JP3057738B2 - CVD equipment - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a CVD apparatus, and more particularly, to an exhaust system structure for preventing a reaction product generated during a chemical reaction by a gas in a reaction tube from being deposited on a cylindrical pipe. It is about.

[Conventional technology]

In a general CVD apparatus, a reaction tube 2 for chemically growing a film on a substrate 1 is used as shown in a front view in which a part of FIG.
And a gas supply source 3 installed to introduce gas into the reaction tube 2
And a heating source 4 installed to heat the substrate 1 and a cylindrical pipe 5 and a vacuum pump 6 installed to exhaust the gas in the reaction tube 2 to grow a film on the substrate 1 by a chemical reaction. I have. Gases that have not been chemically grown on the substrate 1 are deposited as reaction products in the reaction tube 2, and most of the remaining reaction products are discharged from the outlet of the reaction tube 2 and captured by the capture box 7. .

In practice, however, the reaction product is located in the cylindrical pipe 5 behind the reaction pipe 2.
Easily accumulates on the inner wall of the building. This is because the temperature of the cylindrical pipe 5 is lower than that of the inside of the reaction pipe 2 because the cylindrical pipe 5 is installed in a place exposed to the outside air. As a method for preventing the reaction product from adhering to the cylindrical pipe 5 in the conventional CVD apparatus, a device such as shortening the cylindrical pipe 5 as much as possible or making the heat of the heating source 4 easily transmitted so as not to lower the temperature of the cylindrical pipe 5 is adopted. I've been.

[Problems to be solved by the invention]

In the conventional CVD apparatus described above, even if measures are taken so as not to lower the temperature of the cylindrical pipe, the absolute temperature difference between the inside of the reaction pipe and the cylindrical pipe cannot be covered, and the deposition of reaction products on the inner surface of the cylindrical pipe has not been prevented. . Therefore, the diameter of the cylindrical pipe is gradually narrowed by the accumulated reaction products, which causes a decrease in the required amount of exhaust by the vacuum pump, and does not accumulate at the intended location where the products should be captured. Due to such factors, fragments of the reaction product were peeled off, passed through the trapping box, and further reached the vacuum pump, causing troubles such as causing pump overload.

In order to prevent this trouble from occurring, it is necessary to periodically remove the trapping box and the cylindrical pipe from the equipment and clean them. Therefore, the equipment must be stopped inevitably, and the equipment operation rate is reduced by spending cleaning time. That was causing a problem.

[Means for solving the problem]

The CVD apparatus of the present invention includes a reaction tube, an exhaust pipe and a vacuum pump installed to exhaust gas in the reaction tube, and a reaction product generated during a chemical reaction in the reaction tube in the exhaust pipe. With a trap box installed
In the apparatus, at least one cylindrical pipe between the trapping box and the reaction tube, one friction member arranged to friction the inner wall surface of the cylinder with the inner surface of the cylindrical pipe, and the friction member is connected to the cylindrical pipe. A drive motor arranged to rotate about a cylindrical central axis.

〔Example〕

Next, the present invention will be described with reference to the drawings. FIG. 1 is a front view of a first embodiment of the present invention with a partial cross section, FIG. 2 is an enlarged sectional view of a main part of the present invention, and FIG. 3 is a perspective view of a main part of the present invention. .

In this embodiment, as shown in FIG. 1, a reaction tube 2 for chemically growing a film on a substrate 1, a gas supply source 3 for introducing a gas into the reaction tube 2, and a substrate 1 for heating the substrate 1. A heating source 4, a cylindrical pipe 5 and a vacuum pump 6 installed to exhaust gas in the reaction tube 2, and the reaction pipe 2 after the cylindrical pipe 5.
In a CVD apparatus composed of a trapping box 7 installed to trap a reaction product generated during a chemical reaction in the inside, at least one cylindrical pipe 5 between the trapping box 7 and the reaction tube 2, and an inner surface of the cylindrical pipe 5 And at least one friction member 8 arranged to rub the inner wall surface of the cylindrical pipe 5 and a drive motor 9 arranged to rotate the friction member 8 about the cylindrical central axis of the cylindrical pipe 5. doing. The cylindrical pipe and the friction member 8 are formed of metal, and the friction member 8 is formed by combining rods as shown in FIG.

According to this configuration, the friction member 8 is driven by the driving motor 9.
By constantly rotating, the reaction products that are to be deposited on the inner wall of the cylindrical pipe 5 are scraped off and trapped in the catching box 7 at the next stage, so that the reaction products are not deposited in the cylindrical pipe 5. Therefore, there is no need to clean the inside of the cylindrical pipe 5,
It is possible to improve the operation rate of the apparatus and prevent trouble of the vacuum pump 6. In addition, since the friction member 8 and the drive motor 9 have a structure that can be removed from the cylindrical pipe 5, maintenance and the like can be easily performed.

FIG. 4 shows a second embodiment of the present invention and is a partially sectional front view. This embodiment is similar to the first embodiment except that a current monitoring box 10 is attached to a driving motor 9. According to the present embodiment, the current consumption of the drive motor 9 is constantly monitored. If the friction member 8 cannot rotate normally due to the reaction product, the current consumption increases. The system has the advantage of turning on the light 11 and notifying the operator of the inspection time.

〔The invention's effect〕

As described above, the present invention is configured such that the friction member is constantly rotated by the driving motor in the cylindrical pipe, so that the reaction product is prevented from accumulating in the cylindrical pipe, thereby cleaning the cylindrical pipe. , The operation rate of the apparatus can be improved and the trouble of the vacuum pump can be prevented.

[Brief description of the drawings]

FIG. 1 is a front view of a first embodiment of the present invention in which
FIG. 2 is an enlarged cross-sectional view of a main part of the present invention, FIG. 3 is a perspective view of the main part of the present invention, FIG. 4 is a front view of the second embodiment with a partial cross section, and FIG. FIG. 1 is a front view of a conventional CVD apparatus in which a cross section is taken. 1 ... substrate 2 ... reaction tube 3 ... gas supply source 4 ...
Heat source, 5: Cylindrical piping, 6: Vacuum pump, 7: Capture box, 8: Friction member, 9: Motor for driving, 10 ...
Current monitoring box, 11 ... warning light.

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int. Cl. ⁷ , DB name) H01L 21/205 H01L 21/31 H01L 21/365 C23C 16/00-16/56

Claims (1)

(57) [Claims] 1. A reaction tube, an exhaust pipe and a vacuum pump installed to exhaust gas in the reaction tube, and an exhaust pipe installed in the exhaust pipe to capture a reaction product generated during a chemical reaction in the reaction tube. In a CVD apparatus having a trapping box, at least one cylindrical pipe between the trapping box and the reaction tube, at least one friction member disposed to friction the inner wall surface of the cylinder at the inner surface of the cylindrical pipe, A drive motor arranged to rotate the friction member about a cylindrical central axis of the cylindrical pipe.
D equipment.