JPH07240360A - Chemical coating device - Google Patents

Abstract

PURPOSE:To obtain for preventing a chemical, such as a resist liquid, from penetrating into vacuum chuck for the improvement of a chemical spin coating device for the resist liquid or the like. CONSTITUTION:In a chemical coating device of a structure, wherein a chemical 2 is dripped or sprayed on the surface of a substrate 1 through a nozzle 3 and the chemical 2 is spin coated on the substrate 1, flanges 5, which have a diameter smaller than the outer diameter of the substrate 1 and are made the gaps between the flanges 5 and a vacuum chuck 4 approach to an interval of such the extent that the chemical 2 does not creep in the chuck 4 through the gaps, are respectively provided on the side surfaces of the chuck 4 for sucking and fixing the substrate 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor manufacturing apparatus, and more particularly to an improvement of a chemical liquid spin coating device (spinner) for resist liquid or the like.

In the manufacturing process of a semiconductor device, a process of applying a resist solution on a semiconductor substrate and then exposing and developing the resist solution to obtain a resist film pattern is repeated. To apply the resist solution, rotate the semiconductor substrate at high speed,
A spinner for obtaining a uniform coating film thickness of the resist is used.

In recent years, miniaturization of element patterns of semiconductor devices has progressed, and even in a resist coating apparatus, foreign matter on the back surface of a semiconductor substrate, which is a source of defocus and contamination in an exposure process due to uneven coating film thickness, is prevented. It is desired to solve such problems.

[0004]

2. Description of the Related Art FIG. 4 is an explanatory view of a conventional example. In the figure, 1 is a substrate for wafers or masks, 2 is a chemical liquid such as a resist, 3 is a nozzle for discharging a chemical liquid, 4 is a vacuum chuck for adsorbing and fixing a substrate, 6 is a motor for rotating the vacuum chuck, 7
Is a cleaning nozzle for removing the chemical liquid adhering to the back surface of the substrate, 8 is a liquid-proof plate for preventing the chemical liquid from scattering, 11 is a contact flange for preventing the chemical liquid from entering, 12 is a gas flow flange for preventing the chemical liquid from entering with a gas flow, Reference numeral 13 is a gas for preventing the chemical liquid from entering, 14 is a cleaning liquid for removing the adhered chemical liquid, and 15 is a groove for preventing the cleaning liquid 14 from entering.

An example of the semiconductor substrate suction portion of the conventional resist coating apparatus will be described with reference to the sectional view of FIG. FIG. 4 (a) shows a method of contacting a back surface of the substrate 1 with a contact flange 11 having a diameter larger than that of the substrate 1 such as a semiconductor when the chemical solution 2 is applied to prevent the solution 2 from flowing around the back surface of the substrate 1. is there.

FIG. 4B shows a method in which a gas 13 such as nitrogen (N ₂ ) or air or the like is caused to flow from the back surface of the substrate 1 to prevent the chemical solution 2 from flowing around the back surface of the substrate 1. In FIG. 4C, the cleaning liquid 14 is sprayed from the cleaning nozzle 7 to the back surface of the substrate 1 to remove the chemical solution 2 that circulates around, and a groove 15 close to the back surface of the substrate 1 is provided on the outer periphery of the vacuum chuck 4 to clean the cleaning liquid. 4 is a method for preventing the material 4 from submerging into the suction surface of the vacuum chuck 4 due to a capillary phenomenon.

[0007]

Therefore, in the conventional resist coating apparatus, the chemical liquid 2 such as resist dropped on the surface of the substrate 1 spills from the end surface of the substrate 1 to the back surface, and resist film or the like is rotated by high speed rotation. Adhesion of the chemical liquid 2 to the back surface of the substrate 1 poses a problem, and in the prior art, there is a method of bringing a contact flange 11 having a larger diameter than the substrate 1 into close contact with the substrate 1 as shown in FIG.

However, according to this method, the adhesion of foreign matter to the back surface of the substrate 1 due to the close contact and the contamination of the outer periphery of the close contact flange 11 with the chemical liquid 2 such as resist are unavoidable. Also, FIG.
The method of flowing the gas 13 such as nitrogen or the air of (b) is difficult to control the air flow and the temperature in the processing chamber.
The film thickness uniformity may be impaired.

Further, the method shown in FIG. 4 (c) is a method in which the cleaning liquid 14 is not allowed to wrap around the suction surface of the vacuum chuck 4 on the back surface of the substrate 1. However, when the cleaning liquid 14 enters, residues are generated in the adjacent portions. May occur.

The purpose of the flange of the present invention is to prevent adhesion of a chemical solution such as a resist film and to reduce the contact area between isotropicity and the vacuum chuck, and does not utilize the capillary phenomenon. In view of the above points, the present invention is provided for the purpose of obtaining an effective means for preventing a chemical liquid such as a resist from entering the vacuum chuck.

[0011]

FIG. 1 is a diagram for explaining the principle of the present invention. In the figure, 1 is a substrate for a wafer or a mask,
Reference numeral 2 is a chemical liquid such as resist, 3 is a nozzle for discharging the chemical liquid, 4 is a vacuum chuck for adsorbing and fixing the substrate, 6 is a motor for rotating the vacuum chuck, 7 is a cleaning nozzle for removing the chemical liquid adhering to the back surface of the substrate, and 8 is a chemical liquid. Is a liquid-repellent plate for preventing the scattering of the liquid, 9 is the scattered liquid, 10 is the adhered liquid, and 14 is a cleaning liquid for removing the liquid.

The conventional problem is that, as shown in FIG. 1A, a flange 5 provided on the side surface of the vacuum chuck 4 on the back surface of the substrate 1 for preventing the intrusion of a chemical liquid is smaller than the outer diameter of the substrate 1. This can be solved by adopting a method of approaching the gap between the back surface of the substrate 1 and the flange 5 to the extent that the chemical solution 2 does not enter. A flange 5 having an outer diameter smaller than that of the substrate 1 is attached to the outer circumference of the vacuum chuck 4 on the back surface of the substrate 1 and is brought close to a distance of 0.1 to 0.5 mm from the back surface of the substrate 1. Although this interval varies depending on the viscosity of the chemical solution and the number of rotations of the substrate, the photoresist used for the semiconductor substrate generally has a viscosity of about 25 cps.
It has been empirically known that when the distance is 1 to 0.5 mm, the distance does not go down, and at present, the distance is set not too narrow and not too wide.

The flange 5 allows the chemical liquid 2 such as resist to be formed.
Since it can be prevented from entering the back surface of the substrate 1, the suction surface of the flange 5 is reduced to an outer diameter capable of withstanding high-speed rotation. Although the outer diameter of the suction surface varies depending on the size of the substrate 1, foreign matter adhered to the back surface of the substrate 1 due to contact cannot be ignored.

As shown in FIG. 1 (b), according to the present structure, the flange 5 is extended to a range that does not hinder the transfer of the substrate 1, the cleaning liquid 14 is positively taken in, and cleaning is performed every time within the same processing time. , It has a structure that keeps it always clean.

According to the conventional method of FIG. 4, when the outer diameter of the substrate 1 is approached, the chemical liquid 2 such as resist adheres to the adsorption surface. Further, if the outer diameter of the flange is reduced, it is necessary to increase the amount of the cleaning liquid 14 in the rising portion of the chemical liquid 2 on the end surface of the substrate 1 and to form the cleaning nozzle 3 into two systems.

Since the back surface of the substrate 1 covered with the flange 5 close to the substrate 1 is prevented from invading the chemical liquid 2 such as resist, the cleanliness can be secured. Further, since the outer periphery of the flange 5 is away from the suction surface of the vacuum chuck 4, the cleaning liquid 14 does not enter the suction surface and the suction force does not decrease. Also, it can be used for cleaning the vacuum chuck 4.

That is, an object of the present invention is an apparatus for dropping or spraying the chemical liquid 2 onto the surface of the substrate 1 from the nozzle 3 and spin-coating the chemical liquid 2 on the substrate 1, as shown in FIG. Vacuum chuck 4 for sucking and fixing the substrate 1
On the side surface of the substrate 1 having a diameter smaller than the outer diameter of the substrate 1 and having a gap close to the vacuum chuck 4 close to a distance such that the chemical liquid 2 does not penetrate.

[0018]

According to the above-mentioned structure of the present invention, since the contact area between the substrate and the vacuum chuck is reduced, the suction outer diameter of the vacuum chuck is reduced and the back surface of the substrate is 0.1 to 0.5 mm.
By extending the flange close to the substrate to the vicinity of the outer periphery of the substrate, the adhesion of chemicals such as resist is prevented. The chemical liquid such as the resist adhered to the difference between the outer periphery of the flange and the outer periphery of the substrate is cleaned by the cleaning liquid ejected from the nozzle. At this time, part of the cleaning liquid is allowed to enter the gap between the flanges,
It is possible to simultaneously clean the substrate and the vacuum chuck by adjusting the rotation amount of the substrate.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an explanatory view of the principle of the present invention, FIG. 2 is an explanatory view of an embodiment of the present invention, and FIG. 3 is an amount (measured value) of foreign matter on the back surface of a substrate of a conventional example and the present invention.

In the figure, 1 is a substrate for wafers or masks, 2 is a chemical liquid such as resist, 3 is a nozzle for discharging the chemical liquid,
Reference numeral 4 is a vacuum chuck for adsorbing and fixing the substrate, 6 is a motor for rotating the vacuum chuck, 7 is a cleaning nozzle for removing the chemical liquid adhering to the back surface of the substrate, 8 is a liquid-proof plate for preventing the chemical liquid from scattering, 9 is the scattered chemical liquid, 10 Is a chemical liquid attached, and 14 is a cleaning liquid for removing the chemical liquid.

An embodiment of the present invention will be described with reference to FIGS. 1, 2 and 3. As shown in the sectional view of the main part in FIG.
In the apparatus of the present invention, the nozzle 3 for discharging the chemical liquid 2 such as a resist, the vacuum chuck 4 for vacuum-fixing the substrate 1 for the wafer or the mask, and the prevention of the chemical liquid 2 from entering the back surface of the substrate 1 of the present invention are provided. A flange 5 provided on the periphery of the vacuum chuck 4 close to the back surface of the substrate 1, a motor 6 for rotating the vacuum chuck, and a chemical solution 2 as an accessory as shown in FIG.
1 is equipped with a liquid-proof plate 8 for preventing scattering of the liquid, and a cleaning nozzle 7 for ejecting a cleaning liquid 14 for removing the chemical liquid 10 adhering to the back surface of the substrate 1, as shown in FIG. 1 (c).

Now, a first embodiment of the present invention will be described. A 6-inch silicon (Si) wafer is adsorbed on the vacuum chuck 4 as the substrate 1, and a positive resist solution as the chemical solution 2 is dropped from the nozzle 3. The viscosity of the resist was 25 cp (centipoise), the suction force of the vacuum chuck 4 was 600 mmHg, the rotation speed of the substrate 1 was 4,000 rpm, and the discharge amount of the resist from the nozzle 3 was 2 cc.

Vacuum chuck 4 including flange 5 of the present invention
Has an outer diameter of 100 mmφ, and the suction part of the vacuum chuck 4 is 40 mm
φ. Substrate 1 backside cleaning is performed with cleaning liquid 14 from cleaning nozzle 7.
The back surface of the substrate 1 is washed with a rinse liquid.

The above embodiment is an example in which a Si wafer is used as the substrate 1, and the substrate 1 is circular, but it may be a square substrate 1 such as a mask substrate. Further, the shape of the vacuum chuck 4 for sucking the substrate 1 is not limited to a circular shape, and may be a square shape so that it can be applied to a quadrangular substrate 1 such as a mask or a reticle as shown in FIG. 2B.

FIG. 3 shows how foreign matter adheres to the back surface of the substrate 1 according to the above embodiment in comparison with the conventional example. FIG. 3A shows the amount of foreign matter observed in a conventional example having no flange 5 as in the present invention under the same resist film coating conditions as an actual measurement value.

When classified according to the size of foreign matter, L (0.5 μm)
Or more) 3,667 pieces, M (0.3 μm to 0.5 μm diameter) is 6
03, S (0.2 to 0.3 μm), 3,047, a total of 7,317 were observed.

On the other hand, as shown in FIG.
Flange 5 of the present invention under the same resist film coating conditions
In the case where is provided on the periphery of the vacuum chuck 4, L is 540
The number of foreign matters decreased to less than a quarter, which is 1,594 in total, 575 in M, 479 in S, and 479 in S.

[0028]

As described above, according to the present invention,
Since it is possible to eliminate the adhesion of a chemical such as a resist to the back surface of the substrate, it is possible to prevent defocusing due to an increase in the thickness at the time of exposure in the exposure apparatus due to the buildup of the resist film on the peripheral edge of the back surface of the substrate. It is possible to reduce the carry-in of foreign matters and dust to the next process such as diffusion and film formation.

Therefore, it greatly contributes to the improvement of the quality and yield of semiconductor devices.

[Brief description of drawings]

FIG. 1 is an explanatory view of the principle of the present invention.

FIG. 2 is an explanatory diagram of an embodiment of the present invention.

FIG. 3 Amount of foreign matter on the back surface of the substrate of the conventional example and the present invention (measured value)

FIG. 4 is an explanatory diagram of a conventional example.

[Explanation of symbols]

 In the figure, 1 substrate 2 chemical liquid 3 nozzle 4 vacuum chuck 5 flange 6 motor 7 cleaning nozzle 8 liquid-proof plate 9 scattered chemical liquid 10 adhered chemical liquid

Claims (2)

[Claims] 1. An apparatus for dropping or spraying a chemical solution (2) onto a surface of a substrate (1) from a nozzle (3) and spin-coating the chemical solution (2) onto the substrate (1), the substrate (1) On the side of the vacuum chuck (4) that attracts and fixes
A diameter smaller than the outer diameter of the substrate (1) and the vacuum chuck
A chemical solution applying device, characterized in that it has a flange (5) which is close to the clearance (4) so that the chemical solution (2) does not submerge. 2. The distance between the substrate (1) and the vacuum chuck (4) for the chemical liquid (2) is 0.1 to 0.5 mm. 1. The chemical liquid coating device according to 1.