JPS581144A - Method for coating photoresist - Google Patents

Abstract

PURPOSE:To coat a uniform photoresist film used for producing a semiconductor device or a photomask, by spirally dropping a resist liquid from the center of rotation on a substrate. CONSTITUTION:A pipe 16 for supplying a photoresist liquid 20 is moved at a prescribed speed toward the periphery of a substrate 14 with a pipe driving member while the substrate 14 is rotated at a proper low speed and the liquid 20 is dropped at a proper feed rate out of the nozzle 16a of the pipe 16 to spirally drop it onto the surface of the substrate. A number of winding of the liquid 20 spiral may be properly changed at that time in accordance with the surface area of the substrate 14 to be used, and such a method of dropping permits no bubble to be mixed in the liquid 20 dropped onto the substrate 14, and bubbles, if any, to be easily removed. Then, rotation of the substrate 14 is continued, permitting the spiral liquid 20 to flow and enlarge over the substrate surface 14, and a proper uniform thickness to be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improvements in methods for applying photoresists onto various substrates.

A uniform photoresist film is required for the manufacture of semiconductor devices or the manufacture of photomasks used in the manufacture of semiconductor devices, and conventional methods for obtaining such photoresist films include dipping, spraying, and spinner methods. In general, the spinner method, ie, the rotary coating method, is widely used. As shown in FIG. 1, this rotary coating method involves dropping an appropriate amount of photoresist liquid 6 onto the center of, for example, a semiconductor wafer 4 on a rotating disk 8 that is directly connected to a V-gift 2 that is connected to a rotational drive mechanism 1 such as a motor. , the wafer 4 is rotated by the rotation drive mechanism 1 at an appropriate rotational speed, the photoresist liquid 6 on the wafer 4 is spread over the entire surface of the wafer, and the excess photoresist liquid 6 is blown off by centrifugal force. This method forms a thin film of photoresist 6 with a uniform thickness on the wafer surface.

By the way, when applying the photoresist liquid to the wafer surface by the above-mentioned rotary coating method, as mentioned above,
4 from the actual coating amount to the center of the wafer 4 to be coated.
Since an extra amount of the photoresist liquid 6 is locally and overlappingly dropped, bubbles are likely to be generated in the dropped photoresist liquid 5, and the follicle 1/cyst liquid 6 mixed with such bubbles is rotated. When the photoresist film is spread and coated on the wafer during operation, the photoresist film becomes uneven in thickness due to the above-mentioned "complete bubbles", which makes it difficult to obtain a photoresist film with a uniform thickness.

An object of the present invention is to improve the method of dropping a photoresist solution onto a substrate to be coated in order to eliminate the disadvantages of the conventional methods described above, and to provide a photoresist that can coat a uniform photoresist layer. The object of the present invention is to provide a method for applying the same. That is, the object of the present invention is to drop the resist solution from the center of rotation on the substrate to the edge of the scrap in a spiral pattern when dropping the resist solution onto the substrate. .

Embodiments of the coating method according to the present invention will be described in detail below with reference to the drawings.

As shown in FIG. 8, a substrate 14 to be coated with a photoresist solution is placed on a rotating disk 18 directly connected to a V shaft 18 connected to a rotational drive mechanism 11, and a guide arm 1 having a guide arm 1 and A resist liquid supply mechanism 16 equipped with a guide arm 17 is arranged.

In this state, the substrate 14 is rotated at an appropriate low rotational speed, and an appropriate amount of photoresist liquid go is applied from the nozzle/l/16a of the photoresist liquid supply pipe 16 located at the center of the substrate 14. While dropping, the supply pipe 16 is connected to the drive unit 1.
9 to move the substrate 14 toward the peripheral edge at a predetermined speed. Thus, from K, the photoresist liquid is spirally spread on the surface of the substrate 14, as shown in the top view of FIG. 8 and the new view of FIG. 2
Drop 0. The number of drops of the photoresist liquid F 200 in this case may be appropriately changed depending on the size of the surface area of the substrate 14 to be used. There will be no air bubbles mixed in. Furthermore, even if air bubbles are mixed into the spray liquid 80 dropped as described above, they can be easily defoamed.

After that, if the substrate 14 is subsequently rotated by the rotation drive mechanism 11, the spiral photoresist liquid B
O is fluidized and expanded on the surface of the substrate 14 by centrifugal force, and is coated on the surface of the substrate 14 to an appropriate thickness. At this time,
Since there are no air bubbles mixed into the photoresist liquid 80,
There is no unevenness in the coating thickness of the photoresist liquid 20, and the photoresist liquid 20 is coated to a uniform thickness.

As is clear from the above description, the photoresist coating method according to the present invention has the advantage that a photoresist film can be coated on a semiconductor substrate or a photo-F mask substrate, etc. Process yield and reliability improve. According to the method of dropping the resist solution explained in this embodiment, there is no need to drop the resist solution every minute as in the conventional method, and the amount of resist consumed can be significantly reduced, which has excellent practical effects. It is extremely advantageous to apply this method to, for example, coating a diffusion coating agent or a heat-resistant polymer on a semiconductor substrate.

[Brief explanation of the drawing]

Fig. 1 is a diagram explaining a conventional spin coating method, Fig. □8 is a sectional view of a main part of an apparatus used in an embodiment of the photoresist coating method according to the present invention, and Figs. A top view showing a state in which a photoresist liquid is dropped in a spiral shape onto a substrate by the photoresist coating method according to the invention and a new view thereof. In the figure, 11 is a rotational drive mechanism;
18 is a rotating disk, 14 is a substrate, 16 is a resist liquid supply mechanism, 16 is a resist liquid supply pipe, 16a is a nozzle of the supply pipe, 17 is a guide arm, 18 is a guide hole, 19
is a driving part, and Bo is a photoresist solution dropped in a spiral shape. Figure 1 Figure 3 273

Claims (1)

[Claims] In a method in which a substrate to be coated with a resist is placed on a disk having a rotating shaft and a photoresist solution is dropped onto the substrate and coated by rotation, when dropping the photoresist solution onto the substrate, the V A photoresist coating method that involves dropping a diis-F solution onto a substrate in a spiral manner from the center of rotation toward the periphery.