JPH05166710A - Method and device for rotationally applying organic material - Google Patents

Abstract

PURPOSE:To improve the productivity by forming the film of an organic material having a uniform thickness on the surfaces of any kind of substrates. CONSTITUTION:In the title applying method by which an organic film having a prescribed thickness is formed on a substrate 1 by dropping the solution of an organic material prepared by dissolving the material in a solvent on the substrate while the substrate is 1 rotated around a vertical shaft, a desired amount of the solution is dropped on the substrate 1 placed on and fixed to a rotatable placing table 2 in an applying chamber 11. Then cooled air or air mixed with an atomized solvent is blown upon the surface of the rotating substrate from an air blowing port 12 which is provided above a disk 14 so that the port 12 can be coaxially faced to the disk 14, with the disk 14 being coaxially fixed to a position near the substrate 1 in parallel with 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 spin coating method of an organic material for forming an organic material film on the surface of a substrate and the construction of the apparatus, and in particular, a substrate of any size can have a uniform thickness on its surface. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an organic material spin coating method and apparatus for improving productivity by forming an organic material film.

In the manufacturing process of a semiconductor device, a step of forming various patterns on a substrate such as a semiconductor wafer by coating the surface of the substrate with an organic material film such as a resist and then performing a plurality of steps such as exposure and etching. However, in order to form such an organic material film, a spin coating method (spin coating method) in which an organic material liquefied with a solvent is dropped onto a substrate rotating at high speed is often used.

On the other hand, with the progress of technology, the size of the substrate itself is increasing, and at the same time, the miniaturization and high integration of various patterns formed on the substrate are being demanded. How to make the thickness of the above organic material film uniform is a major issue.

[0004]

2. Description of the Related Art FIG. 2 is a conceptual diagram for explaining a conventional spin coating method of an organic material together with its apparatus. In the drawing, a substrate as an organic material coated object is a disk-shaped semiconductor wafer (hereinafter simply referred to as a wafer), and a case of applying a resist on the surface thereof will be described as an example.

In FIG. 2, a wafer 1 is connected to a rotating mechanism (not shown) and can be rotated at a speed of about 3000 rpm.
It is positioned and fixed, for example, by means such as vacuum suction in a state where the center is aligned with the above.

The periphery of the mounting table 2 including the rotary shaft is surrounded by the coating chamber 3 composed of the chamber body 3a and the chamber lid 3b. On the other hand, a resist dispense nozzle 4 (hereinafter simply referred to as a nozzle) fixed to the chamber lid portion 3b is arranged above the mounting table 2 on the rotation axis, with its opening facing downward. From a tank (not shown) connected to the nozzle 4, for example, ethylene glycol monoethyl ether acetate (CH ₃ CO ₂ CH ₂
A liquefied resist liquefied with a solvent such as CH ₂ OC ₂ H ₅ ) is supplied in a preset amount.

Therefore, a wafer 1 as an object to be coated is placed on a mounting table 2 rotatably arranged in the chamber body 3a.
After mounting the above-mentioned means or the like, the chamber lid 3b in which the nozzle 4 is arranged is lowered and fixed to the chamber body 3a, and the mounting table 2 is rotated at 3000 rpm by a rotation mechanism portion (not shown).
When the liquefied resist 5a of a preset amount (for example, about several cc for a wafer having a diameter of several inches) is dropped from the nozzle 4 while rotating at about a certain degree, the liquefied resist 5a is dropped. Is spread on the wafer 1 by the centrifugal force as shown by an arrow A to form a liquefied resist film having a required thickness (for example, 1 to 2 μm) on the surface of the wafer 1. Therefore, the liquefied resist film is required on the wafer 1 after the solvent is vaporized. The resist film 5 having a thickness can be formed.

Since the excess liquefied resist 5a is scattered from the periphery of the wafer 1, the resist film can be formed only on the surface of the wafer 1.

[0009]

As described above, the liquefied resist 5a dropped on the wafer 1 moves toward the periphery while wetting the surface of the wafer 1 and the surplus portion is scattered from the periphery. Therefore, the liquefied resist film 5a and thus the resist film 5 having a substantially uniform thickness can be formed on the wafer 1.

However, since the solvent of the liquefied resist flowing on the wafer 1 is vaporized during flowing, the viscosity increases as the distance from the dropping point increases, and the subsequent liquefied resist easily deposits.

Therefore, the thickness of the liquefied resist film 5a and thus of the resist film 5 increases as it approaches the peripheral portion. This means that the thickness of the resist film 5 between the central portion and the peripheral portion increases as the size of the wafer increases. It means that the difference between is large.

In the conventional general technique, the variation in the thickness is within an allowable value (for example, ± 0.2 μm) within a radius of 100 to 150 mm from the liquefied resist dropping point. The resist film can be formed.

However, in a region exceeding the above range, the thickness of the resist film exceeds the above-mentioned allowable value. For example, in the case of a square wafer having a side of about 300 mm, the resist film thickness at the peripheral corners is in the central part. It has been confirmed that the film thickness is 2 to 10 times.

Therefore, in the conventional method and apparatus for spin coating of organic material, variation in thickness is allowed when the substrate as an object to be coated becomes large and the area of organic material coating exceeds a radius of 100 to 150 mm. There is a problem that it is not possible to form an organic material film having a substantially uniform thickness that falls within the value.

Further, the organic material particles scattered from the periphery of the wafer 1 may be re-attached to the surface of the wafer 1 after bouncing back on the inner wall surface of the chamber, and as a result, the wafer 1
There is a problem that the uniformity of the organic film thickness on the surface may be destroyed or the surface of the wafer 1 may be damaged.

[0016]

[Means for Solving the Problems] The above-mentioned problems are solved by rotating an organic material which is liquefied with a solvent on a substrate which rotates on a vertical axis to form an organic film having a required thickness on the substrate. A coating method, in which a required amount of the liquefied organic material is dropped on a substrate mounted and fixed on a rotatable mounting table in a coating chamber, and then an axis is aligned with a proximity position parallel to the substrate. On the surface of the substrate that rotates the cooled air or the air containing the solvent in the form of a mist from a blower provided coaxially with the disc so as to face the disc above a fixed disc having a predetermined diameter. This is achieved by the method of spin-coating an organic material that is sprayed.

Further, there is provided a spin coating apparatus for an organic material, wherein an organic material liquefied with a solvent is dropped onto a substrate rotating on a vertical axis to form an organic film having a required thickness on the substrate, which is a coating chamber. Above the substrate mounted and fixed on the rotatable mounting table, the substrate is fixed by aligning the substrate and the axis in a proximity position parallel to the substrate after the required amount of the liquefied organic material is dropped. A disc having a predetermined diameter and a blower port coaxially fixed to the disc so that the opening above the disc faces the disc direction. This is achieved by a spin coater of organic material which is configured to blow cooled air or air containing the solvent in the form of mist.

[0018]

When the region where the viscosity of the liquefied organic material increases due to the vaporization of the solvent is cooled, the vaporization of the solvent in the region is suppressed, so that the flow region of the liquefied organic material can be expanded.

Further, when the gas containing the solvent is jetted to the region where the viscosity is high, the solvent is supplied, so that the flow region of the liquefied organic material can be expanded. In particular, the expansion of the flow region of the liquefied organic material in this case means the expansion of the film formation region of uniform thickness.

Therefore, in the present invention, the cooling air or the solvent-containing air is jetted toward the mounting table from above a disk of a predetermined size, which is arranged in a parallel position close to and above the conventional rotating mounting table, so as to be liquefied. The evaporation of the solvent contained in the organic material is suppressed, and the flow region of the liquefied organic material is expanded.

Therefore, by increasing the amount of the liquefied organic material to be supplied, an organic material film having a uniform thickness can be formed on the surface of a substrate of any size, and after being scattered in all directions from the periphery of the substrate, the inner wall surface of the chamber is scattered. It is possible to realize a spin coating method of an organic material and an apparatus therefor capable of suppressing the adhesion of repelling organic material particles to the surface of a substrate.

[0022]

EXAMPLE FIG. 1 is a diagram for explaining the spin coating method according to the present invention together with the apparatus thereof. (1-1) shows the state when the substrate is mounted and (1-2) shows the state when the spin coating is performed. Shows.

In the figure, as in the case of FIG. 2, the substrate to be coated is a wafer and the surface of the substrate is coated with a resist. Therefore, the same target members as those in FIG. It represents.

In (1-1) of FIG. 1, the mounting table 2 described in FIG. 2 connected to a rotation mechanism (not shown) is mounted on the chamber body 3a so as to be freely rotatable. Further, as in FIG. 2, the coating chamber 11 that is engaged with and integrated with the chamber body 3a.
On the ceiling wall 11a _-1 of the chamber lid portion 11a, which is composed of the blower outlet 12 and the blower outlet 12 which are attached to the ceiling wall 11a _-1 via a pipe 12a connected to an external cooling blower (not shown). In the opening, for example, a disc 14 integrated with the rod 14a held and fixed on the central axis of the opening by a plurality of arms 13 is provided with its core aligned.

The diameter of the disk 14 is a radius 100 around the area where an organic material film having a substantially uniform thickness can be formed by the conventional spin coating method described with reference to FIG. The size is about 150 mm.

Therefore, the air blown out from the blower port 12 flows around the disc 14 into the chamber lid 11a and then the coating chamber 11. The positions of the disk 14 in the vertical direction in the drawing with respect to the chamber lid 11b are the wafer and the disk 14 mounted and fixed on the mounting table 2 when the chamber lid 11a is mounted and fixed to the chamber body 3a. Are arranged so as to face each other in parallel with a slight distance therebetween.

Therefore, after mounting the wafer 1 described with reference to FIG. 2 on the mounting table 2 of the chamber main body 3a by means such as vacuum suction as shown by an arrow, the wafer 1 is mounted on the mounting table 2 with a spoid jig 15 as shown in FIG. In a state where a similar amount of liquefied resist 5a is dropped (for example, about several cc), the chamber lid 11a to which the above-mentioned disc 14 is fixed is lowered as shown by an arrow to engage with the chamber body 3a. And fix them, (1-2)
As shown in FIG. 5, a coating chamber 11 that surrounds the wafer 1 together with the mounting table 2 can be configured.

Next, while the mounting table 2 is rotated at about 3000 rpm by a rotating mechanism (not shown), air cooled to about 0 ° C. is blown from the blower port 12 at a pressure of about 10 mm H ₂ O, whereby the cool air is removed. When the wafer 1 is larger than the disk 14, the cold air blows from the circumference of the disk 14 to the peripheral surface of the wafer 1 as shown by an arrow. Wafer 1
The ambient temperature can be cooled, and the evaporation of the solvent from the liquefied resist 5a flowing on the surface of the wafer 1 can be suppressed.

Therefore, the flow region of the liquefied resist 5a can be expanded, and the supply amount thereof can be set in accordance with the size of the wafer 1 so that the wafer 1 of any size can be obtained.
However, the resist film 5 having a uniform thickness can be formed on the surface.

Particularly, in the spin coater having such a structure,
Since the liquefied resist 5a or particles of the resist 5 which are scattered from the periphery of the wafer 1 and bounce off the inner wall of the chamber are hard to adhere to at least the region covered by the disk 14 on the wafer 1, There is also an advantage that defects can be suppressed.

The resist 5 is used instead of the cold air described above.
When the air in which the solvent is mixed in the form of spray is jetted from the blower port 12, only the solvent is supplied to the periphery of the surface of the wafer 1. Therefore, the liquefied resist is the same as when the cold air is jetted. By setting the supply amount of 5a, the resist film 5 having a uniform thickness can be formed on the surface of the wafer 1 of any size.

[0032]

As described above, according to the present invention, a spin coating method of an organic material and an apparatus thereof for improving productivity by forming an organic material film of a uniform thickness on the surface of a substrate of any size are provided. Can be provided.

In the description of the present invention, the case where the organic film is a resist is taken as an example, but the same effect can be obtained even when an organic material other than the resist is used, and the same effect is obtained even when the wafer as the material substrate to be coated has a rectangular shape. It is clear that the effect of is obtained.

[Brief description of drawings]

FIG. 1 is a diagram illustrating a spin coating method according to the present invention together with an apparatus therefor.

FIG. 2 is a conceptual diagram explaining a conventional spin coating method of an organic material together with the apparatus.

[Explanation of symbols]

1 semiconductor wafer (substrate) 2 mounting table 3a chamber body 11 coating chamber 11a chamber lid 11a _-1 ceiling wall 12 air outlet 12a pipe 13 arm 14 disk 14a rod 15 dropper jig

Claims (4)

[Claims] 1. A spin coating method of an organic material, wherein an organic material liquefied with a solvent is dropped on a substrate rotating on a vertical axis to form an organic film having a required thickness on the substrate, which is a coating chamber. After dropping a required amount of the liquefied organic material on the substrate (1) mounted and fixed on the rotatable mounting table (2) in (11), the substrate is placed in a close position parallel to the substrate (1). Air or mist cooled from the blower port (12) provided coaxially with the disc (14) so as to face the disc above the disc (14) fixed with its axis aligned and fixed. 2. A method for spin-coating an organic material, characterized in that air containing the solvent is sprayed onto the surface of the rotating substrate (1). 2. The radius of the disk according to claim 1 is 100 to 15
Spin coating method of organic material characterized by 0 mm. 3. A spin coating apparatus for an organic material, wherein an organic material liquefied with a solvent is dropped onto a substrate rotating on a vertical axis to form an organic film having a required thickness on the substrate, which is a coating chamber. Above the substrate (1) mounted and fixed on the rotatable mounting table (2) in (11), parallel to the substrate (1) after the required amount of the liquefied organic material is dropped. A disk (14) with a predetermined diameter, which is fixed by aligning the substrate (1) with the axis at a close position
And a blower port (12) fixed coaxially with the disc (14) so that the opening faces the disc direction above the disc (14). (12) A spin coater for organic materials, characterized in that cooled air or air containing the solvent in the form of mist is blown out. 4. The radius of the disk according to claim 3 is 100 to 15
Spin coating device for organic materials, characterized by 0 mm.