JP2575959B2 - Rotary coating device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spin coating apparatus (spin coating machine) for uniformly coating a substrate surface with a coating solution using centrifugal force.

[0002]

2. Description of the Related Art A spin coater applies a photoresist solution, a developing solution, an etching solution, a liquid dopant solution or the like to a surface of a semiconductor substrate, a glass substrate such as a glass for liquid crystal, a ceramic substrate or the like, and rotates the substrate. This is a device that uniformly coats the substrate surface with a coating liquid.

Conventionally, as this type of apparatus, for example, a sectional view shown in FIG. 6 (Japanese Patent Laid-Open No. 63-777569),
Alternatively, a sectional view shown in FIG. 7 has been proposed.
6, reference numeral 1 denotes a wafer such as silicon as a semiconductor substrate as an example of a substrate; 2, a spindle for rotating the wafer 1 via a spin chuck 3; 3, a spin chuck for holding the wafer; A rectifying member, which is provided below 1 and is an annular member which is a rectifying means for adjusting an air flow below the wafer 1, 8 is a spin mechanism provided so as to surround the rotating mechanism and the rotating wafer 1, 9 is A nozzle 10 for supplying the coating liquid to the wafer 1 is an exhaust unit for exhausting the inside of the cup.

[0004] The operation of the conventional spin coater configured as described above will be described.

First, the wafer 1 is rotated at a low speed,
A predetermined amount of the coating liquid is supplied onto the wafer 1 from the nozzle 9. Then, the rotational speed is increased to, for example, several thousand r. p. m,
The coating liquid is spread evenly on the wafer 1 and, if necessary, heated to dry and cure the coating. At the time of this spin coating process, the inside of the spin cup 8 is forcibly evacuated by the exhaust unit 10 in order to prevent the droplets of the application liquid from adhering to the front surface and the back surface of the wafer 1 so that clean air, nitrogen gas, etc. Is distributed.

FIG. 7 shows a conventional example in which the upper part of the flow regulating member 14 is cylindrical. Other structures are basically the same as those in FIG. 6, and thus detailed description is omitted.

[0007]

However, according to the prior art, the eddy current (X in FIGS. 6 and 7) is located in the vicinity of the outermost periphery (edge) of the wafer 1 and particularly immediately below the edge of the wafer 1. ) Tends to occur. It is considered that the airflow from above forms a negative pressure portion just below the edge portion, and the airflow is involved. Then, when the vortex X is generated, there is a problem that the spray of the coating liquid easily adheres to the back surface of the wafer 1 accompanying the vortex X. If the droplets of the coating solution adhere to the back surface of the wafer 1, an undesirable operation step must be removed, or the wafer 1 must be discarded from the semiconductor manufacturing process.

In order to solve the above-mentioned problems of the prior art, the present invention has prevented the generation of a vortex just below the edge portion of a substrate such as a wafer, and has prevented the application liquid from adhering to the back surface of the substrate. It is an object to provide a spin coating device.

[0009]

In order to achieve the above object, a spin coating apparatus according to the present invention comprises a spin chuck that rotates while holding a substrate substantially horizontally, and an annular rectifier that regulates airflow below the substrate. Means, comprising a spin cup provided so as to surround the rotating substrate, a spin coating device to exhaust the space between the rectification means and the spin cup,
The rectifying means includes an annular rectifying member having an outer diameter at an upper end equal to or less than the outer diameter of the substrate, and an inner diameter at an upper end is larger than an outer diameter of the substrate at a radially outer side of the rectifying member. And a rectifying plate provided at a position substantially along the annular side surface of the rectifying member with an interval from the side surface.

In the above structure, it is preferable that the straightening member and the straightening plate have a truncated conical shape spreading downward. Here, the truncated cone shape refers to a state where the tip of the cone is cut.

[0011]

According to the structure of the present invention, the annular rectifying means for adjusting the airflow below the substrate is provided with an annular rectifying member having an outer diameter at the upper end equal to or less than the outer diameter of the substrate, and a radial direction of the rectifying member. On the outside, an inner diameter of the upper end is larger than the outer diameter of the substrate, and a rectifying plate is provided at a position substantially along the annular side surface of the rectifying member with a distance from the annular side surface of the rectifying member. Therefore, the airflow just below the edge of the substrate is in a laminar state, so that eddy can be prevented from occurring, and the droplets of the coating liquid can be prevented from adhering to the back surface of the substrate.

According to the preferred configuration of the present invention in which the shape of the rectifying member and the rectifying plate is a frusto-conical shape spreading downward, the air flow immediately below the edge portion of the substrate becomes a more preferable laminar flow state. The generation of the vortex can be prevented, and the splash of the coating liquid (for example, resist mist) can be more effectively prevented from adhering to the back surface of the substrate.

[0013]

The present invention will be described more specifically with reference to the following examples. The present invention is not limited by the following examples.

FIG. 1 is a sectional view of a spin coater according to a first embodiment of the present invention. In FIG. 1, reference numerals 4 and 5 denote rectification means for adjusting the airflow below the wafer 1, and reference numeral 4 denotes an annular rectification member whose outer diameter at the upper end is equal to or smaller than the outer diameter of the rotating wafer 1. Is larger than the outer diameter of the wafer 1 and is spaced radially outward of the rectifying member 4 from the annular side surface of the rectifying member 4 and is outside of the rectifying member and the outer periphery of the rectifying member 4. A current plate provided at a position substantially along the surface. The other part numbers are the same as those in FIG.

The current plate 5 used in the present invention may be a multilayer. If such a rectifying means is provided, the wafer 1 is rotated at a low speed, a predetermined amount of the coating liquid is supplied from the nozzle 9 onto the wafer 1, and the number of rotations is, for example, several thousand rpm. p. m, and even when the coating liquid is spread evenly on the wafer 1, the airflow from above becomes as shown by the arrow Y, and the generation of the vortex can be prevented.

The distance between the rectifying member 4 and the rectifying plate 5 is preferably about 2 to 10 mm, more preferably about 3 to 7 mm. The rectifying member 4 and the rectifying plate 5 can be fixed to each other at, for example, about three to four places on the outer peripheral surface of the rectifying member 4, and any means such as adhesion, fitting, and integral molding may be used. The material of the current plate 5 may be any material such as resin and metal, and is preferably a plastic molded body such as polypropylene.

According to the first embodiment constructed as described above, the air flow from above is as shown by the arrow Y in FIG. 1, and the air flow immediately below the edge of the wafer 1 is in a laminar state. In addition, it is possible to prevent the generation of a vortex, and to prevent the spray of the coating liquid (for example, resist mist) from adhering to the back surface of the wafer.

FIG. 2 is a sectional view of a spin coater according to a second embodiment of the present invention. In FIG. 2, reference numeral 6 denotes a current plate 5
A second rectifying plate provided outside the rectifier. That is, this is an example in which the rectifying plate has two stages. By doing so, the generation of eddy current can be more effectively prevented.

FIG. 3 is a sectional view of a spin coater according to a third embodiment of the present invention, and FIG. 4 is a perspective view of the same. 3 and 4, reference numeral 7 denotes a third rectifying plate provided further outside the second rectifying plate 6. That is, this is an example in which the rectifying plate has three stages. By doing so, the generation of eddy current can be more effectively prevented.

FIG. 5 is a sectional view of a spin coater according to a fourth embodiment of the present invention. FIG. 5 shows an example in which a rectifying plate 5 is provided outside the rectifying member 4 along the outer peripheral surface of the rectifying member. Compared to FIG. 7, a favorable effect is produced in that the air flow immediately below the edge of the wafer 1 in FIG. 7 tends to be a vortex X, whereas in FIG.

As described above, according to the present embodiment, the airflow just below the edge of the wafer 1 is in a laminar state,
Generation of a vortex can be prevented, and droplets of the coating liquid (for example, resist mist) can be effectively prevented from adhering to the back surface of the wafer. Although the above embodiment shows an example of a wafer, the present invention relates to a semiconductor substrate, a glass substrate such as glass for liquid crystal,
For example, a device that applies a photoresist solution, a developing solution, an etching solution, a liquid dopant solution, or the like to the surface of a ceramic substrate, a plastic substrate, an optical disk substrate, or the like, and rotates the substrate to uniformly coat the application surface with the coating solution. It can be applied to any device.

[0022]

As described above, according to the present invention, an annular rectifying means for adjusting the air flow below the substrate, an annular rectifying member whose upper end has an outer diameter equal to or less than the outer diameter of the substrate, Radially outward, an inner diameter of the upper end is larger than an outer diameter of the substrate, and a rectifying plate provided at a position substantially along the annular side surface of the rectifying member with an interval from the annular side surface of the rectifying member. With this configuration, the airflow immediately below the edge of the substrate is in a laminar state, so that a vortex can be prevented from occurring, and a remarkable effect of preventing the spray of the coating liquid from adhering to the back surface of the substrate can be achieved.

According to the preferred configuration of the present invention in which the shape of the rectifying member and the rectifying plate is a frusto-conical shape expanding downward, the air flow immediately below the edge portion of the substrate becomes a more preferable laminar flow state. The generation of the vortex can be prevented, and the splash of the coating liquid (for example, resist mist) can be more effectively prevented from adhering to the back surface of the substrate.

[Brief description of the drawings]

FIG. 1 is a sectional view of a spin coater according to a first embodiment of the present invention.

FIG. 2 is a sectional view of a spin coater according to a second embodiment of the present invention.

FIG. 3 is a sectional view of a spin coater according to a third embodiment of the present invention.

FIG. 4 is a perspective view of the same.

FIG. 5 is a sectional view of a spin coater according to a fourth embodiment of the present invention.

FIG. 6 is a sectional view of a conventional spin coater.

FIG. 7 is a cross-sectional view of another conventional spin coater.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Wafer, 2 ... Spindle, 3 ... Spin chuck, 4 ... Rectifier member, 5 ... First rectifier plate, 6 ... Second rectifier plate, 7 ... Third rectifier plate, 8 ... Spin cup,
9: nozzle, 10: exhaust means.

Claims (2)

(57) [Claims] A spin chuck that rotates while holding the substrate substantially horizontally; an annular rectifying unit that regulates airflow below the substrate; and a spin cup provided so as to surround the rotating substrate. A rotary coating device configured to exhaust air between a rectifying unit and a spin cup, wherein the rectifying unit includes an annular rectifying member having an outer diameter at an upper end equal to or less than an outer diameter of a substrate, and a radial direction of the rectifying member. On the outside, an inner diameter of the upper end is larger than an outer diameter of the substrate, and a rectifying plate is provided at a position substantially along the annular side surface of the rectifying member with a distance from the annular side surface of the rectifying member. Characteristic spin coating device. 2. The spin coating device according to claim 1, wherein the straightening member and the straightening plate have a truncated conical shape spreading downward.