JPH02160074A - Coater - Google Patents

Abstract

PURPOSE:To prevent drying at the front end of a supply pipe by providing a solvent tank and a drying preventive mechanism consisting of a discharge hole which discharges the solvent overflowing form the solvent tank in a container provided with an aperture. CONSTITUTION:A prescribed amt. of resist is supplied from the front end of the supply pipe 8 via this pipe to the central part of a wafer 1 held on a chuck 2. The wafer 1 is rotationally controlled by a motor 3 via a chuck 2. The resist on the wafer 1 surface is diffused from the central part to the peripheral edge part by the centrifugal force generated by this rotation. The wafer 1 is further rotated at a high speed to dry the supplied resist and to form the film of a uniform thickness on the wafer 1 surface. The solvent, such as acetone, is supplied into the solvent tank 14 from a solvent supply pipe 15 to fill the container 12 with the vapor to prevent the change in the properties of the resist and the drying of the resist when the resist is not supplied to the wafer 1 surface from the supply pipe 8.

Description

[Detailed description of the invention] [Purpose of the invention] (Industrial application field) The present invention relates to a coating device.

(Prior Art) In a photolithography process for a substrate to be processed, such as a semiconductor wafer, a resist pattern is formed on the wafer surface by resist coating, exposure, development, and the like. In this resist coating, a resist coating device is used that spin-coats the wafer.

This resist coating device holds the wafer by suction from the back side using a mounting table, such as a spin chuck, and controls the rotation by a motor connected to the spin chuck to apply a predetermined amount onto the wafer surface from a coating liquid supply pipe, such as a resist supply pipe. Rotation processing is performed by supplying a liquid such as resist. Such resist coating techniques are disclosed in, for example, Japanese Patent Application Laid-open Nos. 175569/1980, 15773/1982, and 194829/1982.

When such a resist coating process is repeated a plurality of times, a dried and hardened resist adheres to the tip of the resist supply pipe. When the amount of resist adhered increases, the hole diameter at the tip of the resist supply tube becomes smaller, and a predetermined amount of resist is not supplied to the wafer surface or is not supplied at a predetermined speed, resulting in formation of resist on the wafer surface. There were problems such as the resist film becoming uneven and not being able to obtain a predetermined film thickness. In order to eliminate this problem, a cap is provided to cover the bottom surface of the resist supply pipe to create a sealed structure, and a solvent is stored at the bottom of the cap to prevent the tip of the resist supply pipe from drying due to solvent vapor. A technique for covering the bottom surface of the resist supply pipe as necessary is disclosed in, for example, Japanese Utility Model Publication No. 1981-23581.

(Problem to be Solved by the Invention) However, in the above-mentioned conventional technology, although it is possible to prevent the resist from drying and adhering to the tip of the resist supply pipe, since the solvent to prevent this drying is stored in the cap, It has been difficult to detect the amount of this solvent stored. If this solvent runs out, it will no longer be possible to prevent the resist at the tip of the resist supply tube from drying out, and if there is too much of the solvent, it will adhere to the resist supply tube, and this attached solvent will cause liquid to drop onto the wafer surface. There have been problems such as dripping or adhesion during resist coating, resulting in uneven resist film formation or failure to obtain a predetermined film thickness.

Further, even if a sensor is provided to detect the amount of the solvent, it is difficult to install the sensor due to the closed structure, and there are also problems in that the cost increases.

The present invention has been made in view of the above-mentioned problems, and it is an object of the present invention to provide a coating device that has a drying prevention mechanism that prevents the tip of the supply pipe from drying out with a simple structure and without adversely affecting the substrate to be processed. It is something.

[Structure of the invention]

(Means for Solving the Problems) The present invention provides an apparatus for supplying and coating a coating liquid from a supply pipe onto the surface of a substrate to be processed supported on a support stand, which has an opening into which the tip of the supply pipe can be inserted. A drying prevention mechanism comprising a solvent tank formed to store a solvent for preventing the tip of the supply pipe from drying in a container provided therein, and a discharge hole for discharging overflowing solvent from the solvent tank. A coating device is obtained.

(Operation and Effect) That is, the present invention stores a solvent for preventing the tip of the supply tube from drying in a container provided with an opening into which the tip of the supply tube for supplying the coating liquid to the surface of the substrate to be processed can be inserted. Equipped with a drying prevention mechanism consisting of a solvent tank formed as shown in FIG. The vapor from which the solvent has evaporated, ie, the atmosphere, can prevent the coating liquid from drying and adhering to the tip of the supply pipe without adhesion.

Therefore, it is possible to obtain a predetermined film thickness with good reproducibility without adversely affecting the film coated on the substrate to be processed.

(Example) Hereinafter, an example in which the apparatus of the present invention is applied to a resist coating process in a semiconductor manufacturing process will be described with reference to the drawings.

First, the configuration of the resist coating device will be explained.

A mounting table, such as a chuck (2), which can hold, for example, suction and hold a substrate to be processed, such as a semiconductor wafer (2), is provided. A rotary drive mechanism such as a motor (2) is connected to the chuck (2), and the wafer (2) can be rotated through the chuck (2) by driving the motor (2). This chuck
A cylindrical cup (A) with a bottom is provided so as to be movable up and down so as to surround the wafer (A) held by the cup. This cup is provided so that the part near where it intersects with the extended surface of the surface of the wafer 0 is inclined at an angle A (A≠90'). Even if the resist is scattered, the cup tilted above (
b) The inner wall prevents the resist from rebounding onto the surface of the wafer 0. Further, a resist discharge pipe (1) and a resist discharge pipe (2) are connected to the bottom of the cup (2). The exhaust pipe (■) is connected to a drain box (■) that accommodates the resist after use, and the exhaust pipe (0) is connected to an exhaust mechanism (not shown) for exhausting the inside of the cup (). .

Also, remove the resist from the center axis of the wafer ① above.
A supply pipe is provided so that it can be supplied to the surface.

This supply pipe (2) is supported by a movable support (2), and a moving mechanism (10) consisting of a rotary actuator and an air cylinder, for example, moves X-Y of this support (2).
- It is possible to move integrally by moving in Z and θ.

This movement allows the supply pipe (to) to be moved between the upper part of the wafer (1) and the drying prevention mechanism (11) that prevents the tip of the supply pipe (2) from drying. The supply pipe (2) is configured such that it rises so as not to come into contact with the cup (1) and descends above the drying prevention mechanism (11) so that the supply pipe (2) can be inserted into this drying prevention mechanism (11). As shown in FIG. 2, the drying prevention mechanism (11) includes a substantially sealed container (12) that is placed horizontally on the cup (11). The upper wall of this container (12) is provided with an opening (13) that has approximately the same diameter as the above-mentioned supply pipe or is slightly larger. The tip is insertable. Inside this container (12),
A solvent tank (14) is formed having a lower wall with a smaller area than the lower wall of this container (12). This solvent tank (14) is constructed by providing a partition plate at the inner bottom of the container (12) with a height that does not contact the supply pipe (1), and a solvent supply pipe that supplies the solvent into this solvent tank (14). (15) is the container (12) located at a slightly higher position than the solvent tank (14)
Connected to a side wall or earthen wall.

Furthermore, a container (1) located lower than this solvent supply pipe (15)
2) A discharge hole or solvent discharge pipe (16) for discharging the solvent is connected to the side wall or the lower wall of the container (12). The resist coating device is configured in this manner.

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

First, the cup (a) is lowered, and the wafer (a) is transported onto the chuck (a) in the cup (a) by a transport mechanism (not shown), such as a belt transport or a handling arm, and the center of the wafer (b) and the center of the chuck (b) Combine them and place them on the chuck ■. Then, the placed wafer ω is held by suction by a vacuum mechanism (not shown) connected to the chuck (2). Thereafter, the cup (2) is raised and stopped so that the cup (2) is positioned around the wafer (2). A predetermined amount of resist is supplied from the tip to the center of the wafer (2) held on the chuck (2) through the supply pipe (2).

At this time, since the supply pipe (c) is inserted into the drying prevention mechanism (11) in the normal state, the resist
When supplying to the surface, the moving mechanism (10) lifts the supply pipe (C) and inserts it through the opening (13) of the drying prevention mechanism (11), so that the supply pipe (C) reaches the wafer ω. Drive X-Y or θ so that it is located in the center, and furthermore, the distance from the tip of the supply pipe (8) to the surface of 9160 is 5
It is lowered to ~20mm.

Then, the rotation of the wafer (2) to which a predetermined amount of resist has been supplied is controlled by the motor (2) via the chuck (2). This rotation is automatically controlled based on the acceleration and rotation speed preset by the operator. Due to this rotation, the resist on the surface of the 9160 is diffused from the center to the periphery due to centrifugal force. Then, the wafer (1) is rotated at a higher speed to dry the supplied resist, thereby forming a uniform, predetermined film thickness on the surface of the 9160.

The resist scattered by such rotation is discharged from the discharge pipe 0 provided at the bottom of the cup and collected into the drain box (2). In addition, during the resist coating process, the thickness and uniformity of the resist formed on the surface of 9160 is affected by the atmosphere inside the cup (a), so if necessary, an exhaust pipe provided at the bottom of the cup (a) may be used. Exhaust is controlled from 0.

When this kind of resist is applied, the above supply pipe (to)
The resist remaining on the tip dries and solidifies. If the resist is applied to the next wafer after the resist has solidified, the desired resist film thickness and uniformity may not be obtained. If you do not want to supply the resist to the surface of 9160 from the supply pipe (c), there is a problem that the yield will decrease. This is done by inserting the resist inside the container (
12) A solvent such as acetone or ECA (ethyl cellosolve acetate) is supplied from the solvent supply pipe (15) into the solvent tank (14) formed inside, and the inside of the container (12) is By meeting the requirements, deterioration and drying of the resist described above are prevented. At this time,
When the amount of solvent supplied from the solvent supply pipe (15) into the solvent tank (14) is large, it overflows from the solvent tank (14) and flows into the container (12).

The solvent is discharged from the solvent discharge pipe (16), and the solvent in the container (12) can be maintained at a predetermined level W, that is, at a liquid level that does not come into contact with the supply pipe (3), and this solvent flows into the supply pipe (C). It is possible to prevent adverse effects on the wafer ω due to liquid dripping onto the surface of the wafer ω due to adhesion. This solvent may be supplied periodically from the solvent supply pipe (15) and the supply of the solvent may be stopped when some solvent has been discharged from the solvent discharge pipe (16), or the solvent evaporation rate may be taken into consideration. Alternatively, a predetermined amount of solvent may be supplied periodically.

In addition, if the resist coating process is not performed for a long time, the resist inside the supply pipe (■) may deteriorate.
The resist is configured to be automatically discharged from the supply pipe (2) when the resist coating process is not performed for a predetermined period of time or more.

Discharging of the resist in this case can also be performed within the container (12). At this time, the supply pipe (
c) The position of the opening (13) into which the solvent tank (1) is inserted is
4) It is preferable to form the resist at a position away from the top, so that the discharged resist is discharged from the solvent discharge pipe (16) together with the solvent.

In the above embodiment, the resist coating process for semiconductor wafers has been described, but the process is not limited to this. For example, polyimide coating, SOG (Spinonglass)
) A similar effect can be obtained by coating or by using an LCD substrate or a printed circuit board used in a screen display device such as a liquid crystal TV.

As described above, according to this embodiment, a solvent for preventing the tip of the supply tube from drying is placed in a container provided with an opening into which the tip of the supply tube for supplying the coating liquid to the surface of the substrate to be processed can be inserted. Equipped with a drying prevention mechanism consisting of a solvent tank formed to collect the solvent and a discharge hole for discharging the overflowing solvent from the solvent tank, the solvent will not accumulate above a certain amount, and this solvent will be able to be used as the supply source. The vapor from which the solvent evaporates, that is, the atmosphere, can prevent the coating liquid from drying and adhering to the tip of the supply pipe without adhering to the pipe. Therefore, it is possible to obtain a predetermined film thickness with good reproducibility without adversely affecting the film coated on the substrate to be processed.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a resist coating apparatus for explaining one embodiment of the apparatus of the present invention, and FIGS. 2 and 3 are explanatory diagrams of the drying prevention mechanism of FIG. 1. l...Wafer 8...Supply pipe 11...
Drying prevention mechanism 12... Container 13... Open hole 14... Solvent tank 15... Solvent supply pipe
16...Solvent discharge pipe Patent applicant Tokyo Electron Ltd. Figure 2 Figure 3

Claims (1)

[Claims] In an apparatus that supplies a coating liquid from a supply tube to the surface of a substrate to be processed supported on a support stand, the tip of the supply tube is dried in a container provided with an opening into which the tip of the supply tube can be inserted. What is claimed is: 1. A coating device comprising a drying prevention mechanism comprising a solvent tank formed to store a solvent for preventing drying and a discharge hole for discharging overflowing solvent from the solvent tank.