JPH11102872A - Reaction furnace - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reaction furnace with which the durability of an O-ring can be improved and the airtightness of its reaction chamber can be maintained easily. SOLUTION: A flange 3 of a reaction tube 1 is provided airtightly on an introducing part 5 through an O-ring, the flange part 3 is pinched by a gas inlet part 5 and a reaction tube pressing flange 11, and the reaction tube pressing flange 11 is energized by an elastic body 17 to the direction of the gas inlet part 5. The reaction tube pressing flange 11 is always fixed close to the flange part 3 by the repulsive force of the elastic body 17, the thermal resistivity between both of them is decreased, the greater part of the heat transmitted to the flange part from the heated cylindrical body is conducted to the reaction tube pressing flange 11, the heat is also radiated to outside, and the quantity of heat transferred to the O-ring is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reactor for a semiconductor manufacturing apparatus for performing various processes such as diffusion and chemical vapor deposition on a substrate to be processed.

[0002]

2. Description of the Related Art A series of processing steps of a semiconductor manufacturing apparatus for forming various thin films on a substrate to be processed such as a wafer or a glass substrate or performing etching or the like to form a large number of semiconductor elements on the surface of the substrate to be processed. One of them is a step of heating in a reaction furnace.

[0003] Such heating may be performed under reduced pressure or normal pressure in the reaction chamber of the reaction furnace. In any case, the reaction chamber must be kept airtight. Are usually hermetically joined via an O-ring.

However, since the O-ring has a problem in heat resistance,
Considering the means for cooling the O-ring in the reactor,
It prevents deterioration and burning of the ring due to heat.

Referring to FIGS. 4 and 5, a description will be given of a conventional semiconductor manufacturing apparatus, particularly a reactor in a single-wafer semiconductor manufacturing apparatus.

In FIG. 1, reference numeral 1 denotes a reaction tube made of quartz. The reaction tube 1 comprises a flat rectangular tubular body 2 and flange portions 3 formed at both ends of the tubular body 2. A gas inlet 5 is hermetically provided in the flange 3 with an O-ring 4 interposed therebetween to define a reaction chamber 6.

A reaction tube holding flange 7 made of a material having a high thermal conductivity is fixed to the gas introduction portion 5 by a required number of bolts 8. The flange portion 3 is formed by the gas introduction portion 5 and the reaction tube holding flange 7. It is pinched.

Hereinafter, a case in which the inside of the reaction chamber 6 is processed under reduced pressure will be described.

One or more wafers (not shown) are loaded into the reaction chamber 6 by a wafer transfer device (not shown) provided outside.

After the inside of the reaction chamber 6 is evacuated, a reaction gas is introduced into the reaction chamber 6 by the gas introduction unit 5. The reaction chamber 6 is heated via the tubular body 2 by a heating device (not shown) provided around the reaction tube 1,
A film forming process is performed on the wafer (not shown) in the reaction chamber 6.

[0011]

In the conventional reactor described above, when the inside of the reaction chamber 6 is processed under normal pressure,
The tightening of the bolts causes the flange portion 3 and the reaction tube holding flange 7 to come into close contact with each other, thereby reducing the thermal resistance between them. However, when the inside of the reaction chamber 6 is treated under reduced pressure, the outside and the inside Due to the pressure difference, the gas introduction section 5 and the flange section 3 are displaced in the approaching direction, and the surface pressure between the flange section 3 and the reaction tube holding flange 7 is reduced, or the flange section 3 and the reaction tube holding flange are reduced. 7, the thermal resistance between the two increases, and the O-ring 4 is crushed, so that the contact area between the O-ring 4 and the flange 3 increases, and the thermal resistance between the two increases. Become smaller. Therefore, when the inside of the reaction chamber 6 is at normal pressure, much of the heat conducted from the heated cylindrical body 2 to the flange portion 3 moves to the reaction tube holding flange 7 and the heat of the O-ring 4 Although the deterioration can be prevented, when the pressure in the reaction chamber 6 is reduced, the amount of heat transfer from the heated cylindrical body 2 to the reaction tube holding flange 7 via the flange portion 3 is reduced, There is a problem that the amount of heat transmitted to the O-ring 4 increases, and the O-ring 4 is likely to be thermally deteriorated.

Further, the reaction tube holding flange 7 is fixed to the gas introduction portion 5 with the bolt 8, and the flange portion 3 is provided in the gas introduction portion 5 in an airtight manner to maintain the airtightness of the reaction chamber. It is necessary to strictly control the tightening torque of the bolt 8, and it is not easy to maintain the airtightness of the reaction chamber.

The present invention has been made in view of the above circumstances, and has as its object to provide a reactor capable of improving the durability of an O-ring and easily maintaining the airtightness of a reaction chamber.

[0014]

According to the present invention, a flange portion of a reaction tube is hermetically provided at a gas introduction portion via an O-ring, and the flange portion is held between the gas introduction portion and a reaction tube holding flange. The reaction tube holding flange is related to a reaction furnace in which the flange is urged in the direction of the gas introduction portion by an elastic body, and the reaction tube holding flange is always in close contact with the flange portion due to the repulsive force of the elastic body. The thermal resistance is reduced, and most of the heat conducted from the heated cylinder to the flange portion is conducted to the reaction tube holding flange, radiating heat to the outside and reducing the amount of heat transmitted to the O-ring.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 1 to 3, FIG.
5 are denoted by the same reference numerals, and description thereof is omitted.

A gas inlet 5 is provided in the flange 3 of the reaction tube 1 with an O-ring 4 interposed therebetween in an airtight manner, and a reaction chamber 6 is defined.

An annular reaction tube holding flange 11 made of a material having a high thermal conductivity, for example, an aluminum alloy, is fixed to the gas introducing portion 5 with a required number of bolts 8. The flange portion 3 is connected to the gas introducing portion 5. It is held by the reaction tube holding flange 11.

The reaction tube holding flange 11 has an outer peripheral portion 12.
And an inner peripheral portion 13 having a thickness smaller than that of the outer peripheral portion 12. The inner peripheral portion 13 is in close contact with the flange portion 3.

A borehole 14 is formed in the outer peripheral portion 12, and the bolt 8 passes through the bottom of the borehole 14.
A spring 17 is fitted between the bottom of the counterbore 14 and the head 16 of the bolt 8 in a compressed state.
7, the reaction tube holding flange 11 is urged in the direction of the gas introduction section 5.

The inside of the inner peripheral portion 13 extends over the entire circumference,
A cooling water passage 18 is formed in an annular shape, and a cooling water supply pipe and a cooling water discharge pipe (not shown) are connected to the cooling water path 18 so that the cooling water can circulate in the cooling water path 18.

The operation will be described below.

One or a plurality of wafers (not shown) are loaded into the reaction chamber 6, and the flange portion 3 crushes the O-ring 4 by the repulsive force of the spring 17,
The initial crushing amount of the O-ring 4 is secured, and the inside of the reaction chamber 6 is kept airtight. After the inside of the reaction chamber 6 is evacuated,
A reaction gas is introduced from the gas introduction unit 5.

Due to the pressure difference between the outside and the inside of the reaction chamber 6, the gas introduction part 5 moves in the direction of approach to the flange part 3, the O-ring 4 is crushed, and the reaction chamber 6 is kept airtight. Dripping. Due to the repulsive force of the spring 17, the initial crushing amount of the O-ring 4 is ensured, and the inner peripheral portion 13 of the reaction tube holding flange 11 comes into close contact with the flange portion 3.

Cooling water is supplied into the cooling water passage 18 from the cooling water supply pipe (not shown), and the reaction chamber 6 is heated via the cylindrical body 2 by a heating device (not shown). A film forming process is performed on the wafer (not shown) in 6.

The heat conducted from the heated cylinder 2 to the flange 3 is conducted to the inner peripheral portion 13 and to the O-ring 4.

Since the inner peripheral portion 13 has a larger contact area with the flange portion 3 than the O-ring 4, the thermal resistance is small. Further, the inner peripheral portion 13 is cooled by the cooling water in the cooling water passage 18, and the inner peripheral portion 13 and the flange portion 3 are cooled.
Is larger than the temperature difference between the O-ring 4 and the flange 3. Therefore, the heat transfer coefficient between the flange portion 3 and the inner peripheral portion 13 is larger than the heat transfer coefficient between the flange portion 3 and the O-ring 4, and most of the heat is transmitted to the inner peripheral portion 13. The heat is radiated to the outside from the surface of the inner peripheral portion 13, and the cooling water is removed from the flange 3, so that the amount of heat transferred to the O-ring 4 is reduced.

In the above embodiment, the flange portion 3 and the inner peripheral portion 13 are in close contact with each other, but as shown in FIG. Alternatively, a flexible member having high thermal conductivity, such as a silicone rubber 19 for heat radiation, may be interposed. In this case, the adhesion ratio between the flange portion 3 and the inner peripheral portion 13 increases, and the contact thermal resistance can be further reduced.
3 increases, and the amount of heat transfer to the O-ring 4 decreases.

In the above-described embodiment, the spring 17 is provided in the counterbore 14.
May be omitted, and the spring 17 may be exposed outside the reaction tube holding flange 11. Further, instead of the spring 17, another elastic body such as synthetic rubber may be provided. Further, the reaction tube holding flange 11 is made of an aluminum alloy, but may be made of another material having high thermal conductivity such as copper or a copper alloy.

[0029]

As described above, according to the present invention, the contact between the flange portion and the reaction tube holding flange is always maintained by the repulsive force of the elastic body regardless of the pressure state in the reaction chamber,
The thermal resistance between the two becomes small, most of the heat transferred from the heated cylinder to the flange portion is transferred to the reaction tube holding flange, and the amount of heat transferred to the O-ring is reduced. Deterioration can be prevented, durability of the O-ring can be improved, and safety can be improved.

Further, the airtightness between the flange portion and the gas introduction portion can be maintained by the repulsive force of the elastic body without strict control of the bolt tightening torque, so that the airtightness of the reaction chamber can be maintained. It exhibits various excellent effects such as being easy.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a state where a reaction chamber is evacuated in the embodiment.

FIG. 3 is a cross-sectional view showing a state where a heat-dissipating silicone rubber is sandwiched between a flange portion and an inner peripheral portion in the embodiment.

FIG. 4 is a sectional view showing a conventional example.

FIG. 5 is a cross-sectional view showing a state where a reaction chamber is evacuated in a conventional example.

[Explanation of symbols]

 3 Flange part 4 O-ring 8 Bolt 11 Reaction tube holding flange 14 Counterboring hole 17 Spring

Claims (1)

[Claims] A flange portion of a reaction tube is hermetically provided at a gas introduction portion with an O-ring interposed therebetween, and the flange portion is held between the gas introduction portion and a reaction tube holding flange, and the reaction tube holding flange is elastic. A reaction furnace characterized by being urged by a body in the direction of the gas inlet.