JP2002175988A - Valve unit and heat treatment apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress adherence of a reaction product on the surface of bellows in a valve chest. SOLUTION: A valve apparatus 4, provided in an exhaust shell 3 of a heat treatment furnace 2 comprises a valve chest 23 which includes a gas inlet 21 and a gas outlet 22 connected through to the exhaust shell 3; a valve body 24 for opening and closing the gas inlet 21 side provided in the valve chest 23; a driving section 26 for opening and closing the valve body 24 provided outside of the valve chest 23 via a valve bar 27; a bellows 30 provided between the valve chest 23 and the valve body 24 for sealing a valve bar penetration bore section 29 for the valve chest 23; and a bellows-storing chamber 31 for storing the bellows 30, when the valve body 24 provided in the valve chest 23 opens.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a valve device and a heat treatment device.

[0002]

2. Description of the Related Art In the manufacture of semiconductor devices, an object to be processed, for example, a semiconductor wafer, is oxidized, diffused, and CVD (Chemical).
ical Vapor Deposition)
Various heat treatment apparatuses are used. The heat treatment apparatus includes a heat treatment furnace that accommodates a semiconductor wafer and performs a predetermined heat treatment under a predetermined processing gas atmosphere, and a valve device provided in an exhaust system of the heat treatment furnace.

The valve device includes a valve chamber having a gas inlet and a gas outlet communicating with the exhaust system, a valve body provided in the valve chamber to open and close the gas inlet side, and the valve provided outside the valve chamber. A drive unit for opening and closing the body via a valve stem is provided with a bellows interposed between the valve chamber and the valve body to seal a valve stem penetration portion of the valve chamber.

[0004]

The exhaust gas exhausted through the exhaust system contains excess processing gas (reactive gas) during the heat treatment. There is a problem that the product adheres. Therefore, in order to prevent this, the valve chamber is provided with a heating means for heating the valve chamber to a constant temperature, for example, 170 ° C.

However, it is difficult to uniformly heat the bellows due to its structure. For this reason, it is difficult to suppress the reaction product from adhering to the surface of the bellows. This can be a source of wafer contamination.

The present invention has been made in view of the above circumstances, and has as its object to provide a valve device and a heat treatment device that can suppress the adhesion of reaction products to the surface of a bellows in a valve chamber. I do.

[0007]

Means for Solving the Problems In the present invention, claim 1 is provided.
The present invention is a valve device provided in an exhaust system of a heat treatment furnace, comprising: a valve chamber having a gas inlet and a gas outlet communicating with the exhaust system; and a valve body provided in the valve chamber to open and close the gas inlet side. A drive unit provided outside the valve chamber and driving the valve body to open and close via a valve rod; and a drive unit disposed between the valve chamber and the valve body to seal a valve rod penetration part of the valve chamber. A bellows storage chamber provided in the valve chamber for storing the bellows when a valve element is opened.

According to a second aspect of the present invention, in the valve device according to the first aspect, the valve body has an airtight member that seals the bellows storage chamber when the valve is opened.

According to a third aspect of the present invention, in the valve device according to the first aspect, an inert gas introduction portion for introducing an inert gas into the bellows storage chamber is provided.

According to a fourth aspect of the present invention, there is provided a heat treatment apparatus having a valve device in an exhaust system of a heat treatment furnace, wherein the valve device has a valve chamber having a gas inlet and a gas outlet communicating with the exhaust system. A valve body provided in the valve chamber for opening and closing the gas inlet side, a drive unit provided outside the valve chamber for driving the valve body to open and close via a valve rod, and a valve rod penetration part of the valve chamber is sealed. A bellows is provided between the valve chamber and the valve body, and a bellows storage chamber is provided in the valve chamber and stores the bellows when the valve body is opened.

[0011]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a configuration diagram of a heat treatment apparatus showing a first embodiment of the present invention.

As shown in FIG. 1, a heat treatment apparatus 1 includes a heat treatment furnace 2 that accommodates an object to be processed, for example, a semiconductor wafer W, and performs a heat treatment under a predetermined processing gas atmosphere and a predetermined high temperature. The exhaust system 3 is provided with, for example, a main valve 4 which is a valve device. Heat treatment furnace 1 shown in the figure
Is provided with a heat-resistant, e.g. quartz-made reaction tube (processing vessel) 5 having a vertically long cylindrical shape having an upper end closed and an open lower end,
It is configured as a vertical batch furnace capable of heat-treating a large number of, for example, about 150 wafers w at a time.

The illustrated reaction tube 5 has a double tube structure in which an inner tube 5a and an outer tube 5b are arranged concentrically, but may have a single tube structure. The reaction tube 5 constitutes a highly airtight heat treatment furnace 2 with its lower end opening, which is open as a furnace port, airtightly closed by a lid 6. On the lid 6, a wafer support 7, for example, a quartz wafer boat 7, which is a substrate support for supporting a large number of wafers W in a horizontal state and spaced vertically in a multi-stage manner, is provided via a rotatable boat mounting table 8. It is placed.

The lid 6 is configured to load (load) and unload (unload) the wafer boat 7 into the processing furnace 2 and open and close the furnace port by a lifting mechanism (not shown). Around the reaction tube 5 is provided a heater 11 composed of a resistance heating element capable of controlling the inside of the furnace to a predetermined temperature, for example, 300 to 1000 ° C. The periphery of the heater 11 is covered with a cooling jacket 12.

At the lower side of the reaction tube 5, there is provided a gas introduction tube 13 for introducing a processing gas.
Is connected to a processing gas supply system. An exhaust pipe section 14 for exhausting the inside of the reaction tube 5 is provided below the reaction pipe 5, and the exhaust system 3 is connected to the exhaust pipe section 14. The exhaust system 3 is composed of, for example, a stainless steel pipe (exhaust pipe), and a decompression pump (vacuum pump) 15 and an abatement device (not shown) are connected downstream.

A bypass pipe 16 for bypassing the main valve 4 is connected to the exhaust system 3.
6 is provided with a sub-valve (auxiliary valve) 17. The bypass pipe 16 has a smaller diameter than the pipe of the exhaust system 3,
This method is used when, for example, vacuum exhausting the inside of the reaction tube 5 is performed to perform slow exhaust so as not to wind up particles. A butterfly valve 1 for controlling pressure is provided between the main valve 4 of the exhaust system 3 and the pressure reducing pump 15 (downstream from a downstream connection portion of the bypass pipe 16).
8 are provided.

A pressure sensor 19 is provided between the heat treatment furnace 2 of the exhaust system 3 and the main valve 4, and based on the pressure (detected value) detected by the pressure sensor 19, the inside of the heat treatment furnace 2, that is, the reaction tube 5 is detected. The opening of the butterfly valve 18 is controlled by a control unit (controller) 20 so that the internal pressure becomes a desired set pressure (installed value). Further, the main valve 4 and the sub-valve 17 are controlled by the control unit 20.
Are switched, and opening / closing (on / off) is controlled.

On the other hand, the main valve 4 has a valve chamber 23 having a gas inlet 21 and a gas outlet 22 communicating with the exhaust system 3. Gas inlet 21 at the bottom of valve chamber 23
Is provided, and a gas outlet 22 is provided on the side of the valve chamber 23, and the main valve 4 is configured as a so-called angle valve. A circular valve element 24 for opening and closing the gas inlet 21 side is provided in the valve chamber 23, and a drive for opening and closing the valve element 24 via a valve rod 25 is provided above the valve chamber 23 (outside the valve chamber). A section (actuator) 26 is provided. The drive unit 26 is preferably of a drive system using an air cylinder, but may be a drive system using an electric motor.

A valve seat 27 on which a valve body 24 is seated is provided on the side of the gas inlet 21 in the valve chamber 23, and an airtight member for sealing a space between the valve seat 27 and the valve seat 27 when the valve is closed. For example, an O-ring 28 is provided. The valve stem 25 penetrates the ceiling of the valve chamber 23, and straddles between the ceiling of the valve chamber 23 and the upper part of the valve body 24 to seal the valve stem penetration part 29 of the valve chamber 23. For example, a stretchable bellows 30 made of stainless steel is interposed. Bellows 30 is valve stem 25
Is provided concentrically with the valve stem 25 so as to surround the shaft.

In the valve chamber 23, a bellows storage chamber for storing the bellows 30, which is contracted with the upward movement of the valve body 24 when the valve body 24 is moved upward and opened. 31 are formed. The bellows storage chamber 31 is formed in an upper region in the valve chamber 23 by a partition wall 32 provided in the valve chamber 23 so as to partition the inside of the valve chamber 23 up and down. The partition wall 32 has an opening 33 (opening of the bellows storage chamber) through which the bellows 30 penetrates loosely.

When the valve 24 is opened, it is discharged from the heat treatment furnace 2 and passes through the valve chamber 23 from the gas inlet 21 to the gas outlet 2.
In order to prevent the exhaust gas flowing into the bellows 2 from entering the bellows storage chamber 31, an airtight member such as O is provided on the upper part of the valve body 24 to abut the lower surface of the partition wall 32 to seal the bellows storage chamber 31. A ring 34 is provided. In this case, the valve body 24 is formed to have a larger diameter than the opening 33 of the partition wall 32 so that the opening 33 of the bellows storage chamber 31 can be covered (closed) by the opened valve body 24. However, an O-ring 34 for sealing between the valve body 24 and the partition wall 32 in order to provide airtightness at that time.
Is preferably provided. The exhaust gas discharged from the heat treatment furnace 1 contains unreacted processing gas, and when the processing gas component falls below a predetermined temperature, for example, 150 ° C., it precipitates as a reaction product. A heating means for heating (heating) a portion in contact with the exhaust gas to a predetermined temperature, for example, 170 ° C., for example, a resistance heating element is attached to the piping of the exhaust system 3 and the main valve 4 (not shown).

Next, the operation of the main valve and the heat treatment apparatus configured as described above will be described. Reaction tube 5 of heat treatment furnace 2
When the wafer boat 7 loaded with the wafer w therein is loaded and the furnace port is sealed with the lid 6, the main valve 4 is closed, the sub-valve 17 is opened, and the inside of the reaction tube 5 is driven by the decompression pump 15. Depressurized by slow exhaust to a predetermined pressure,
Next, the main valve 4 is switched to open to reduce the pressure to the processing pressure.

Then, the wafer w is heated and raised to a predetermined heat treatment temperature by the heater 11, and a predetermined heat treatment such as a CVD process is performed on the wafer w by introducing a processing gas into the reaction tube 5. In the course of this heat treatment, the butterfly valve 4 is controlled by the control unit 20 so that the pressure in the reaction tube 5 becomes a predetermined set pressure based on the pressure detected by the pressure sensor 19.
Is controlled by the opening degree control. The exhaust gas from the reaction tube 5 of the heat treatment furnace 2 is supplied to the main valve 4 of the exhaust system 3.
Has been exhausted via.

Although the unreacted processing gas is also contained in the exhaust gas, the piping of the exhaust system 3 and the valve chamber 2 of the main valve 4
3. In some cases, the valve body 24 is also preheated to a predetermined temperature by a heating means, for example, a resistance heating element, so that reaction products are unlikely to adhere to and generate even when in contact with exhaust gas. When the processing gas comes into contact with the surface of the bellows 30 having a large diameter, a reaction product is liable to be attached and generated.

However, in the main valve 4, since the bellows storage chamber 31 for storing the bellows 30 when the valve body 24 is opened is provided in the valve chamber 23, it is difficult for exhaust gas to contact the bellows 30. , Valve room 23
It is possible to suppress the reaction product from adhering to the surface of the bellows 30 in the inside. In particular, in the main valve 4 of the above embodiment, since the valve body 24 is provided with the O-ring 34 that seals the opening 33 of the bellows storage chamber 31 when the valve is opened, It is possible to prevent or prevent intrusion of exhaust gas, and it is possible to sufficiently suppress or prevent reaction products from adhering to the surface of the bellows 30 in the valve chamber 23.

Therefore, according to the main valve 4 and the heat treatment apparatus 1, it is difficult for reactive products to adhere to the surface of the bellows 30 of the main valve 4, so that it is possible to suppress or prevent a source of contamination of the wafer w. it can. Further, since the adhesion of the reaction product in the bellows storage chamber 31 in the valve chamber 23 is suppressed, the heating of the bellows storage chamber 31 in the valve chamber 23 becomes unnecessary, and the conventional main valve that heats the entire valve chamber is used. , The heating range can be reduced.

FIG. 2 is a block diagram of a heat treatment apparatus showing a second embodiment of the present invention. In the present embodiment, FIG.
The same parts as those of the first embodiment are denoted by the same reference numerals, description thereof will be omitted, and different parts will be described. In the heat treatment apparatus 1 of the present embodiment, instead of the valve body 24 of the main valve 4 not being provided with an O-ring for sealing the bellows storage chamber 31, an inert gas such as nitrogen gas is provided in the bellows storage chamber 31. An inert gas introduction unit 35 for introducing N ₂ is provided.

The inert gas introduction section 35 has an inert introduction pipe 36 which is a pipe for introducing an inert gas.
One end of the inert gas introduction pipe 36 is connected to the inside of the bellows storage chamber 31. The other end of the inert gas introduction pipe 36 is connected to a mass flow controller (Mass Flow Control).
ller) 37 and an inert gas source via an on-off valve (not shown). The flow control device 37 includes:
The control unit 2 is configured to introduce a predetermined amount of inert gas into the bellows storage chamber 31 based on the pressure detected by the pressure sensor 19.
It is configured to be controlled by 0. The inert gas is heated to a predetermined temperature, for example, 170 ° C. by providing a heating means, for example, a resistance heating element in the inert gas introduction pipe 36 so as not to cool the surfaces of the valve body 24 and the bellows 30 in the valve chamber 23. It is preferred that

According to the main valve 4 and the heat treatment apparatus 1 configured as described above, the same effect as that of the embodiment of FIG. 1 can be obtained, and also, an inert gas is introduced into the bellows storage chamber 31. Of the bellows storage chamber 31 can be suppressed or prevented by the inert gas, and the reaction product adheres to the surface of the bellows 30 in the valve chamber 23. Can be sufficiently suppressed. Further, ballast pressure control for introducing an inert gas into the exhaust system 3 becomes possible.

Although the preferred embodiments of the present invention have been described in detail with reference to the drawings, the present invention is not limited to the above-discussed preferred embodiments, and various design changes and the like are possible without departing from the gist of the present invention. Is possible. For example, the heat treatment apparatus is not limited to the batch type, and may be a single-wafer type in which the objects to be processed are heat-treated one by one. The object to be processed is not limited to a semiconductor wafer, and may be, for example, a glass substrate, an LCD substrate, or the like.

[0031]

In summary, according to the present invention, the following effects can be obtained.

(1) According to the first aspect of the present invention, there is provided a valve device provided in an exhaust system of a heat treatment furnace, wherein a valve chamber having a gas inlet and a gas outlet communicating with the exhaust system is provided. A valve body provided for opening and closing the gas inlet side, a driving unit provided outside the valve chamber for driving the valve body to open and close via a valve rod, and a valve chamber for sealing a valve rod penetration portion of the valve chamber. And a bellows provided between the valve body and the bellows, and a bellows storage chamber provided in the valve chamber and storing the bellows when the valve body is opened, so that exhaust gas does not easily come into contact with the bellows. In addition, it is possible to suppress the reaction product from adhering to the surface of the bellows in the valve chamber.

(2) According to the second aspect of the present invention, since the valve element has an airtight member that seals the bellows storage chamber when the valve is opened, it is possible to prevent exhaust gas from entering the bellows storage chamber. Adhesion of the reaction product to the surface of the bellows in the valve chamber can be sufficiently suppressed.

(3) According to the third aspect of the present invention, since the inert gas introduction portion for introducing the inert gas into the bellows storage chamber is provided, it is possible to prevent the exhaust gas from entering the bellows storage chamber. The reaction gas can be prevented by the active gas, and the adhesion of the reaction product to the surface of the bellows in the valve chamber can be sufficiently suppressed. Further, ballast pressure control for introducing an inert gas into the exhaust system becomes possible.

(4) According to the invention of claim 4, a heat treatment apparatus provided with a valve device in an exhaust system of the heat treatment furnace, wherein the valve device has a gas inlet and a gas outlet communicating with the exhaust system. A valve chamber, a valve body provided in the valve chamber for opening and closing the gas inlet side, a driving unit provided outside the valve chamber for driving the valve body to open and close via a valve rod, and a valve rod penetrating the valve chamber. A bellows provided between the valve chamber and the valve body to seal the portion, and a bellows storage chamber provided in the valve chamber and storing the bellows when the valve body is opened, Exhaust gas hardly comes into contact with the bellows, so that reaction products can be prevented from adhering to the surface of the bellows in the valve chamber.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a heat treatment apparatus showing a first embodiment of the present invention.

FIG. 2 is a configuration diagram of a heat treatment apparatus showing a second embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Heat treatment apparatus 2 Heat treatment furnace 3 Exhaust system 4 Main valve (valve device) 21 Gas inlet 22 Gas outlet 23 Valve room 24 Valve element 25 Valve stem 26 Drive part 29 Valve stem penetration part 30 Bellows 31 Bellows storage room 35 Inert gas introduction Department

Claims (4)

[Claims] 1. A valve device provided in an exhaust system of a heat treatment furnace, comprising: a valve chamber having a gas inlet and a gas outlet communicating with the exhaust system; and a valve provided in the valve chamber for opening and closing the gas inlet side. A valve body, a drive unit provided outside the valve chamber, for driving the valve body to open and close via a valve rod, and a valve body and a valve body interposed between the valve chamber and the valve chamber to seal a valve rod penetration portion of the valve chamber. And a bellows storage chamber provided in the valve chamber and storing the bellows when the valve element is opened. 2. The valve device according to claim 1, wherein the valve body has an airtight member that seals the bellows storage chamber when the valve is opened. 3. The valve device according to claim 1, further comprising an inert gas introduction section for introducing an inert gas into the bellows storage chamber. 4. A heat treatment apparatus having a valve device in an exhaust system of a heat treatment furnace, wherein the valve device is provided in a valve chamber having a gas inlet and a gas outlet communicating with the exhaust system. A valve body that opens and closes the gas inlet side, a driving unit that is provided outside the valve chamber and drives the valve body to open and close via a valve rod, and a valve chamber and a valve that seal a valve rod penetration part of the valve chamber. A heat treatment apparatus comprising: a bellows interposed between the bellows; and a bellows storage chamber provided in the valve chamber and storing the bellows when the valve body is opened.