JPH05226240A - Resist coating apparatus - Google Patents

Abstract

PURPOSE:To prevent the splash of a resist from adhering to the rear of a substrate without spoiling the uniformity of a coating film thickness in the structure of an apparatus wherein the substrate is spin-coated with the resist. CONSTITUTION:The apparatus is provided with the following: a cup 15; a rebound-preveting plate 14 which surrounds the side part of a substrate 1; and a partition ring 16 which is composed of an inner-wall ring 17, an outer-wall ring 18 and a surface ring 19 and which partitions the inside of the cup 15. An evacuation port 15a which leads to a ring-shaped space R formed of the cup 15 and the partition ring 16 and an intake port 15c which is opened to the center from the partition ring 16 are made in the bottom face of the cup 15. A first ventilation port 16a which is opened in the outer-wall ring 18 and a second ventilation port 16b which is opened near the lower part of the peripheral edge part of the substrate 1 of the surface ring 19 are made in the partition ring 16. When the ring-shaped space R is evacuated forcibly form the evacuation port 15a, an air current which is directed to the second ventilation port 16b from the upper part of the substrate 1 and form the lower part of the cup 15 is generated, and it is possible to prevent the splash of a resist form creeping to the rear of the substrate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the structure of a resist coating apparatus used for manufacturing semiconductor devices and the like. In a manufacturing process of a semiconductor device, a process of applying a resist on a wafer and then exposing and developing the resist to obtain a resist pattern is repeated. Among them, for the resist coating, a spin coating type coating apparatus is used which obtains uniformity of a coating film by rotating the wafer at a high speed.

In recent years, semiconductor devices have been made finer in pattern in response to the demand for higher integration and higher density. Therefore, in a resist coating apparatus, variations in coating film that deteriorate pattern accuracy, and It is desired that no foreign matter adheres to the back surface of the wafer, which causes defocus in the exposure process.

[0003]

2. Description of the Related Art An example of a conventional resist coating apparatus will be described with reference to FIG. FIG. 2 is a schematic sectional view showing a conventional example. In the figure, the same components as those in FIG. 1 are designated by the same reference numerals. 1 is a substrate (semiconductor wafer or the like) of an object to be coated, 11 is a chuck, 12 is a rotating means including a motor,
13 is a resist nozzle, 14 is a bounce prevention plate, 25 is a cup, and 26 is a partition ring.

The bounce prevention plate 14 has a frustoconical ring shape and is attached to the cup 25. The inner diameter is slightly larger than the outer diameter of the substrate 1, the inner edge position is slightly higher than the substrate 1 coated surface, and the outer edge position is lower than the substrate 1 coated surface. Therefore, during the spin coating, excess resist flying from the coated surface of the substrate 1 hits the inner slope of this conical surface and falls down. At this time, part of the resist becomes droplets and floats below the bounce prevention plate 14 (hereinafter referred to as resist mist).
The cup 25 supports the bounce prevention plate 14 below the bounce prevention plate 14 and accommodates excess resist scattered from the coated surface of the substrate 1.

A partition ring 26 is provided on the bottom surface of the cup 25.
Is stuck. This partition ring 26 is an inner wall ring 27.
An outer wall ring 28 and an upper surface ring 29, and these and the bottom surface of the cup 25 form a ring-shaped space R. The outer wall ring 28 of the partition ring 26 is provided with a vent hole 26a, and the inner edge side of the upper surface ring 29 is located immediately below the peripheral portion of the back surface of the substrate 1. An exhaust port 25a communicating with the ring-shaped space R is provided below the partition ring 26 on the bottom surface of the cup 25, and a drain port 25b is provided outside the partition ring 26. Exhaust port 25
a communicates with an exhaust means (not shown).

When the resist is applied to the substrate 1 by the resist coating apparatus, the temperature-adjusted clean air is gently dropped from above the substrate 1 (that is, above the apparatus), and the inside of the ring-shaped space R is moved. Exhaust from the exhaust port 25a.
As a result, the air on the substrate 1 is sucked, an airflow is generated from the vicinity of the outer periphery of the substrate 1 to the ventilation hole 26a, and is discharged from the exhaust port 25a via the ring-shaped space R together with the resist mist. The resist waste liquid does not enter the ring-shaped space R but is discharged from the liquid discharge port 25b.

[0007]

However, in such a conventional resist coating apparatus, all of the generated resist mist cannot be discharged together with the airflow from the vicinity of the outer periphery of the substrate to the ventilation hole, and a part of the resist mist cannot be discharged. Adhered around the back surface of the substrate. If the resist mist adheres to the back surface of the substrate, it may cause contamination of equipment or dust in subsequent steps, defocusing during exposure, and the like. By exhausting the inside of the cup more strongly, it is possible to reduce the adhesion of this resist mist, but of the air flow on the resist coated surface of the substrate, especially in its peripheral area, the speed is increased to accelerate the evaporation of the resist solvent,
As a result, the uniformity of the coating film thickness is impaired. The non-uniformity of the coating film thickness reduces the accuracy of the resist pattern.
The conventional resist coating apparatus has the above problems.

It is an object of the present invention to solve such problems and to provide a resist coating apparatus capable of preventing the adhesion of resist mist to the back surface of a substrate without impairing the uniformity of the coating film thickness. And

[0009]

According to the present invention, an object of the present invention is to provide an apparatus for spin-coating a resist on a surface of a substrate, wherein the cup and a bouncing prevention that surrounds the side of the substrate above the cup. An exhaust port that has a plate, a partition ring composed of an inner wall ring, an outer peripheral ring, and an upper surface ring that concentrically divides the inside of the cup, and the cup has a bottom surface that communicates with a ring-shaped space formed by the cup and the partition ring. And a suction port that is open closer to the center than the partition ring, the partition ring having a first ventilation port that opens to the outer wall ring and a second ventilation port that opens near the lower edge of the substrate of the top ring. And a gas flow from the upper side of the substrate and the lower side of the cup toward the second ventilation port by forcibly exhausting the ring-shaped space from the exhaust port. By a coating apparatus, it is achieved.

[0010]

In the resist coating apparatus of the present invention, the second vent hole is provided just below the peripheral edge of the substrate on the upper surface of the partition ring, and
Since the intake port is provided in the center of the cup bottom, when the ring-shaped space formed by the partition ring and the cup bottom is forcibly exhausted from the exhaust port, the air flow from above the substrate to near the outer periphery of the substrate to the first ventilation port In addition, a substantially vertical airflow is generated to reach the second ventilation port, and air is also sucked from below the cup to generate an airflow from the center of the substrate toward the outer periphery along the back surface of the substrate to the second ventilation port. The two air streams reaching the second vent hole both prevent the resist mist from wrapping around to the back surface of the substrate.

On the other hand, since the air is also sucked from the lower side of the cup by the forced exhaust from the exhaust port as described above, if the exhaust amount is made equal to that of the conventional device, the air sucked amount from the upper side of the substrate is reduced. Become. Therefore, the flow velocity of the air flow above the peripheral portion of the substrate decreases, and the uniformity of the film thickness is improved. If it is not necessary to reduce the flow velocity of the air flow on the substrate,
By slightly increasing the exhaust amount, it is possible to more reliably prevent the resist mist from flowing around to the back surface of the substrate.

From the above, the resist coating apparatus of the present invention can prevent the resist mist from adhering to the back surface of the substrate without impairing the uniformity of the film thickness.

[0013]

EXAMPLE An example of a resist coating apparatus according to the present invention will be described with reference to FIG. FIG. 1 is a schematic sectional view showing an embodiment of the present invention. In the figure, reference numeral 1 is a substrate (semiconductor wafer or the like) of an object to be coated. Reference numeral 11 is a chuck for vacuum-sucking the substrate 1. Reference numeral 12 is a rotating means including a motor or the like, and rotates the chuck 11 that has adsorbed the substrate 1 at a desired rotation speed. Reference numeral 13 is a resist nozzle for dropping the resist onto the substrate 1. 14 is a bounce prevention plate, 15 is a cup, and 16 is a partition ring.

The bounce prevention plate 14 has a frustoconical ring shape and is attached to the cup 15. The inner diameter is slightly larger than the outer diameter of the substrate 1, the inner edge position is slightly higher than the substrate 1 coated surface, and the outer edge position is lower than the substrate 1 coated surface. Therefore, during the spin coating, excess resist flying from the coated surface of the substrate 1 hits the inner slope of this conical surface and falls down. The cup 15 supports it under the bounce prevention plate 14 and
The excess resist scattered from the coated surface is stored.

A partition ring 16 is provided at the bottom of the cup 15.
Is stuck. This partition ring 16 is an inner wall ring 17
The outer wall ring 18 and the upper surface ring 19 divide the inside of the cup 15 into concentric circles, and a ring-shaped space R is formed between them and the bottom surface of the cup 15. The inner edge side of the upper surface ring 19 of the partition ring 16 is close to immediately below the peripheral portion of the back surface of the substrate 1, and a second vent hole 16 having a large number of small holes arranged in a ring shape in this portion.
b, and the outer wall ring 18 has a first vent 16a
Is provided.

An exhaust port 15a communicating with the ring-shaped space R is formed below the partition ring 16 on the bottom surface of the cup 15, a drain port 15b is located outside the partition ring 16, and is located inside the partition ring 16, that is, in the central portion. Each has an intake port 15c. The exhaust port 15a communicates with an exhaust unit (not shown).

Using this resist coating apparatus, the exhaust port 15
As a result of spin-coating the resist on the substrate 1 with the forced exhaust amount from a equal to that when using the conventional resist coating device, the adhesion of resist mist to the back surface of the substrate was almost eliminated, and the uniformity of the coating film thickness was slightly improved. did.

The present invention is not limited to the above embodiments, but can be implemented with various modifications.

[0019]

As described above, according to the present invention,
It is possible to provide a resist coating apparatus capable of preventing the adhesion of the resist mist to the back surface of the substrate without impairing the uniformity of the coating film thickness, which contributes to an improvement in yield in semiconductor device manufacturing.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing an embodiment of the present invention.

FIG. 2 is a schematic cross-sectional view showing a conventional example.

[Explanation of symbols]

 1 substrate 11 chuck 12 rotating means 13 resist nozzle 14 bounce prevention plate 15, 25 cup 15a, 25a exhaust port 15b, 25b drain port 15c intake port 16, 26 partition ring 16a first vent port 16b second vent port 17 , 27 Inner wall ring 18, 28 Outer wall ring 19, 29 Top ring 26a Vent R Ring space

Claims (1)

[Claims] 1. A device for spin-coating a resist on the surface of a substrate (1), comprising a cup (15) and a bounce prevention plate (1) surrounding the side of the substrate (1) above the cup (15). 14), and an inner wall ring (17), an outer wall ring (18) and a top ring (19), and a partition ring (16) for partitioning the inside of the cup (15) by concentric circles, the cup (15) The cup (15) and the partition ring (1
6) Exhaust port (15a) leading to the ring-shaped space (R) formed by
And the intake port (1 that opens closer to the center than the partition ring (16)
5c), and the partition ring (16) opens in the vicinity of the first vent hole (16a) opening to the outer wall ring (18) and the lower peripheral portion of the substrate (1) of the upper surface ring (19). A second ventilation port (16b), and by forcibly exhausting the ring-shaped space (R) from the exhaust port (15a), the second ventilation port is provided from above the substrate (1) and below the cup (15). A resist coating apparatus, which is configured to generate an airflow toward the ventilation port (16b).