JPH01259174A - Method for preventing adhesion of unnecessary grown film in cvd device - Google Patents

Abstract

PURPOSE:To prevent the adhesion of an unnecessary film grown by CVD to the inner wall of a reaction chamber by keeping the temp. of the wall of the chamber higher than the reaction temp. of a reactive gas in the chamber. CONSTITUTION:The reaction chamber (opaque quartz tube) 1 of a CVD device is heated with a heater 7 placed around the chamber 1 to keep the temp. of the wall of the chamber 1 higher than the reaction temp. of the reactive gas. CVD is then carried out in the CVD device while preventing the formation of the film grown by CVD on the wall of the chamber 1.

Description

[Detailed Description of the Invention] [Summary] Regarding a method for preventing the formation of an unnecessary grown film that adheres to the chamber wall of a CVD apparatus, the present invention relates to a method for preventing the formation of an unnecessary grown film that adheres to the chamber wall of a CVD apparatus. With the aim of providing a method for preventing the deposition of unnecessary grown films in a CVD apparatus that can prevent the formation of CVD grown films, the temperature of the chamber wall of the reaction chamber of the CVD apparatus is maintained at a higher temperature than the reaction temperature of the reaction gas. Configure the CVD apparatus to operate in this state.

[Industrial application field]

The present invention relates to a CVD apparatus, and more particularly to a method for preventing the formation of an unnecessary grown film adhering to a chamber wall of a CVD apparatus.

CVD equipment is used in the CVD film formation process in the manufacturing process of semiconductor devices, but normally there is almost no difference between the temperature inside the reaction chamber of the CVD equipment and the temperature of the chamber wall of the reaction chamber, and they are almost the same. It is maintained at a temperature of –.

Therefore, a semiconductor substrate is placed in the reaction chamber, and C
When a VD-grown film is formed, the CVD-grown film is also formed on the wall of the reaction chamber at approximately the same temperature as the CVD-grown film, and if this film peels off later, it becomes a source of dust in the subsequent CVD process.

Therefore, after the CVD film has been grown multiple times, the operation of the CVD apparatus must be stopped in order to remove the CVD growth pattern that has grown and adhered to the reaction chamber wall by dry etching or wet chemical etching. Therefore, this is one of the causes of a decrease in the operating rate of the CV I-'g station.

Under the above circumstances, there is a need for a method for preventing the formation of CVD grown films on the walls of the reaction chamber, which prevents the deposition of unnecessary grown films on CVR)W.

[Conventional technology]

The general structure of the conventional CVD equipment commonly used is shown in Section 5.
This will be explained using figures.

As shown in FIG. 5, the conventional CVD apparatus uses a transparent quartz tube 11 as a reaction chamber, and end camps are provided at both ends of the tube to seal the transparent quartz tube 11.

The end camp 12 on the reaction gas introduction side is provided with a reaction gas inlet 12a, and the end camp 13 on the reaction gas exhaust side is provided with a reaction gas exhaust port 13a, for introducing and exhausting the reaction gas.

A semiconductor substrate 14 is placed inside such a transparent quartz tube 11, and the semiconductor substrate 14 is maintained at the reaction temperature of the reaction gas by a heater 15 disposed around the transparent quartz tube 11, and CVD is applied to the surface of the semiconductor substrate 14. An M film is formed.

[Problem to be solved by the invention]

In the conventional CVT device described above, there is almost no difference between the temperature inside the transparent quartz tube, which is the reaction chamber of the CVD device, and the temperature of the tube wall of the transparent quartz tube, so the semiconductor substrate is placed inside the transparent quartz tube. However, when a CVD-grown film is formed on the surface, the CVD-grown film is also formed on the transparent quartz tube wall at the temperature between the tubes, and if it peels off later, it will cause problems in the subsequent CVD treatment process. It causes In addition, there was a problem in that the operation near the CVD W r had to be stopped in order to remove the CVD growth film that had grown and adhered to the transparent quartz tube wall.

With the present invention, C V I) Modification of the device can be carried out simply and easily in situations such as 71 and above. 1: To provide a method for preventing unnecessary grown films of CVD equipment from forming, which can prevent the formation of CVD grown films adhering to the walls of the reaction chamber.
It was targeted.

[Means to solve the problem]

The above problem occurs when the temperature of the chamber wall of the reaction chamber of the CVD apparatus is maintained at a higher temperature than the reaction temperature of the reaction gas.
This problem is solved by the method of preventing unnecessary growth of film in a CVD apparatus according to the present invention when operating the apparatus.

[Effect]

That is, in the present invention, since the CVD apparatus is operated with the temperature of the chamber wall of the reaction chamber of the CVD apparatus maintained at a higher temperature than the reaction temperature of the reaction gas, CVD growth can occur on the semiconductor substrate placed in the reaction chamber. However, it is possible to prevent the CVD-grown film from forming on the high-temperature walls of the reaction chamber.

(Embodiments) First to fourth embodiments of the present invention will be described below with reference to FIGS. 1 to 4.

The first embodiment is a method using an opaque quartz tube as the reaction chamber. In this case, heating is performed by a heater 7 disposed around the opaque quartz tube 1, and the temperature inside the opaque quartz tube 1 is controlled by the reaction chamber. Even when the reaction temperature of the opaque quartz tube is set to
It becomes possible to prevent the VD growth film from forming and forming a J foil.

Similar effects can be obtained by using silicon carbide (SiC) in addition to the opaque quartz tube 1 as the +A quality 7 of the reaction tube.

The second embodiment is a method in which a transparent quartz tube is used as the reaction gamma (gamma). ) - Layer 4 is heated slightly higher than the temperature of the tube wall of the transparent quartz tube 3 or the temperature of the reaction scum inside the transparent quartz tube 3 to achieve the same effect as in the first embodiment. The soil is falling.

The third embodiment is a method using a transparent quartz tube or an opaque quartz tube as a reaction tube. In this case, the inner diameter of the quartz tube 5 is the diameter of the semiconductor substrate 2 to be processed, and the For example, the temperature of the tube wall of the quartz tube 5 is made higher than the temperature of the reaction residue inside the transparent quartz tube 3, so that the same effect as in the first embodiment is achieved. There is.

The fourth embodiment is a method in which a transparent quartz tube or an opaque quartz tube is used as the reaction tube. , by introducing a reaction gas heated by a heater (not shown) from this shell 6 and causing the reaction gas on the tube wall to flow along the tube wall at high speed, heat transfer within the reaction tube is suppressed.
The temperature of the tube wall of the quartz tube 5 is made higher than the temperature of the reaction gas inside the transparent quartz tube 3, thereby achieving the same effect as in the first embodiment.

By making the temperature of the reaction chamber wall of the CVD apparatus higher than the reaction temperature of the reaction gas in the reaction chamber by various means as described above, it is possible to prevent the CVD grown film from adhering to the inner wall of the reaction chamber. becomes possible.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, CVD
By improving the extremely simple structure of the apparatus, the temperature of the reaction chamber wall is made higher than the reaction temperature of the reaction gas in the reaction chamber, thereby preventing the CVD-grown film from adhering to the inner wall of the reaction chamber. becomes possible.

Therefore, there is an advantage that it is not necessary to stop the operation of the CVD equipment to remove unnecessary CVD-grown films attached to the inner wall, and a significant economical and reliability improvement effect can be expected. is extremely useful.

[Brief explanation of the drawing]

1 shows a first embodiment of the invention, FIG. 2 shows a second embodiment of the invention, FIG. 3 shows a third embodiment of the invention, and 4 The figure shows the fourth embodiment according to the present invention.
FIG. 5 is a side sectional view showing a schematic structure of a conventional CV l) device. In the figure, 1 is an opaque quartz tube, 2 is a half-column integrated substrate, 3 is a transparent quartz tube, 4 is a gold plating layer, 5 is a quartz tube, 6 is a jet nozzle, and 7 is a heater.

Claims (1)

[Claims] A method for preventing unnecessary growth film adhesion in a CVD apparatus, which comprises operating the CVD apparatus while maintaining the temperature of the chamber wall of the reaction chamber at a higher temperature than the reaction temperature of the reaction gas.