JP4070832B2 - Semiconductor manufacturing equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a semiconductor manufacturing apparatus having a reaction furnace, and more particularly to a semiconductor manufacturing apparatus with improved cooling characteristics.
[0002]
[Prior art]
One of the semiconductor manufacturing processes is a process such as diffusion of impurities into a silicon wafer, formation of a thin film by chemical vapor deposition, or annealing. These processes are performed by introducing a reaction gas in a state where a wafer is charged in a reaction furnace and maintained at a predetermined temperature.
[0003]
A conventional semiconductor manufacturing reactor will be described with reference to FIG.
[0004]
A cylindrical heater 1 whose upper end is closed is erected, and an external reaction tube 2 is disposed in the heater 1, and the external reaction tube 2 is erected by loosely fitting a base 5, and the external reaction tube An internal reaction tube 3 having an open upper end is concentrically provided in 2. The internal reaction tube 3 is loaded with a boat 4 loaded with a large number of wafers. The boat 4 is mounted on a furnace port lid 7 via a boat support base 6 and is not shown. It is lifted and lowered by an elevator. An intake pipe 8 communicates with the upper end portion of the heater 1, and a radiator 9 and a blower 10 are provided on the intake pipe 8 from the upstream side to constitute an exhaust heat system.
[0005]
The processing of the wafer is performed by evacuating the external reaction tube 2 from an exhaust pipe (not shown) while being heated to a predetermined temperature by the heater 1 and then introducing a reaction gas from a reaction gas supply pipe (not shown).
[0006]
In order to prevent unnecessary oxidation of the wafer, the heater 1, the external reaction tube 2, etc. are cooled to the required temperature, and then the boat 4 is pulled out, the wafer is transported, and the unprocessed wafer for the next batch is loaded. In the cooling, air was sucked from the space 11 between the heater 1 and the external reaction tube 2 by the blower 10, cooled by the radiator 9 and discharged.
[0007]
[Problems to be solved by the invention]
When the air is discharged from the space 11, the outside air suction port is a gap between the base 5 and the external reaction tube 2, and a heat insulating material 12 is wound around the base 5 through hole of the heater 1. For example, the suction port is narrow. Therefore, the pressure loss when sucked by the blower 10 is large, especially when the temperature is 400 ° C. or less, the amount of circulating air is not sufficient, the temperature decreasing rate is remarkably deteriorated, and the cooling time hinders the improvement of the throughput of the apparatus. There was a problem that.
[0008]
[Means for Solving the Problems]
In the present invention, a cylindrical heater whose upper end is closed is erected on a base via a heater pedestal of a ring-shaped heat insulating material, a reaction tube is disposed in the heater, and a space is provided between the heater and the reaction tube. A semiconductor manufacturing apparatus in which the reaction tube is erected through a base, a required number of blowing holes communicating with the space are provided in the heater base, and an exhaust heat system is communicated with an upper end portion of the space; A semiconductor manufacturing apparatus in which the inner diameter of the heater pedestal is smaller than the inner diameter of the heater, and the inner end side of the blowing hole faces upward, the reaction tube through hole and the reaction tube of the base are sealed with a heat insulating material, A semiconductor manufacturing apparatus with a heater pedestal as an inlay, a semiconductor manufacturing apparatus having a required number of fins on at least one of the outer and inner surfaces of the external reaction tube, and a required number on at least one of the outer and inner surfaces of the inner reaction tube Semiconductor manufacturing equipment with fins Are those relating to, Therefore, it is possible to increase the cooling rate, it can be shortened cooling time.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0010]
In FIG. 1, the same components as those shown in FIG.
[0011]
A cylindrical heater 1 whose upper end is closed is erected on a base 5 via a heater pedestal 14 made of a ring-shaped heat insulating material. An external reaction tube 2 is disposed in the heater 1, the external reaction tube 2 is erected through the base 5, and a penetration portion of the base 5 is sealed with a heat insulating material 12.
[0012]
The heater pedestal 14 has a smaller diameter than the inner diameter of the heater 1 and projects to the inside. The heater pedestal 14 has a required number of blow holes 15 formed therein, and the inner end of the blow holes 15 has a gas flow. And the inner end port 16 is formed on the upper surface of the inner overhanging portion of the heater pedestal 14 , that is, the upper surface on the outer reaction tube 2 side, and the inner end port 16 is formed between the heater 1 and the outer reaction tube 2. Open to the space 11.
[0013]
An internal reaction tube 3 having an open upper end is provided concentrically in the external reaction tube 2, and a boat 4 loaded with a large number of wafers is loaded in the internal reaction tube 3. The boat 4 is mounted on the furnace port lid 7 via the boat support 6 and is raised and lowered by a boat elevator (not shown). An intake pipe 8 communicates with the upper end portion of the heater 1, and a radiator 9 and a blower 10 are provided on the intake pipe 8 from the upstream side to constitute an exhaust heat system.
[0014]
When cooling is performed, a cooling medium such as air is blown from the blowing hole 15, and the atmospheric gas in the space 11 is sucked and discharged by the blower 10. The blowing hole 15 has an opening area sufficient to blow a sufficient amount of the cooling medium, and the cooling medium is actively blown from the blowing hole 15 so that the flow rate of the cooling medium flowing in the space 11 is increased. Sufficiently secured. In addition, since the blowing hole 15 is formed and a sufficient opening area is ensured, even if the cooling medium is not blown positively from the blowing hole 15, the temperature drop characteristic can be sufficiently improved by suction by the blower 10. It can be seen.
[0015]
As described above, since the inner end portion of the blowing hole 15 is directed upward, the pressure loss in the blowing hole 15 can be reduced, and the leakage of the cooling medium from the gap between the heat insulating material 12 and the external reaction tube 2 can be reduced. Can be reduced.
[0016]
FIG. 2 shows another embodiment, in which the slope of the inner end portion of the blow hole 15 is curved to further smooth the flow of the cooling medium, The heater pedestal 14 and the heat insulating material 12 are made into an inlay method, and leakage of the cooling medium from the gap between the heater pedestal 14 and the heat insulating material 12 is suppressed.
[0017]
Next, an embodiment in which the heat dissipation effect in the furnace is enhanced will be described with reference to FIGS.
[0018]
A plurality of fins (12 in this embodiment) are fixed to the outer surface of the external reaction tube 2 at a required pitch along the circumference along the generatrix direction. By fixing the fins 17, the heat radiation area of the external reaction tube 2 is increased, and the heat radiation characteristics are improved.
[0019]
5 and 6 show an example in which fins 18 are provided in the internal reaction tube 3. A plurality of fins 18 extending along the generatrix direction are provided on the outer surface of the internal reaction tube 3 at a required pitch along the circumference. A sheet (12 sheets in this embodiment) is fixed. Also in this embodiment, the heat dissipation area of the internal reaction tube 3 is increased, and the heat dissipation characteristics are improved. The fins may be provided on the inner surfaces of the outer reaction tube 2 and the inner reaction tube 3, or may be provided on both the outer surface and the inner surface.
[0020]
A comparison between the temperature drop characteristics in the present embodiment and the conventional temperature drop characteristics when the fins 17 are provided in the external reaction tube 2 will be described with reference to FIG. In the present embodiment, the measured temperature drop characteristic is indicated by A, the average temperature drop characteristic is indicated by A ′, the conventional measured temperature drop characteristic is indicated by B, and the average temperature drop characteristic is indicated by B ′.
[0021]
Comparing the time taken to drop from 400 ° C. to 100 ° C. in the actual measurement values, it can be seen that the present embodiment and the conventional example are significantly shortened to about 4000 sec and the conventional example to about 5100 sec. The average temperature drop rate is 4.65 ° C./min in the present embodiment and 3.58 ° C./min in the conventional example.
[0022]
【The invention's effect】
As described above, according to the present invention, the temperature lowering rate can be increased and the cooling time can be shortened, so that the excellent effect of improving the throughput of the semiconductor manufacturing apparatus is exhibited.
[Brief description of the drawings]
FIG. 1 is an elevational cross-sectional view showing a part of an embodiment of the present invention.
FIG. 2 is a partial cross-sectional view showing another embodiment.
FIG. 3 is a cross-sectional view showing an example of an external reaction tube used in the present embodiment.
FIG. 4 is a plan view of the same.
FIG. 5 is a cross-sectional view showing an example of an internal reaction tube used in the present embodiment.
FIG. 6 is a plan view of the same.
FIG. 7 is a graph showing temperature drop characteristics of the present embodiment and a conventional example.
FIG. 8 is a vertical sectional view of a conventional example.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Heater 2 External reaction pipe 3 Internal reaction pipe 5 Base 8 Intake pipe 9 Radiator 10 Blower 14 Heater base 15 Blow-in hole 16 Inner end port 17 Fin 18 Fin

Claims (1)

  A reaction tube, a cylindrical heater containing the reaction tube and closed at the upper end, a base having a through hole through which the reaction tube passes, and a gap between the through hole of the base and the reaction tube are sealed The heater is a semiconductor manufacturing apparatus in which the heater is erected on the base via a heater pedestal, and a gas as a cooling medium flows between the reaction tube and the heater. The heater pedestal is provided with a flow path that is open to an outer wall surface of the heater pedestal, and is formed between an opening of the outer wall surface and an inner end opening that is open to an upper surface of the heater pedestal on the reaction tube side, The end of the flow channel on the side of the reaction tube is formed so that the gas flowing in from the opening of the outer wall face upward from the inner end, and the heater base engages with the heat insulating material in an inlay manner The semiconductor manufacturing apparatus characterized by the above-mentioned.

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