JPS6269611A - Coating device - Google Patents

Abstract

PURPOSE:To contrive improvement in the uniformity of thickness of the film formed on the material to be coated by a method wherein a rotary stand is supported by a rotary inversion mechanism which can be rotated on the plane surface intersecting with the rotating surface, and to enable the material to be treated to make an inversion on the rotary stand. CONSTITUTION:An inversion mechanism 7 is operated, it is inverted in such a manner that the coated surface of a photoresist 5 is facing downward while the wafer 3 retained by a spin chuck 2 is being rotated, and the above-mentioned state is maintained for the prescribed period. At this time, as the coated surface of the wafer 3 is facing downward, the excessive photoresist 5 remaining in the gap of pattern protrudingly formed on the coated plane surface of the wafer due to the surface tension and the like, for example, is removed from the gap of pattern by means of resultant force of the weight of the inversion mechanism 7 itself and the centrifugal force generated by the rotation of the wafer 3. As a result, a uniform film of photoresist 5 can be formed on the surface of the wafer 3 along the cross-sectional shape of the roughened part formed by patterning.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a coating technique, and particularly to a technique that is effective when applied to a process of coating a wafer with a photoresist in the manufacture of semiconductor devices.

[Background Art] In the manufacture of semiconductor devices, photolithography technology is usually used to form wiring structures, insulating films, etc. in predetermined patterns on a semiconductor substrate, ie, a wafer, made of silicon or the like.

In the photolithography technique described above, the following methods can be considered for applying a photoresist, which is a photosensitive agent, to the wafer surface prior to the etching operation.

In other words, the wafer is held horizontally and rotated with the coating surface facing upward, and a predetermined amount of photoresist is dropped onto the center of the rotated wafer, and the photoresist is uniformly applied over the entire surface of the wafer by the centrifugal force caused by the rotation of the wafer. A predetermined photoresist film is formed on the wafer surface by dispersing the photoresist.

On the other hand, in the process of applying photoresist to a wafer, for example, if the wafer surface has unevenness due to a pattern such as an already formed wiring structure, the photoresist film applied to the wafer will be applied along the cross-sectional shape of the unevenness. Uniform formation is important from the viewpoint of reducing variations in etching in subsequent etching steps.

However, when the distance between the convex patterns formed on the wafer plane is relatively small due to the miniaturization and high integration of semiconductor elements formed on the wafer, the surface tension of the photoresist causes the adjacent convexities to become smaller. Excess photoresist remains between the areas, and the film thickness in those areas becomes larger than that in other flat areas, which is the cause of inhibiting the uniformity of the photoresist film thickness applied to the wafer surface. The present inventor found that.

In addition, the literature explaining the photoresist coating technique is Kogyo Kenkyukai Co., Ltd., November 1982.
"Electronic Materials" 1983 special edition, published on the 15th of May, P92-P
There are 96.

[Object of the Invention] An object of the present invention is to provide a coating technique that can improve the uniformity of the coating film thickness.

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.

[Summary of the Invention] A brief overview of typical inventions disclosed in this application is as follows.

In other words, the rotary table on which the object to be coated is removably placed is
The workpiece is configured to be held by a reversing mechanism that is rotatable within a plane intersecting the rotation plane of the rotary table, and the workpiece is configured to be reversible while placed on the rotary table. By performing the rotation coating operation of the coating liquid with the application plane of the object to be coated facing downward, for example, excess coating liquid remaining on the uneven parts formed on the application plane of the object to be coated is removed, and the coating surface of the object to be coated is The coating film is formed uniformly along the cross-sectional shape of the uneven portion formed on the coating plane,
The uniformity of the film thickness of the coating liquid formed on the object to be coated is improved.

[Embodiment 1] FIG. 1 is a front view showing the main parts of a coating device according to an embodiment of the present invention, and FIG. 2 is a side view thereof.

A spin chuck 2 (
The wafer 3 (object to be coated) is configured to be removably placed on the rotary table, for example, by vacuum suction.

Furthermore, a dropping nozzle 4 is provided above the center of the spin chuck 2, and a predetermined amount of photoresist 5 (
A coating liquid) is dropped and dispersed over the entire surface of the wafer 3 by the centrifugal force generated by the rotation of the spin chuck 2.

In this case, the servo motor 1 and the spin chuck 2 rotated by the servo motor 1 are configured to be held by a reversing mechanism 7 that is rotatably provided in a vertical plane about a rotation shaft 6, and At this time, the spin chuck 2, which is being rotated while holding the wafer 3, can be reversed from the horizontally upward position to the downward position shown by the two-dot chain line in FIG.

The operation of this embodiment will be explained below.

First, the spin chuck 2 is held still in a "horizontal" orientation, and the wafer 3 is fixed by vacuum suction.

Next, a predetermined amount of photoresist 5 is applied from the drip nozzle 4 to the center of the wafer 3 positioned at the second position of the spin chuck 2.
is dripped.

Thereafter, rotation of the spin chuck 2 by the servo motor 1 is started, and the photoresist 5 dropped onto the center of the wafer 3 rotated together with the spin chuck 2 is dispersed over the entire surface of the wafer 3 by centrifugal force.

Next, the reversing mechanism 7 is activated, and while the wafer 3 held by the spin chuck 2 is rotated, it is reversed so that the surface coated with the photoresist 5 faces downward, as shown by the two-dot chain line in FIG. It is held for a predetermined period of time.

At this time, since the coating surface of the wafer 3 is facing downward,
For example, excessive photoresist 5 remaining in the gaps between patterns (not shown) formed in a convex shape on the coating plane of the wafer 3 due to surface tension, etc., is affected by its own weight acting downward and the wafer \3. The photoresist 5 is removed from the gap between the patterns by the combined force with the centrifugal force caused by the rotation, and a uniform coating film of the photoresist 5 is formed on the coating surface of the wafer 3 along the cross-sectional shape of the uneven portion due to the formed pattern. Ru.

After a predetermined period of time has elapsed, the spin chuck 1 holding the wafer 2 is returned to a horizontally upward position and its rotation is stopped.

Then, the fixation state of the wafer 3 by vacuum suction is released, and the wafer 3 on which the uniform coating film of the photoresist 5 has been formed is transported to the next process.

[Effects] (1) A rotary table on which the object to be coated is removably placed, of a coating device that forms a coating film by dropping a coating liquid onto the object rotated once, is rotated once. It is held by a reversing mechanism that can freely rotate within a plane that intersects the rotation plane,
Since the object to be treated can be turned over while placed on the rotary table, the object to be coated can be rotated, for example, by performing a rotational coating operation of the coating liquid with the application surface of the object facing downward. The excess coating liquid remaining in the gaps between the uneven parts formed on the coating plane of the object is removed by the weight of the coating liquid and the centrifugal force of rotation, and the cross section of the uneven parts formed on the coating plane of the object is removed. It becomes possible to form a coating film uniformly along the shape, and the uniformity of the film thickness of the coating liquid formed on the object to be coated can be improved.

(2), above! As a result of No. 11, variations in etching results due to non-uniformity of the photoresist film thickness in the etching process are reduced, and the yield in manufacturing semiconductor devices is improved.

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 above-mentioned examples and can be modified in various ways without departing from the gist thereof. Nor.

[Field of Application] In the above explanation, the invention made by the present inventor was mainly applied to the field of application which is the background of the invention, which is the technique of applying photoresist to sea urchins, but the present invention is not limited thereto. It can be widely applied to coating techniques that require the formation of a coating film of uniform thickness.

[Brief explanation of drawings]

FIG. 1 is a front view showing the main parts of a coating device according to an embodiment of the present invention, and FIG. 2 is a side view thereof. 1... Servo motor, 2... Spin chuck (rotating table), 3... Wafer (object to be coated), 4... Dripping nozzle, 5... Photoresist (coating liquid), 6...・Rotation axis, 7...Reversing mechanism.

Claims (1)

[Scope of Claims] 1. A coating device that forms a coating film by dropping a coating liquid onto a rotated object, the rotary table on which the object to be coated is removably placed; 1. A coating device, wherein the coating device is held by a reversing mechanism that is rotatable within a plane intersecting a rotation plane of a rotary table, and the object to be processed can be reversed while being placed on the rotary table. 2. The coating apparatus according to claim 1, wherein the object to be coated and the coating liquid are a wafer and a photoresist, respectively.