JPH11211383A - Heat exchange structure - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To improve the heating efficiency by uniformly heating pipes and reducing the amount of heat radiation to the outside. In a heat exchange structure in which a heater (12) for heating the pipe is wound around the outer circumference of a pipe (7) and a heat insulating material (15) is wound around the outer circumference of the heater, a space between the pipe and the heater is provided. A coating material 21 having a heat diffusion function is interposed, and heat generated by the heater is transmitted to the coating material,
The coating material has a uniform temperature and heats the pipes evenly.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat exchange structure between a pipe heater and a pipe, and in particular, to prevent solidification of a reaction by-product contained in exhaust gas generated in a semiconductor manufacturing process. The present invention relates to a heat exchange structure between a pipe heater wound around an exhaust pipe and an exhaust pipe.

[0002]

2. Description of the Related Art Exhaust gas generated in the process of forming a Si ₃ N ₄ film on a substrate to be processed such as a wafer contains NH ₄ Cl as a reaction by-product. Since NH ₄ Cl has a high solidification temperature and becomes solid at room temperature, it is easily solidified in an exhaust pipe, and the solidified NH ₄ Cl may flow back into the reaction chamber. The NH ₄ Cl that has flowed back floats as particles in the reaction chamber, adheres to the substrate to be processed, and may contaminate the substrate to be processed, which causes a reduction in product quality and yield.

Therefore, the exhaust pipe is conventionally heated to prevent the reaction by-products in the exhaust gas from solidifying.

Referring to FIGS. 2 and 3, a semiconductor manufacturing apparatus having a conventional heat exchange structure will be described.

A tubular external reaction tube 1 having an upper end closed and an open lower end is provided inside a heater (not shown). Inside the outer reaction tube 1, an internal reaction tube 2 having an open upper end is provided. Are arranged concentrically with the external reaction tube 1. The lower ends of the outer reaction tube 1 and the inner reaction tube 2 are supported by a furnace port flange 3, the space between the outer reaction tube 1 and the furnace port flange 3 is sealed by an O-ring 4, and the reaction chamber 5 is formed by the inner reaction tube 2. Is defined.

The opening at the lower end of the furnace port flange 3 is hermetically closed by a seal cap 6. The seal cap 6 is raised and lowered by a boat elevator (not shown),
The lower end opening of the furnace port flange 3 is closed. A boat (not shown) is provided upright on the seal cap 6, and wafers to be processed are loaded in multiple stages in a horizontal posture. A reaction gas introduction pipe (not shown) is connected to a lower portion of the furnace port flange 3 so as to communicate with the inside of the internal reaction pipe 2.

The main exhaust pipe 7 is made of stainless steel and is connected to the furnace port flange 3 so as to communicate with the lower end of a cylindrical space 8 formed between the external reaction tube 1 and the internal reaction tube 2. I have. The main exhaust pipe 7 is provided with a main exhaust valve 9, and a sub exhaust pipe 10 made of stainless steel is connected to the main exhaust pipe 7 so as to extend between the upstream side of the main exhaust valve 9 and the downstream side of the main exhaust valve 9. The sub exhaust pipe 10 is provided with a sub exhaust valve 11.

The outer periphery of the main exhaust pipe 7 from the connection of the main exhaust pipe 7 to the furnace port flange 3 to the main exhaust valve 9 and the outer periphery of the sub exhaust pipe 10 from the sub exhaust valve 11 A planar heater 12 is wound.

The heater 12 has a configuration in which a large number of heating wires 13, for example, nickel alloy resistance wires, which are wired in parallel at a predetermined pitch, are sandwiched between two flexible and thin insulating sheets 14, for example, silicon rubber. The heater 12 is attached to the main exhaust pipe 7 and the sub exhaust pipe 10 with an adhesive.

Further, a heat insulating material 15 having a required thickness is further wound around the outer periphery of the heater 12.

The boat (not shown) is connected to the boat elevator (not shown) via the seal cap 6 by the boat elevator (not shown).
And the boat is loaded with wafers. After loading, the boat is loaded into the internal reaction tube 2 by the boat elevator. After completely sealing the lower end of the furnace port flange 3 with the seal cap 6, the main exhaust valve 9
Is closed, the auxiliary exhaust valve 11 is opened, and the inside of the reaction chamber 5 is gently exhausted through the auxiliary exhaust pipe 10.
When the pressure in the reaction chamber 5 drops to a required pressure, the sub exhaust valve 1
1 is closed and the main exhaust valve 9 is opened. The inside of the reaction chamber 5 is evacuated via the main exhaust pipe 7, the inside of the reaction chamber 5 is evacuated, and the heater (not shown) is always energized to heat the inside of the reaction chamber 5.

When the pressure is reduced to a predetermined pressure, a predetermined process such as introducing a reaction gas to form a film on the wafer surface is performed.
The exhaust gas containing the reaction by-product after the reaction is exhausted through the main exhaust pipe 7.

When the heating wire 13 is energized, the heating wire 13 generates heat and heats the main exhaust pipe 7 and the sub-exhaust pipe 10 via an adhesive layer. The exhaust gas is supplied with heat through the tube wall of the exhaust gas. By this heat supply, the exhaust gas is maintained at a temperature equal to or higher than the solidification temperature of the reaction by-product.

When the treatment is completed, the introduction of the reaction gas is stopped, an inert gas such as nitrogen gas is introduced into the reaction chamber 5, the gas is purged, and the inside of the reaction chamber 5 is returned to normal pressure. Thereafter, the seal cap 6 is opened, and the boat (not shown) is pulled out by the boat elevator (not shown).

[0015]

In the above-mentioned conventional heat exchange structure, the heating wires 13 of the heater 12 are wired in parallel at a predetermined pitch, and the heating wires 13 are further connected to the main exhaust pipe 7 and the sub exhaust pipe. It is almost directly attached to 10. Therefore, the mode of heating the main exhaust pipe 7 and the sub-exhaust pipe 10 by the heating wire 13 is not surface heating, but line heating.
A non-heating zone is generated between the heating pipe 13 and the heating line 13 and the main exhaust pipe 7
It is difficult to uniformly heat the auxiliary exhaust pipe 10, and the internal pipe temperature does not partially rise to the solidification temperature of the reaction by-product,
There was a possibility that the reaction by-product was solidified.

Further, it is extremely difficult to adhere the entire surface of the heater 12 to the outer surfaces of the main exhaust pipe 7 and the sub exhaust pipe 10 by closely contacting the entire surface thereof, and it is difficult to avoid mixing of air into the bonded portion. . Further, the construction is more difficult at the bent portion 16 and the branch portion 17, and a gap is easily generated between the heater 12 and the main exhaust pipe 7 or the sub exhaust pipe 10. The gap significantly reduces heat transfer characteristics between the heater 12 and the main exhaust pipe 7 and the sub exhaust pipe 10. Therefore, the amount of heat transferred from the heater 12 to the main exhaust pipe 7 or the sub exhaust pipe 10 is reduced,
The main exhaust pipe 7 or the sub-exhaust pipe 10 is difficult to heat, and the amount of heat radiation to the outside increases, so that there is a possibility that the heating efficiency cannot be improved.

Further, in order to reduce the amount of heat radiated to the outside, it is necessary to increase the thickness of the heat insulating material 15, and there is a problem that the cost cannot be reduced.

In view of the above circumstances, the present invention aims to improve the heating efficiency by uniformly heating the main exhaust pipe 7 and the sub-exhaust pipe 10 and reducing the amount of heat radiation to the outside.

[0019]

The present invention provides a heat exchange structure in which a heater for heating the pipe is wound around the outer circumference of the pipe, and a heat insulating material is wound around the outer circumference of the heater. The present invention relates to a heat exchange structure in which a coating material having a heat diffusion function is interposed between a heater and a heat exchange structure in which the coating material has good thermal conductivity, and further, the coating material has elasticity. According to the heat exchange structure, heat generated by the heater is transmitted to the coating material, so that the coating material has a uniform temperature and uniformly heats the piping. Further, the thermal resistance between the heater and the pipe is reduced, the amount of heat transferred from the heater to the pipe is increased, and the amount of heat radiation to the outside is reduced.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG. In FIG. 1, the same components as those shown in FIGS. 2 and 3 are denoted by the same reference numerals, and description thereof is omitted.

The outer peripheral surface of the main exhaust pipe 7 is coated with a coating material 21 having a heat diffusion function and a good thermal conductivity and elasticity, for example, a black material such as titania or nickel oxide. I have.

The heater 12 is wound around the outer periphery of the coating material 21 in close contact therewith, and the heater 12 is attached to the coating material 21 with an adhesive.

A heat insulating material 15 having a required thickness is wound around the outer periphery of the heater 12.

The operation will be described below.

When the heater 12 is energized, the heating wire 13
The coating material 21 is heated by the heat generated by the heating wire 13, and the heat generated from the heating wire 13 reaches the main exhaust pipe 7 and the sub exhaust pipe 10 via the coating material 21. The coating material 21 has a heat diffusion function, so that the temperature of the coating material 21 is equalized in the process of transmitting the heat through the coating material 21, and at a boundary surface between the coating material 21 and the main exhaust pipe 7 and the sub exhaust pipe 10. Are equalized.
Thus, the heater 12, the main exhaust pipe 7, and the sub exhaust pipe 1
0, the main exhaust pipe 7 and the sub exhaust pipe 10 can be uniformly heated by interposing the coating material 21 therebetween.

Further, since the coating material 21 has good conductivity, the overall thermal resistance between the heater 12 and the main exhaust pipe 7 and the sub exhaust pipe 10 is reduced. Therefore, the amount of heat generated from the heating wire 13 is more effectively transmitted to the main exhaust pipe 7 and the sub exhaust pipe 10, and the amount of heat radiation to the outside can be reduced.

In the above embodiment, the heater 12 is adhered to the outer periphery of the coating material 21 via an adhesive, but the coating material 21 has elasticity and no adhesive. However, since the heater can be in close contact, the adhesive need not be applied.

In the above-described embodiment, the exhaust pipe of the semiconductor manufacturing apparatus has been described. However, in order to prevent freezing in a cold region, a heater is wound around an outdoor exposed pipe, for example. Needless to say, this is feasible.

[0029]

As described above, according to the present invention, since heating is performed with a coating material having a heat diffusion function interposed therebetween, the pipe can be heated uniformly, and the temperature in the pipe can be kept uniform. It becomes possible.

Further, since heating is performed with a coating material having good thermal conductivity interposed therebetween, the thermal resistance between the heater and the pipe can be reduced, and the time required for raising the temperature in the pipe to a required temperature can be reduced. Becomes

Further, since the coating material has elasticity and the heater easily adheres, the workability can be improved. Also, since the gap between the pipe and the heater can be reduced and the thermal resistance can be reduced by the interposition of the coating material, the amount of heat transfer from the heater to the pipe can be increased, and the amount of heat radiation to the outside can be reduced. The heating efficiency of the heater can be improved.

Further, the thickness of the heat insulating material can be reduced by reducing the amount of heat radiation to the outside, and the energy consumption can be reduced by improving the heating efficiency of the heater, so that various advantages such as cost reduction can be achieved. It has the effect.

[Brief description of the drawings]

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

FIG. 2 is a sectional view showing a conventional example.

FIG. 3 is a schematic explanatory view showing an exhaust piping device of the semiconductor manufacturing apparatus.

[Explanation of symbols]

 7 Main exhaust pipe 12 Heater 13 Heating wire 14 Insulation sheet 15 Insulation material 21 Coating material

Claims (1)

[Claims] In a heat exchange structure in which a heater for heating the pipe is wound around the outer circumference of the pipe and a heat insulating material is wound around the outer circumference of the heater, a heat diffusion function is provided between the pipe and the heater. A heat exchange structure, comprising a coating material having: