JP2003093955A - Method and device for coating thin film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a method for coating a thin film by which a thin film raw material can be uniformly applied onto a wafer even when the wafer has unevenness to occur no application inferiority and used amount of a resin film and a resist of high cost can be suppressed to a relatively small amount. SOLUTION: In the method for coating the thin film by which the thin film raw material is coated on the wafer 1 by a spin method, the thin film raw material 2 is applied on the wafer in a spiral shape at the time of dropping the thin film raw material 2 before rotating the wafer and then the wafer is rotated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thin film coating method and a thin film coating apparatus, which are suitable for coating mainly when a wafer has irregularities.

[0002]

2. Description of the Related Art FIG. 3 is an explanatory view of a conventional thin film coating method. Here, a manufacturing process of a conventional thin film (here, a resin film) coating method will be described with reference to FIG. In the resin film raw material dropping step shown in FIG. 3A, the resin film 4 is appropriately dropped on the center of the wafer 1.

Here, the distance between the outer periphery of the resin film and the outer periphery of the wafer is B. In the wafer rotating step shown in FIG. 3B, when the wafer 1 is rotated, the resin film 4 dropped on the wafer 1 flows from the center toward the outer periphery with respect to the wafer 1 and the resin on the wafer surface. The membrane is coated.

FIG. 3C is a diagram in which the rotation of the wafer 1 is completed. The thin film 5 coated with the resin film raw material on the wafer 1 and the coating failure portion 6 in the portion not coated with the resin film are formed. Here, if the amount of thin film raw material dropped is small or if the wafer 1 has irregularities, the defective coating portion 6 is more likely to be formed.

[0005]

In the above-mentioned conventional thin film coating method, a relatively large amount of thin film raw material must be dropped so as to prevent defective coating on the wafer surface. In addition, when the wafer has irregularities, especially in the outer peripheral portion of the wafer, the flow of the thin film raw material tends to flow in the direction in which the thin film once flows, so that the thin film flow becomes non-uniform. Further, when the wafer has irregularities, there is a problem that a large amount of thin film raw material has to be dropped.

An object of the present invention is to apply a thin film raw material uniformly to a wafer even if the wafer has irregularities, to prevent defective coating, and to use a relatively small amount of expensive resin or resist. To provide a thin film coating method and a thin film coating apparatus.

[0007]

Therefore, according to the present invention, in a method of coating a thin film on a silicon wafer by a spin method, a relatively small amount of thin film raw material is applied by spirally applying the thin film raw material before the thin film raw material is dropped before the wafer is rotated. The thin film raw material can be uniformly coated by the amount of the thin film raw material dropped and without causing coating defects even if the wafer has irregularities.

Furthermore, when the coating film thickness is large, it is necessary to slow down the spin rotation speed, so it is necessary to consider the wafer rotation direction and the thin film raw material dropping direction (spiral direction). As described above, since the thin film source can be coated on the wafer with the minimum amount of the thin film raw material, it is possible to provide the thin film coating method capable of reducing the cost and reducing the coating failure.

That is, according to the present invention, in a thin film coating method of coating a thin film raw material on a wafer by a spin method, when the thin film raw material is dropped before the wafer is rotated, the thin film raw material is spirally coated on the wafer and the wafer is rotated. This is a thin film coating method.

In the thin film coating method of the present invention, the thin film raw material is applied onto the wafer by first dripping the raw material into the central portion of the wafer and spirally applying the thin film raw material.

Further, according to the present invention, in a thin film coating apparatus composed of a thin film raw material dropping section, a wafer rotating section and a cover, the nozzle of the thin film raw material dropping section is a predetermined distance from the substantially central portion of the wafer toward the outer periphery. This is a thin film coating apparatus in which a thin film raw material is spirally coated on a wafer by moving a distance, and then a wafer rotating unit rotates the wafer.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION A thin film coating method and a thin film coating apparatus according to an embodiment of the present invention,
This will be described below.

(First Embodiment) FIG. 1 is an explanatory view of a thin film coating method according to a first embodiment of the present invention. FIG. 1A is a diagram showing a state after the thin film raw material is dropped, FIG.
FIG. 1B is a diagram showing a state in which the wafer is being rotated, and FIG. 1C is a diagram showing a state after the wafer rotation is completed.

The features of the thin film coating method of the present invention are:
By dropping the thin film source in a spiral shape (even better if it is in the opposite direction to the substrate rotation direction), it is possible to coat the thin film raw material even with a relatively small amount of thin film raw material, thus reducing costs, and even for uneven wafers. It is a thin film coating method that can coat thin film raw materials uniformly without causing coating defects.

In the spiral thin film raw material dropping step shown in FIG. 1A, the wafer is slowly rotated while the thin film raw material 2 is dropped on the wafer 1 at the center of the substrate, and the nozzle of the thin film raw material dropping portion is moved from the center of the wafer. Move to the outer circumference. Here, the resin film distance α is shorter than the resin film-wafer outer circumference distance β of FIG.

In the wafer rotating step shown in FIG. 1B, when the wafer 1 is rotated at a medium speed, the flow of the thin film raw material 2 with respect to the wafer 1 is from the center to the outer peripheral portion. Here, since the distance A between the resin films is short, the thin film raw material 2 can easily cover the entire surface of the wafer 1 relatively easily even when the dropping amount of the thin film raw material is small.

Further, even if the wafer 1 is uneven, the distance α between the resin films is short as in the above case, so that the wafer 1 can be easily covered completely. Next, the wafer is rotated at high speed so that the target film thickness is reached as it is. In FIG. 1C, a coated thin film 3 is formed which completely covers the wafer 1 which has completed the rotation of the wafer, and no coating failure occurs.

(Embodiment 2) FIG. 2 is an explanatory view of a thin film coating apparatus according to Embodiment 2 of the present invention. The thin film coating apparatus of FIG. 2 includes a wafer support plate 11, a rotation system including a spinner 15 and a cover 14, a nozzle 13, a resist container 17, and a resin supply system including a linear actuator 16. It is configured.

The nozzle 13 is linearly moved by the linear actuator 16 along the radial direction of the wafer 12. Immediately before applying the thin film raw material, the nozzle 1
No. 3 is in the center of the wafer 12, and a predetermined amount of thin film raw material is dropped, then the wafer 12 rotates at a low speed, and then the nozzle 13 moves linearly toward the outside of the wafer 12. , The thin film raw material is applied in a spiral shape. After the thin film raw material is spirally applied, the spinner 15 rotates at high speed to form a uniform thin film.

[0020]

According to the present invention, in a method of coating a thin film on a wafer by a spin method, the thin film raw material can be dripped in a spiral shape to reduce the dropping amount of the thin film raw material, thereby reducing the cost. Can be made.
Further, it is possible to provide a thin film coating method and a thin film coating apparatus capable of uniformly coating the thin film raw material on the wafer even if the wafer has irregularities and preventing coating defects.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a thin film coating method according to a first embodiment of the present invention. 1A is a diagram showing a state after the thin film raw material is dropped, FIG. 1B is a diagram showing a state in which the wafer is being rotated, and FIG. 1C is a state after the wafer is rotated. FIG.

FIG. 2 is an explanatory diagram of a thin film coating apparatus according to a second embodiment of the present invention.

FIG. 3 is an explanatory view of a conventional thin film coating method. Figure 3
3A is a diagram showing a state after the thin film raw material is dropped, FIG.
FIG. 3B is a diagram showing a state in which the wafer is being rotated, and FIG. 3C is a diagram showing a state after the wafer is rotated.

[Explanation of symbols]

1,1 'wafer 2 Thin film raw material 3,5 coated thin film 4 resin film 6 Bad coating area 11 Wafer support plate 12 wafers 13 nozzles 14 cover 15 Spinner 16 Linear actuator 17 Resist container

Claims (3)

[Claims] 1. A thin film coating method for coating a thin film raw material on a wafer by a spin method, wherein when the thin film raw material is dropped before the wafer is rotated, the thin film raw material is spirally applied on the wafer and the wafer is rotated. And a thin film coating method. 2. The thin film coating method according to claim 1, wherein the thin film raw material is applied onto the wafer by first dripping it onto the central portion of the wafer and then applying it in a spiral shape.
The thin film coating method according to. 3. A thin film coating apparatus comprising a thin film raw material dropping section, a wafer rotating section and a cover, wherein a nozzle of the thin film raw material dropping section is moved by a predetermined distance from a substantially central portion of the wafer toward the outer periphery. A thin film coating apparatus characterized in that a thin film raw material is spirally applied on a wafer and then a wafer rotating unit rotates the wafer.