JPH11260745A - Substrate processing equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a substrate processing equipment such that even if the power applied to a heater is reduced at the cooling of substrates such as wafers, cooling speed can be set equal for cooling among all substrates. SOLUTION: A reaction pipe 10 is provided within a heater 30, a boat 12 is provided within the pipe 10 and a plurality of semiconductor wafers 5 can be mounted, while being laminated on the boat 12. An inner quartz sleeve 16 and an outer quarts sleeve 18 surrounding the lower portion of the pipe 10 are arranged between the heater 30 and the pipe 10. Cooling air introduced from a cooling port 60 does not come in direct contact with a lower portion such that it is surrounded by the sleeve 16, so that such a lower portion is prevented from being cooled excessively, and thus the cooling speed is decreased. As a result, even if the heater output at the lowermost zone 32 is reduced during cooling, all the wafers 5 can be cooled uniformly. Therefore, the power consumption is kept low, and the line of the heater 30 is also increased. Furthermore, the sleeve 18 prevents the cooling air from being blown directly onto the heating element wires, and thus the life of the heater 30 is prolonged.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a substrate processing apparatus, and more particularly to a so-called vertical semiconductor wafer processing apparatus for processing semiconductor wafers in a state in which a plurality of semiconductor wafers are stacked in a reaction tube and accommodated in a vertical direction. Things.

[0002]

2. Description of the Related Art In such a vertical semiconductor wafer processing apparatus 200, for example, as shown in FIG.
A reaction tube 10 is provided inside the reaction tube, a boat 12 is provided in the reaction tube 10, a plurality of semiconductor wafers 5 are stacked on the boat 12, and the semiconductor wafer 5 is heated and heated by the heater 30. Perform processing. After the processing is completed, the boat 12 on which the semiconductor wafer 5 is mounted is pulled out to the lower side of the reaction tube 10 as shown by a broken line in the figure. If the boat 12 is pulled out to the side, a rapid temperature difference occurs in the plane of the semiconductor wafer 5 and the worst case may occur. Therefore, cooling is first performed while the boat 12 is provided in the reaction tube 10.

A conventional quenching mechanism for performing cooling with the boat 12 provided in the reaction tube 10 has a heater 30 of a vertical type.
In this system, cooling air is introduced from a lower cooling port 66, an exhaust hole 52 is opened in the upper ceiling 50, and air is exhausted therefrom.

[0004] In this method, the temperature near the cooling port 66 cools first, and the temperature of the essential wafer region is hardly lowered. The heater 30 has four zones 32, 3 in the vertical direction.
4, 36, and 38, and these three zones
When cooling air is introduced from the cooling port 66 without turning on / off any of the heater powers of 2, 34, 36, and 38, as shown in FIG. The cooling speed of the zone 32 is the fastest, and the cooling speed decreases as the zone 32, 36, and 38 move upward. As a result, the cooling speed between the plurality of wafers 5 stacked on the boat 12 greatly differs depending on the mounting position. . After a predetermined time has elapsed from the start of cooling, for example, in the lowermost zone 32, the heater is turned on for a time 82 so that the temperature of the zone 32 is controlled to T2.

In order to make the characteristics of each wafer 5 the same, it is necessary to cool all the wafers 5 uniformly because of the thermal history of the wafers 5. Therefore, if all the wafers 5 are to be cooled within a certain temperature difference range, it is necessary to perform heating simultaneously in a region where the temperature is easily cooled to match the zone with the slowest cooling rate. FIG. 6 shows the temperature drop characteristics when the zones 32, 34, 36, and 38 are heated during cooling in order to cool all the wafers 5 within a certain temperature difference range. In zone 32 at the bottom, time 8
For 4 hours, the heater output had to be 100%. As described above, in the prior art, full-power heating is performed at the same time as cooling, so that power consumption is large, damage to the heating wire is also large, and the life is greatly affected.

[0006]

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a substrate processing apparatus capable of equalizing the cooling speed among all substrates even when the power applied to the heater during cooling of a substrate such as a wafer is suppressed. Is to do.

[0007]

According to the present invention, a reaction tube, substrate holding means capable of holding a plurality of substrates in the reaction tube in a stacked manner, and heating means provided outside the reaction tube are provided. And a cooling medium inflow port through which a cooling medium can flow between the reaction tube and the heating means from below the reaction tube, wherein the first processing unit surrounds a lower portion of the reaction tube.
Is provided between the reaction tube and the heating means,
The cooling medium flowing from the cooling medium inlet flows outside the first sleeve, and the cooling medium flowing from the cooling medium inlet flows into the lower portion of the reaction tube surrounded by the first sleeve. There is provided a substrate processing apparatus characterized in that direct contact does not occur.

In this way, the lower part of the reaction tube is prevented from being excessively cooled by the cooling medium, and as a result,
Even when the cooling medium is supplied from the cooling medium inflow port to cool the substrates and the electric power applied to the heating means is suppressed, the cooling speed can be equalized between all the substrates and cooling can be performed.

According to a second aspect of the present invention, the apparatus further comprises a second sleeve provided between the first sleeve and the heating means and provided below the reaction tube. Item 1. A substrate processing apparatus according to item 1 is provided.

With this configuration, it is possible to prevent the cooling medium flowing from the cooling medium inflow port from directly hitting the heating means, and it is possible to prevent the life of the heating means from being shortened by the cooling medium.

[0011]

Next, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic sectional view for explaining a semiconductor wafer processing apparatus according to one embodiment of the present invention. FIG. 2 and FIG. 3 are graphs for explaining the temperature drop characteristics in the semiconductor wafer processing apparatus according to one embodiment of the present invention.

As shown in FIG. 1, in a semiconductor wafer processing apparatus 100 according to an embodiment of the present invention, a heater 3 is provided.
0, a reaction tube 10 is provided, and a boat 12 is provided in the reaction tube 10. The boat 12 has a plurality of semiconductor wafers 5 stacked and mounted in a substantially vertical direction. The boat 12 is mounted on a cap 14 and is moved up and down by an elevator 70.

The heater 30 is of a vertical type and is composed of four zones 32, 34, 36, 38 in the vertical direction.
In each of the zones 32, 34, 36, and 38, a heating section 40 is provided so as to be controllable independently of each other. Each zone 32,
The temperatures of 34, 36, 38 are determined by thermocouples 42, 44, 46, 4
8, and controls the heat generating sections 40 of the respective zones 32, 34, 36, 38 using the respective output values.

The heating section 40 of the heater 30 and the reaction tube 10 are provided at a predetermined distance from each other, and a space 80 extending in the vertical direction is formed between them. The lower end of the space 80 below the reaction tube 10 is
It is 0. A cooling air line 62 communicates with the cooling port 60, and a suction valve 63 and an air blower 64 are inserted in the cooling air line 62. Heater 30
An exhaust hole 52 is provided in the ceiling portion 50 of the, and an exhaust line 54 communicates with the exhaust hole 52. Exhaust line 5
4 is an exhaust valve 53, a radiator 56, an exhaust valve 5
9 is inserted, and a fan 58 is inserted behind it.

An inner quartz sleeve 16 surrounding the lower portion of the reaction tube 10 is provided in a space 80 between the heating section 40 of the heater 30 and the reaction tube 10, and the inner quartz sleeve 16 and the heater 3
The outer quartz sleeve 18 is provided between the heating section 40 and the heating section 40. The upper end of the inner sleeve 16 is the cap 14
And extends above the lower end of the wafer 5 mounting portion of the boat 12. The upper part of the outer quartz sleeve 18 extends above the upper part of the inner quartz sleeve 16, and the upper end of the outer quartz sleeve is inclined inward, that is, toward the reaction tube 10.
The inner quartz sleeve 16 and the outer quartz sleeve 18 are made of transparent quartz.

First, a plurality of semiconductor wafers 5 are loaded on a boat 1
2, the boat 12 is provided in the reaction tube 10, and the semiconductor wafer 5 such as a film forming process is processed while being heated by the heater 30.

After the processing is completed, the semiconductor wafer 5 is cooled. To cool the semiconductor wafer 5, the suction valve 63 is opened by the blower 64, and the cooling air line 6 is opened.
Cooling air is introduced into the space 80 between the heat generating portion 40 of the heater 30 and the reaction tube 10 through the cooling port 60 through the cooling water 2.
The introduced cooling air flows upward in the space 80 and flows into the exhaust valve 53 and the exhaust line 54 through the exhaust hole 52 provided in the ceiling 50 of the heater 30, and thereafter, the radiator 56 and the exhaust valve 59. , And is exhausted via the fan 58.

In the present embodiment, the inner quartz sleeve 16 surrounding the lower part of the reaction tube 10 is
The upper end of the inner sleeve 16 extends above the cap 14 and extends above the lower end of the wafer 5 mounting portion of the boat 12. Therefore, the cooling air introduced from the cooling port 60 does not directly contact the lower part of the reaction tube 10 surrounded by the inner quartz sleeve 16, but flows upward from below on the outside of the inner quartz sleeve 16, Above 16, the reaction tube 10 comes into complete contact and flows upward.

The cooling air introduced from the cooling port 60 performs heat exchange on the surface of the reaction tube 10 to lower the temperature of the wafer atmosphere inside the reaction tube 10, but in the present embodiment, the cooling air is used. Since the lower portion of the reaction tube 10 having the highest cooling rate is surrounded by the inner quartz sleeve 16,
It is prevented from being excessively cooled by the cooling air, and the cooling rate is reduced accordingly. As a result, the difference between the cooling rate in the upper region of the reaction tube 10 and the cooling rate is reduced, so that even when the heater output in the lowermost zone 32 is suppressed during cooling, the entire semiconductor wafer 5 is cooled substantially uniformly. . As a result, power consumption is suppressed, damage to the heating wire is reduced, and its life is prolonged.

The inner quartz sleeve 16 and the heater 30
The outer quartz sleeve 18 is provided between the heating unit 40 and the heating unit 40. The upper portion of the outer quartz sleeve 18 extends above the upper portion of the inner quartz sleeve 16, and the upper end of the outer quartz sleeve faces inward, that is, the reaction tube 1.
It is inclined toward the 0 side. In this way, the outer quartz sleeve 18 can prevent the cooling air from directly hitting the strand, and as a result, a sharp temperature difference does not occur on the surface of the heating wire and the life is extended. . In addition, since the upper end of the outer quartz sleeve is inclined inward, that is, toward the reaction tube 10 side, the cooling air can be concentrated toward the reaction tube 10 which is a cooling object, so that the cooling air can be concentrated on a portion which has been difficult to cool. A cooling effect can also be expected, and as a result, each zone 32, 34, 3
The cooling rate between 6 and 38 becomes more uniform.

FIG. 2 is a diagram showing the temperature drop characteristic when cooling air is introduced from the cooling port 60 without turning on / off the heater power of the zones 32, 34, 36 and 38. It can be seen that the cooling rate of the lowermost zone 32 is smaller, and the difference in cooling rate between the zones is considerably smaller. After a predetermined time has elapsed from the start of cooling, for example, in the lowermost zone 32, the heater 30 is turned on for a time 86 so that the temperature of the zone 32 is controlled to T2.

Next, in order to cool all the semiconductor wafers 5 within a certain temperature difference range, heating is simultaneously performed in a region where cooling is easy, and the cooling speed is adjusted to a zone having the slowest cooling speed. FIG. 3 shows that each zone 32, 3, 3 is cooled to cool all the wafers 5 within a certain temperature difference range.
4 shows the temperature drop characteristics when heating is performed for 4, 36, and 38. Even in the lowermost zone 32, it was necessary to supply some power at the beginning, but it was not necessary to increase the heater output to 100% even during the time 88. Accordingly, power consumption is suppressed accordingly, damage to the heating wire is reduced, and the life is prolonged.

After the cooling process is completed as described above,
As shown by the broken line in the figure, the boat 12 on which the semiconductor wafer 5 is mounted is pulled out by the elevator 70 to the lower side of the reaction tube 12.

[0025]

According to the present invention, the lower portion of the reaction tube is prevented from being excessively cooled by the cooling medium.
Even when the cooling medium is supplied from the cooling medium inflow port to cool the substrates and the electric power applied to the heating means is suppressed, the cooling speed can be equalized between all the substrates and cooling can be performed. as a result,
Power consumption is suppressed, and the life of the heating means is prolonged. Further, since the sleeve of the present invention can be retrofitted as an attachment inside the heating means such as a heater, it can be used without having to replace a conventionally used quartz reaction tube or the like.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view illustrating a semiconductor wafer processing apparatus according to an embodiment of the present invention.

FIG. 2 is a graph for explaining temperature drop characteristics in the semiconductor wafer processing apparatus according to one embodiment of the present invention.

FIG. 3 is a graph for explaining temperature drop characteristics in the semiconductor wafer processing apparatus according to one embodiment of the present invention.

FIG. 4 is a schematic sectional view illustrating a conventional semiconductor wafer processing apparatus.

FIG. 5 is a graph for explaining a temperature drop characteristic in a conventional semiconductor wafer processing apparatus.

FIG. 6 is a graph for explaining a temperature drop characteristic in a conventional semiconductor wafer processing apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 5 ... Semiconductor wafer 10 ... Reaction tube 12 ... Boat 16 ... Inner quartz sleeve 18 ... Outer quartz sleeve 30 ... Heater 32, 34, 36, 38 ... Zone 40 ... Heating part 52 ... Exhaust holes 53, 59 ... Exhaust valve 54 ... Exhaust Line 56: Radiator 58: Fan 60, 66: Cooling port 62: Cooling air line 63: Suction valve 64: Ventilation blower 80: Space 100, 200: Semiconductor manufacturing equipment

Claims (2)

[Claims] 1. A reaction tube, substrate holding means capable of stacking and holding a plurality of substrates in the reaction tube, heating means provided outside the reaction tube, and a cooling medium disposed below the reaction tube. And a cooling medium inlet capable of flowing between the reaction tube and the heating means from the reaction tube, wherein a first sleeve surrounding a lower part of the reaction tube is provided between the reaction tube and the heating means. The reaction tube, wherein the cooling medium flowing from the cooling medium inlet flows outside the first sleeve, and the cooling medium flowing from the cooling medium inlet is surrounded by the first sleeve. A substrate processing apparatus wherein the lower portion is not directly contacted. 2. A substrate processing apparatus according to claim 1, further comprising a second sleeve provided between said first sleeve and said heating means and provided below said reaction tube. .