JPH01258418A - Device for manufacturing semiconductor device - Google Patents

Abstract

PURPOSE:To completely prevent the engulfing of fine particles and the outside air from the outside of a reaction tube by a gas stream by a method wherein a doping system, with which a barrier by a gas stream is formed, is provided on the aperture edge of the reaction tube. CONSTITUTION:An external tube 12 is provided around a reaction tube 14 and an aperture part 19. The first reaction gas introducing hole 16 and the second reaction gas introducing hole 21 of the reaction tube 14 are connected to a doping system 17. The gap 13 between the reaction tube 14 and the external tube 12, forms a gas stream barrier around the aperture part 19 of the reaction tube 14. The engulfing of the outside fine particles and the outside air, which are going to be intruded into the reaction tube 4 from the circumferential part of the aperture 19, are prevented by the gas stream formed by the high pressure nitrogen gas stream.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a semiconductor device manufacturing apparatus, and particularly to a semiconductor substrate heat treatment apparatus.

[Conventional technology]

Generally, a horizontal furnace system or a vertical furnace system is used in heat treatment processes such as impurity diffusion in semiconductor substrates.

For example, in a horizontal furnace, loading is performed by inserting a jig supporting a semiconductor substrate into or pulling it out from the reaction tube. However, in the case of a large-diameter semiconductor substrate, the weight of the entire semiconductor substrate increases, and the generation of fine particles due to friction between the inner wall of the reaction tube and the jig may increase. It is also possible to insert and withdraw the jig using a cantilever so as not to rub it against the reaction tube.
The material for the cantilever is usually quartz, which is limited in terms of strength due to cost and contamination considerations.

Furthermore, since the temperature at the top of the reaction tube is higher than the temperature at the bottom of the reaction tube, when heat-treating a large diameter semiconductor substrate, the temperature distribution within the semiconductor substrate becomes uneven and crystal defects are likely to occur. There is.

On the other hand, in the case of a vertical furnace in which the jig supporting the semiconductor substrate is loaded vertically, there is no contact with the reaction tube at all.
In addition, since the semiconductor substrate is supported in the direction of gravity, the strength can be maintained even against the weight of the semiconductor substrate. Furthermore, since the flow of the reaction gas is vertical and the jig supporting the semiconductor substrate can be rotated, it is possible to maintain uniform heat distribution within the semiconductor substrate. Under these circumstances, as the diameter of semiconductor substrates becomes larger, the demand for vertical furnaces is increasing.

[Problem to be solved by the invention]

In the conventional reaction tube structure described above, when a semiconductor substrate is heat-treated, it is known that fine particles and outside air present inside the reaction tube have a significant effect on the quality and characteristics of the semiconductor device being manufactured.

For this reason, in a horizontal furnace, for example, as shown in FIG. 4(a), an outer cap 52 is attached to the opening of the horizontal reaction tube 51, or as shown in FIG. 4(b), the reaction tube 51 is A structure has been proposed in which an inner cap 53 is attached to the opening to prevent fine particles and outside air from entering the reaction tube from the outside. however,
As described above, it is difficult to suppress fine particles generated inside the reaction tube as semiconductor substrates are loaded.

On the other hand, for a vertical furnace with high demands, the furnace body 55 and reaction tube 57 are fixed on the upper side as shown in FIG. 5(a), and the semiconductor substrate
One method is to insert a jig 56 supporting semiconductor substrate 4 from the bottom to the top, and the other is a method in which a jig 56 supporting semiconductor substrate 54 is inserted with a furnace body 55 and a reaction tube 57 placed on the bottom side as shown in FIG. 5(b). 56 is suspended from above. However, although this vertical furnace can prevent the generation of fine particles inside the reaction tube,
Since it is difficult to close the opening of the reaction tube, there is a problem in that it is difficult to prevent fine particles and outside air from being drawn in from the outside.

In particular, in the case of the latter method, since the flow direction of the reaction gas is from the bottom to the top, the flow rate of the reaction gas becomes faster and outside air is more likely to be drawn in accordingly.

In addition, in the case of the former method, the flow direction of the reaction gas is from the top to the bottom, so the flow rate of the reaction gas is slowed down, making it less likely that outside air will be drawn in. However, outside air will still be drawn into the reaction tube. However, there is a problem that the deep part of the reaction tube gets caught up.

In order to prevent this entrainment of fine particles and outside air from the outside,
It is possible to install a cap like in the case of a horizontal furnace, but
There are many problems such as how to support the cap and the generation of fine particles due to friction between the cap and the reaction tube.

SUMMARY OF THE INVENTION An object of the present invention is to provide a semiconductor device manufacturing apparatus that can effectively prevent particulate matter and outside air from being drawn in from the outside.

[Differences between the invention and the prior art]

In contrast to the above-mentioned conventional heat treatment equipment for semiconductor substrates, which is equipped with a lid such as a cap to prevent particulates and outside air from being drawn in from the outside, the present invention uses high-pressure gas to surround the opening of the reaction tube. creates a gas flow barrier for
The difference is that this gas flow barrier is used to prevent particulate matter and outside air from being drawn in from the outside.

[Means to solve the problem]

In order to achieve the above object, the present invention provides a semiconductor device manufacturing apparatus equipped with a reaction tube for maintaining the interior at a predetermined gas atmosphere and temperature and for heat-treating a semiconductor substrate installed therein, in which an opening of the reaction tube is provided. It includes a doping system that forms a gas flow barrier at the edges.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

(Example 1) FIGS. 1 and 2 show a first embodiment of the semiconductor device manufacturing apparatus of the present invention, in which FIG. 1 is an overall vertical cross-sectional view, and FIG. FIG. 2 is a flowchart showing the case where the present invention is applied to a vertical furnace.

In Fig. 1, a reaction tube 1 made of quartz with a diameter of about 30all is shown.
4 surrounds this reaction tube 14 and its opening 19
an outer tube 1 made of quartz forming a gap 13 of about 5-
2 are arranged, and the first reaction gas introduction port 16 and the second reaction gas introduction port 21 of the reaction tube 14 are connected to a doping system 17.
It is connected to. 15 is a furnace body.

Next, the effect will be explained.

In FIGS. 1 and 2, semiconductor substrates 18, 18...
is mounted on the jig 20 and inserted into the opening 19 of the vertical reaction tube 14.
and installed inside it. In this state, the reaction gas such as nitrogen gas 24 flowing in the gap 13 between the reaction tube 14 and the external tube 12 is maintained at a high pressure, for example 3.0×10'Pa, and the gap 13 between the reaction tube 14 and the external tube 12 The flow of high pressure nitrogen gas 23 ejected from the reactor tube 14 forms a gas flow barrier 22 around the opening 19 of the reaction tube 14 . 24 indicates the nitrogen gas flowing inside the reaction tube 14, thus opening 1
The gas flow barrier 22 formed by the flow of high-pressure nitrogen gas 24 prevents the entrainment of external particulates and outside air that try to enter the reaction tube 14 from the peripheral edge of the reaction tube 9 .

(Example 2) FIG. 3 is a longitudinal sectional view of a second embodiment of the invention.

As in the first embodiment, an external tube 42 made of quartz is disposed around the reaction tube 43, surrounding the reaction tube 43 and forming a gap 46 around its open end. In this example,
At the opening 47, the reaction tube 43 and the external tube 42 are joined together at half regions in the circumferential direction to form the closed portion 41. As a result, the gap 46 formed between the reaction tube 43 and the external tube 42 is formed in an open state only in half of the reaction tube in the circumferential direction.

The reaction tube 43 having this configuration is installed in a horizontal furnace with the closed portion 41 facing upward. In the case of a horizontal furnace, as shown in FIG. 3, a reaction gas, for example nitrogen gas 45, flows through the reaction tube 43 from left to right in the drawing. Further, high pressure nitrogen gas 44 flowing within the gap 46, for example 3. OX 10'Pa also flows within the gap 46 from the left to the right as shown.

At this time, the flow direction of the high-pressure nitrogen gas 44 is changed by the closing part 41, and after flowing along the circumferential direction, it merges with the flow of the high-pressure nitrogen gas 44 flowing through the gap below the reaction tube 43, and then flows through the opening. 47 and forms a gas flow barrier 48.

Therefore, this gas flow barrier 48 can prevent particulates and outside air from entering from below the external tube 42 in the horizontal furnace.

Incidentally, in each of the above embodiments, the case where quartz was used as the material of the reaction tube was shown, but the present invention is not limited to these materials, and can be similarly applied to other materials.

〔Effect of the invention〕

As explained above, the present invention provides an external tube that is provided surrounding the reaction tube and forms an opening around the open end of the reaction tube together with the reaction tube, and a high-pressure reaction gas in the gap between the reaction tube and the external tube. By configuring a doping system that allows gas to flow and forms a gas flow barrier over the opening, the gas flow can reliably prevent particulates and outside air from being drawn in from outside the reaction tube during the heat treatment process for semiconductor substrates. In particular, even when the reaction tube is constructed as a vertical furnace, entrainment can be prevented, and there is an effect that it is possible to prevent the generation of fine particles and the like inside and to realize effective heat treatment.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view showing the first embodiment of the present invention, FIG. 2 is a cross-sectional view for explaining the operation of the first embodiment, and FIG. 3 is a cross-sectional view for explaining the second embodiment. Longitudinal cross-sectional view of Figure 4 (a
) and FIG. 4(b) are sectional views showing different conventional horizontal furnace systems, and FIGS. 5(a) and 5(b) are sectional views showing different conventional vertical furnace systems. 12.42...External tube 13.46...
Gap 14.43...Reaction tube 15...Furnace body 16...First reaction gas inlet 17...Doping system 18...Semiconductor substrate 19.
47... Opening 20... Jig 2
1...Second reaction gas inlet 22.48...Gas flow barrier 41...Closing part 44...High pressure nitrogen gas

Claims (1)

[Claims] (1) In a semiconductor device manufacturing apparatus equipped with a reaction tube for maintaining the interior at a predetermined gas atmosphere and temperature and for heat-treating the semiconductor substrate inside, a barrier is formed by a gas flow at the opening edge of the reaction tube. A semiconductor device manufacturing apparatus characterized by including a doping system.