JPH0631241A - Spin coating method - Google Patents

Abstract

PURPOSE:To provide a spin coating method by which an inside of a recessed part on the surface of a substrate is coated while the recessed part is filled with the coating liquid and defoaming of the liquid is carried out easily. CONSTITUTION:A substrate 2 is rotated by a motor through a substrate supporting part 6 in a container 5 to apply a coating liquid 3 to the surface of the substrate 2. Then. the container is evacuated to become vacuum and the substrate 2 and the coating liquid 3 are kept in the vacuum atmosphere.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary coating method suitable for coating a coating solution such as a resist on the surface of a substrate having a recess on the surface such as a sintered metal wafer.

[0002]

2. Description of the Related Art Conventionally, when a coating liquid is applied to the surface of a substrate by utilizing centrifugal force, the coating liquid is placed at the center of the surface of a horizontal substrate and the substrate is rotated to apply the coating liquid to the surface. Was applied using centrifugal force. In this case, the coating thickness of the coating liquid was adjusted by adjusting the rotation speed and the rotation time.

[0003]

However, in such a spin coating method, in the case of a substrate 2 such as a sintered metal wafer having concave portions 1 on its surface as shown in FIG.
There is a problem that the coating liquid 3 cannot be uniformly applied to the inside of the recess 1 because the air is trapped in the recess 1.

Further, even when the bubbles 4 are mixed in the coating liquid 3 before the coating, the bubbles 4 remain until the end and there is a problem that this becomes a defective portion.

An object of the present invention is to provide a rotary coating method capable of filling and coating a coating liquid even in a concave portion of the surface of a substrate and easily defoaming the coating liquid. Especially.

[0006]

The means of the present invention for achieving the above object will be described below.

According to a first aspect of the present invention, the coating liquid is placed at the center of the surface of a horizontal substrate, the substrate is rotated, and the coating liquid is applied to the surface of the substrate by using centrifugal force. In the coating method, the substrate and the coating liquid are placed in an atmosphere in which the substrate and the coating liquid are evacuated while or while the coating liquid is being coated on the surface of the substrate.

According to a second aspect of the present invention, the substrate is adsorbed horizontally on the substrate supporting portion, the coating solution is placed at the center of the surface of the substrate, and the substrate supporting portion is rotated to rotate the substrate. In a rotary coating method of applying the coating solution to the surface of the substrate using centrifugal force, the substrate is rotated in a container at atmospheric pressure to apply the coating solution onto the surface of the substrate, While the rotation of the substrate is stopped, the inside of the container is evacuated and left for a predetermined time, and then the substrate is rotated in the container at atmospheric pressure to adjust the coating thickness of the coating liquid. Characterize.

[0009]

According to the present invention, when the substrate and the coating liquid are placed in a vacuumed atmosphere while or at the time of applying the coating liquid to the surface of the substrate, the air in the concave portion of the surface of the substrate And the bubbles in the coating liquid can be easily removed.

When the substrate is rotated in the container at atmospheric pressure to apply the coating liquid on the surface of the substrate, and then the inside of the container is evacuated while the rotation of the substrate is stopped. Even when performing work by adsorbing the substrate to the substrate support part, since the inside of the container is not evacuated when rotating the substrate, it is possible to avoid dropping the substrate from the substrate support part by vacuuming and defoaming. You can do the work.

After degassing, the substrate is rotated again at atmospheric pressure to adjust the coating thickness of the coating liquid, so that the coating thickness can be adjusted while preventing the substrate from falling off the substrate supporting portion. it can. Further, if the coating thickness is adjusted after defoaming, it is possible to easily correct the coating thickness of the coating liquid when the thickness becomes thin due to defoaming.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a rotary coating apparatus used in the first embodiment of the present invention. In this embodiment, the substrate supporting portion 6 is arranged in the container 5, and the substrate supporting portion 6 is rotated by the motor 7 outside the container 5 via the rotating shaft 8. The rotary shaft 8 is hollow so that the substrate 2 can be adsorbed on the substrate support 6 by using the hole of the rotary shaft 8. The substrate 2 is adapted to be horizontally supported by suction on the upper surface of the substrate support portion 6. The container 5 is configured such that the upper portion thereof is opened and closed by the lid 9. A vacuum evacuation port 10 is provided at the bottom of the container 5. On the upper surface of the substrate 2, the coating liquid supply nozzle 11 is supplied from the outside of the container 5.
The coating liquid 3 is supplied by.

Next, the rotary coating method of this embodiment using such a rotary coating apparatus will be described with reference to FIGS. 1 and 2.

The substrate 2 is horizontally adsorbed and supported by the substrate supporting portion 6 in the container 5, and the coating liquid 3 is supplied to the center of the surface of the substrate 2 by the coating liquid supply nozzle 11. In such a state, FIG.
As shown in (A), the substrate 2 is rotated under atmospheric pressure by the motor 7 via the substrate supporting portion 6, and the coating liquid 3 is applied to the surface of the substrate 2 by centrifugal force.

Next, the rotation is stopped and the inside of the container 5 is shown in FIG.
As shown in (a), a vacuum is drawn for a predetermined time. At this time, the inside of the container 5 is held at about 5 Torr for about 10 seconds. This allows
The air in the concave portion 1 on the surface of the substrate 2 and the bubbles 4 in the coating liquid 3 can be easily removed.

Next, as shown in FIG. 2C, the atmosphere is introduced into the container 5 to return the inside of the container 5 to the atmospheric pressure state, and
As shown in (d), the substrate 2 is rotated at a high speed by the motor 7 through the substrate supporting portion 6 under the atmospheric pressure, and the coating film thickness of the coating liquid 3 is adjusted by adjusting the rotation speed and the rotation time.

2 (c) shows the operation timing of the valve for introducing the atmosphere.

With this coating method, the air in the recess 1 on the surface of the substrate 2 and the bubbles 4 in the coating liquid 3 can be easily removed by vacuuming the container 5. You can do it.

After defoaming, the substrate 2 is rotated again under atmospheric pressure, so that the coating thickness can be adjusted while preventing the substrate 2 from falling off the substrate supporting portion 6.

Further, since the coating thickness of the coating liquid 3 is adjusted after defoaming, it is possible to easily correct the coating thickness of the coating liquid 3 when the thickness becomes thin due to defoaming.

FIG. 4 shows a rotary coating apparatus used in the second embodiment of the present invention. In the present embodiment, an example of a structure in which the rotary coating device mechanically supports the substrate 2 on the substrate support 6 by the chuck 12 is shown.

Next, the rotary coating method of this embodiment using such a rotary coating apparatus will be described with reference to FIGS. 4 and 5.

The substrate 2 is horizontally supported by the chuck 12 in the container 5 in the container 5, and the coating liquid 3 is supplied to the center of the surface of the substrate 2 by the coating liquid supply nozzle 11. In this state, the inside of the container 5 is evacuated for a predetermined time as shown in FIG. 5A, and the substrate 2 is rotated at a low speed by the motor 7 via the substrate support 6 as shown in FIG. 5B. The coating liquid 3 is applied to the surface of the substrate 2 by centrifugal force.

Next, as shown in FIG. 5 (c), the atmosphere is introduced into the container 5 to return the inside of the container 5 to the atmospheric pressure state.
As shown in (d), the substrate 7 is rotated at a high speed by the motor 7 via the substrate supporting portion 6 under the atmospheric pressure, and the coating film thickness of the coating liquid 3 is adjusted by adjusting the rotation speed and the rotation time.

5 (c) shows the operation timing of the valve for introducing the atmosphere.

Even with such a coating method, the air in the concave portion 1 on the surface of the substrate 2 and the bubbles 4 in the coating liquid 3 can be easily degassed by evacuation of the container 5.

After degassing, the substrate 2 is rotated at high speed under atmospheric pressure, so that the coating thickness of the coating liquid 3 can be easily adjusted.

Further, since the coating thickness of the coating liquid 3 is adjusted after defoaming, it is possible to easily correct the coating thickness of the coating liquid 3 when the thickness becomes thin due to defoaming.

[0029]

As described above, according to the rotary coating method of the present invention, the following effects can be obtained.

In the rotary coating method according to the first aspect, the coating liquid is applied to the surface of the substrate or at the stage of applying the coating liquid.
Since the substrate and its coating liquid are placed in a vacuumed atmosphere, it is possible to easily deaerate the air in the recesses on the surface of the substrate and the bubbles in the coating liquid.

In the rotary coating method according to the second aspect of the present invention, the substrate is rotated in the container at atmospheric pressure to apply the coating liquid on the surface of the substrate, and then the container is stopped while the rotation of the substrate is stopped. Since the inside is evacuated, even when performing work by adsorbing the substrate to the substrate support part, since the inside of the container is not evacuated when the substrate is rotated, the substrate can be dropped from the substrate support part by vacuuming. By avoiding this, defoaming work can be performed.

After defoaming, the substrate is rotated again at atmospheric pressure, so that the coating thickness can be adjusted while preventing the substrate from falling off the substrate supporting portion. Further, since the coating thickness is adjusted after defoaming, it is possible to easily correct the coating thickness of the coating liquid when the thickness becomes thin due to defoaming.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing a first embodiment of a rotary coating apparatus for carrying out a rotary coating method according to the present invention.

FIG. 2 is an explanatory diagram showing an operation sequence of the rotary coating method according to the first embodiment.

FIG. 3 is an enlarged sectional view of an essential part showing a state in which a substrate is coated with a coating liquid by the rotary coating method according to the first embodiment.

FIG. 4 is a vertical cross-sectional view showing a second embodiment of the rotary coating apparatus for carrying out the rotary coating method according to the present invention.

FIG. 5 is an explanatory diagram showing an operation sequence of the rotary coating method according to the second embodiment.

FIG. 6 is an enlarged sectional view of an essential part showing a state in which a substrate is coated with a coating liquid by a conventional rotary coating method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 recessed part 2 substrate 3 coating liquid 4 air bubble 5 container 6 substrate support 7 motor 8 rotating shaft 9 lid 10 vacuum evacuation port 11 coating liquid supply nozzle 12 chuck

Claims (2)

[Claims] 1. A rotary coating method in which a coating solution is placed on the center of a horizontal substrate surface, and the substrate is rotated to apply the coating solution to the surface of the substrate by using centrifugal force. A rotary coating method characterized in that the substrate and the coating liquid are placed in an atmosphere in which the substrate and the coating liquid are evacuated while the coating liquid is being coated on the surface or at the stage of coating. 2. The substrate is adsorbed horizontally on the substrate support, the coating liquid is placed on the center of the surface of the substrate, and the substrate is rotated by rotating the substrate support to apply the coating on the surface of the substrate. In a rotary coating method of coating a liquid by using centrifugal force, the substrate is rotated in a container at atmospheric pressure to coat the surface of the substrate with the coating liquid, and then the rotation of the substrate is stopped. In this state, the container is evacuated and left for a predetermined time, and then the substrate is rotated in the container at atmospheric pressure to adjust the coating thickness of the coating liquid, thereby performing a rotary coating method. .