JPS63260130A - Wafer treatment apparatus - Google Patents

Abstract

PURPOSE:To make an apparatus compact and to improve the reliability and the yield rote of semiconductor elements, by providing a diaphragm, which covers an exhaust port and constitutes an exhausting flow path along the entire outer surface of a wafer at the lower side of the wafer, and uniformly dispersing negative pressure at the lower side of the diaphragm at the time of exhaustion. CONSTITUTION:A wafer 2 is sucked with vacuum on a spin chuck 3. Resist is dropped through a resist dropping nozzle 6. The wafer 2 is rotated at a high speed with a motor 4. The resist dropped on the wafer 2 is radially expanded uniformly along the direction of the radius of the wafer with eccentric force. At this time, gas in an applying cup 1 is exhausted through an exhaust port 1d. Negative pressure, which is yielded at the time of exhaustion, is uniformly dispersed at the lower side of the diaphragm 11. The exhaustion of the inside of the treating cup 1 is carried out through an exhaust flow path, which s formed along the entire outer surface of the wafer with the dispersed negative pressure. The exhausting speed in the treating cup is made uniform in this way, and the flow rate of exhaustion can be reduced. As a result, the apparatus is made compact and the reliability and the yield rate o+ semiconductor elements are improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a technique that is particularly effective when applied to semiconductor device manufacturing technology and further to wafer processing technology.

For example, it relates to a technique that is effective when applying a resist onto a wafer.

[Prior Art] Regarding the technique of applying a resist onto a wafer, for example, see pages 89 to 89 of the Electronic Materials Special Edition "Ultra LSIII Fabrication and Testing Equipment Guidebook" published by Kogyo Kenkyukai on November 20, 1985. It is described on page 94. The outline is as follows.

FIG. 5 shows an example of a conventional resist coating apparatus.

In the figure, the reference numeral 1 represents a coating cup, and although the coating cup 1 has an inner wall 1b that is formed concentrically with the outer wall 1a, it has an approximately cylindrical shape with a bottom as a whole. It is formed. In this applicator cup 1, an opening 1c is formed in a portion surrounded by an inner wall 1b. Further, a motor 4 is disposed on the lower side of the coating cup 1, and the upper end of a rotating shaft 4a connected to the motor 4 faces into the coating cup 1 through the opening 1a, and a wafer 2 is attached to the upper end of the rotating shaft 4a. A spin chuck 3 is attached to support the spin chuck 3. The wafer 2 supported by the spin chuck 3 is rotated at high speed by the motor 4. In addition, a communication tube (not shown) whose one end opens on the upper surface of the spin chuck 3 is provided in the spin chuck 3 and the rotating shaft 4a, and the wafer 2 is vacuum-adsorbed onto the spin chuck 3 through the communication tube by a vacuum pump (not shown). It is supposed to be done. Furthermore, application cup 1
As shown in FIG. 6, two exhaust ports 1d are provided on the outside of the inner wall 1b at the bottom, and the inside of the coating cup 1 can be exhausted through the exhaust ports 1d by an exhaust pump (not shown). There is. This evacuation is done to prevent the resist from rebounding.

On the other hand, a resist dripping nozzle 6 is provided above the center of the spin chuck 3.
This allows the resist to be dropped onto the center of the wafer 2.

Next, the operation of such a resist coating device will be explained.

First, the wafer 2 is vacuum-adsorbed onto the spin chuck 3. Next, resist is dropped from the resist dropping nozzle 6, and the wafer 2 is rotated at high speed by the motor 4. As a result, the resist dropped onto the wafer 2 is uniformly spread in the radial direction of the wafer 2 by centrifugal force. At this time, the resist blown outward from the wafer 2 by centrifugal force is prevented from rebounding by exhausting the coating cup 1 through the exhaust port 1d. Further, the inner wall 1b of the coating cup 1 prevents the resist blown outward from the wafer 2 from adhering to the motor 4 and the rotating shaft 4a. In this way, the resist 1 is coated onto the wafer 2.

[Problems to be Solved by the Invention] However, the resist coating apparatus having such a configuration has the following problems.

That is, in this resist coating apparatus, the exhaust port 1d is connected to the wafer 2.
Since it is located outside and directly exposed inside the application cup 1, when exhausting through the exhaust port 1d, the negative pressure is high in the vicinity of the exhaust port 1d.

On the other hand, the negative pressure is low in the area away from the exhaust port 1d, and therefore the exhaust air velocity within the application cup 1 is not equalized.In other words, the exhaust air velocity is large near the exhaust port 1d; In the area separated from 1d, the exhaust air speed becomes small.

Therefore, it is necessary to increase the exhaust air speed in a region away from the exhaust port 1d to prevent the resist from rebounding, but in this case, the amount of exhaust air by the exhaust pump must be increased.

There is a problem that the resist coating device itself becomes large. Furthermore, when the exhaust volume by the exhaust pump is increased, the exhaust air speed near the exhaust port 1d also increases, which accelerates the drying of the resist on the outer periphery of the wafer 2. Variations occur in the resist film thickness between the center and the outer periphery, reducing pattern accuracy.
As a result, the reliability of the semiconductor device is reduced.

On the other hand, if the exhaust volume by the exhaust pump is reduced to eliminate this variation in resist film thickness, resist rebound will occur in a region away from the exhaust port 1d where the exhaust air velocity is low, and this rebound will reduce the yield in semiconductor device manufacturing. A decrease is induced.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a wafer processing apparatus that is suitable for downsizing of equipment and is capable of improving the reliability and yield of semiconductor devices.

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 the Problems] Representative inventions disclosed in this application will be summarized as follows.

That is, a partition plate is provided below the wafer that covers the exhaust port and forms an exhaust flow path around the entire outer circumference of the wafer, and the negative pressure during exhaust is uniformed under the partition plate. It was designed to be dispersed into

[Function] According to the above-described means, the negative pressure during exhaust is uniformly distributed under the partition plate, and this distributed negative pressure allows the process to be carried out through the exhaust flow path configured over the entire outer circumference of the wafer. Due to the effect of exhausting the inside of the cup, the speed of exhaust air inside the processing cup is made uniform, and as a result, the exhaust flow rate can be reduced. This achieves the above-mentioned objectives of downsizing the equipment and improving the reliability and yield of semiconductor devices.

[Example] Embodiments of the present invention will be described below based on the drawings.

1 and 2 show a resist coating apparatus according to a first embodiment of the present invention. This resist coating apparatus is basically constructed almost the same as the conventional one (FIGS. 5 and 6). Therefore, the same reference numerals are given to the same components as in the prior art, and redundant explanations will be omitted.

First, the differences between the resist coating apparatus of the embodiment and the conventional one will be explained.

The resist coating apparatus of this embodiment differs from the conventional one in that a partition plate 11 is provided below the wafer 2 supported by the spin chuck 3.

Outside the coating cup 1 and inside the wafer 2
A protrusion 12 that protrudes inward of the application cup 1 is provided at a position above the applicator cup 1 .

Here, the partition plate 11 extends from below the wafer 2 to the outside thereof with a predetermined downward slope, and the exhaust port 1d is covered by the partition plate 11, and the exhaust port 1d is covered with the partition plate 11. is not directly exposed in the applicator cup 1. The partition plate 11 is formed integrally into a ring shape as a whole, or is formed so as to be divisible into a plurality of pieces in the circumferential direction. When installing the partition plate 11, the inner circumference of the partition plate 11 is attached to the applicator cup 1.
It is designed to be fitted onto the upper end of the inner wall 1b. Also,
The outer edge of the partition plate 11 forms a predetermined gap with the inner circumferential surface of the outer wall of the application cup 1, and the gap constitutes an exhaust flow path. This exhaust flow path is constructed over the entire outer circumference of the wafer.

Further, the lower surface of the protrusion 12 extends toward its base end with a steeper slope than the partition plate 11,
As a result, the lower surface of this protrusion 12 and the partition plate 11
The exhaust flow path becomes narrower toward the downstream. In other words, the exhaust air speed increases as it approaches the outer wall of the coating cup 1 during exhaust.

Next, the operation of the resist coating apparatus configured as described above will be explained.

First, the wafer 2 is vacuum-adsorbed onto the spin chuck 3. Next, resist is dropped from the resist dropping nozzle 6, and the wafer 2 is rotated at high speed by the motor 4. As a result, the resist dropped onto the wafer 2 is uniformly spread radially along the radial direction of the wafer 2 by centrifugal force. At this time, the inside of the coating cup 1 is exhausted through the exhaust port 1d. In this case, the negative pressure generated during evacuation is uniformly dispersed below the partition plate 11, and this dispersed negative pressure causes the evacuation inside the processing cup 1 to be carried out through the exhaust flow path configured around the entire outer circumference of the wafer. will be done. This effectively prevents the resist blown outward from the wafer 2 by centrifugal force from rebounding. Also, by this partition plate 11.

The resist blown outward from the wafer 2 is prevented from adhering to the motor 4 and rotating shaft 4a. In this way, the resist is applied onto the wafer 2.

According to the resist coating apparatus of the embodiment configured as described above, the following effects can be obtained.

That is, the partition plate 11 is provided to uniformly disperse the negative pressure under the fin, and the dispersed negative pressure causes the exhaust inside the processing cup 1 to be exhausted through the exhaust flow path configured around the entire outer circumference of the wafer. Since this is done, the velocity of the exhaust air inside the coating cup 1 is made uniform, thereby making it possible to reduce the amount of exhaust air and to make the resist film thickness uniform. As a result, it is possible to achieve the effect of improving the reliability and yield of semiconductor elements.

Furthermore, since the exhaust flow path is narrowed toward the downstream between the lower surface of the protruding portion 12 and the partition plate 11, the exhaust air velocity can be increased near the outer wall 1a in the coating cup 1, thereby increasing the resist flow rate. The rebound is further reduced, and as a result, the displacement can be further reduced.

FIG. 3 shows a resist coating apparatus according to a second embodiment of the present invention.

The resist coating apparatus of this embodiment differs from that of the first embodiment in that a notch lla is provided at a portion of the outer periphery of the partition plate 11 away from the exhaust port 1d. That is, in the resist coating apparatus of this embodiment, the exhaust flow path is expanded at the notch 11a forming portion of the partition plate 11, and the exhaust flow rate at the core portion is increased. In other words, the gap forming the exhaust flow path should be made smaller near the exhaust port 1d. This configuration is based on the fact that even in the case of the first embodiment, the negative pressure in the vicinity of the exhaust port 1d is somewhat higher than in the area distant from the exhaust port 1d.

According to the resist coating apparatus of this embodiment, the partition plate 11
The notch 11a is provided in a part separated from the exhaust port 1d, and the exhaust flow rate is increased in a region separated from the exhaust port 1d where the negative pressure should be relatively low. This means that the exhaust air speed can be made more uniform than in the case of the conventional method.

Further, FIG. 4 shows a resist coating apparatus according to a third embodiment of the present invention.

The resist coating apparatus of this embodiment differs from that of the second embodiment in that the partition plate 11 is constructed in a substantially elliptical shape. That is, in the resist coating apparatus of this embodiment, the gap between the partition plate 11 and the inner peripheral surface of the coating cup 1 gradually increases as the distance from the exhaust port 1d increases.

According to the resist coating apparatus of this embodiment, the exhaust flow rate is gradually increased toward the area separated from the exhaust port 1d where the negative pressure should be relatively low. Controllability of exhaust air speed 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 Examples and can be modified in various ways without departing from the gist thereof. For example, in the above embodiment, two exhaust ports are provided, but it is also possible to have three or more exhaust ports, or one exhaust port, and the shape of the exhaust ports may be of any shape. It is. In that case, the shape of the partition plate 11 may be changed as appropriate depending on the number and shape of the exhaust ports 1d.

In the above explanation, the invention made by the present inventor has mainly been explained with respect to the resist coating technology, which is the field of application that forms the background of the invention, but the development processing technology or SOG
It can also be used in thin film formation techniques such as spin-on-glass (spin-on-glass) films.

[Effects of the Invention] The effects obtained by typical inventions disclosed in this application are briefly explained below.

That is, a partition plate is provided below the wafer to cover the exhaust port and form an exhaust flow path around the entire outer circumference of the wafer, and the negative pressure during exhaust is uniformly distributed under this partition plate. As a result, this dispersed negative pressure causes the inside of the processing cup to be exhausted through the exhaust flow path configured around the entire outer circumference of the wafer, making the exhaust air velocity within the processing cup uniform and reducing the exhaust flow rate. can be reduced. As a result, it is possible to downsize the equipment and improve the reliability and yield of semiconductor devices.

[Brief explanation of drawings]

FIG. 1 is a vertical cross-sectional view of a resist coating device according to a first embodiment of the present invention, FIG. 2 is a plan view of the resist coating device of FIG. 1, and FIG. 3 is a resist coating device according to a second embodiment of the present invention. FIG. 3 is a plan view of the coating device. FIG. 4 is a plan view of a resist coating apparatus according to a third embodiment of the present invention, FIG. 5 is a longitudinal sectional view of a conventional resist coating apparatus, and FIG. 6 is a plan view of the resist coating apparatus of FIG. 5. . 1... Coating cup (processing cup), 1d... Low cut, 2... Wafer, 11... Partition plate. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 1 Figure 6

Claims (1)

[Scope of Claims] 1. In a wafer processing apparatus that processes a wafer placed in a processing cup while exhausting air from an exhaust port provided at the bottom of the processing cup, the underside of the wafer is A partition plate is provided that covers the exhaust port and forms an exhaust flow path around the entire outer circumference of the wafer, and the negative pressure during exhaust is uniformly distributed below the partition plate. A wafer processing device featuring: 2. The exhaust flow path is constituted by a gap between the partition plate and the inner circumferential surface of the processing cup, and this gap is smaller near the exhaust port than in other parts. The wafer processing apparatus described in Section 1.