JPH0444213A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To obtain a thin resist film thickness by a simpler method by applying a resist liquid to the surface of a semiconductor substrate in such a state that the ambient environment of the substrate is made coincident with the atmosphere of a solvent contained in the resist liquid. CONSTITUTION:A semiconductor substrate 2 is set on a chucking table 3 in a sealed coater cup 5. After setting the substrate 2, inside of the coater cup 5 is set to the atmosphere of the solvent (conventionally, acetone, ethyl cellosolve acetate, etc., are used in general) contained in a resist liquid by injecting the vaporized product of the solvent into the cup 5 through a gas pipe 6 connected with the cup 5. Then a resist film having a uniform thickness is formed on the substrate 2 by rotating the substrate 2 by means of a spin motor 4 while the resist liquid is dropped onto the substrate 2 from a resist liquid nozzle 1. Since the vaporizing speed of the solvent from the resist can be decreased at the time of application by making the ambient environment of the substrate 2 coincident with the atmosphere of the solvent, a thin resist film can be obtained even from a resist liquid having a relatively high viscosity.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for manufacturing a semiconductor device, and particularly to an improvement in a technique for applying a resist liquid onto a semiconductor substrate.

[Conventional technology]

Conventionally, when applying a resist solution onto a semiconductor substrate, the environment around the semiconductor substrate is the same as the atmosphere inside the room in which the device is placed.

In other words, FIGS. 1 to 4.15 are cross-sectional views of semiconductor devices manufactured by conventional methods. A simple explanation of the conventional method is
First, the semiconductor substrate 2 is set on the chucking table 3 in the unsealed coater cup 15. Next, the resist solution is dripped onto the semiconductor substrate 2 from the resist dripping nozzle 1, and the semiconductor substrate 2 is placed by the spin motor 4. is rotated to form a uniform resist film on the semiconductor substrate 2.

In the conventional method, the inside of the coater cup is not sealed, so the environment around the semiconductor substrate 2 is always maintained at atmospheric pressure.

[Problem to be solved by the invention]

Normally, when manufacturing semiconductors, there are around 10 steps to apply resist solution, and the resist film thickness is 2 to 3 times.
Generally, there are various types of conditions. By the way, in order to obtain a desired resist film thickness, it is necessary to obtain each resist film thickness by changing the viscosity of the resist solution. In particular, in order to obtain a thin resist film, a low viscosity resist solution is required. Ta.

However, with a low viscosity resist solution, it is difficult to prevent the resist solution from dripping inside the nozzle after the resist solution is applied through the nozzle, and when the drop occurs, there is a problem in that the coating becomes uneven.

The present invention is intended to solve the problems of the conventional semiconductor device manufacturing method, and its purpose is to develop a semiconductor device manufacturing method that can obtain a thin resist film thickness using a simpler method. It's there to encourage it.

[Means for solving problems]

The semiconductor device manufacturing method of the present invention is characterized in that when applying the resist solution, the environment around the semiconductor substrate is brought into an atmosphere of the solvent in the resist solution, and the resist solution is applied.

〔Example〕

1 to 6 are cross-sectional views of a semiconductor device according to an embodiment of the present invention.

A semiconductor substrate 2 is set on a chucking table 3 in a sealed coater cup 5. Thereafter, a vaporized solvent in the resist solution (conventionally acetone, ethyl cell solve acetate, etc. is commonly used) is injected into the coater cup 5 through the gas pipe 6 connected to the coater cup 5. A resist solution is dropped onto the semiconductor substrate 2 from the cyst dropping nozzle 1, and the semiconductor substrate 2 is rotated by the spin motor 4 to form a uniform resist film on the semiconductor substrate 2.

By the way, the factors that determine the resist film thickness are the viscosity of the resist solution, the rotation speed of the semiconductor substrate after dropping the resist solution,
There are three possible rates of evaporation of solvent from the resist during rotation. FIG. 2 is a cross-sectional view of a semiconductor device manufactured by a conventional method. As is clear from the figure, since the coater cup 5 is not in a sealed state, the environment around the semiconductor substrate 2 is always The interior of the room is surrounded by air. Therefore, the evaporation rate of the solvent from the resist during resist coating is always kept constant. Furthermore, regarding the rotation speed, the in-plane uniformity of the resist film thickness deteriorates at low speeds, and there is a limit to the ability of the spin motor at high speeds, so the practical range is approximately 3000 to 6000 rotations/min. Within this rotational speed, the film thickness could not be changed significantly. Therefore, conventionally, a thin resist film has been formed by lowering the viscosity of a resist solution.

According to the present invention, by making the environment around the semiconductor substrate 2 an atmosphere of the solvent in the resist solution when applying the resist solution, it is possible to reduce the evaporation rate of the solvent from the resist during the application of the resist solution. A thin resist film can be obtained using a resist solution with a high viscosity.

〔Effect of the invention〕

As described above, according to the present invention, by making the atmosphere in the coater cup at the time of applying the resist solution to be the atmosphere of the solvent in the resist solution, the evaporation rate of the solvent from the resist can be suppressed, so that the rate of evaporation of the solvent from the resist can be suppressed. Even with a viscous resist solution, a thin resist film can be formed, and dripping inside the nozzle can be completely prevented, and a high-quality resist film without uneven coating can be formed.

[Brief explanation of drawings]

FIG. 1 is a sectional view C of a semiconductor device according to the present invention. The second diagram is a cross-sectional view of a conventional semiconductor device. that's all

Claims (1)

[Claims] 1. A method for manufacturing a semiconductor device, which comprises applying a resist solution onto a surface of a semiconductor substrate by making the environment around the semiconductor substrate into an atmosphere of a solvent in the resist solution.