JPS6092618A - Coating applicator - Google Patents

Abstract

PURPOSE:To obtain a coating excellent in both the uniformity of film thickness and the number of foregin matters by mounting a solvent atmosphere introducing mechanism for an applying liquid to the inner cylinder of a device to a coating applicator through which a film, such as a silica film, a resist, etc. is formed on a semiconductor wafer. CONSTITUTION:A wafer 6 is sucked by a chuck 7, an air-operated valve 2 and a butterfly valve 4 are opened, and an ethyl alcohol atmosphere is forwarded onto the wafer 6 through a solvent introducing port 5. An silica applying liquid is dropped, and the chuck 7 is turned. When the number of revolution reaches to a fixed value, the valve 2 and the valve 4 are closed, and the wafer is dried by air introduced from a section just above the chuck. The angular velocity of the revolution of the chuck after the liquid is dropped is reduced in order to decrease the number of foreign matters on application, and a solvent atmosphere is fed onto the wafer in order to inhibit the evaporation of a solvent for the applying liquid.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a coating machine for forming a film such as a silica film or a resist on a semiconductor wafer 1.

Coating machines are widely used as devices for forming films such as silica films and resists on semiconductor wafers, and are indispensable devices in the semiconductor device manufacturing process.

However, with conventional coating machines, the uniformity of the film thickness on the semiconductor wafer and the number of foreign particles after coating are contradictory items, and a compromise between the two is used.

It is. Figure 1 shows the relationship. The chuck is rotated after dropping the coating liquid, and the number of foreign particles increases when the angular acceleration (hereinafter referred to as chuck rotation angular acceleration) is large. C,
This is because the coating liquid falls down again and adheres to the wafer, and the film thickness becomes large when the chuck rotation angular velocity is small.The reason why the film thickness uniformity deteriorates is when the coating liquid is The solvent evaporates, the viscosity increases, and the coating solution becomes thicker.

This is because the film spreads onto the semiconductor wafer and dries before the film has a uniform thickness.

An object of the present invention is to provide a coating device that can achieve both of the above-mentioned contradictory aspects of improving uniformity and reducing the number of foreign particles after coating.

In order to achieve the above object, the apparatus of the present invention is provided with a mechanism for introducing a solvent atmosphere into the inner cylinder of the apparatus for introducing the coating liquid into the solvent atmosphere.

In the following, a method of using the device according to the present invention will be explained.

In order to reduce the number of foreign substances during coating, the chuck rotational angular acceleration after dropping the droplet is kept small. From the time the coating solution is dropped until the chuck rotational speed becomes constant, a solvent atmosphere is fed onto the wafer to suppress the evaporation of the solvent in the coating solution. The application is completed by blowing in air and drying it.

By using the above-mentioned apparatus and method, it is possible to form a coating film with a uniform thickness and less foreign matter, which has the advantage of improving the yield of semiconductor devices.

The present invention will be specifically explained below using the drawings.

FIG. 2 is a schematic diagram showing an embodiment of the present invention.

In the diagram, 1 is the nitrogen introduction pipe, 2 is the air operated valve, and 3
The female solvent is ethyl alcohol, 4 is a butterfly valve, 5 is a solvent inlet, 6 is a semiconductor wafer, 7 is a wafer chuck, 8 is an exhaust port, and 9 is an inner cylinder.

A method of applying a silica film onto a silicon wafer using an apparatus configured in this manner will be described.

A normally processed wafer 6 is sucked with a chuck 7, and a silica chemical solution is dropped. At this time, the air operated valve 2 and the butterfly valve 4 are opened, and the ethyl alcohol gas is sent through the solvent inlet 5 onto the semiconductor wafer 6. Subsequently, a silica coating liquid is dropped, and then the chuck 7 is rotated. Rotation start-up is performed at 0.05 sei;/11000 rpm. When the rotation speed reaches a certain value at 400 rpm, close the air operated valve 2 and the butterfly valve 4. Thereafter, the process is completed by drying as usual with air introduced directly above the chuck. This makes it possible to obtain a coating film with excellent film thickness uniformity and the number of foreign particles.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the relationship between the chuck rotation angular velocity, the number of foreign objects, the film thickness, and the uniformity of the film thickness within the wafer. FIG. 2 is a schematic diagram showing an embodiment of a coating machine according to the present invention. In the same figure, 1... nitrogen introduction pipe, 2...
...Air operated valve, 3...Ethyl alcohol. 4... Butterfly valve, 5... Solvent inlet, 6... Semiconductor wafer, 7...
Urchin/'-Chuck, 8...Exhaust port, 9...
...Inner cylinder. Child Yasoku Box 1 μ angle addition L→ Chuck rotation angle 1to” J1→ Hand Yasoku 7 rotation angle addition J Rainbow→

Claims (1)

[Claims] In a coating machine comprising a wafer chuck having a suction plate for fixing a semiconductor wafer at the tip of a rotating shaft, and an inner cylinder having an insertion opening for the wafer on the upper end surface, introducing a solvent atmosphere of a coating liquid into the inner cylinder. It is characterized by having a mechanism. Coating machine.