JPH01139172A - Coating equipment - Google Patents

Abstract

PURPOSE:To prevent splashes of coating material coming from a material to be coated from returning back in the direction of the material and to form a uniform coating film on the material by arranging a plurality of splash-back blades annularly and slantly facing the external circumference of the material contained in a treating vessel. CONSTITUTION:Splash-back preventing impellers 11 are provided rotatively on the external circumference of the material 6 to be coated in the treating vessel 1 which contains the material (e.g., wafer) 6 and coats it with coating material (e.g., resist liquid) 7. A plurality of splash-back preventing blades 14 arranged on this impeller 11 are provided slantly to the normal of the material 6. When this material 6 is revolved by a driving gear 4, the coating material 7 dropped on the center of the material 6 is diffused by centrifugal force in the radial direction and a coating film 20 is formed on the surface of the material 6, the splashes 21 coming from the material 6 collide with the blades 14 arranged slantly on the revolving impeller 11, are reflected by the angle of inclination of the blade 14 in the radial and external direction and are not attached again to the material 6 to form a coating film 20 of uniform thickness.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a coating technology, particularly a technology for applying a coating material while an object to be coated is accommodated in a processing container, and is used, for example, in the manufacturing process of electronic devices. , relates to a technique effective for applying resist onto a wafer.

(Prior Art) Japanese Patent Publication No. 53-37189 is used as a coating device for coating resist on a wafer in the manufacturing process of electronic devices.
As described in the publication, a wafer is placed and held on a rotatable spin head provided inside a processing container, and a resist solution is supplied onto the surface of the wafer while the wafer is rotated to centrifuge the resist. Some are configured to spread the application by force.

[Problem that the invention seeks to solve]

In such a resist coating device, during high-speed rotation, the resist solution scatters around the wafer, collides with the inner circumferential surface of the processing container, bounces off, and reattaches to the wafer, effectively covering the coated surface of the wafer. The inventor of the present invention has discovered that there is a problem in that the product is damaged.

An object of the present invention is to provide a coating technique that can reliably prevent re-adhesion due to splashing of the coating material.

The above and other objects and novel features of the present invention will become apparent from the description of this specification and the accompanying drawings.

[Means for solving problems]

An overview of typical inventions disclosed in this application is as follows.

That is, a group of anti-repelling blades is arranged in a ring shape to face the outer periphery of the object to be coated in a processing container that accommodates the object to be coated and applies the coating material, and these blades are aligned with respect to the normal line of the object to be coated. It is configured to be tilted.

[Effect]

According to the above-mentioned means, the droplets scattered from the object to be coated collide with the blades arranged on the outer periphery of the object and are reflected radially outward according to the inclination angle of the blades, so that they do not return to the object to be coated. do not have. Furthermore, even if the droplets directly collide with the inner circumferential wall of the processing container and bounce back in the direction they came from, they will collide with the back surface of the blade and be reflected outward in the radial direction. It never flies.

[Embodiment 1] FIG. 1 is a plan sectional view taken along the line 1--1 in FIG. 2 showing a resist coating apparatus according to an embodiment of the present invention, and FIG. 2 is a vertical sectional view thereof.

In this embodiment, this resist coating apparatus includes a processing container 1
The container l is formed into a substantially cylindrical shape with open upper and lower surfaces.

A substantially cylindrical bottom plate 2 is arranged concentrically in the center of the processing container l, and a rotating shaft 3 rotated by a suitable drive device 4 such as a servo motor is mounted on the bottom plate 2 on the center line. It is arranged and inserted in . A spin head 5 is arranged and fixed to the upper end of the rotating shaft 3 in the processing container 1 so as to be able to rotate horizontally, and the spin head 5 is capable of holding a wafer 6 as an object to be coated by vacuum suction. It is configured. Directly above the spin head 5, a dropping tube 8 for dropping a resist liquid 7 as a coating material is arranged concentrically and inserted vertically downward.

A splash prevention part 9 is arranged in a circular ring shape at the upper end opening of the processing container 1 and protrudes radially inward, and the splash prevention part 9 is arranged so that its lower surface gradually rises as it goes inward. By being inclined so as to prevent droplets that collide with the inclined surface from bouncing back toward the wafer 6. On the other hand, an exhaust port 10 is formed in the lower end opening of the processing container 1 in the shape of a circular ring between the exhaust port 10 and the cylindrical outer periphery of the bottom plate 2.

In this embodiment, an impeller 11 for preventing rebound is disposed outside the spin head 5 in a concentric circle with the spin head 5 and rotatably supported in the processing container 1. That is, this impeller 11 has a frame member 12 formed in a circular ring shape.
The frame member 12 is disposed concentrically with the rotating shaft 3 and is rotatably supported by a bearing member 13 provided on the bottom plate 2. On the upper surface of the frame member 12, a plurality of anti-repelling blades 14 are arranged approximately vertically at approximately equal intervals in the circumferential direction, and the upper end of each anti-repelling blade 14 is connected to the slope of the anti-repelling portion 9. It is placed as close as possible so as not to interfere with the bottom surface. As shown in FIG. 1, each anti-rebound blade 14 is arranged so as to be inclined backward in the rotational direction with respect to the normal line of the wafer 6 as it goes radially outward, and the inclination angle is As will be described later, when droplets from the wafer 6 collide with the blades 14, they are set so as to prevent the droplets from being reflected in the direction of the wafer 6.

Further, a rotating shaft 16 rotated by a suitable drive device 15 such as a servo motor is inserted into the bottom plate 2 and is arranged parallel to the axis of the impeller frame member 12. A gear 17 is arranged and fixed to the upper end so as to be rotatable by hand, and the gear 17 is meshed with an internal gear 18 formed on the inner peripheral surface of the frame member 12. That is, the impeller 11 is configured to be rotationally driven by the drive device 15 via the rotating shaft 16 gear 17 and the internal gear 18.

Next, the effect will be explained.

A wafer 6 as an object to be coated is placed on a spin head 5 and held by suitable means such as vacuum suction, and then rotated via a rotation shaft 3 by a drive device 4. When this rotation is stabilized, when the resist liquid 7 is dropped onto the center of the wafer 6 from the dropping tube 8, the resist liquid 7 is diffused in the radial direction due to centrifugal force, so that a coating film 20 is formed on the surface of the wafer 6. will be formed.

At this time, exhaust force is applied to the exhaust port 10, and
Since the impeller 11 is rotated by the drive device 15 in the direction of the arrow as shown in FIG. After being gently blown onto the surface, the exhaust port lO
The airflow that gets sucked in! 9 is formed.

When the airflow flowing down from the upper end opening of the processing container 1 is sucked into the impeller 11 that performs the exhaust action, the flow velocity becomes faster, but because the change in flow velocity occurs suddenly, the flow velocity over the entire upper surface of the wafer 6, The pressure and flow rate will be equalized throughout and will be sprayed very slowly. As a result, the drying of the applied resist solution is uniformed over the entire surface, so that the thickness distribution of the coating film 20 formed on the wafer 6 is uniformized over the entire surface.

When the resist liquid 7 is dropped and dispersed in the radial direction by centrifugal force, droplets 21 are scattered radially outward from the outer peripheral edge of the wafer 6 .

By the way, if there is no blade group on the outer periphery of the wafer and the surface of the processing container facing the outer periphery of the wafer is formed as a flat surface, the resist liquid droplets will bounce off the flat surface and the incident angle with respect to the flat surface will change. Depending on the direction of the airflow, the droplets may return to the original direction, causing them to re-deposit on the wafer.

In this manner, if the droplets re-deposit on the wafer, the resist coated surface will be substantially damaged, thereby disrupting the lithography process.

However, in this embodiment, an impeller 11 for preventing rebound is provided in the processing container 1 on the outer periphery of the wafer 6, and a plurality of impellers 14 for preventing rebound are arranged at a predetermined inclination. Since the droplets 21 flying from the wafer 6 are prevented from bouncing back to the wafer 6, the droplets 21 are prevented from re-adhering to the wafer 6. It turns out.

That is, as shown in FIGS. 1 and 2,
The droplets 21 flying from the outer periphery of the wafer 6 are
Since the impeller 11 is rotating around the outer periphery of the impeller 11, it will inevitably collide with one of the groups of the anti-rebound blades 14. The droplets 21 that collide with the anti-rebound blade 14 are reflected outward in the radial direction because the blade 14 is tilted rearward in the rotational direction. Even if the droplets 21 flying from the outer periphery of the wafer 6 pass between the adjacent blades 14 and 14 and collide with the inner peripheral surface of the processing container 1 and are reflected radially inward, the processing Since the impeller 11 is rotated in the circumferential direction of the container 1, it will inevitably collide with the back surface (outward surface) of one of the groups of anti-repelling blades 14. The droplets 21 that collide with the back surface of the blade 14 are reflected outward in the radial direction because the blade 14 is tilted backward in the rotational direction. That is, in any case, since the droplets 21 scattered from the outside of the wafer 6 do not return toward the wafer 6, re-adhesion of the droplets 21 to the wafer 6 is avoided.

The droplets 21 reflected outward in the radial direction by the anti-rebound blades 14 ride on the airflow 19 flowing in the direction of the exhaust port 10, and are therefore discharged from the exhaust port 10 without returning toward the wafer 6.

When the application of the resist liquid to the wafer 6 is completed,
The wafer 6 on which the coating film has been formed is taken out from the upper opening of the processing container l.

According to the embodiment described above, the following effects can be obtained.

fi+ By arranging multiple blades at an appropriate inclination angle in the processing container, it is possible to reliably reflect the coating liquid droplets flying from the object to be coated outward in the radial direction, so that the droplets can be reflected radially outward in the direction of the object to be coated. It is possible to prevent the droplets from rebounding and to prevent the droplets from re-adhering to the object to be coated.

(2) By rotating the anti-repellent blade group, the exhaust flow velocity is accelerated only around the outer periphery of the object to be coated.
Since the flow velocity of the airflow formed on the surface of the object to be coated can be made uniform over the entire surface, the drying of the coating material can be made uniform over the entire surface, thereby reducing the thickness of the coating film formed on the object to be coated. The distribution can be made uniform throughout.

(3) By preventing the droplets from re-adhering to the object to be coated, the quality of the coating film can be improved, so the reliability of the coating operation can be improved.

(4) By increasing the quality of the coating film and the reliability of the work, if the coating film is a resist liquid film, the quality and reliability of the lithography process can be improved;
Product manufacturing yield can be increased.

(5) By creating an airflow inside the processing container from above the wafer to below the processing container, the fine particles of the coating material reflected by the anti-repellent blades can be carried by the exhaust flow and discharged to other locations. Re-adhesion to objects can be reliably prevented.

[Embodiment 2] FIG. 3 is a plan sectional view taken along line m-nr in FIG. 4 showing a resist coating apparatus according to another embodiment of the present invention, and FIG. 4 is a vertical sectional view thereof.

This second embodiment differs from the above-mentioned embodiment I in that the impeller 11A
is configured to be rotated using the exhaust flow. That is, the internal gear of the impeller, the gear, and its drive device are eliminated, and the blades 14A are also slightly inclined in the axial direction so that they can be easily rotated by the airflow. Then, when the airflow sucked into the upper end opening of the processing container 1 blows through from the inside to the outside of the impeller 11A, the impeller 11A is forcibly rotated in the direction of the arrow.

Although the invention made by the present inventor has been specifically explained above based on Examples, it goes without saying that the present invention is not limited to the Examples and can be modified in various ways without departing from the gist thereof. Nor.

For example, the anti-rebound blade group is not limited to being configured to rotate, but may be configured to be fixed.

The blade group is not limited to being arranged in a single layer, but may be arranged in double or more.

In the above explanation, the invention made by the present inventor was mainly applied to an apparatus for coating a resist on a wafer, which is the background field of application of the invention, but the invention is not limited to this. It can also be used when applying.

〔Effect of the invention〕

A brief explanation of the effects obtained by typical inventions disclosed in this application is as follows.

By arranging a plurality of anti-repelling blades around the outer periphery of the object to be coated in the processing container, it is possible to prevent droplets of coating material that have come from the object to be coated from rebounding in the direction of the object to be coated. Therefore, it is possible to reliably prevent droplets from re-adhering to the object to be coated, and it is also possible to form an even airflow over the entire surface of the object to be coated, so that the droplets are not formed on the object to be coated. The thickness distribution of the coating film can be made uniform over the entire area.

[Brief explanation of the drawing]

FIG. 1 is a plan sectional view taken along line 2--2 in FIG. 2 showing a resist coating apparatus according to an embodiment of the present invention, and FIG. 2 is a vertical sectional view thereof. FIG. 3 is a plan sectional view taken along line 1--2 in FIG. 4 showing a resist coating apparatus according to another embodiment of the present invention, and FIG. 4 is a vertical sectional view thereof. l...processing container, 2...bottom plate, 3...rotating shaft, 4
... Drive device, 5... Spin head, 6... Wafer (object to be coated), 7... Resist liquid (coating material), 8...
... Dripping pipe, 9... Splash prevention part, 10... Exhaust port, 11... Impeller, 12... Frame member, 13...
Bearing member, 14... Anti-rebound blade, 15... Drive device, 16... Rotating shaft, 17... Gear, 18...
・Internal gear, 19... Air flow, 20... Coating film, 21
···splash. Figure 3

Claims (1)

[Scope of Claims] 1. A group of anti-repelling blades is arranged in a ring shape to face the outer periphery of the object to be coated in a processing container that accommodates the object to be coated and applies the coating material. A coating device characterized in that it is configured to be inclined with respect to the normal line of an object. 2. The coating device according to claim 1, wherein the anti-repelling blade group is constituted by a rotatable impeller. 3. The coating device according to claim 2, wherein the impeller is configured to be rotated by an air flow forced through the processing container. 4. The coating device according to claim 2, wherein the impeller is configured to be rotated by a drive device. 5. The coating device according to claim 1, wherein the anti-repellent blade is inclined so that its radially outer side projects rearward in the rotational direction of the object to be coated.