JPH0254656B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for baking a film such as a resist applied to a substrate such as a plate or wafer in the manufacturing process of semiconductor devices and the like.

In order to manufacture semiconductor devices, it is necessary to accurately form fine patterns at predetermined positions, and such patterns are generally formed by photolithography.

Photolithography is typically performed in the following manner.

A photosensitive photoresist is applied onto a substrate such as a metal plate for a photomask or a silicon wafer on which a pattern is to be formed, and after baking, the photoresist is exposed to ultraviolet light. Next, when the photoresist is developed, a resist pattern is formed on the substrate and the desired portion of the substrate is exposed.
This portion is then etched to form the desired pattern.

In this photolithography, the baking process is performed for the purpose of improving the adhesion between the photoresist and the substrate and evaporating solvents contained in the photoresist, such as ethyl cellosolve acetate and xylene.

As a baking device for the above baking process,
Ovens that circulate warm air and devices that utilize infrared rays have been common, but they have drawbacks such as long baking times and insufficient temperature uniformity for the resist on the substrate. For this reason, a method using a hot plate is being put into practical use as a baking device that can bake in a short time and has good temperature uniformity.

As shown in FIG. 1, this method requires a short baking time because the substrate 13 coated with the resist 12 is placed on a glass or metal plate 11 heated by a heater 14, and is a single-wafer process. Therefore, it has excellent heat coverage between substrates and temperature uniformity within the substrate.

However, when a hot plate is installed in a clean room, the heat generated from the hot plate affects the temperature balance in the clean room, and the organic solvent contained in the resist on the substrate evaporates, polluting the atmosphere in the clean room.

Furthermore, when the entire hot plate is covered with a cover, the cleanliness inside the cover becomes poor, and furthermore, heat is trapped and the temperature distribution becomes uneven, making it impossible for the advantages of hot plate baking to fully shine.

The present invention is an improved apparatus for the above-mentioned hot plate method for baking the resist so that its performance can be fully demonstrated without adversely affecting the inside of the clean room.

That is, a feature of the present invention is that, in a hot plate type baking apparatus for baking a substrate whose surface is coated with resist, exhaust holes are provided on both sides of the hot plate without covering the entire hot plate with a cover. The resist baking apparatus is provided with a side wall from a hollow box connected to a duct on the opposite side thereof, and is configured to exhaust air containing an organic solvent from the hot plate side through the exhaust hole.

Hereinafter, the present invention will be explained in detail with reference to the drawings.

FIG. 2 is a sectional view of a main part showing an embodiment of the present invention. In the figure, from the top surface of the hot plate 21 on both sides of the hot plate 21 having the heater 24,
Create a side wall 25 that is 50 cm higher. This side wall is a hollow box made of, for example, transparent PVC, with an exhaust hole 26 on the side of the hot plate, and the air is exhausted to the outside of the clean room through a duct 27 from a part on the side opposite to the hot plate. When the substrate 23 coated with the resist 22 is placed on a hot plate, the organic solvent in the resist evaporates, but is not exhausted from the exhaust hole and contaminates the clean room. Unlike the case where the entire hot plate is covered, this method does not trap the heat of the hot plate and make the baking conditions of the board uneven, and unnecessary heat is conducted outside the clean room without affecting the clean room. It will be destroyed.

Furthermore, since the upper part of the hot plate is open, there is no possibility of dust being drawn in and contaminating the resist surface, and maintenance can be easily performed from above.

According to the present invention as described above, even when a large number of substrates are processed using a multi-stage baking device having a large number of hot plates and generating a large amount of heat, baking can be performed safely and accurately.

[Brief explanation of the drawing]

Figure 1 is a sectional view of a conventional hot plate, Figure 2 is a cross-sectional view of a conventional hot plate.
The figure is a sectional view of one embodiment of the present invention. 21...hot plate, 22...resist,
23... Board, 24... Heater, 25... Side wall, 26... Hole, 27... Duct.

Claims (1)

[Claims] 1. In a hot plate type baking device that bakes a substrate whose surface has been coated with resist, the hot plate is not entirely covered with a cover, but has exhaust holes on both sides of the hot plate and a duct on the opposite side of the hot plate. 1. A resist baking apparatus, comprising a side wall formed of a connected hollow box, and air containing an organic solvent on the hot plate side is exhausted from the exhaust hole.