JPH05259052A - Spin coating on semiconductor substrate and device - Google Patents

Abstract

PURPOSE:To form a coating layer having no dead spot regardless of the presence or absence of a defect in the surface of a semiconductor substrate by a method wherein before a coating solution is dripped, a solvent is sprayed on the whole surface of the semiconductor substrate in a spray form. CONSTITUTION:A solvent spray nozzle 7 is moved to the central part of a substrate 1 to position and a solvent is sprayed on the whole surface of the substrate 1 in a spray form through a funnel-shaped blow-off port 7. Then, after the nozzle 7 is moved aside to the side part of the substrate, a coating nozzle 4 is positioned to the central part of the substrate 1 and a coating solution 5 is dripped on the central part in a prescribed amount. After that, a rotating stage 2 is rotated in the direction indicated by arrow F at high speed via a spindle shaft 6 and the solution 5 is spread on the whole surface of the substrate 1. Thereby, regardless of the presence or absence of a defect in the surface of the substrate 1 a coating layer having no dead spot can be obtained and the quality and yield of the substrate can be improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for spin coating a semiconductor substrate.

[0002]

2. Description of the Related Art Conventionally, there has been a spin coating method as a typical method for coating a semiconductor substrate such as a silicon wafer or a mask substrate with a coating solution such as a photoresist or an adhesive wax. This spin coating method
As shown in FIG. 3, a coating solution 5 is applied by a coating nozzle 4 whose axis A is vertical to a semiconductor substrate (hereinafter, simply referred to as a substrate) 1 which is suction-fixed on a rotary table 2 by a wafer chuck 3 of a vacuum type or the like. Is dropped on the central portion 1a of the wafer 1,
This is a method in which the motor 7 is rotated at a high speed in the direction of the arrow F through the spindle shaft 6 to spread the solution by utilizing the centrifugal force that acts so as to obtain a coating layer 5a having a uniform thickness. The film thickness of the coating layer 5a at this time is determined by the solution concentration, the volatilization rate of the solvent, the spin rotation speed, etc., and the volatilization rate of the solvent is affected by the environmental temperature, humidity, the solution temperature, the temperature of the substrate 1, and the like.

[0003]

However, in the conventional spin coating method as described above, when the surface of the substrate 1 has steps, particles, defects such as crystal defects, the coating solution 5 is applied in the vicinity of the outside thereof. However, there is a drawback that a coating layer with dead spots is formed.

As a countermeasure against such dead spots, for example, as disclosed in Japanese Patent Laid-Open No. 61-150332, a solvent of a resist having a viscosity smaller than that of the resist is dropped before dropping the resist onto the wafer. A semiconductor resist coating method has been proposed in which the solvent is dropped onto a wafer and then the wafer is rotated to diffuse the solvent over the entire front surface of the wafer, and then a resist is dropped to similarly diffuse the solvent. However, even with this method, it is difficult to eliminate local dead spots because the spin coating method is used.

An object of the present invention is to provide a method and apparatus for coating a semiconductor substrate, which solves the above problems of the prior art.

[0006]

According to the present invention, a coating solution such as a photoresist or an adhesive wax is dropped onto a semiconductor substrate fixed to a turntable and then spin-coated at a high speed to drop the coating solution. The method is a spin coating method for a semiconductor substrate, characterized in that a solvent is sprayed onto the entire surface of the semiconductor substrate before.

Further, according to the present invention, a coating solution such as a photoresist or an adhesive wax is dropped onto a semiconductor substrate removably fixed to a turntable through a coating nozzle, and then the turntable is rotated at a high speed for spin coating. In the apparatus described above, a solvent spray nozzle having a funnel-shaped outlet is provided above the rotary table.

[0008]

[Operation] According to the present invention, the solvent is sprayed onto the entire surface of the semiconductor substrate before dropping the coating solution, so that the coating layer having no dead spot is present regardless of the presence or absence of defects on the surface of the substrate. Can be formed.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. In the drawings, the same members as those of the conventional example are designated by the same reference numerals and the description thereof will be omitted. FIG. 1 is a side view schematically showing a configuration of an embodiment of the present invention, and a solvent spray nozzle 7 used in the present invention is arranged on an upper side portion of a rotary table 2. The solvent spray nozzle 7 has a funnel-shaped outlet 7a, and the solvent is supplied from a solvent tank (not shown).

Therefore, spin coating is performed according to the following procedure. First, as shown in FIG. 2, the solvent spray nozzle 7 is moved to the central portion 1a of the substrate 1 and positioned, and the solvent 8 is sprayed from the outlet 7a onto the entire surface of the substrate 1 in a mist state. Then, the solvent spray nozzle 7 is retracted to the side, and then the coating nozzle 4 is moved to the substrate 1 as shown in FIG.
The coating solution 5 is dropped onto the central portion 1a by a predetermined amount. After that, the rotary base 2 is indicated by the arrow F through the spindle shaft 6.
When the coating solution 5 is rotated at a high speed in the direction, the coating solution 5 spreads over the entire surface of the substrate 1. After a predetermined time has elapsed, the rotary table 2 is stopped and the spin coating is completed. Thereby, the coating solution can be coated on the entire surface of the substrate 1 regardless of the presence or absence of defects on the surface of the substrate 1.

The method of the present invention was used when spin-coating a silicon wafer using an adhesive wax as a coating solution. First, after spraying the solvent on the entire surface of the silicon wafer, apply liquid wax to the center of the wafer for about 2.
4 cc was dropped. Then, the rotary table was rotated at a high speed of 4000 rpm to form a wax film, and a coating layer without dead spots could be obtained.

[0012]

As described above, according to the present invention, the solvent is sprayed onto the entire surface of the substrate before spin coating, so that a coating layer having no dead spots can be obtained and the quality and yield can be improved. Contribute.

[Brief description of drawings]

FIG. 1 is a side view schematically showing a configuration of a spin coating apparatus of the present invention.

FIG. 2 is a side view illustrating the operation of the present invention.

FIG. 3 is a side view schematically showing the configuration of a conventional spin coating apparatus.

[Explanation of symbols]

 1 substrate (semiconductor substrate) 2 turntable 3 wafer chuck 4 coating nozzle 5 coating solution 5a coating layer 6 spindle shaft 7 solvent spray nozzle 7a outlet 8 solvent

Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location G03F 7/16 502

Claims (2)

[Claims] 1. A method of dropping a coating solution such as a photoresist or an adhesive wax onto a semiconductor substrate fixed to a turntable and then spin-coating at a high speed, wherein a solvent is applied to the entire surface of the semiconductor substrate before dropping the coating solution. A method for spin-coating a semiconductor substrate, which comprises spraying in a mist state. 2. An apparatus for spin coating by dripping a coating solution such as a photoresist or an adhesive wax through a coating nozzle onto a semiconductor substrate detachably fixed to a turntable and then rotating the turntable at high speed.
A spin coating apparatus for a semiconductor substrate, wherein a solvent spray nozzle having a funnel-shaped outlet is arranged above the rotary table.