JPH0132357Y2 - - Google Patents

Description

[Detailed description of the invention] (a) Technical field of the invention The invention relates to a resist coating device used in a photoprocessing process, and particularly relates to a resist coating device that applies a resist solution to a flat sample using a spin coating method. Concerning improvements to equipment.

(b) Background of the technology In recent years, with the progress of microfabrication technology, samples to be processed, such as wafers for semiconductor devices, are becoming larger and more densely processed.

Therefore, the above-mentioned resist coating equipment is designed to form a resist film with a uniform thickness so as not to hinder the formation of fine patterns even on large samples, and to use the resist solution efficiently. It is hoped that

(c) Prior Art and Problems FIG. 1 is a block diagram showing a conventional resist coating apparatus.

In the figure, this resist coating apparatus applies a resist solution onto a sample such as a semiconductor wafer 3 by a spin coating method in a clean booth 2 which is constantly supplied with clean air and has a clean atmosphere.

That is, a certain amount of resist liquid is sent from the resist tank 6 to the bellows pump 5 via the cylinder 4,
Furthermore, the bellows pump 5 is pressurized to drop a certain amount of resist liquid onto the center of the semiconductor wafer 3. Thereafter, by rotating the holder 7 holding the semiconductor wafer 3 at high speed, the dropped resist solution is spread from the center to the periphery of the semiconductor wafer 3, and the excess resist solution is scattered to form a desired film thickness on the semiconductor wafer 3. form a resist film. The thickness of the resist film obtained by this spin coating method is determined as a function of the viscosity of the resist solution, the solvent of the resist solution, the rotational speed, and the initial rotational acceleration.

However, in the above-mentioned apparatus, the amount of resist liquid deposited on the semiconductor wafer 3 is 1% of the amount dropped.
However, the problem is that the efficiency of using the resist solution is low.

Further, as the size of the semiconductor wafer 3 increases, the variation in the film thickness distribution of the resist film increases.

(d) Purpose of the invention In view of the above points, the purpose of the present invention is to provide a resist coating device that uses a combination of spray coating and spin diffusion of the resist solution, thereby improving the efficiency of using the resist solution and making it more economical. shall be.

(e) Structure of the invention According to the invention, the above purpose is to provide a holder which is rotatable and holds the center part of the back surface of a flat sample;
A spray nozzle that sprays resist solution onto the sample held in the holder, a shaft hole that is inserted into the rotating shaft of the holder, and a shaft hole that is arranged concentrically with the shaft hole and that sprays the resist solution onto the back surface of the sample during the spray application. a liquid ejection opening that injects liquid to the outer periphery; a gas that is arranged concentrically with the shaft hole and inside the liquid ejection opening, and that injects gas to the inside of the outer periphery during the spray application; This is achieved by a resist coating device having a fluid supply mechanism having a jetting opening.

(f) Example of implementation of the idea Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 2 is a configuration diagram showing a resist coating apparatus which is an embodiment of the present invention, and FIG. 3 is a plan view of a fluid supply mechanism in the embodiment.

As shown in FIG. 2, within the chamber 12, a rotatable holder 14 holds a semiconductor wafer 1.
Hold the center part of the back side of 3. The spray nozzle 11 having a swinging mechanism injects and sprays resist liquid onto the semiconductor wafer 13 held in the holder 14 .

The rotating shaft 14a of the holder 14 is inserted into the shaft hole of a fluid supply mechanism 15, which is a cylindrical block shown by diagonal lines and is provided with a liquid supply passage 16 and a gas supply passage 17. As shown in FIG. 3, the liquid supply path 16 and the gas supply path 17 have openings arranged concentrically on the outer periphery and inside of the fluid supply mechanism 15, respectively, and the liquid supply path 16 is located on the back surface of the semiconductor wafer 13. The gas supply path 17 injects a liquid such as ethyl methyl ketone to the outer circumferential side, and a gas such as nitrogen gas to the inner circumferential side.

Furthermore, a gas inlet 18 and an exhaust port 19 are provided to gasify and introduce the solvent to control the atmosphere within the chamber 12 and prevent the resist solution from evaporating during coating.

The procedure for resist coating is as follows.

First, while rotating the semiconductor wafer 13 at a low speed (for example, 30 rpm) by rotating the holder 14, a resist solution is sprayed from the spray nozzle 11 to spray coat the entire surface of the semiconductor wafer 13. Dilute the resist solution with a solvent and apply it to the spray nozzle 1.
Prevent clogging in step 1.

In this spray coating, the resist liquid flows around and is applied to the back surface of the semiconductor wafer 13, and may even flow into the rotating shaft 14a.
This deteriorates the flatness of the back surface of the semiconductor wafer 13 and adversely affects the subsequent exposure process, and also causes trouble in the rotation of the holder 14.

Therefore, in order to prevent such problems from occurring, the fluid supply mechanism 15 is
The liquid and gas mentioned above are injected. The liquid strongly prevents the resist liquid from flowing around to the back surface of the semiconductor wafer 13, and the gas prevents the liquid from flowing into the rotating shaft 14a.

Next, when the spray coating is completed, the injection of the liquid and gas is stopped, and the rotation of the semiconductor wafer 13 is increased to a high speed (500 to 10,000 rpm) to spread the spray-coated resist solution from the center to the periphery of the semiconductor wafer 13. , the excess resist solution is scattered to form a resist film with a desired thickness on the semiconductor wafer 13. The film thickness at this time is also determined as a function of the viscosity of the resist solution, the solvent of the resist solution, the rotational speed, and the initial rotational acceleration, so the rotational speed of the high-speed rotation is appropriately regulated.

In the above-described procedure, since the spray application is completed instantaneously, the timing of spray, liquid, and gas injection is controlled by hardware or by a program.

In this example, when the film thickness is set to 1 μm (3000 rpm), the usage efficiency of the resist solution is improved from 1% of the conventional device (5000 rpm) to 10%, and even in the case of a large 5-inch semiconductor wafer 13. It was confirmed that the variation in film thickness distribution was within 4%, and that no resist adhered to the back surface of the semiconductor wafer 13. In addition, the rotating shaft 14a of the holder 14
There was no evidence that liquid had flowed into the tank.

In this way, by using the resist coating device of the present invention that combines spray coating and spin diffusion of resist solution, it is possible to significantly reduce the amount of resist solution used while making the resist film uniform in thickness even for large samples. With this, it is possible to stably prevent resist from adhering to the back surface of the sample.

In the embodiment, methyl ethyl ketone was used as the liquid to be injected from the fluid supply mechanism 15, and nitrogen gas was used as the gas, but the former is not limited to these. The latter may be air or the like.

(g) Effects of the invention As explained in detail above, according to the invention, spray coating and spin diffusion of the resist solution are combined, and the resist solution is prevented from going around to the back surface of the sample, thereby preventing the resist from adhering to the back surface of the sample. A resist coating device is provided that improves the efficiency of use of resist solution while eliminating the problem and uniforming the thickness of the resist film even for large samples, making it possible to economize on resist solution while performing desired resist coating. It has the effect of making you

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram showing a conventional resist coating device, FIG. 2 is a configuration diagram showing a resist coating device that is an embodiment of the present invention, and FIG. 3 is a plan view of a fluid supply mechanism in that embodiment. be. In the figure, 11 is a spray nozzle, 12 is a chamber, 13 is a semiconductor wafer (sample), 14 is a holder, 15 is a fluid supply mechanism, 16 is a liquid supply path, 17 is a gas supply path, 18 is a gas inlet, 19
is an exhaust port.

Claims (1)

[Scope of utility model registration request] A holder that is rotatable and holds the central part of the back surface of a flat sample, a spray nozzle that sprays a resist solution onto the sample held in the holder, a shaft hole that is inserted into the rotating shaft of the holder, and a liquid ejection opening arranged concentrically with respect to the shaft hole and injecting liquid to the outer periphery of the back surface of the sample during the spray application; a liquid ejection opening arranged concentrically with the shaft hole and inside the liquid ejection opening; A resist coating apparatus comprising: a fluid supply mechanism having a gas ejection opening that injects gas to the inside of the outer peripheral portion during the spray coating.