KR200175409Y1 - Photoresist coating device - Google Patents

Abstract

The present invention provides a photoresist coating apparatus which first disperses the photoresist supplied to the wafer surface at a constant pressure generated by the pressing means, and then rotates the wafer at a high speed to more uniformly disperse the dispersed photoresist. .

The pressing means used in the present invention is composed of a cylindrical cylinder fixed to the upper side cover of the coating chamber, and a piston for vertically conveying the inside of the cylinder, the piston uses a disk member having a diameter slightly smaller than the inner diameter of the cylinder.

In the present invention, by installing a plurality of fans together with the pressurizing means to generate the wind pressure can improve the efficiency.

Description

Photoresist Coating Equipment

The present invention relates to a photoresist coating apparatus, and more particularly, to a photoresist coating apparatus capable of forming a coating film having a uniform thickness by applying a constant pressure during photoresist injection.

In the semiconductor manufacturing process, a lithography process for forming a pattern forms a photoresist film on the wafer surface. The photoresist is a polymer solution in which a photoresist is added to a resin and then dissolved in a solvent. The photoresist is coated by spraying about 3 to 5 CC onto a wafer surface rotating at a high speed in a coating chamber. The thickness of the photoresist film formed through the coating process depends on the viscosity of the photoresist, the concentration, and the rotational speed of the wafer. In particular, the rotational speed of the wafer serves as a main factor in determining the thickness of the photoresist film. As the wafer rotates at high speed, the photoresist injected at the center of the wafer spreads outward due to the centrifugal force, so that the photoresist theoretically forms a coating film evenly over the entire surface of the wafer. This photoresist coating process will be described with reference to FIG. 1 as follows.

1 is a front sectional view of a general photoresist coating apparatus, in which a rotating shaft 4 penetrating a base 2 is positioned inside a coating chamber 10 having an open upper portion, and a wafer 6 is placed on an upper upper rotating shaft 4. The disk 5 on which is placed is fixed. Above the coating chamber 10 is a nozzle 1 for injecting photoresist R into the center of the wafer 6 surface. On the other hand, the upper portion 3A of the side cover 3 integrally formed with the base 2 is bent toward the center of the coating chamber 10, which is a photoresist R sprayed onto the rotating wafer 6 surface. This is to prevent the dispersion to the outside due to the centrifugal force.

The photoresist R injected to the center of the surface of the wafer 6 rotating at high speed through the nozzle 1 spreads to the outer portion due to the centrifugal force generated by the high speed rotation of the wafer 6 as described above. In theory, the photoresist R is uniformly dispersed throughout the wafer 6 to form a photoresist film. However, since the solvent contained in the rotating photoresist (R) in accordance with the rotation of the wafer 6 is volatilized during rotation, the thickness of the film becomes thinner. In addition, due to the high-speed rotation of the wafer 6, the extra photoresist is pushed toward the edge of the wafer 6, which exhibits the greatest centrifugal force, and the pushed photoresist is edged due to the surface tension of the wafer 6. This phenomenon is called "edge bead". After removing the edge beads, the photoresist coating process is completed by baking at a temperature of 80 to 100 ° C.

In the photoresist coating process using the photoresist coating apparatus, as the wafer rotation speed increases, the thickness of the coated photoresist film becomes thinner, but the viscosity of the photoresist is limited. I can not make it. Therefore, there are constraints to forming a thin photoresist film. In addition, the coating process of the photoresist as described above is difficult to form a photoresist film of uniform thickness on the entire surface of the wafer by using only the centrifugal force generated by the rotation of the wafer. That is, even on the same wafer surface, the centrifugal force between the center and the edges is different from each other, so that a thicker photoresist film is formed on the edges.

The present invention is to solve the above-mentioned problems occurring during the photoresist coating process, a photoresist capable of forming a photoresist film having a uniform thickness by dispersing the sprayed photoresist first using a pressure and then rotating at high speed The purpose is to provide a coating apparatus.

The present invention for realizing the above object is to equip the side cover constituting the photoresist coating chamber with a pressurizing means for sealing the internal space, and to first disperse the photoresist supplied to the wafer surface at a constant pressure. do. The pressurizing means used in the present invention consists of a cylindrical cylinder fixed to the upper side cover of the coating chamber, and a piston for vertically conveying the inside of the cylinder, the piston uses a disk-shaped member having a diameter slightly smaller than the inner diameter of the cylinder. In addition, the present invention can improve the efficiency by mounting a fan for generating a predetermined size of the wind pressure in the pressing means.

1 is a front sectional view of a general photoresist coating apparatus.

Figure 2 is a front sectional view of a first embodiment of the present invention.

3 is a front sectional view of a second embodiment of the present invention;

<Description of the symbols for the main parts of the drawings>

20 and 40: coating chambers 21 and 41: base

22 and 42: side cover 26 and 46: wafer

25 and 45 nozzles 30 and 50 pressurizing means

31 and 51: cylinders 32 and 52: piston

60: fan

Hereinafter, with reference to the accompanying drawings an embodiment of the present invention will be described in detail.

2 is a front sectional view of the first embodiment of the present invention, the biggest feature of this embodiment is that the pressure is applied to the surface of the wafer by forming a pressing means on top of a general photoresist coating apparatus.

A rotating shaft 23 penetrating the base 21 is positioned inside the coating chamber 20 having an upper portion, and a disk 24 on which the wafer 26 is placed is fixed to the upper rotating shaft 23. The upper portion 22A of the side cover 22 integrally formed with the base 21 is bent toward the center of the coating chamber 20, and the pressing means 30 is attached to the upper portion 22A of the side cover 22. Consists of.

The pressurizing means 30 consists of a cylindrical cylinder 31 fixed to the upper side 22A of the side cover 22 of the coating chamber 20, and a piston 32 for vertically conveying the inside of the cylinder 31. The piston 32 is a disk-shaped member having a diameter slightly smaller than the inner diameter of the cylinder 31, and can be moved up and down along the inner wall of the cylinder 31. A support 33 connected to a conveying means (not shown) is fixed to the upper portion of the piston 32, and a nozzle 25 for spraying the photoresist R onto the surface of the wafer 26 is mounted at the center thereof. . Since the nozzle 25 is configured independently of the piston 32, its position does not change when the piston 32 is vertically conveyed. Here, the inner space of the coating chamber 20 is sealed from the outside by the cylinder 31 and the piston 32.

The operation and function of the first embodiment of the present invention configured as described above will be described.

First, the photoresist R is injected through the nozzle 25 onto the surface of the wafer 26 rotating at a low speed, and at the same time, the driving unit is operated to transfer the piston 32 downward toward the wafer 26. At this time, a constant pressure acts in the space of the coating chamber 20 sealed by the piston 32 which is downwardly transported, and thus the pressure pressurizes the photoresist R supplied to the wafer 26 surface. The result is that the resist R is first uniformly dispersed. Subsequently, when the wafer 26 is rotated at a higher speed, the first uniformly dispersed photoresist R is more uniformly dispersed by centrifugal force and the thickness thereof becomes thinner.

Figure 3 is a front sectional view of a second embodiment of the present invention, the biggest feature of this embodiment is that the fan as well as the pressurizing means is installed on the top of the chamber. A fan was installed under the pressurizing means, and for this purpose, the pressurizing means was installed to enable rotation and vertical transfer. This will be described in more detail as follows.

A rotating shaft 43 penetrating the base 41 is positioned inside the coating chamber 20 having an open top, and a disk 44 on which the wafer 46 is placed is fixed to the upper rotating shaft 43. The upper portion 42A of the side cover 42 integrally formed with the base 41 is bent toward the center of the coating chamber 40, and the pressing means 50 and the fan are mounted on the upper portion 42A of the side cover 42. 60 is comprised.

The pressurizing means 50 consists of a cylindrical cylinder 51 fixed to the upper side 42A of the side cover 42 of the coating chamber 40, and a piston 52 which is moved and rotated inside the cylinder 51. The piston 52 is a disc-shaped member having a diameter slightly smaller than the inner diameter of the cylinder 51, and the support 53 is connected to the upper and lower conveying and rotating means (not shown). At the center of the piston 52, a nozzle 45 for injecting the photoresist R onto the surface of the wafer 46 is mounted. The nozzle 25 is installed to be vertically conveyed together with the piston 52 at the time of vertically conveying the piston 52, but is independently provided for the rotation of the piston 52. On the other hand, a plurality of fans 60 are fixed to the lower surface of the piston 52, so that the wind pressure of a certain size is caused by the fan 60 rotating according to the rotation of the piston 52. 46, of course.

Referring to the operation and function of the second embodiment of the present invention configured as described above are as follows.

First, the photoresist R is sprayed onto the surface of the wafer 46 rotating at a low speed through the nozzle 45. At the same time, the driving unit is operated to transfer the piston 52 downward toward the wafer 46. Accordingly, the pressure is increased due to the piston 52 which is conveyed downward in the inner space of the sealed coating chamber 40, which pressurizes the photoresist R supplied to the surface of the wafer 46, thereby causing the photoresist to be pressed. A result of uniformly dispersing (R) first is obtained. At the same time, by rotating the piston 52, the fan 60 mounted on the lower part of the piston 52 also rotates at a constant speed, and the wind generated by the rotation of the fan 60 prevents the dispersion of the photoresist R. Of course, it can be promoted to form a more uniform photoresist coating film.

Subsequently, when the wafer 46 is rotated at a high speed, the first uniformly dispersed photoresist R is more uniformly dispersed by the centrifugal force and the thickness thereof becomes thinner. Even if the wafer 46 rotates at the same rotational speed as previously, the thickness of the photoresist R becomes thinner due to the downward pressure of the piston 52 and the strong wind pressure of the rotating fan 35.

On the other hand, as described above, the fan may be fixed to the lower part of the piston, and alternatively, by configuring the lower surface of the piston so that the shape of the fan may not be fixed to a separate fan of a separate piston.

As described above, the present invention may first disperse the photoresist supplied to the wafer surface at a constant pressure by using a downwardly moving piston, and then rotate the wafer at a high speed to more uniformly disperse the dispersed photoresist. It is possible to form a photoresist film of uniform thickness on the entire surface of the wafer.

On the contrary, the fan is fixed to the lower part of the piston to apply a wind pressure generated when the fan is rotated by the rotation of the piston to the photoresist, thereby having a great effect in forming a thin and uniform photoresist film.

In the above description, the apparatus for spraying and coating the photoresist has been described as an example, but it can be applied to the apparatus for coating another process solution having similar conditions to the photoresist, that is, viscosity.

Claims (3)

A photoresist is formed by dispersing a photoresist supplied to a surface of a rotating wafer, which is composed of a base and a side cover, a rotating shaft penetrating the base, a disk fixed to an upper end of the rotating shaft, and a disk and a corresponding nozzle. In the photoresist coating apparatus for forming a film, Equipped with a pressing means for sealing the inner space on the side cover to pressurize and disperse the photoresist supplied to the rotating wafer surface at a constant pressure and uniformly disperse the photoresist dispersed by centrifugal force by the high-speed rotation of the wafer Photoresist coating apparatus, characterized in that the coating. The method of claim 1, The pressing means is composed of a cylindrical cylinder fixed to the upper side cover of the coating chamber and a piston pumped from the inside of the cylinder, the center portion of the piston is characterized in that the nozzle for applying a photoresist penetrates Resist coating apparatus. The method of claim 1, The pressurizing means comprises a cylindrical cylinder fixed to the upper side cover of the coating chamber and a piston which can be vertically transported and rotated inside the cylinder, wherein the fan is fixed to the lower part of the piston and a nozzle for applying photoresist at the center thereof. A photoresist coating apparatus, characterized in that penetrated.