JPS58114426A - Resist coating device - Google Patents

Abstract

PURPOSE:To obtain a resist layer with stable film thickness by a method wherein a vacuum chuck which adsorbs a semiconductor wafer is surrounded by a vessel which has a circular surplus resist reservoir and is opened in the upper part, further it is surrounded by a hood, then scattered resist is contained in the resist reservoir, and particle or cotton suspended matters are exhausted via a duct produced between the vessel and the hood. CONSTITUTION:The wafer 11 is adsorbed on the vaccum chuck 12 rotated by a motor 17, and the outer periphery thereof is surrounded by the vessel 15 which has the circular surplus resist reservoir 15d and is opened 15g in the upper part. Further, the outer periphery of the vessel 15, while producing the duct space 14, is surrounded by the hood 13 having a wide aperture part 13a, and a wide aperture part 13b for exhaust is provided on the bottom surface. Thus constituted, liquid resist is dripped from the aperture part 13a, first accordingly a resist R1 is deposited on the wafer 11, and the resist scattered by rotating the wafer 11 is contained in the reservoir 15d, while the suspended matters are exhausted to the outside via the duct space 14.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for applying a chemical solution such as photoresist to a resist-coated body such as a silicon wafer or a glass mask during the manufacture of semiconductor devices.

A conventional rotary resist coating apparatus will be explained with reference to FIG. In the first vA, reference numeral 1 denotes a silicon wafer which is a resist-coated body, and the silicon wafer 1 is vacuum-adsorbed onto the rotating chuck 2 . Reference numeral 3 designates an exhaust duct for exhausting air from the inside of the 7-V%4Fi7-dead 4 covering the wafer 1 and the chuck 2 (C) JIB, and 5 designates a motor connected to the chuck 2.

Ma'fe b R1e & t Re t Ra+ R
b@Re indicates resist F like photoresist,
The islands represent a single droplet of liquid-like resist that has been dropped and a light flocculent resist that occurs at the final stage of coating, respectively. f indicates the flow of air generated outside and inside the 7-door 3 due to the exhaust air from the exhaust duct 4).

When a conventional resist coating device as described above is operated,
First, photoresist is dropped onto the center of the surface of the wafer 1 from a nozzle (not shown) disposed above the chuck 2 . The dropped photoresist is first spread over the entire surface of the wafer by the motor 5 rotating at a low speed (several hundred rpm), and then by rotating the motor 5 at a high speed (several thousand rpm).
) to scatter the unnecessary liquid around the wafer 1 and apply it to the wafer 1 to a desired thickness. At this time, the scattered photoresist B-a-Rs adheres to the inner surface of the hood 3,
Exhaust duct) extends to 4F3. Photoresist is generally a highly viscous liquid containing a volatile solvent. A large amount of photoresist adheres to and solidifies on the inner surface of the exhaust duct 4, greatly affecting the exhaust volume. The exhaust volume determines the volatilization rate of the solvent during photoresist application, and has a large effect on the film thickness of 1L photoresist.As mentioned above, the scattered liquid photoresist adheres to the inner surface of the 7-dore 30, but it is light. Particulate photoresist and cotton-like photoresist that occurs at the end of coating) R
Some of a, Rb t, and Re adhere to the inner surface of the hood 3, while others are discharged to the outside of the hood 3 by the exhaust flow. In addition, since the air flow f due to exhaust air is from the front side to the back side of the wafer 1, an air vortex f1 is generated on the back side of the peripheral part of the thin disc-shaped wafer 1, and nine particles riding on this vortex f1 are created. light cotton-like photoresist Ra
, Rb or Re may adhere to the back surface of the wafer 1. The photoresist thus applied to the back surface of the wafer 1 prevents the adhesion of the wafer 1 to the plane of a vertical chuck and causes stones when the wafer 1 is attracted to the plane of a vertical chuck during exposure in the next step. Furthermore, it is well known that the above-mentioned floating matter should not adhere to the front page of wafer 1.
This is because problems such as pattern breakage may occur.This invention uses the conventional device described above to temporarily store the scattered Y cyst liquid before flowing it into the exhaust duct, and removes resist particles and flocs. The above-mentioned problem can be solved by providing a container that has the function of scattering only floating substances such as particles from the surface of a resist-coated object such as a wafer to the surrounding area. It is an object of the present invention to provide a resist coating device that can prevent variations in film thickness and adhesion of floating materials of the resist to the back surface of a resist coating.

The implementation and examples of this invention will be described below with reference to the drawings.

FIG. 2 shows a resist coating apparatus according to a first embodiment of the present invention. In Figure 2, 1.11 is Regis.

The wafer 11 is covered with a semiconductor wafer, and the reference numeral 12 is a vacuum chuck that holds the wafer 11 under vacuum. 13
This is a 7-hole wafer 11 that is suction-protected by this holder 12 and is placed so as to surround the hole wafer 11.
A wide opening 13m having a diameter larger than that of Ueno S11 is formed in the upper part, and an opening 13b connected to an exhaust pump (not shown) is formed in the lower part. 15 is a container supported within the hood 13, and the container 15 has a bottom wall 15. Inner and outer peripheral walls 15b and 15c are integrally protruded above the outer peripheral part of a, and an excess resist reservoir 15d is formed inside surrounded by these walls. The inner circumferential wall 15b is formed into a cylindrical shape and has an inner diameter into which the chuck 12 is fitted, and has a top surface 1. tm
is arranged, and the inside of the top surface 15 is open. The upper end 15f of the outer circumferential wall 15c is located above the horizontally extending surface of the wafer 11 that is attracted to the chuck 12, and the wide mouth opening 1.3a of the hood 13 is located inside the upper end 15f.
An opening 15g having a slightly larger diameter is formed, and a truncated conical inclined portion is formed on the inner surface 154 of the outer peripheral wall 15b.
A duct space 14, which constitutes an exhaust duct, is formed between the outer surface 15 of the outer wall 15cO and the inner circumferential surface of the hood 13. 16 is a donut-shaped support ring provided on the bottom 13e of the hood 13, and the container 15 is placed on this ring 16. 17 is a motor connected to the chuck 12. Further, &, Re, & represent liquid photoresist, Ra, Rb, and Re represent floating photoresist, and f represents the air flow caused by the operation of the exhaust pump.

Next, the operation of the resist coating apparatus of the first embodiment configured as described above will be explained. The particles dropped onto the wafer 11 are blown around the wafer 7111 by centrifugal force when the motor 17 rotates at high speed. At this time, the scattered resist & adheres to the truncated conical portion formed on the inner surface 15C1 of the outer peripheral wall 15e of the container 15, and
The resist particles 54 drip down or bounce off by colliding with the inner surface 1-5elK, and these resist particles accumulate in the excess resist reservoir 15d. On the other hand, light particulate resists and dry, flocculent resists Ra, Rh, and Re float around the wafer 11, but are carried by the air flow f caused by the exhaust air and exit the hood 13 through the duct space 14. It is discharged. Therefore, during the application of photoresist, excess photoresist mostly accumulates in the resist reservoir 15d of the container 15 and does not adhere to the 7-door 1'3 or the duct space 14. In addition, if particulate resist or dry flocculent resist (Ra, Rb, and Re) is generated from the surface of the wafer 111, these particles are directed in one direction by the air flow f caused by exhaust and are removed from the periphery of the wafer 11. Since it is guided diagonally upward and discharged to the outside of the hood 13 through the duct space 14, the chips and containers 1 attached to the front and back surfaces of the wafers 11 are removed.
There is nothing to do if you remain within 5.

FIG. 3 shows a resist coating apparatus according to a second embodiment of the invention. This coating device includes Ueno 11 and container 1.
The cylindrical 7-door 13 surrounding the 5 is 1is13A and the main body 1
The resist reservoir 15d of the container 15 is divided into upper and lower parts 3B.
When the container 13 is filled with surplus regimen) &, the main body 13B is removed from the lid 13m, the container 15 is removed, and replaced with another empty container, and then the lid 13A is reattached to the main body 13BK. ◎ In the second embodiment, the surplus resist reservoir 15 in the container 15
d outer diameter D=180m, inner diameter d-80m.

If the height h=25m, the internal volume V=510cc. Furthermore, if the amount of photoresist dropped per 111 wafers during coating is ice, and the coating time is 1 minute, it is possible to coat 500 wafers S11 with one container 15, and it takes about 80 minutes to replace the container 15. Once in an hour. In addition, excess photoresist and photoresist accumulated in the resist reservoir 15dK of the container 15 is not exposed to the exhaust flow, so that it does not solidify and can be easily washed with a solvent. In this second embodiment, by removing the container 15, the excess photoresist accumulated in the resist reservoir 15d can be easily taken out from the top of the apparatus, thereby eliminating the need for maintenance inside the resist coating apparatus. Furthermore, several resist coating devices can be installed in parallel, and these devices can be operated continuously without having to be stopped for a long period of time.

It should be noted that the reference numerals attached to each part in Fig. 3 are the same as the parts already explained in Fig. 2.
The explanation will be omitted.

As explained above, the resist coating device of the present invention has the following features:
Resist floating objects near a resist coating such as a wafer are unilaterally discharged from the surface of the resist coating upward to its outer periphery by the exhaust flow, so that the floating objects do not adhere to the front and back surfaces of the resist coating. In addition, the liquid resist scattered around the photoresist by rotation of the resist coating after dropping the photoresist will not accumulate in the resist reservoir inside the container, and excess resist will not flow into the exhaust system, ensuring stable exhaust gas even after long-term use. can maintain its condition. Therefore, according to this invention.

[Over a long period of time], the effect is obtained that resist floating substances do not adhere to the resist coating, and a resist having a stable film thickness of t+ can be applied.

[Brief explanation of the drawing]

Figure 1 is a vertical cross-sectional view showing a conventional resist coating device;
FIG. 3 is a vertical sectional view showing a resist coating apparatus according to another embodiment of the present invention. 11... Wafer (resist coating), 12... Chuck, 13... Hood, 13 people... Lid, 13B
... Main body, 13a... Wide opening, 13b...
Opening, 13c...Bottom, 14...Duct space, 15
...Container, 15&...Bottom wall% 15b, 15c...
Inner, outer peripheral wall, 15c, , 15~...Inner surface, outer surface, 15d...Excess resist reservoir, 15e...Top surface, 1
5f...Top end, 15g...Opening, 16...Support ring, 17...Motor. , > fI M Spear 2 Figure Haruki Shimada, Commissioner of the Patent Office 1. Indication of the case Showa SS year, Zen Hu Petition No. 2098432, Issued @04, I/Stock Coating Prosthesis 3, Person making the amendment Relationship to the case Zen Hu Applicant (02G) Oki Electric Industry Co., Ltd. 4, Agent 5, Date of amendment order Showa year, month, day (spontaneous) 6, Subject of amendment @ Specification OIi @ 01111 Atk explanation C) @ 7, Contents of amendment 1 - Mockery = 1) II Specification 9 page easy line r8G! IIJ rllomJ
I am corrected.

Claims (1)

[Claims] (1) A vacuum chuck that is connected to a motor and that holds the resist coating by suction, and a wide opening that is installed to surround the resist coating that is attracted to the vacuum chuck and has a wide opening at the top that allows the coating to be attached and removed. It comprises a 7-hood having an opening and further having an opening connected to the exhaust pump at the bottom, and a container supported within the hood,
This container has inner and outer peripheral walls on the inner and outer peripheral parts of the bottom wall,
A surplus resist reservoir is formed in the interior surrounded by the bottom wall and inner and outer peripheral walls, and the inner peripheral wall has a size such that the vacuum chuck fits inside, and the inside of the top surface is open below the upper surface of the vacuum chuck, and the inner peripheral wall has an opening slightly larger than the wide opening of the hood, the upper end of which is located above the horizontally extending surface of the resist coating to be sucked by the vacuum chuck, and the inner surface of the outer circumferential wall has an opening that is slightly larger than the wide opening of the hood. The resist reservoir is formed in a shape that covers the upper part of the resist reservoir so as to accommodate the excess resist in the resist reservoir, and a duct space that constitutes an exhaust duct is formed between the outer surface of the outer peripheral wall and the inner peripheral surface of the seventh door. 9. The resist coating device according to claim 1, wherein the IV resist coating device (2) is divided into a lid portion and a main body portion, and the container is detachable.