JPS59151434A - Vapor growth device - Google Patents

Abstract

PURPOSE:To prevent generation of an undesirable oxide film on the surface of a substrate when a vapor-growth method is performed by a method wherein, when a plurality of semiconductor substrates are provided in upright position leaving intervals between them on the heating jig which constitutes a vapor growth device, a cap is inserted between said semiconductor substrates in grouped form, and also a cooling region is provided at the end point of insertion of a processing tube wherein a jig will be inserted. CONSTITUTION:When a plurality of semiconductor substrates are provided in upright position leaving intervals on a heating jig 1, the substrates are divided into groups of 4, 4' and 4'' and the like, and caps 3, 3' and 3'' having approximately 80% of the cross- sectional area of a processing tube 6 are inserted between said groups. Also, heating device 5 is provided on the outer circumference of the processing tube 6 ranging approximately one half of its length, and the gas coming from a gas feeding device 9 is sent into the tube 6 located on the side of the heating device 5 through the intermediary of a piping 8 and a coupling 7. Also, a cooling region 6' is provided at the extended part of the tube 6, and a jig 1 goes in or out from the side using a draw-out rod 2. Thus, when the jig goes in or out, it passes through the cooling region 6' without fail, thereby enabling to prevent the generation of useless oxide film on the substrate.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vapor phase growth apparatus. In a conventional vapor phase growth apparatus, a semiconductor substrate is inserted into a heating apparatus, a cap is placed on the inlet of the heating apparatus, and a desired gas is introduced. , heat treatment is carried out for a predetermined period of time.O Hereinafter, a conventional vapor phase growth apparatus will be represented by an atmospheric pressure vapor phase growth apparatus using nitrogen gas as a carrier gas. explain.

Referring to FIG. 1, semiconductor substrates 4° 4' to be heated are arranged on a heat processing jig l having a cap 3 at the end (
Fig. 1 (1)'), the heat treatment jig 1 is inserted into the treatment pipe 6 installed in the heating device 5 using a pull rod 2, and connected by a hand 7 and piping 8. gas supply device 9
A desired gas is introduced into the processing tube 6 and heat treatment is performed for a predetermined period of time (Figure 1 (b)). By being accommodated in the processing tube at this point, it serves as a cap.゛However, when the semiconductor substrate processed in the above-mentioned conventional atmospheric pressure vapor phase growth apparatus is inserted into or taken out of the processing tube placed in the heating device, atmospheric oxygen is released near the entrance of the processing tube. Therefore, even though the semiconductor substrate is heat-treated with nitrogen gas, which is an inert gas and serves as a carrier gas, the semiconductor substrate and oxygen react with each other, resulting in unwanted oxides being deposited on the surface of the semiconductor substrate. formed.

This has the drawback of causing an unfavorable situation in the manufacture of semiconductor devices.

Conventionally, the method used to compensate for this drawback is to rapidly heat or cool the space between the inside of the heating device and the room temperature, that is, to modify the semiconductor substrate.
1c, t□ya15. □. 1. A method was used to maintain the mold heating temperature. According to this conventional method, the semiconductor substrate is rapidly cooled or heated to room temperature or a desired heating temperature.
This method attempts to reduce the formation of undesired oxides by taking advantage of the shorter reaction time with oxygen in the atmosphere. However, when this conventional method is adopted, rapid temperature changes cause damage to the semiconductor substrate. 9. Stress is added. There are situations where semiconductor substrates warp and crack.

This warpage is a fatal flaw in manufacturing semiconductor devices, and a decrease in yield and quality is unavoidable.

Since the warpage of 90% is amplified, it is also a difficult problem to overcome in the manufacturing of semiconductor devices.

SUMMARY OF THE INVENTION An object of the present invention is to provide a vapor phase growth system that does not cause warpage or cracking of a semiconductor substrate and does not cause undesired oxides to be formed on the surface of a semiconductor substrate.

According to the present invention, there is provided a heating device capable of heating the entire heat treatment jig to a uniform temperature, and a cooling area outside the heating device having a length equal to or longer than the distance between the caps on the heat treatment jig, Further, a processing tube installed in the entire interior area of the heating device, a pull-out rod for inserting and extracting the heat treatment jig into a desired position in the processing tube, a gas supply device for supplying a desired gas into the processing tube, and the processing tube. A vapor phase growth apparatus is obtained which includes multi-stage caps having a cross-sectional area equivalent to 80% or more of the inner diameter cross-sectional area and a heat treatment jig for placing a semiconductor substrate to be heated between the caps.

Embodiments of the present invention will be described in detail below with reference to FIG.

Referring to FIG. 2, three stages of caps 3.3', 3'' are arranged on the heat treatment jig 1, and semiconductor substrates to be heated 4.4', 4'' are placed between the caps. (Fig. 2(a)) o Pull out the heat treatment jig 1 in this state and use the rod 2 to insert the treatment tube 6 installed in the heating device.
I put it in and take it out to 173.

At this time, the 71st stage cap 3 installed in the cooling zone 6' on the extension of the processing tube 6 is not exposed to the end of the cooling zone 6', that is, the conventional normal pressure ≧ where oxygen in the atmosphere exists.
Even in the same condition as in the vapor phase growth apparatus, the semiconductor substrate 4t to be heated is still located in the cooling zone 6', so even though there is oxygen in the atmosphere, the semiconductor substrate 4'' and the oxygen No reaction occurs with the caps, and undesired oxides are not formed on the surface of the semiconductor substrate.The length of the cooling zone must be longer than the distance between the caps placed on the heat treatment jig. When the heat treatment jig is further inserted into the processing tube, the first stage cap 3i fits into the processing tube 6 and functions as a cap, retaining the nitrogen gas introduced into the processing tube 61C. 9. The influence of oxygen in the atmosphere is completely blocked.

Thereafter, the second stage cap 3' plays the same role as 3'' as described above, and in the inserted state, the third stage cap 3 plays the same role as 3'' as described above.

10,000, also when pulling out the heat treatment jig l from the treatment tube 6,
Exactly the same situation as during insertion occurs, but due to the role of the caps 3.3', 3'' and the cooling zone 6', which are similar to those during insertion, no unwanted oxides are formed on the semiconductor surface.

The size of the cap, that is, the cross-sectional area, depends on the inner diameter cross-sectional area of the processing tube, but it has been found that it is effective if it is 80% or more of the inner diameter cross-sectional area of the processing tube, and prevents unwanted oxides from forming on the semiconductor surface. It never happens.

6- Table Iff shows the effects of the present invention, and shows the phosphoric acid film, which is an oxide, measured after introducing nitrogen gas into the processing tube at 850'C, inserting a silicon substrate, which is a semiconductor substrate, and processing for 30 minutes. The results of measuring the thickness using an ellipsometer are shown by comparing and contrasting a conventional atmospheric pressure vapor phase growth apparatus and an uninvented atmospheric pressure vapor phase growth apparatus.

Note that the values measured with the ellipsometer are those with 15 A added as a background, and the silicon substrate used is boron dot 10.8 to 1.0 X.
10 (cm) (D).

As can be seen from Table 1, it can be seen that the present invention does not cause the formation of undesired oxides.

The present invention has been described above using a typical atmospheric pressure vapor phase growth apparatus using nitrogen gas as a carrier gas. Equipment that must not be used, namely, polycrystalline silicon formation vapor phase growth equipment that mainly uses silane gas to form polycrystalline silicon films, and nitride formation vapor phase growth equipment that mainly uses 7 run gas and ammonia gas to form nitrides. growth equipment.

It is widely used in molybdenum formation vapor phase epitaxy equipment that uses MoCl3 etc. as the main gas to form molybdenum films, and tungsten formation vapor phase growth equipment I that uses W(2a etc. as the main gas) to form tungsten films. In addition, although the number of stages of caps on the heat treatment jig 1 was limited to three stages, by increasing the length of the processing tube 6 and the temperature uniform area of the heating device, even the caps can be expanded. If a large number of caps can be arranged, it is possible to create a vapor phase growth apparatus having three or more stages of caps.

Furthermore, it is obvious that a reduced pressure type vapor phase growth apparatus VC can also be applied to the present invention.

[Brief explanation of drawings]

8- FIG. 1 is a schematic diagram and a cross-sectional model diagram showing a conventional atmospheric pressure vapor phase growth apparatus, and FIG. 2 is a schematic diagram and a cross-sectional model diagram showing an embodiment of the present invention. In Figure 1, a 1μ heat treatment jig, 2 a pull-out rod,
3.3', 3" caps 4, 41, 41/ are semiconductor substrates, 5 is a heating device, 6rX processing tube, 6' is a cooling area, 7 is a joint, 8 is a pipe, and 9 is a gas supply device. 9-2/Figure 1'

Claims (1)

[Claims] A heating device capable of heating the entire heat treatment jig to a uniform temperature;
A cooling area having a length longer than the distance between the caps on the heat treatment jig is provided outside the heating device. Further, a processing tube installed in the entire interior area of the heating device, a pull-out rod for inserting and removing the heat treatment jig into and out of the processing tube at a desired position in the BVC, a gas supply device for supplying a desired gas into the processing tube, and the processing Vapor phase growth characterized by comprising: a heat treatment jig for arranging multistage caps having a cross-sectional area equivalent to 80% or more of the cross-sectional area of the inner diameter of the tube, and for arranging all the semiconductor substrates to be heated between the caps; Device.