JPH02122615A - Spin coater - Google Patents

Abstract

PURPOSE:To make the thickness of a coat film uniform and prevent the generation of cracks, etc., in the film, by providing a wafer cooling means at the periphery of a wafer stage. CONSTITUTION:Liquid nitrogen is sent being gasified, from a plurality of liquid nitrogen intakes 7 provided in the vicinity of a wafer stage 2, to cool a wafer 6 and the stage, etc. And, the gasifying speed of a coating solution made by dissolving a silicon compound in a solvent such as alcohol, etc., becomes extremely small by cooling the wafer 6, as the gasifying speed of an organic solvent, ethyl alcohol for example, in the coating solution to be dropped on to the wafer 6 surface from a dripping nozzle 3 has a tendency to become greater as temperature rises. Accordingly, it becomes possible to form a film of the silicon compound slowly on the surface of the wafer 6. And, this makes the coat film have a uniform thickness and prevents the generation of cracks.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a spin coating apparatus used for manufacturing semiconductor integrated circuits.

[Conventional technology]

Conventionally, as shown in FIG. 2, a spin coating apparatus used for manufacturing semiconductor integrated circuits places a wafer 6 on a wafer mounting table 2 directly connected to a rotating shaft 1, fixes it by vacuum or the like, rotates the wafer 6, and rotates the wafer 6. It was configured such that a photoresist solution or a coating solution in which a silicon compound was dissolved in an organic solvent (alcohol, etc.) was dropped from a dropping nozzle 3 to form a thin film on a wafer 6. In addition, in order to prevent the coating liquid from scattering and adhering to the wafer after coating when the wafer 6 is rotated,
A suction duct 5 was attached above the cup 4 for the application liquid receiver, and the application liquid in the form of mist was sucked in and removed.

[Problem to be solved by the invention]

However, in the conventional spin coating device described above, the mist of the coating solution is sucked in through the suction duct 5.
Since the solvent is rapidly vaporized from the liquid applied onto the wafer 6, there are disadvantages in that the thickness of the coating film varies and cracks and the like occur in the coating film.

[Means to solve the problem]

The rotary coating device of the present invention includes a wafer mounting table connected to a rotating shaft, a cup for receiving a coating liquid provided around the wafer mounting table, and a nozzle provided on the upper part of the wafer mounting table. In the spin coating apparatus, a wafer cooling means is provided around the wafer mounting table.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a sectional view of an embodiment of the present invention.

In FIG. 1, the rotary coating apparatus includes a wafer mounting table 2 connected to a rotating shaft 1, a cup 4 for receiving a coating liquid provided around the wafer mounting table 2, and a wafer mounting table 2.
A drip nozzle 3 provided on the top of the wafer mounting table 2
It mainly consists of a liquid nitrogen introduction lower for cooling the wafer 6 placed above.

According to the present embodiment configured in this way, liquid nitrogen is vaporized and fed at a flow rate of 50 to 500 N/miR from the plurality of liquid nitrogen introducing lowers provided near the wafer mounting table 2, and the wafer 6 and the wafer Cool the mounting table 2 to -5
It can be cooled to ~10°C.

As shown in FIG. 3, the rate of vaporization of organic solvents, such as ethyl alcohol, in the coating solution dripped onto the surface of the wafer 6 from the dripping nozzle 3 tends to increase as the temperature rises. Therefore, by cooling the wafer 6 as in this embodiment, the vaporization rate of the coating solution containing a silicon compound dissolved in a solvent such as alcohol becomes extremely low, so that the film of the silicon compound is slowly deposited on the surface of the wafer 6. can be formed. Therefore, the coating film has a uniform thickness, and cracks do not occur as in the conventional case.

Note that the same effect can be obtained by using cooled helium or the like instead of liquid nitrogen.

〔Effect of the invention〕

As explained above, the present invention provides a wafer cooling means around the wafer mounting table of the spin coating apparatus,
The evaporation rate of the solvent components in the coating solution can be reduced.
This has the effect of making the thickness of the coating film formed on the wafer uniform and preventing cracks from occurring in the coating film.

[Brief explanation of drawings]

FIG. 1 is a sectional view of an embodiment of the present invention, FIG. 2 is a sectional view of a conventional example, and FIG. 3 is a diagram showing the vapor pressure of ethyl alcohol. DESCRIPTION OF SYMBOLS 1... Rotating shaft, 2... Wafer mounting table, 3... Dripping nozzle, 4... Cup, 5... Suction duct, 6...
...Wafer, 7...Liquid nitrogen inlet.

Claims (1)

[Claims] A rotary coating apparatus having a wafer mounting table connected to a rotating shaft, a cup for receiving a coating liquid provided around the wafer mounting table, and a nozzle provided at an upper part of the wafer mounting table. A rotary coating device characterized in that a wafer cooling means is provided around a mounting table.