JPH03232219A - Photoresist coating device - Google Patents

Abstract

PURPOSE:To prevent the clogging of an exhaust piping caused by the deposition of solid resist by a method wherein a cup, in which a semiconductor wafer can be housed, is formed by a cup which has a light source for irradiation of ultraviolet rays around it, an ultraviolet ray transmitting window, where ultraviolet rays are transmitted, is provided on the circumferential wall of the above-mentioned cup, and a developing treatment solution feeding port is opened through the upper part of the transmitting window. CONSTITUTION:The photosensitizer contained in the positive type photoresist adhered to the inner wall of a spin cup 11 is dissolved by projecting ultraviolet rays thereon, and the photosensitizer is liquefied by the alkali aqueous solution fed into the spin cup. The above-mentioned dissolved solution is discharged outside of the spin cup 11 from the spin cup 11 through a draining hole 13. In this case, the positive type photoresist consists of the compound containing naphthoquinonediazido group, which is alkali-soluble resin and photosensitizer, and as it is dissolved by the organic solvent such as ethylcellosolveacetate and the like, carbene and kelene are generated successively when the naphthoquinonediazido, as a photosensitizer, absorbs ultraviolet rays, then it turned to indenecarboxylic acid by reacting with the moisture in the system, and it is dissolved into the alkali aqueous solution of a developer.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a photoresist coating apparatus used in a semiconductor manufacturing process.

[Prior Art] In general, a method for applying photoresist onto a semiconductor wafer is a spin method in which photoresist is dropped onto the semiconductor wafer in a spin cup and a uniform photoresist film is formed by rotating the semiconductor wafer. The code method is known.

By the way, in this type of spin code method, a large amount of photoresist scatters and adheres to the inner surface of the spin cup from the rotating semiconductor wafer when applying the photoresist, so this is constantly removed using a rinsing liquid and then the spin The inside of the cup needs to be cleaned. In other words, if there is no cleaning with a rinse solution, the photoresist will bounce off the photoresist deposits on the inner surface of the spin cup during coating and be dropped onto the semiconductor wafer again, making it impossible to form a photoresist film with high precision. be.

Next, a conventional photoresist coating device and a method for removing photoresist deposits using this coating device will be described with reference to FIG.

First, the photoresist coating apparatus will be explained. In the figure, the symbol l is a spin cup that has a rinsing liquid inlet 2 and can accommodate a semiconductor wafer 3 to be coated with a positive photoresist, and 4 is a spin cup for this spin cup. A wafer chuck 5 is provided in the cup 1 and rotates at high speed, and a nozzle 5 is provided above the wafer chuck 4 and sprays photoresist onto the semiconductor wafer 3. Further, 6 is an exhaust port for evacuating the inside of the spin cup 1, and 7 is an exhaust port for discharging the rinsing liquid (organic solvent) 8 to the outside of the spin cup 1. It is assumed that a pipe (not shown) for discharging a rinse liquid is connected to this discharge lower.

Next, to explain the method for removing photoresist deposits, the rinsing liquid 8 is injected into the spin cup 1 to dissolve the photoresist deposits (splatters) A on the inner surface of the spin cup 1, and the photoresist solution is removed. The rinsing liquid 8 is used to discharge the spin cup 1 from the discharge lower.

[Problem to be solved by the invention]

By the way, in conventional photoresist coating equipment,
It does not have a function to disassemble and clean the positive photoresist, and as a result, the solvent of the positive photoresist solution discharged from the discharge lower evaporates during the discharge, resulting in solid resist content in the piping (not shown). was precipitated. As a result, it becomes necessary to continuously inject a large amount of rinsing liquid 8 into the spin cup 1, resulting in the problem of increased costs.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a photoresist coating device that can reduce the amount of rinsing liquid required for the inner surface of a cup, thereby reducing costs. be.

[Means to solve the problem]

A photoresist coating apparatus according to the present invention includes a cup capable of accommodating a semiconductor wafer therein, which is formed by a cup having a light source for irradiating ultraviolet rays around the cup, and a transmitting window through which ultraviolet rays pass through the peripheral wall of the cup. At the same time, a supply port for supplying a developing solution is opened above the transmission window.

[For production]

In the present invention, the photosensitizer in the positive photoresist can be decomposed by irradiation with ultraviolet rays, and the positive photoresist can be dissolved by supplying a developing treatment solution.

〔Example〕

EMBODIMENT OF THE INVENTION Hereinafter, the structure etc. of this invention will be explained in detail by the Example shown in the figure.

FIG. 1 is a cross-sectional view showing a photoresist coating apparatus according to the present invention. In this figure, the same members as in FIG. 3 are designated by the same reference numerals, and detailed description thereof will be omitted. In the figure, what is indicated by the reference numeral 11 is a spin cup having a light source unit 12 for ultraviolet irradiation around it, a drain port 13 at the bottom for draining positive photoresist waste liquid, and an exhaust port 14 for exhausting the inside of the cup. A transmission window 16 through which ultraviolet rays 15 pass is provided on the peripheral wall.

Further, above the transmission window 16, a supply port 18 is opened for supplying an alkaline aqueous solution 17 such as a tetramethylammonium hydroxide aqueous solution as a developing treatment liquid.

Note that the spin cup 11 is set so that the ultraviolet rays 15 do not leak, and is also set so that the nozzle 5 is not irradiated with the ultraviolet rays 15.

In the photoresist coating apparatus configured in this manner, the photosensitizer in the positive photoresist can be decomposed by irradiation with ultraviolet rays 15, and the positive photoresist can be dissolved by supplying the alkaline aqueous solution 17.

Therefore, in this embodiment, it is possible to prevent clogging in the discharge pipe (not shown) due to the precipitation of resist solid content, and therefore it is possible to reduce the amount of rinsing liquid required for the inner surface of the spin cup 11. .

Next, a method for removing photoresist deposits according to the present invention will be explained.

That is, to remove the photoresist deposits, first, the photosensitizer (naphthoquinone diazide) in the positive photoresist that adheres to the inner surface of the spin cup 11 is decomposed by irradiation with ultraviolet rays, and then this is supplied into the spin cup 11. It is dissolved by the alkaline aqueous solution 16. In addition,
This solution is discharged from inside the spin cup 11 to the outside of the spin cup 11 through the drain port 13.

In this case, the positive photoresist used in -g is made of an alkali-soluble resin and a compound containing a naphthoquinone cyacyto group as a photosensitizer, and is dissolved in an organic solvent such as ethyl cellosolve acetate. However, as shown in Figure 2, when naphthoquinone siacite as a photosensitizer absorbs ultraviolet rays, it sequentially converts into carhene and ketene, and then reacts with moisture present in the system to form indene carboxylic acid, which is then released into the developer. Dissolved in alkaline aqueous solution.

〔Effect of the invention〕

As explained above, according to the present invention, a cup capable of housing a semiconductor wafer therein is formed by a cup having a light source for irradiating ultraviolet rays around the cup, and a transparent window through which ultraviolet rays are transmitted is provided on the peripheral wall of the cup. At the same time, a supply port for supplying the developing processing solution was opened above this transmission window, so that the photosensitizer in the positive photoresist is decomposed by irradiation with ultraviolet rays, and the positive photoresist is processed by supplying the developing processing solution. can be dissolved. Therefore, clogging in the discharge pipe due to precipitation of resist solids can be prevented, so the required volume of rinsing liquid for the inner surface of the cup can be reduced, and costs can be reduced.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a photoresist coating apparatus according to the present invention, FIG. 2 is a view showing a reaction state of a positive type photoresist, and FIG. 3 is a sectional view showing a conventional photoresist removal apparatus. 11...Spin cup, 12...Light source unit, 13...Drain port, 14...Exhaust port, 15...
...Ultraviolet light, 16...Transmission window, 17...Alkaline aqueous solution, 18...Supply port. Agent Masuo Oiwa

Claims (1)

[Claims] In a photoresist coating apparatus equipped with a cup capable of accommodating a semiconductor wafer to be coated with a positive photoresist, the cup is formed by a cup having a light source for ultraviolet irradiation around the cup, and a peripheral wall of the cup is provided. 1. A photoresist coating apparatus, comprising: a transmission window through which ultraviolet rays pass; and a supply port for supplying a developing solution opened above the transmission window.