JPH09106957A - Reaction furnace for semiconductor manufacture use - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the generation of a crack in the reaction tube of a reaction furnace for semiconductor manufacturing due to the cooling of the fixed end of the reaction tube or to eliminate the effect to the state that the interior of the furnace is heated due to the cooling of the fixed end in the case where the fixed end is cooled. SOLUTION: A buffer strip 26 is formed on the part, which is continued to a fixed end 13, which is cooled, of a reaction tube 2, of the tube 2 to reduce the thermal gradient of the tube 2, which is generated by the cooling of the end 13, to prevent the generation of a crack in the tube 2 due to the cooling of the end 13 and to prevent the effect of the cooling from the end 13 from being exerted greatly on parts other than the part which is continued to the end 13.

Description

Detailed Description of the Invention

[0001]

The present invention relates to a semiconductor manufacturing apparatus.
The present invention relates to a semiconductor manufacturing reactor.

[0002]

2. Description of the Related Art An outline of a semiconductor manufacturing reactor will be described with reference to FIG.

A reaction tube flange 1 is provided on a base (not shown), and a quartz reaction tube 2 is provided on the upper end of the reaction tube flange 1.
And an inner reaction tube 3 made of quartz and concentric with the reaction tube 2.
Are supported near the lower end of the reaction tube flange 1.
A furnace port cover 4 provided in a boat elevator (not shown) can hermetically seal the lower end of the reaction tube flange 1, and a boat 6 is erected on the furnace port cover 4 via a boat cap 5.

A gas port 9 and a gas port 10 are provided at the upper and lower portions of the reaction tube flange 1, respectively, and the gas port 9 communicates with a cylindrical space 11 formed by the reaction tube 2 and the internal reaction tube 3. , The gas port 10 is an internal reaction tube 3
The reaction gas is introduced from the gas port 10 and discharged from the gas port 9 while communicating with the inside of the gas.

A heater base 7 is provided above the reaction tube flange 1, and the reaction tube 2 is provided with the heater base 7.
Penetrates through and extends upward. A cylindrical heater unit 8 concentric with the reaction tube 2 and covering the reaction tube 2 is erected on the heater base 7.

Wafers (not shown) are horizontally loaded into the boat 6 in multiple stages, the wafers are loaded into the reaction tube 2, reaction gas is supplied from a gas port 9, and the heater unit 8 is further provided. The heat treatment of the wafer is performed by heating the wafer in the furnace.

Further, the details of the furnace opening of the conventional reaction furnace for semiconductor manufacturing will be described with reference to FIG.

A flange 12 is provided at the upper end of the reaction tube flange 1, and a lower end flange 13 of the reaction tube 2 is fixed to the flange 12 by a reaction tube pressing ring 14. An O-ring 15 and a heat-resistant synthetic resin, for example, a buffer material 16 such as a fluorine resin are interposed between the flange 12 and the lower end flange 13, and a heat-resistant synthetic resin is provided between the lower end flange 13 and the reaction tube holding ring 14. A cushioning material 17 such as a fluororesin is interposed.

The flange 12 has a cooling water passage 18,
A cooling water passage 19 is formed in the reaction tube pressing ring 14, and the cooling water passage 18 and the cooling water passage 1 are formed.
By circulating cooling water through 9, the O-ring 15, the cushioning material 16, and the cushioning material 17 are cooled to prevent seizure.
In the figure, 20 is a heater unit base block.

[0010]

The heat resistant temperature of the O-ring 15, the cushioning material 16, and the cushioning material 17 is about 290 ° C.,
The O-ring 15, the cushioning material 16, and the cushioning material 17 are cooled to about 150 ° C. by circulating the cooling water through the cooling water passage 18 and the cooling water passage 19. On the other hand, the temperature in the furnace is 1000 ° C. or higher. For example, when a wafer is processed at a furnace temperature of 1200 ° C., the temperature of the furnace opening, that is, the lower end of the reaction tube 2 is about 900 ° C. Accordingly, the temperature difference between the lower end flange 13 cooled through the flange 12 and the reaction tube holding ring 14 and the lower end portion of the reaction tube 2 connected to the lower end flange 13 is 600 ° C. or more, and the reaction with the lower end flange 13 occurs. Large stress is generated at the joint with the lower end of the tube 2 and cracks occur. Therefore, when the material of the reaction tube 2 is SiC, which is a material that can withstand high temperatures, SiC has a higher thermal conductivity than quartz, and a large thermal stress is generated in the lower end flange 13, which also causes cracks, or There was a problem that the cooling effect was reached up to the soaking zone in the furnace and the temperature at the lower part of the furnace mouth could not rise to a predetermined temperature.

In view of the above situation, the present invention is intended to eliminate the occurrence of cracks due to cooling or the influence on the heating state in the furnace when the lower end flange which is the fixed end of the reaction tube is cooled. is there.

[0012]

According to the present invention, a buffer zone is formed in a portion continuous with a fixed end of a reaction tube to be cooled, and a heat medium for cooling the fixed end of the reaction tube is a liquid. A heat-insulating space is formed around a portion continuous to the end, a heat medium for gas is circulated in the heat-insulating space, and the heat medium for cooling the fixed end of the reaction tube is water, and the heat medium is circulated in the heat-insulating space. Is an inert gas.

A buffer zone is formed in a portion continuous to the fixed end of the reaction tube to reduce the thermal gradient generated by cooling the fixed end, prevent the generation of cracks due to cooling, and influence the cooling from the fixed end. Make sure that it doesn't extend much to the part.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, the same parts as those shown in FIG. 3 are designated by the same reference numerals and the description thereof will be omitted.

The lower part of the heater unit base block 21 on which the heater unit 8 is mounted on the center side is removed, and a space 22 is formed around the outer periphery of the lower end of the reaction tube 2. A cover ring 23 having an inverted L-shaped cross section that covers the lower end of the reaction tube 2 in the space 22.
The lower end of the cover ring 23 is brought into airtight contact with the reaction tube pressing ring 14, and the inner peripheral end is brought into airtight contact with the reaction tube 2. The cover ring 23 is a heat insulating material, and a heat insulating material 25 is interposed between the upper surface of the cover ring 23 and the heater unit base block. A ring-shaped heat insulating space 24 is formed by the reaction tube 2, the cover ring 23, and the reaction tube pressing ring 14.

A gas, preferably an inert gas such as nitrogen gas, argon gas or helium gas, is filled and circulated in the heat insulating space 24 as a heat medium. Cooling water is circulated through the cooling water passage 18 and the cooling water passage 19 to cool the lower end flange 13. The heat insulation space 24 of the reaction tube 2
The heat insulating space 24 and the cover ring 23 suppress the radiation of heat by radiant heat, convection, etc., and the cooling of the lower end flange 13 is suppressed from moving upward in the reaction tube 2. The material of the cover ring 23 is a heat insulating material, and the cover ring 23 and the space 22 are
Since the heat insulating material 25 is further interposed between and, heat conduction through the cover ring 23 itself is also suppressed.

Therefore, heat transfer and heat dissipation at the lower end of the reaction tube 2 covered with the cover ring 23 is suppressed, and the lower end serves as a heat transfer buffer zone 26. Therefore, even if the lower end flange 13 is cooled, a large thermal gradient is prevented from occurring in the vicinity of the boundary between the lower end flange 13 and the lower end of the reaction tube 2. By forming the buffer zone 26, the conventional temperature difference of 600 ° C. or more can be reduced to about 400 ° C. Further, the thermal stress that causes the crack has a correlation with the temperature gradient, and the reduction of the temperature gradient reduces the generation of thermal stress and prevents the generation of cracks.

Further, an inert gas supply source is connected to the heat insulating space 24 via a heat exchanger (not shown) and a temperature controller to heat or cool the inert gas circulating in the heat insulating space 24. The temperature gradient can be further reduced by controlling the temperature.

The cooling water passage 18 and the cooling water passage 19
It goes without saying that the cooling medium for circulating the liquid may be a fluid other than water. Further, it is needless to say that the present invention can be applied to a horizontal reactor.

As described above, since the buffer zone 26 is provided to suppress the heat transfer, the reaction tube 2 can be made of a material having a high heat conductivity but a high heat resistance, such as SiC.

[0022]

As described above, according to the present invention, since the thermal buffer zone is formed in the vicinity of the cooling portion, the temperature gradient can be reduced, the generation of cracks due to thermal stress can be prevented, and the material having high heat resistance can be used. Since it can be used, the durability of the parts is increased, the process from low temperature to high temperature can be continuously performed at one time, and various excellent effects such as improvement of the mobility and throughput of the device can be achieved. .

[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 of a semiconductor manufacturing reaction furnace.

FIG. 3 is a sectional view showing a conventional example.

[Explanation of symbols]

 1 Reaction Tube Flange 2 Reaction Tube 3 Internal Reaction Tube 13 Lower End Flange 14 Reaction Tube Holding Ring 15 O-ring 16 Buffer Material 18 Cooling Water Flow Channel 19 Cooling Water Flow Channel 21 Heater Unit Block 22 Space 23 Cover Ring 24 Thermal Insulation Space 25 Insulation Material 26 Buffer zone

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Internal reference number FI Technical indication location H01L 21/324 H01L 21/324 D (72) Inventor Yoshihide Endo 3-14, Higashi-Nakano, Nakano-ku, Tokyo No. 20 Kokusai Electric Co., Ltd. (72) Inventor Mitsuhiko Dozono 4-533 Kitahama, Chuo-ku, Osaka-shi, Osaka Prefecture Sumitomo Metal Industries, Ltd. (72) Kiyoshi Hasegawa 4-chome, Kitahama, Chuo-ku, Osaka-shi, Osaka 5-33 Sumitomo Metal Industries, Ltd. (72) Inventor Yoshio Murashita 4-53-3 Kitahama, Chuo-ku, Osaka City, Osaka Prefecture Sumitomo Metal Industries, Ltd.

Claims (3)

[Claims] 1. A reaction furnace for semiconductor manufacturing, wherein a buffer zone is formed in a portion continuous with a fixed end of a reaction tube to be cooled. 2. The heat medium for cooling the fixed end of the reaction tube is a liquid, a heat insulating space is formed around a portion continuous with the fixed end of the reaction tube, and a gas heat medium is circulated in the heat insulating space. Reactor for semiconductor manufacturing. 3. The reaction furnace for semiconductor production according to claim 2, wherein the heat medium for cooling the fixed end of the reaction tube is water, and the heat medium to be circulated in the heat insulating space is an inert gas.