JPH0716531A - Vacuum adsorption spinner, coating method of coating liquid using the same, and developing method of coating film - Google Patents

Abstract

(57) [Summary] [Effect] The present invention is configured as described above, and has a problem that the backside of the coating liquid on the back surface of the substrate occurs in the coating technique using the conventional vacuum adsorption type spinner. In other words, the remarkable effect that the application of the coating liquid and the development with the coating liquid can be performed satisfactorily is exhibited.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum adsorption type spinner used for coating a substrate with a coating liquid or developing a coating film formed on a substrate with a developer.

[0002]

2. Description of the Related Art In the fields of semiconductors, mounting substrates, liquid crystals, etc., spin coating, dip coating, rolls are used as coating methods for coating viscous coating liquids such as photoresists and polyimide precursors on substrates. There are coating and spray coating. Of these, spin coating, which is excellent in terms of uniformity of coating film thickness and coating unevenness, is most commonly used. In spin coating, a vacuum adsorption type spinner is generally used. The coating method of the coating liquid using the vacuum adsorption type spinner is that the substrate is first vacuum-adsorbed on the rotary table and the coating liquid is placed in the center of the substrate. Then, by rotating the turntable at a predetermined number of rotations, the coating liquid receives a centrifugal force, spreads while wetting the surface of the substrate, and covers the entire surface of the substrate.

However, when the viscosity of the coating liquid is high and the coating liquid is rotated at a high speed, a phenomenon occurs in which the coating liquid does not partly scatter out of the substrate and flows around and adheres to the back side of the substrate. Such a phenomenon will be referred to as "backing" here, but if this backing occurs, it will hinder the subsequent steps. For example, when the substrate is heat-treated by a hot plate in the next step, the hot plate surface is contaminated. Further, when the substrate is exposed in a later step, it may be impossible to set the substrate on the exposure device due to the thickness of the coating liquid on the back side. In addition, it also causes problems during inspections such as film thickness. Therefore, it is extremely important in the manufacture of semiconductors and substrates to prevent the coating liquid from backing during coating. Therefore, conventionally, a method of turning over the substrate after heat treatment after coating, removing the coating liquid backed by a knife, or spraying a liquid for removing the coating liquid backed on the back side of the substrate at the time of coating, The coating liquid on the back side was removed.

[0004]

However, in such a conventional removal method, removal was incomplete, workability was poor, and a large-scale device was required.
This backing also occurs when a spinner is used to develop and rinse the polymer on the substrate adsorbed by the spinner with a coating solution such as a developing solution or a rinsing solution. There is a case that it will go around on the back side of the and will soak into the suction table of the spinner, adversely affecting the vacuum system. In this case, it has been difficult to prevent backing with the conventional technology.

The present invention was devised in view of the above-mentioned various drawbacks of the related art, and an object thereof is to apply a coating liquid onto a substrate or to form a substrate-like coating using a vacuum adsorption type spinner. It is an object of the present invention to provide a vacuum adsorption type spinner having a mechanism such that a coating liquid does not go around when developing a film.

[0006]

The object of the present invention is as follows.
This is achieved by the following configuration.

(1) In a vacuum adsorption type spinner equipped with a turntable for attracting a substrate on the uppermost part of a rotary shaft, a cylindrical shape around the rotary shaft so as to surround the rotary table. A vacuum adsorption spinner that is equipped with a backing prevention plate.

(2) The backing prevention plate is provided with a cushion material capable of contracting when a substrate is adsorbed.
(1) The vacuum adsorption spinner as described above.

(3) The uppermost position of the backing prevention plate is 0 to 2 mm lower than the uppermost position of the rotary table, or is retractable to a lower position of 0 to 2 mm. The vacuum adsorption spinner according to (1) or (2).

A vacuum adsorption type spinner according to the present invention will be described with reference to FIGS. FIG. 1 is a perspective view showing an example of a vacuum adsorption type spinner according to the present invention. A rotary table 1 for vacuum-adsorbing a substrate is arranged on the uppermost part of the rotary shaft 2 in the center of the spinner. The rotary table 1 is interlocked with a motor and can rotate at a predetermined rotation speed. In addition, it is preferable to have a function of adjusting not only the rotation speed but also the rotation time and the acceleration to a predetermined value.

Further, on the circumference around the rotary shaft 2,
A cylindrical backing prevention plate 4 is arranged so as to surround the turntable 1, and a lower portion thereof is fixed to the resin plate 3. The backing prevention plate has a cylindrical structure made of, for example, resin such as Teflon or polypropylene, metal, ceramics, or rubber.

The outer diameter of the backing prevention plate is preferably equal to or smaller than the diameter of the substrate used, and more preferably the same as the diameter of the substrate. If it is larger than the diameter of the substrate, it is almost impossible to prevent the backing. Further, even when the diameter is smaller than the diameter of the substrate, the effect of preventing backing is insufficient. Also, as the height of the backing prevention plate,
It is preferable that the uppermost position of the backing prevention plate is at a position 0 to 2 mm lower than the uppermost position of the turntable, or it can be contracted to that position. This is because when the substrate is adsorbed, the gap between the back surface of the substrate and the uppermost part of the backing prevention plate is 0 to
This is because it is preferably 2 mm. 0 to the gap
By setting it to 2 mm, more preferably 0 to 1 mm, and even more preferably 0, it is possible to reliably prevent the backing. Further, it is preferable that the backing prevention plate has such a thickness that the cylindrical structure is not deformed by the rotation of the substrate.

The backing prevention plate 4 is made of a cushion material 5.
Has a structure in which the top and bottom are connected. Although a cushioning material is not always necessary, this structure allows the cushioning material to be attached when the substrate is adsorbed even when the uppermost position of the back-rotation prevention plate is higher than the uppermost position of the turntable when stopped. By contracting, the back surface of the substrate comes into contact with the uppermost portion of the backing prevention plate, and the gap can be made zero.

The cushion material may be, for example, a spring or rubber, but a spring is preferable. The number of springs, strength, number of spirals, diameter of spirals, diameter of metal wire forming the springs, material, etc. are not particularly limited, but during rotation of the substrate,
When the back surface of the substrate and the top of the backing prevention plate are always in contact with each other, a frictional force may act on the top of the backing prevention plate, causing the top circumference to deviate from the circumference of the board. Therefore, it is preferable to properly design the spring so that this phenomenon does not occur.

A resin plate 3 is arranged so as to surround the backing prevention plate 4. The resin plate is a dish-shaped enclosure that receives the excess coating solution that is scattered outside the substrate due to centrifugal force when applying the coating solution, so that it does not scatter around.
The whole spinner is in it.

FIG. 2 is a side view showing an example of a vacuum adsorption type spinner according to the present invention. In this figure, the state before the substrate is sucked is shown, and the uppermost position of the backing prevention plate is higher than the uppermost position of the turntable.

FIG. 3 is a side view showing the state of the vacuum suction type spinner shown in FIG. 2 during substrate suction. Here, the substrate 6 is vacuum-adsorbed on the turntable 1. Further, the circumference of the substrate 6 and the top circumference of the backing prevention plate 3 are exactly aligned. The uppermost part of the backing prevention plate 3 is pressed by the back surface of the substrate, and the cushion material 5 contracts accordingly, so the back surface of the substrate and the uppermost part of the backing prevention plate are always in contact with each other. Is in a state. Even if the turntable is rotated in this state, the back surface of the substrate is always in contact with the uppermost part of the anti-backing plate, so excess coating liquid may be scattered outside the substrate or adhere to the anti-backing plate. There is no turning around on the back side.

Using the vacuum adsorption type spinner of the present invention, it is possible to apply a coating solution on a substrate, develop a coating film formed on the substrate with a developing solution, rinse with a rinsing solution, and the like.

In any case, first, the substrate is vacuum-sucked on the turntable, and the coating liquid is placed in the center of the substrate. Then, by rotating the turntable at a predetermined number of rotations, the coating liquid receives a centrifugal force, spreads while wetting the substrate, and the entire surface of the substrate can be coated.

The substrate is usually a circular substrate,
Examples thereof include those made of silicon, aluminum, zirconia, sapphire, glass, alumina and the like.

Examples of the coating liquid include liquids such as photoresist, polyimide varnish, polyimide precursor varnish, and color paste, a developing liquid, and a rinse liquid.

[0022]

EXAMPLES The present invention will now be described in detail with reference to examples, but the present invention is not limited thereto.

Example 1 A circular 4-inch alumina substrate was accurately placed on a rotary table of a vacuum adsorption type spinner with a backing prevention plate shown in FIG. 1 so that the circumference of the substrate and the top circumference of the backing prevention plate were accurately measured. Vacuum adsorption was performed so as to match. Approximately 5 g of a polyimide precursor varnish with a viscosity of 130 poise (“Semicofine” SP-780 manufactured by Toray Industries, Inc.) was dropped at approximately the center of the substrate, and then the substrate was rotated at 2500 rpm for 30 seconds to form a varnish. Applied. As a result, the underside of the varnish was not observed on the back surface of the substrate.

Comparative Example 1 The same method as in Example 1 except that a general vacuum adsorption spinner without a backing prevention plate was used instead of the vacuum adsorption spinner with a backing prevention plate. Then, the varnish was applied. As a result, the underside of the varnish was observed on the back surface of the substrate.

Example 2 Instead of applying the varnish by rotating the substrate at 2500 revolutions per minute for 30 seconds in Example 1, 5 minutes per minute
The varnish was applied in exactly the same manner except that the varnish was applied by rotating the substrate at 00 revolutions for 10 seconds and then at 3000 revolutions per minute for 30 seconds.
As a result, the underside of the varnish was not observed on the back surface of the substrate.

Comparative Example 2 A varnish was prepared in the same manner as in Example 2, except that a vacuum adsorption type spinner having no backing prevention plate was used instead of the vacuum adsorption type spinner having a backing prevention plate. Application was performed. As a result, the underside of the varnish was observed on the back surface of the substrate.

Example 3 A circular 4-inch alumina substrate was used in Example 1 on a rotary table of a vacuum adsorption type spinner with a backing prevention plate, and the circumference of the substrate and the top circumference of the backing prevention plate were accurate. Vacuum adsorption was performed so that Approximately 5 g of a polyimide precursor varnish (“Photo Nice” UR-3140 manufactured by Toray Industries, Inc.) having a viscosity of 40 poise was dropped almost at the center of the substrate, and then the substrate was rotated at 2200 rpm for 30 seconds to form a varnish. Applied. As a result, the underside of the varnish was not observed on the back surface of the substrate. Next, this substrate was pre-baked on a hot plate at 80 ° C. for 10 minutes, and then exposed using an exposure device (PLA-501F manufactured by Canon Inc.) at an exposure amount of 300 mJ / cm ² . Then, this substrate was vacuum-adsorbed on the rotary table of the vacuum adsorption type spinner with the backing prevention plate as in the previous case.

Then, a developing solution (DV-60 manufactured by Toray Industries, Inc.)
5) 10 ml was applied every 1 minute to the entire surface of the polyimide precursor polymer on the substrate and developed for 5 minutes. At this time, the backside of the developer on the back surface of the substrate was not observed.

Comparative Example 3 After prebaking and exposure in Example 3, development was performed using a vacuum adsorption type spinner having no backing prevention plate instead of development using a vacuum adsorption type spinner having a backing prevention plate. Except for this, the experiment was conducted in exactly the same manner. As a result, the backside of the developer was observed on the back surface of the substrate.

[0030]

The present invention is constructed as described above,
The problem that the coating liquid does not spread around the back surface of the substrate, which has been found in the coating technique using the conventional vacuum adsorption type spinner, does not occur, and the coating liquid can be coated satisfactorily.

[Brief description of drawings]

FIG. 1 is a perspective view showing an example of a vacuum adsorption type spinner according to the present invention.

FIG. 2 is a side view showing an example of a vacuum adsorption type spinner according to the present invention.

FIG. 3 is a side view showing a state of the vacuum suction type spinner shown in FIG. 2 during substrate suction.

[Explanation of symbols]

 1: Rotating table 2: Rotating shaft 3: Resin plate 4: Backing prevention plate 5: Spring 6: Board

Claims (9)

[Claims] 1. A vacuum suction type spinner having a turntable for attracting a substrate on the uppermost part of a rotary shaft, wherein a cylindrical backing surrounds the turntable around a circumference centered on the rotary shaft. A vacuum suction spinner that is equipped with a rotation prevention plate. 2. The vacuum suction type spinner according to claim 1, wherein the backing prevention plate has a cushioning material which can shrink when the substrate is sucked. 3. The position of the uppermost part of the backing prevention plate is 0 to 2 mm lower than the position of the uppermost part of the turntable, or 0.
The vacuum adsorption type spinner according to claim 1 or 2, wherein the vacuum adsorption type spinner is capable of contracting to a position lower by ~ 2 mm. 4. A method of applying a coating liquid onto a substrate,
A method for applying a coating liquid, which comprises using the vacuum adsorption type spinner according to claim 1. 5. The method of applying a coating solution according to claim 4, wherein the diameter of the substrate is the same as the outer diameter of the backing prevention plate. 6. The method for applying a coating liquid according to claim 4, wherein the gap between the back surface of the substrate and the uppermost portion of the backing prevention plate at the time of adsorbing the substrate is 0 to 2 mm. 7. A method for developing a coating film formed on a substrate using a developing solution, wherein the vacuum adsorption spinner according to claim 1 is used. Method. 8. The method of developing a coating film according to claim 7, wherein the diameter of the substrate is the same as the outer diameter of the backing prevention plate. 9. The method for developing a coating film according to claim 6, wherein the gap between the back surface of the substrate and the uppermost portion of the backing prevention plate at the time of substrate adsorption is 0 to 2 mm.