JPS586535Y2 - Rotary coating device - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a rotary coating device (hereinafter also simply referred to as a coating device) that applies a coating agent to the surface of an object to be treated using centrifugal force by rotating the object. .

Such a coating device has the advantage of being able to form a relatively thin coating film, and is therefore widely used, particularly in the field of semiconductor device manufacturing.

For example, masks used in the photo-etching process for semiconductor substrates (wafers) are made by sequentially depositing a chromium (Cr) film and a photoresist (photosensitive material) film on the surface of a mask substrate such as soda glass. The photoresist film is formed by exposing a pattern using a master mask and then performing a chemical treatment, and the above-mentioned coating device is used to form the photoresist film in this case.

It is also used when forming a pattern protective film on a mask after pattern formation.

Rotary coating equipment generally has a structure in which the object to be processed is held by suction on a spinner head (rotary head) using a vacuum chuck, but in the conventional type, one vacuum chuck is placed concentrically with the rotational center line of the spinner head. It is configured to attract and hold the object to be processed in its central region.

However, there are the following problems when using such a conventional apparatus for coating (or forming) a photoresist film on a Mac substrate.

The first problem is that the mask substrate is relatively thin and easily deformed, so if it is adsorbed in its central region, it deforms into a mortar shape, and as a result, the photoresist film is thicker in the center and thicker in the periphery. The film thickness becomes non-uniform as it becomes thinner in some parts.

Non-uniformity in the thickness of the photoresist film adversely affects the pattern exposure and chemical processing steps of the photoresist film, thus causing a reduction in mask pattern accuracy.

The second problem is that when a pattern forming liquid is applied to a pattern protective film on a mask, the central effective area of the mask substrate (i.e., the area where the desired pattern is formed on the semiconductor wafer) is damaged due to contact with the vacuum chuck. It is pollution.

1. In other words, a vacuum chuck is composed of, for example, an air suction port and an O-ring surrounding it, but contact of the O-ring with the mask substrate causes contamination such as clouding in the central effective area. Another drawback is that the pattern shape is damaged during pattern exposure of a semiconductor wafer.

Therefore, an object of the present invention is to solve the above-mentioned problems.

In order to achieve the above object, the present invention provides a spinner head with a plurality of vacuum chucks arranged at approximately equal angular intervals in a peripheral area away from its center of rotation, and a mask substrate is placed in an effective area in the center of the spinner head. It is configured so that it can be attracted to a vacuum chuck in the outer peripheral area.

According to this structure, the mask substrate is held by suction at multiple points in the peripheral area, so that the bowl-like deformation described above is prevented and coating with a uniform thickness can be obtained. Contamination of the central effective area by the vacuum chuck is also avoided.

Hereinafter, the present invention will be described in detail based on embodiments with reference to the accompanying drawings.

The main parts of one embodiment of the rotary coating device according to the present invention are shown in the first embodiment.
It is shown in a plan view and a partially sectional side view in FIG. 2 and FIG. 2, respectively.

This coating device is used for coating the aforementioned mask substrate with a photoresist material, etc.

This coating device has a disk-shaped spinner head 1.

The spinner head is connected to the main shaft 3 of the motor 2 and is rotated at about 300 rpm.

The spinner head 1 is provided with four vacuum chucks 4 at approximately equal angular intervals in a peripheral area remote from its center of rotation (ie, the center line of the motor spindle 3).

The vacuum chuck 4 has a structure in which an air suction port 5 is surrounded by an O-ring 6, and the air suction port 5 is connected to a passage 7 formed in the spinner head 1 and a passage formed in the motor main shaft 3 (not shown). to a vacuum pump (not shown).

An O-ring 8 for sealing the air passage is provided at the joint between the spinner head 1 and the motor main shaft 3.

Next, the application of the photoresist material to the above-mentioned mask substrate using the above-mentioned coating apparatus will be explained.

As shown by the two-dot chain line in FIGS. 1 and 2, the mask substrate 10 is a square glass plate larger than a semiconductor wafer (not shown), on which a chromium film 11 is first formed by sputtering, and then This is held by suction on the spinner head 1 with a vacuum chuck 4.

When the spinner head 1 is rotated by the motor 2 and the photoresist material is supplied to the center of the mask substrate 10, the photoresist material is spread over the upper surface of the mask substrate 10 by centrifugal force and coated in a thin film. Then, a photoresist film 12 is formed.

In the coating apparatus of the present invention, a vacuum chuck 4 is disposed around the spinner head 1, and a mask substrate 10 is
is to be attracted to the vacuum chuck 4 in the peripheral area outside the central effective area S (that is, the pattern forming area, which is approximately the same shape as the semiconductor wafer) shown by the two-dot chain line 13 in FIG. be.

Therefore, the mask substrate 10 is not deformed into a mortar shape as in the conventional case, and the photo mask substrate 10 has a substantially uniform thickness over the entire surface.
A resist film 12 is formed.

Further, the central effective region S of the mask substrate 10 is not contaminated due to contact with the O-ring 6 of the vacuum chuck 4.

As is clear from the above description, the rotary coating apparatus according to the present invention is extremely effective for mask substrates that are easily deformed and where contamination of the central region is a problem.

[Brief explanation of drawings]

FIG. 1 is a plan view of the main parts of an embodiment of a rotary coating device according to the present invention, and FIG. 2 is a partially sectional side view taken along line II--II in FIG. In the figure, 1 is a spinner head, 2 is a drive motor, 3 is a main shaft, 4 is a vacuum chuck, 5 is an air suction port, 6 is an O-ring, 7 is a passage, 10 is a mask substrate, 11 is a chrome film, 12 denotes the photoresist film, and S denotes the central effective area of the mask substrate.

Claims (1)

[Scope of utility model registration request] In the rotary coating apparatus, a mask substrate for semiconductor device manufacturing is held by suction on a spinner head using a vacuum chuck, and a coating agent is applied to the surface of the mask substrate using centrifugal force caused by rotation of the spinner head. Spinner
A plurality of vacuum chucks are disposed on the head at approximately equal angular intervals in a peripheral region away from the center line of rotation, and the mask substrate can be attracted to the vacuum chucks in a peripheral region outside the central effective region. A rotary coating device characterized by: