JPS62185322A - Applicator for photo-resist - Google Patents

Abstract

PURPOSE:To set the optimum conditions of dropping easily, and to reduce the quantity of a photo-resist while equalizing film thickness by using an ultrasonic spray nozzle as a nozzle for dropping the resist and moving the ultrasonic spray nozzle in the radial direction just above a semiconductor wafer. CONSTITUTION:An ultrasonic spray nozzle 3 atomizing and dropping a photo- resist 3 is hung from a moving mechanism 7 at a position just above a semiconductor wafer 2, and the nozzle 3 is mounted movably up to a distance longer than the radius of a wafer 2 in the peripheral direction from the center of rotation of the wafer 2. The wafer 2 is sucked to a spinning chuck 1 for a treating cup 4, and the wafer 2 is turned and the resist is injected, shifting the nozzle 3 in the radial direction from the center of the wafer 2 by the mechanism 7 and the resist is applied uniformly onto the whole surface of the wafer 2. The optimum conditions of dropping are set, and the quantity of the resist is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an apparatus for applying a photoresist to the surface of a semiconductor wafer in photolithography.

[Conventional technology]

Conventionally, this type of photoresist coating apparatus drops photoresist from a discharge nozzle 6 onto the surface of a semiconductor wafer 2 vacuum-adsorbed on a spin chuck 1, as shown in FIG. It is applied by rotation.

[Problem that the invention seeks to solve]

The conventional photoresist coating method described above first drops a photoresist 5 onto the center of the wafer 2 as shown in FIG.
A photoresist is placed on the wafer surface.

Next, by rotating the wafer 2, the photoresist on the wafer is spread out by the action of centrifugal force, so that the entire surface of the wafer is covered with the photoresist (FIG. 4).

By further continuing the rotation, the photoresist is stretched, and the excess photoresist is blown off toward the outer periphery, thereby forming a photoresist coating film of a predetermined thickness on the wafer surface (FIG. 5).

In this conventional technique, most of the photoresist dropped at the stage shown in Fig. 3 is blown away until a photoresist coating film of a predetermined thickness is formed, so the efficiency of using the photoresist is low. It was extremely low. Furthermore, as the diameter of the wafer becomes larger, the amount of photoresist consumed further increases, and the conventional technique has the disadvantage that the amount of photoresist used increases. In addition, in this coating method, if the amount of photoresist dropped is too small, the amount of photoresist at the stage shown in FIG.
At the stage shown in the figure, variations in film thickness occur.

For the above reasons, it has been extremely difficult to reduce the amount of photoresist used in the conventional techniques.

An object of the present invention is to provide a photoresist coating device that reduces the amount of photoresist used.

Means for Solving Problem c] The present invention is a device that rotates a semiconductor wafer and applies photoresist onto the wafer by the action of centrifugal force. This photoresist coating apparatus is characterized in that the ultrasonic spray nozzle is installed directly above a semiconductor wafer so as to be movable in the radial direction of the wafer.

〔Example〕

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

In FIG. 1, the photoresist coating apparatus of the present invention uses an ultrasonic spray nozzle 3 that atomizes and drops photoresist as a photoresist dropping nozzle.
is suspended from a lateral movement mechanism 7 directly above the semiconductor wafer 2, and the nozzle 3 is installed so as to be movable from the center of rotation of the wafer 2 toward the periphery over a distance equal to or longer than the radius of the wafer. 4 is a processing cup that accommodates the wafer 2 attracted to the spin chuck 1.

In one embodiment, the photoresist atomized by the nozzle 3 adheres to the semiconductor wafer surface by free fall, but in this case, the wafer is rotated and the lateral movement mechanism 7
While moving the nozzle 3 in the radial direction from the center of the wafer 2, the photoresist is sprayed and coated on the entire surface of the wafer 2.

According to the present invention, the photoresist is atomized from the spray nozzle 3 and sprayed onto the wafer 2, and the nozzle 3
Since the photoresist moves in the radial direction of the wafer 2, the entire wafer can be covered with the photoresist as thin as possible.

Thereafter, the wafer 2 is further rotated by the spin chuck 1 at a predetermined rotation speed to form a photoresist coating film of a desired thickness.

Therefore, according to the present invention, by using a movable ultrasonic spray nozzle to drop photoresist onto the surface of a semiconductor wafer, the process shown in FIG. 3 can be omitted, and the process shown in FIG. The action can start from the process. Furthermore, in this case, by setting appropriate conditions, variations in the amount of photoresist used and the film thickness can be minimized.

〔Effect of the invention〕

As explained above, the present invention allows photoresist to be coated on a wafer with the minimum necessary film thickness, minimizes the amount of photoresist used, and coats the wafer while moving the nozzle in the radial direction of the wafer. Therefore, it has the effect of suppressing variations in film thickness to the maximum.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view showing a photoresist coating apparatus of the present invention, FIG. 2 is a sectional view showing a conventional resist coating apparatus, and FIG. Figure 4 is a diagram showing the initial state when the wafer is rotated after the state shown in Figure 3. Figure 5 is a diagram showing the initial state when the wafer is rotated after the state shown in Figure 3. Figure 5 shows that the rotational coating is completed and a predetermined photoresist coating film is formed on the wafer surface. FIG. 1... Spin chuck, 2... Semiconductor wafer, 3
... Ultrasonic spray nozzle, 4... Processing cup, 5... Photoresist. Figure S Figure 4 Figure 5

Claims (1)

[Claims] (1) In an apparatus that rotates a semiconductor wafer and applies centrifugal force to the photoresist on the wafer, an ultrasonic spray nozzle that atomizes and drops the photoresist is used as the photoresist dropping nozzle, A photoresist coating apparatus characterized in that the ultrasonic spray nozzle is installed directly above a semiconductor wafer so as to be movable in the radial direction of the wafer.