JP2001023991A - Heat treatment unit for semiconductor substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten time required for gas replacement and to produce an uniform gas atmosphere by making the substrate treatment space adjustable, according to the number of substrates for improving the diffusion accuracy and for reducing the amount of gas used. SOLUTION: In a quartz tube 2, a movable blocking board 12 with a diameter, which is slightly smaller than the inside diameter of the quartz tube 2, is placed so that a required clearance which passes a gas is formed between the quartz tube 2 and blocking board 12. The blocking board 12 can be moved so as to adjust the substrate treatment space in the tube, according to the number of semiconductor substrate to be subjected to heat treatment.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor substrate heat treatment apparatus for heat treatment of an aluminum sinter or the like in an inert atmosphere such as nitrogen gas.

[0002]

2. Description of the Related Art A schematic configuration of a conventional semiconductor substrate heat treatment apparatus will be described with reference to FIG. In the figure, reference numeral 1 denotes the entire semiconductor substrate heat treatment apparatus. The processing apparatus 1 has a quartz tube 2, one end of which is converged to form a gas inlet 3. The other end of the quartz tube 2 is closed by a cap 5 having a gas outlet 4.

When heat treatment of an aluminum sinter or the like is performed by the above-described apparatus, the cap 5 of the quartz tube 2 is removed, and the semiconductor substrate 6 is inserted into the quartz tube 2. That is, the semiconductor substrate 6 is laid in parallel on the quartz boat 7 at a predetermined interval, and dummy wafers 8 are erected on both ends thereof. It is stored in the heating section 9.

The dimension (L) of the heat equalizing section 9 is 60 to
Assuming 100 cm, the overall length of the quartz tube is generally 200 cm
Reach

Although not shown, a heating element is arranged on the outer periphery of the quartz tube 2, and the heating element heats the semiconductor substrate 6 in the quartz tube 2 to a predetermined temperature so that the semiconductor substrate 6 is made of aluminum in a predetermined gas atmosphere. This is a procedure in which heat treatment such as sintering is performed.

The inner diameter (D3) of the quartz tube 2 is 12 cm.
Then, the internal volume (V) of the soaking section 9 is V = π (D3)
↑ 2/4 × L = about 22,608 cm ↑ 3. Also,
When the semiconductor substrate 6 is placed on the quartz boat 7 and inserted into the quartz tube 2 and subjected to heat treatment, the semiconductor substrate 6 at any position must be treated under the same gas atmosphere condition.
It is necessary to replace the gas immediately.

Next, a description will be given of a conventional work procedure when the semiconductor substrate 6 is heat-treated. It is assumed that the semiconductor substrate 6 of the heat equalizing section 9 has been subjected to another heat treatment in manufacturing the semiconductor device. At this time, the heat equalizing section 9 has already been replaced by, for example, nitrogen gas flowing from the gas inlet 3.

Next, a cap 5 at the other end of the quartz tube 2
Is removed, and the semiconductor substrate 6 is taken out to the outside together with the quartz boat 7 using an apparatus (not shown). At this time, air flows into the quartz tube 2 from the other end of the quartz tube 2.

Next, the quartz boat 7 on which another semiconductor substrate 6 to be subjected to the heat treatment is mounted is inserted up to the heat equalizing section 9 using the above-mentioned apparatus, and then the cap 5 is closed.

Next, nitrogen gas is supplied from the gas inlet 3 until the air flowing into the quartz tube 2 is completely replaced with nitrogen gas. After the replacement with the nitrogen gas, a predetermined gas is flowed and the semiconductor substrate 6 is subjected to a heat treatment such as an aluminum sinter.

[0011]

Since the heat treatment of a semiconductor substrate using a conventional semiconductor substrate heat treatment apparatus is performed as described above, there are the following problems to be solved. (1) When the cap 5 of the quartz tube 2 is opened and the boat 7 for mounting the semiconductor substrate is inserted into the quartz tube 2, the outside air flows back into the quartz tube 2. Therefore, it takes a long time after the cap 5 of the quartz tube 2 is closed until the inside of the quartz tube 2 is replaced with an inert gas. (2) The above gas replacement time is determined by the internal volume of the heat equalizing section 9 irrespective of the number of processed semiconductor substrates 6, and when the internal volume becomes large, the replacement takes a long time. Therefore, it was necessary to flow a large amount of gas.

[0012]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and has a variable substrate processing space in accordance with the number of processed semiconductor substrates, thereby shortening a gas replacement time.
It is another object of the present invention to provide a semiconductor substrate heat treatment apparatus in which a uniform gas atmosphere is formed, diffusion accuracy is improved, and the amount of gas used is reduced.

[0013]

According to a first aspect of the present invention, an inert gas flows in from a gas inlet at one end of a pipe and flows out from a gas outlet at the other end of the pipe. In the tube, a semiconductor substrate heat treatment apparatus for performing a predetermined heat treatment by inserting a semiconductor substrate mounted on a board, in the gas inlet side from the position of the semiconductor substrate inserted into the tube, At one end of the tube, a shielding plate having a diameter slightly smaller than the inner diameter of the tube is arranged to form a substrate processing space in the tube, and the processing space is provided between the tube and the shielding plate. A gap that becomes a flow path of the inert gas is formed.

According to a second aspect of the present invention, the shielding plate can be moved in the longitudinal direction of the tube in the tube, and the substrate processing space can be changed according to the number of heat treatments of the semiconductor substrate. Is what you do.

A third invention is characterized in that the tube is formed of a quartz tube.

According to a fourth aspect of the present invention, the gap serving as a flow path of the inert gas to the substrate processing space is provided between the processing space defined by the shielding plate and the front chamber when the semiconductor substrate to be heat-treated is taken in and out. It is a gap that satisfies the condition that the outside air does not flow backward.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. FIG. 2 is a sectional view taken along line AA of FIG. The same components as those of the conventional semiconductor substrate heat treatment apparatus are denoted by the same reference numerals. The present invention is characterized in that the shielding plate 12 supported by the shielding plate support member 13 is provided inside the quartz tube 1 so as to be movable in the longitudinal direction of the quartz tube 1.

Another feature of the present invention is that a predetermined gap d is formed between the inside of the quartz tube 1 and the outside of the shielding plate 12. The total area e of the gaps formed over the entire circumference is determined by the gap d. The total area e of the entire circumference formed by the gap d is 70 cm ↑ 2 when the gas flow rate is 2 liters / minute, and 140 cm ↑ 2 and 8 liters / minute when the gas flow rate is 4 liters / minute. At that time, it was found that the gas was replaced at 280 cm @ 2. Further, a plurality of portions of the shielding plate 12 have a diameter of 1 to
A through hole 14 of about 2 mm may be provided with a predetermined gap.

Next, a heat treatment procedure for the semiconductor substrate 6 using the semiconductor substrate heat treatment apparatus 1 having the above-described configuration will be described. The semiconductor substrate 6 on the quartz boat 7 in FIG.
It is assumed that other heat treatments have already been completed. Also,
It is assumed that gas is flowing from the gas inlet 3 at one end of the quartz tube 2 and the inside of the front chamber 14 and the substrate processing space 10 is replaced with an inert gas, for example, nitrogen gas.

First, the cap 5 of the quartz tube 2 is removed,
The quartz boat 7 on which the semiconductor substrate 6 stands is pulled out. At this time, the outside air flows into the substrate processing space 10. However, the nitrogen gas in the anterior chamber 14 flows from the gap d of the shielding plate 12 (see FIG.
0, the backflow of outside air to the front chamber 14 is prevented.

Next, a quartz boat 7 on which a semiconductor substrate 6 to be heat-treated such as an aluminum sinter is mounted is inserted into the substrate processing space 10 by using a predetermined device. Next, the cap 5 is closed and the inside of the substrate processing space 10 is replaced with nitrogen gas. If the number of semiconductor substrates 6 inserted into the quartz tube 2 is small, the length of the quartz boat 7 on which the substrates 6 are placed can be shortened.
The illustrated shielding plate 12 moves to the right in the illustration to reduce the internal volume of the substrate processing space 10.

That is, by making the processing space 10 smaller, the replacement time with nitrogen gas can be further reduced. Here, a comparison is made with a case where a quartz tube 2 having the same length and diameter as the conventional one is used. In this embodiment, the position of the shielding plate 12 is the left end position of the conventional heat equalizing section 9 (FIG. 3).
), The internal volume of the substrate processing space 10 is about / of the conventional one, that is, 15,000 cm ↑.
It will be about 3. Therefore, the gas replacement time is also reduced by reducing the internal volume, which is about 2/3 of the conventional value of about 40 minutes.
In addition, since there is no backflow of the outside air to the front chamber 14 due to the presence of the shielding plate 12, a uniform gas atmosphere can be created in the substrate processing space 10, and the diffusion accuracy at the time of the heat treatment can be improved.

In the above embodiment, a quartz tube is used as the tube. However, the tube is not limited to the quartz tube but may be any tube that can be widely used for heat treatment.

[0024]

As described above, according to the present invention, the processing space in the tube can be changed by the shield plate, so that the processing space can be set according to the number of heat treatments of the semiconductor substrate. Furthermore, there are excellent effects such as shortening the gas replacement time, creating a uniform gas atmosphere, improving the accuracy of diffusion, and reducing the amount of gas used.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a schematic configuration of a semiconductor substrate heat treatment apparatus of the present invention.

FIG. 2 is a cross-sectional view taken along the line AA of FIG.

FIG. 3 is a longitudinal sectional view showing a schematic configuration of a conventional semiconductor substrate heat treatment apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Semiconductor substrate heat processing apparatus 2 Quartz tube 3 Gas inlet 4 Gas outlet 5 Cap 6 Semiconductor substrate 7 Quartz boat 8 Dummy wafer 10 Substrate processing space 12 Shielding plate 13 Shielding plate support member 14 Through hole d Gap

Claims (4)

[Claims] 1. A boat is mounted in a pipe into which an inert gas flows from a gas inlet at one end of the pipe and an inert gas flows out from a gas outlet at the other end of the pipe. A semiconductor substrate heat treatment apparatus that performs a predetermined heat treatment by inserting the semiconductor substrate into the gas inflow port side from the position of the semiconductor substrate inserted into the pipe, to one end side of the pipe, A shield plate having a diameter slightly smaller than the inner diameter of the tube is arranged to form a substrate processing space in the tube, and a gap between the tube and the shield plate serving as a flow path of an inert gas to the processing space. A semiconductor substrate heat treatment apparatus comprising: 2. The semiconductor device according to claim 1, wherein said shielding plate is movable in a longitudinal direction of said tube in said tube, and said substrate processing space can be changed according to the number of heat-treated semiconductor substrates. 3. The semiconductor substrate heat treatment apparatus according to item 1. 3. The semiconductor substrate heat treatment apparatus according to claim 1, wherein said tube is made of a quartz tube. 4. A gap, which serves as a flow path of an inert gas to and from the substrate processing space, prevents external air from flowing back into the front chamber from the processing space defined by the shielding plate when the semiconductor substrate to be heat-treated is taken in and out. The semiconductor substrate heat treatment apparatus according to claim 1, wherein the gap satisfies a condition.