron core when the coil is energized. In a solenoid valve with a mass flowmeter having a solenoid having a solenoid and a valve seat that is opened and closed by driving the movable iron core to switch communication between ports, in order to prevent the gas from liquefying, the coil is always A solenoid valve with a mass flowmeter, comprising a control means for supplying a bias current. 3. The solenoid valve with mass flowmeter according to claim 2, wherein an inlet and an outlet of the conduit are separated on both sides of the coil.