JP2690269B2 - 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 device used in a semiconductor manufacturing apparatus or the like, and more specifically, it has a high vaporization temperature and is easily liquefied at room temperature unless external heat is applied. The present invention relates to a gas supply device that supplies process gas such as SiH ₂ Cl ₂ ), tungsten hexafluoride (WF ₆ ), chlorine trifluoride (ClF ₃ ) and the like with high accuracy without liquefying.

[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 normal temperature and normal pressure, but also a material such as dichlorosilane that is easily liquefied at normal temperature and normal pressure are used. .

When a process gas such as dichlorosilane that is easily liquefied is supplied, it is necessary to heat a gas line such as a high pressure cylinder, a pipe, a mass flow controller, which is a process gas supply route. The reason is that if dichlorosilane is liquefied in the middle of the gas line, the amount of gas supplied to the reaction chamber becomes inaccurate because the flow rate cannot be measured accurately, and the performance of the semiconductor integrated circuit etc. to be manufactured deteriorates. is there. There is also a problem that liquefied dichlorosilane or the like blocks the narrow tube of the mass flow meter-equipped flow control valve to shorten the life. In order to prevent liquefaction of process gas such as dichlorosilane, in a conventional gas supply device, as shown in FIG. 7, for example, a tape-shaped heater 51 is provided with pipes, joints, gas valves 52 and 54, and a mass flowmeter-equipped electromagnetic valve. By arranging along the both sides of the gas line constituted by the valve 53 and the like and fixing it with the binding band 56, the heating temperature was kept so that the dichlorosilane and the like became the vaporization temperature or higher.

[0004]

However, the conventional gas supply apparatus has the following problems in heating and keeping the temperature. As shown in FIG. 7, the gas supply device includes a plurality of gas valves 52 and 54 having different shapes, a joint and a solenoid valve 53 with a mass flowmeter.
However, the tape-shaped heater 51 is liable to cause breakage of the core wire, and the life is shortened particularly when the tape heater 51 is bent at a right angle or an acute angle. Skilledness was required to evenly adhere and fix the joint and the surface of the solenoid valve with mass flowmeter 53.

In particular, the gas valves 52, 54, the joint and the solenoid valve 53 with a mass flowmeter have different outer wall thicknesses.
If the temperature of the supplied process gas fluctuates greatly even before it is not liquefied, the mass flow rate of the solenoid valve 53 with the mass flow meter becomes inaccurate and adversely affects the semiconductor manufacturing process. It is necessary to control the temperature of the process gas as constant as possible. Therefore, if the tape-shaped heater 51 is attached in any way, the gas valves 52 and 54, the joint and the solenoid valve 53 with a mass flow meter
Whether liquefaction can be prevented by uniformly heating and keeping the liquefied process gas passing through the inside depends on the experience of the operator. However, in the method using the conventional tape-shaped heater 51, since it is left to the experience of the worker,
Temperature irregularities tended to occur, such as the occurrence of parts to which heat did not reach. Therefore, it is necessary to take measures to cover the heater 51 in the form of a tape and further cover the heater 51 with a heat insulating material.

For this reason, when replacing the solenoid valve 53 with a mass flow meter for maintenance, it is necessary to remove the heat insulating material or the tape-shaped heater 51 one by one. This was an obstacle to improving the process availability. In particular, the solenoid valve 53 with a mass flow meter has a large problem because it is a component that requires frequent maintenance in a gas line. Further, since gas lines for other process gases and other equipment are usually densely packed around the gas line, and work access is not good, it is extremely complicated to attach and detach the heat insulating material. Furthermore, since the method of covering the heat insulating material cannot be accurately reproduced, the process conditions after the maintenance change, which may adversely affect the semiconductor manufacturing process.

The present invention solves the above-mentioned problems of the prior art and provides a gas supply device capable of accurately supplying a predetermined amount while heating a process gas that is likely to be liquefied at room temperature and normal pressure and keeping it at a constant temperature. The flow control valve with mass flowmeter can be easily attached and removed without removing the tape-shaped heater, etc., and the temperature conditions after installation on the gas line can be accurately reproduced regardless of the experience of the operator. An object is to provide a possible gas supply device.

[0008]

In order to achieve this object, a gas supply device of the present invention has a mass flowmeter-equipped flow rate which allows a gas having a predetermined mass flow rate to pass while measuring the mass flow rate of the supplied gas. A control valve, an input block connected to the input port of the mass flow meter-equipped flow control valve, and an output block connected to the output port of the mass flow meter-equipped flow control valve,
A gas supply device for supplying a gas that is easily liquefied at room temperature and normal pressure, and a connecting means for attaching and detaching the mass flow meter-equipped flow control valve to and from the input block and the output block by operating from above. An open holding groove and a contact surface that comes into contact with the lower surface of the mass flow meter-equipped flow control valve are formed, and the heat generated by the heat generating means inserted into the holding groove is transferred to the mass flow meter through the contact surface. And a heat transfer member for preventing liquefaction of the gas which is transmitted to the flow rate control valve and is supplied.

Further, in the flow control valve with a mass flowmeter of the gas supply device of the present invention, the heat transfer member is arranged in a direction in which the contact surface of the heat transfer member is in close contact with the lower surface of the flow control valve with a mass flowmeter. The above-mentioned configuration is characterized in that it has elastic means for urging. Further, the flow rate control valve with the mass flowmeter of the gas supply device of the present invention has the second holding groove which is opened at the upper side,
A second heat transfer member for transferring the heat generated by the heat generating means inserted in the second holding groove to the input block or the output block to prevent liquefaction of the supplied gas is provided in the input block or the output block. The above configuration is characterized in that it is provided on at least one side surface.

[0010]

In the gas supply device of the present invention having the above-mentioned structure, the mass flow rate is measured by the mass flow meter-equipped flow rate control valve, and a gas that is easily liquefied is supplied at a predetermined temperature and pressure. Here, the heat transfer member provided below the mass flow meter-equipped flow control valve transfers heat from the heat generating means held in the holding groove opened upward to the mass flow meter-equipped flow control valve via the contact surface. Prevents liquefaction of the gas that is transmitted and supplied. The mass flow meter-equipped flow control valve is attached to the input block and the output block through the connecting means by operation from above. Further, in the gas supply device of the present invention, the elastic means presses the contact surface of the heat transfer member against the lower surface of the mass flow meter-equipped flow rate control valve to improve heat transfer efficiency. Further, in the gas supply device of the present invention, the second heat transfer member transfers the heat of the heat generating means inserted in the second holding groove to the input block or the output block,
Prevents liquefaction of the supplied gas.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A gas supply device as an embodiment 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 10 is attached to the input port of the mass flowmeter-equipped solenoid valve 53, which is a mass flowmeter-equipped flow control valve, via a mounting block 24. An input opening / closing valve 54 and a purge valve 55 are attached to the upper surface of the input block 10. An output block 11 is attached to the output port of the mass flowmeter-equipped solenoid valve 53 via a mounting block 25. An output opening / closing valve 56 is attached to the upper surface of the output block 11.

In the input block 10, the output port of the input on-off valve 54 and the input port of the solenoid valve 53 with a mass flow meter are connected through the communication passage 20 connected to the input port of the input on-off valve 54 and the communication passage of the mounting block 24. A communication passage 19 that communicates with the output port of the purge valve 55 and a communication passage 26 that connects to the input port of the purge valve 55 are provided. The communication passage 20 has a process gas (here, dichlorosilane F).
And) supply source. In addition, the communication passage 26
Is connected to a nitrogen gas supply source for purging through a communication passage formed in a transverse block 126 that transversely connects the input block 10.

The output block 11 has a communication passage 16 connected to the output port of the output on-off valve 56, and the mounting block 2.
A communication passage 1 for communicating the input port of the output on-off valve 56 and the output port of the solenoid valve 53 with a mass flow meter through the communication passage 5
And 8 are perforated. The communication passage 16 communicates with a supply destination using dichlorosilane F in the semiconductor process. The mass flowmeter-equipped solenoid valve 53 is a known mass flowmeter-equipped solenoid valve having a mass flowmeter portion and a solenoid valve portion. Further, the input opening / closing valve 54, the purge valve 55 and the output opening / closing valve 56 are
Each is an air operated valve that connects or disconnects the input port and the output port. Solenoid valve 53 with mass flow meter,
Input on-off valve 54, purge valve 55 and output on-off valve 56
Are controlled by a controller (not shown).

In the gas supply system of the present embodiment having the above-mentioned conceptual structure, as shown in the perspective view of FIG. 2, the mass flow meter-equipped solenoid valve 53, the input opening / closing valve 54, the purge valve 55, and the output opening / closing valve 56. Is an input block 10 to which these are attached,
It is arranged on the base 27 via the output block 11 and the mounting blocks 24 and 25. Mounting block 24, 25
Are attached to the input block 10 and the output block 11 by attaching screws 22 provided on the upper surface.
By operating the mounting screws 22 and 22 from above with a screw driver, hexagon wrench, etc., the solenoid valve with mass flowmeter 5
3 can be attached to and detached from the input block 10 and the output block 11 together with the attachment blocks 24 and 25.

A heat transfer block 1 is provided below the mass flow meter equipped solenoid valve 53. Heat transfer block 1
Is a substantially rectangular parallelepiped member made of a material having high thermal conductivity (eg, aluminum or aluminum alloy), and the pressing spring 2
It is pressed against the lower surface of the solenoid valve 53 with a mass flowmeter by the urging force of. Also, the input block 10 and the output block 1
A sub heat transfer block 3 is screwed to the side surface of 1. The sub heat transfer block 3 is a substantially rectangular parallelepiped member made of the same material as the heat transfer block 1. Holding grooves 6 and 7 are formed in the heat transfer block 1 and the sub heat transfer block 3, and a tape-shaped heater 51 is held in the holding grooves 6 and 7. The tape-shaped heater 51 is a band-shaped heating device having a heating wire inserted therein, and is arranged around the gas supply device while being held in the holding grooves 6 and 7 of the heat transfer block 1 and the sub heat transfer block 3. It is set up. FIG. 6 shows a state in which the tape-shaped heater 51 is removed from the gas supply device shown in FIG.

The heat transfer block 1 will be described with reference to FIG. FIG. 3 is a cross-sectional view showing a state in which the mass flow meter-equipped solenoid valve 53 is removed together with the mounting blocks 24 and 25 from the gas supply device, and the tape-shaped heater 51 is also removed. The upper surface of the heat transfer block 1 is a contact surface 4 that comes into contact with the mass flowmeter-equipped solenoid valve 53 from below. On the lower surface of the heat transfer block 1, sandwiching portions 5 and 5 that sandwich the pressing spring 2 with the base 27 are provided. The recesses 8 and 8 are provided at positions on the contact surface 4 that face the sandwiching portions 5 and 5, respectively.
Through holes 31 and 31 are formed so as to penetrate through the holding portions 5 and 5. On the other hand, mounting holes 28, 28 are formed in the base 27 at positions facing the recesses 8, 8 and the holding portions 5, 5. In the mounting holes 28, 28, the columnar support 1
4, 14 are fixedly attached. Screw holes 30, 30 are formed in the upper ends of the columns 14, 14 from above.

The pressing springs 2 and 2 having an inner diameter slightly larger than the outer diameters of the columns 14 and 14 are placed on the columns 14 and 14, and the upper ends of the pressing springs 2 and 2 are fitted to the holding portions 5 and 5, respectively.
Attach the heat transfer block 1. And heat transfer block 1
While pressing down, the bolts 9, 9 are screwed into the screw holes 30, 30 while the spacers 15, 15 are being fitted. At this time, the pressing springs 2 and 2 are held between the holding portions 5 and 5 and the base 27. The heat transfer block 1 is provided with the pressing springs 2 and 2.
The bottom surfaces of the recesses 8 and 8 come into contact with the spacers 15 and 15 and stop while being biased upward by. In this state, when the contact surface 4 of the heat transfer block 1 is pressed from above, the heat transfer block 1 moves downward against the elasticity of the pressing springs 2 and 2. Here, the columns 14 prevent lateral displacement.

As shown in FIG. 4, when the mass flowmeter-equipped solenoid valve 53 is attached with the attachment screws 22 and 22, the pressing spring 2 is attached.
The contact surface 4 of the heat transfer block 1 is pressed against the lower surface of the mass flowmeter-equipped solenoid valve 53 by the urging of. In FIG. 4, the pressing spring 2 is slightly contracted from the state of FIG. 3, and the heat transfer block 1
It can be understood that is urged toward the solenoid valve with mass flowmeter 53. On the side surface of the heat transfer block 1, a holding groove 6 opened upward is provided as shown in FIG. A tape-shaped heater 51 can be inserted into and removed from the holding groove 6 by an operation from above. The holding groove 6 may be formed by cutting the heat transfer block 1 from the upper surface,
Further, it may be formed by joining a wall-shaped member to the side surface.

Next, the sub heat transfer block 3 will be described. A total of four sub heat transfer blocks 3 are attached to both side surfaces of the input block 10 and the output block 11. However, the four sub heat transfer blocks 3 are shaped according to the position where they are attached. The side surface of each sub heat transfer block 3 has a holding groove 7 similar to the holding groove 6 of the heat transfer block 1.
Is provided, and the tape-shaped heater 51 can be inserted and removed by an operation from above. A hole 13 is formed in the wall portion 12 of the holding groove 7. The sub heat transfer block 3 is provided with an input block 10 and an output block 11 by operating a screw driver or the like from the lateral direction.
This is because it is screwed to the screwdriver so that the screwdriver can pass through.

Next, the operation of the gas supply device having the above structure will be described. First, the overall operation of the gas supply device will be described. When supplying dichlorosilane F to the semiconductor manufacturing process, a solenoid valve 53 with a mass flow meter,
The input opening / closing valve 54 and the output opening / closing valve 56 are opened, and the purge valve 55 is closed. At this time, as shown in FIG. 1, the supplied dichlorosilane F is supplied to the communication passage 20 of the input block 10, the input opening / closing valve 54, and the communication passage 1 of the input block 10.
9, communication passage of mounting block 24, solenoid valve 5 with mass flowmeter
3, the communication path of the mounting block 25, the communication path 18 of the output block 11, the output opening / closing valve 56, and the communication path 16 of the output block 11 toward the supply destination. At this time, the mass flow rate can be measured and adjusted by the solenoid valve with mass flow meter 53.

Next, when the supply of dichlorosilane F is stopped, the input on-off valve 54 is closed and the dichlorosilane F is closed.
Cut off the flow. Then, the purge valve 55 is opened and nitrogen gas for purging is introduced from the nitrogen gas supply source. At this time, the solenoid valve 53 with a mass flowmeter is fully opened. As a result, the supplied nitrogen gas passes through the communication path 2 of the transverse block 126.
6, purge valve 55, communication passage 19 of input block 10, communication passage of mounting block 24, solenoid valve 53 with mass flow meter, communication passage of mounting block 25, communication passage 1 of output block 11
8, the output on-off valve 56, and the communication passage 16 of the output block 11 toward the exhaust system. In this way, the dichlorosilane F remaining in the mass flow meter equipped solenoid valve 53 and the like is discharged and filled with nitrogen gas. After a predetermined time, the purge valve 55
To close the nitrogen flow.

There are two purposes of introducing nitrogen gas. One is to prevent the clogging and inaccurate measurement of the mass flow rate when the dichlorosilane F stays in the mass flowmeter-equipped solenoid valve 53 for a long period of time. Another one
One purpose is to scavenge dichlorosilane F when performing maintenance work such as replacement of the solenoid valve 53 with a mass flow meter.

Next, the operation of the heat transfer block 1 and the sub heat transfer block 3 in the gas supply device will be described. The heat transfer block 1 and the sub heat transfer block 3 are used by arranging the tape-shaped heater 51 in the holding grooves 6 and 7 as described above. FIG. 5 shows a top view of a state in which the tape-shaped heater 51 is arranged in the gas supply device. When dichlorosilane F is flowing through the gas supply device, if the heating wire of the tape-shaped heater 51 is energized to generate Joule heat, the heat is transferred via the heat transfer block 1 to the solenoid valve with mass flowmeter. 53 to the input block 1 via the sub heat transfer block 3
0, transmitted to the output block 11. Thus, the temperature inside the solenoid valve 53 with a mass flowmeter, etc.
It is maintained above the condensation temperature of 1, and various problems due to liquefaction of dichlorsilane F in the gas supply device are prevented.

Here, since the heat transfer block 1 and the sub heat transfer block 3 are made of a material having high heat conductivity such as aluminum or aluminum alloy, the heat transfer efficiency is good. Further, the heat transfer block 1 is brought into close contact with the mass flowmeter-equipped solenoid valve 53 by the urging of the pressing spring 2, and the sub heat transfer block 3 is fixed by screws to the input block 10 or the output block 11.
The fact that it is closely attached also contributes to good heat transfer efficiency. Then, the tape-shaped heater 51 is attached to the holding grooves 6 and 7
Since it can be uniformly arranged along the whole of the gas supply device, the temperature of each part in the gas supply device can be kept substantially constant. A thermocouple was attached to each of the input opening / closing valve 54, the purge valve 55, the mass flowmeter-equipped solenoid valve 53, and the output opening / closing valve 56 of the gas supply device, and a temperature measurement test was performed. 45.5 ° C with the purge valve 55,
49.6 ° C with solenoid valve 53 with mass flowmeter, output on-off valve 56
The excellent result of 48.7 ° C. was obtained.

Further, the insertion and removal of the tape-shaped heater 51 from the holding grooves 6 and 7 of the heat transfer block 1 and the sub heat transfer block 3 can be easily performed only by the operation from above and no skill is required. And reproducibility is good. Therefore, even if the tape-shaped heater 51 is once removed and reattached for maintenance reasons, the same temperature condition as before the maintenance can be easily obtained. Furthermore, not only the tape-shaped heater 51 but also the solenoid valve 53 with a mass flowmeter can be easily attached and detached by only operating from above.

As described in detail above, according to the gas supply apparatus of this embodiment, the heat transfer block 1 is provided below the solenoid valve 53 with a mass flowmeter and is closely contacted by the urging force of the pressing spring 2. The heat of the tape-shaped heater 51 is transferred to the solenoid valve 53 with a mass flowmeter. Further, the heat of the tape-shaped heater 51 is transferred to the input block 10 via the sub heat transfer block 3 attached to the input block 10 and the output block 11.
And to the output block 11. Therefore, even when supplying a gas that is easily liquefied, such as dichlorsilane F, the gas can be reliably supplied without being liquefied.

Further, in the heat transfer block 1 and the sub heat transfer block 3, since they are held in the holding grooves 6 and 7 which are opened at the upper side, they can be evenly attached to the gas supply device only by the operation from above, and once removed. The reproducibility when re-installed is also good. Therefore, the temperature uniformity and stability inside the gas supply device are excellent. Further, since the mass flowmeter-equipped solenoid valve 53 is mounted via the mounting blocks 24 and 25 which can be mounted / removed only by an operation from above, the mounting / dismounting work is easy and a large maintenance space is not required.

The above-mentioned embodiment does not limit the present invention at all, and it is needless to say that various modifications and improvements can be made without departing from the scope of the invention. For example, in this embodiment, the gas supply device for supplying dichlorosilane F is used. However, any gas that easily supplies a gas such as tungsten hexafluoride or chlorine trifluoride may be used as long as the gas is easily liquefied. It does not preclude the use of a gas such as monosilane which is unlikely to be liquefied. Further, the material of the heat transfer block 1 and the sub heat transfer block 3 is not limited to aluminum or an aluminum alloy, and may be any material having high thermal conductivity. In addition, although the solenoid valve 53 of the solenoid valve type with a mass flow meter is used as the flow control valve with a mass flow meter, a piezo type or a thermal type other than the solenoid valve type may be used. Although the input opening / closing valve 54, the purge valve 55, and the output opening / closing valve 56 are air operated valves, they may be electromagnetic valves.

[0029]

As is apparent from the above description, according to the present invention, the heat of the heat generating means is transmitted to the mass flowmeter-equipped flow control valve via the heat transfer member which is closely contacted by the biasing force of the pressing spring. Since the heat of the heat generating means is transferred to the input block and the output block via the second heat transfer member, the gas passage in the gas supply device can be uniformly heated and kept at a temperature equal to or higher than a predetermined temperature, such as dichlorosilane. It is possible to provide an excellent gas supply device capable of surely supplying the required amount of the gas that is easily liquefied without liquefying it. Thereby, the product yield in the semiconductor manufacturing process or the like can be improved.

Further, since the heat generating means, the flow rate control valve with a mass flow meter, and the like can be attached and detached only by operating from above, workability is good and an excessive maintenance space is not required. Also, even if the heat generating means or the like is once removed or re-installed for disassembly and maintenance, the state before replacement or disassembly and maintenance can be restored regardless of the skill of the operator, and the reproducibility of temperature conditions, etc. Well can improve the stability of process operation.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram showing a configuration of a gas supply device according to one embodiment of the present invention.

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

FIG. 3 is a diagram illustrating a heat transfer block in the gas supply device.

FIG. 4 is a view showing a state in which a solenoid valve with a mass flowmeter is attached to the one shown in FIG.

FIG. 5 is a view of the gas supply device as viewed from above.

FIG. 6 is a diagram showing a state in which a tape heater is removed from the one shown in FIG.

FIG. 7 is an external view showing a conventional heat retaining method for a solenoid valve with a mass flowmeter.

[Explanation of symbols]

 1 Heat Transfer Member 2 Pressing Spring 3 Second Heat Transfer Member 4 Contact Surface 6, 7 Holding Groove 10 Input Block 11 Output Block 22 Mounting Screw 24, 25 Mounting Block 51 Tape Heater 53 Flow Control Valve with Mass Flow Meter F Dichlorsilane

Continuation of the front page (56) Reference JP-A-58-24819 (JP, A) Actually opened 58-185744 (JP, U) Actually opened 61-58522 (JP, U)

Claims (3)

(57) [Claims] 1. A flow control valve with a mass flow meter, which allows a gas having a predetermined mass flow rate to pass while measuring a mass flow rate of a supplied gas, and an input block connected to an input port of the flow control valve with a mass flow meter. A gas supply device having an output block connected to the output port of the mass flow meter-equipped flow control valve and supplying a gas that is easily liquefied at room temperature and normal pressure. Connecting means for attaching / detaching to / from the input block and the output block, a holding groove having an upper opening, and a contact surface for contacting the lower surface of the mass flow meter-equipped flow control valve are formed and inserted into the holding groove. And a heat transfer member for preventing the liquefaction of the supplied gas by transmitting the heat generated by the heat generating means to the flow rate control valve with the mass flow meter via the contact surface. 2. The gas supply device according to claim 1, wherein the elastic means urges the heat transfer member in a direction in which the contact surface of the heat transfer member is in close contact with the lower surface of the mass flow meter-equipped flow control valve. A gas supply device comprising: 3. The gas supply device according to claim 1 or 2, wherein the gas supply device has a second holding groove that is open at the top,
A second heat transfer member for transferring the heat generated by the heat generating means inserted in the second holding groove to the input block or the output block to prevent liquefaction of the supplied gas is provided in the input block or the output block. A gas supply device having at least one side surface.