JPH097920A - Coating liquid application method and coating liquid application device - Google Patents

Abstract

PURPOSE: To provide a coating liquid application method and a coating liquid application device by a method wherein non-uniformity in a film thickness due to readhesion of the coating liquid is prevented and generation of film thickness variations is prevented so as to prevent a yield drop of a product for application due to film thickness variations. CONSTITUTION: A coating liquid shatterproof means 7 is provided so as to form a gas flow 10 on the surface of the coating liquid shatterproof means 7 at the time of rotating a coating target 1 such as a mounted wafer with drips of the coating liquid 4 such as a resist liquid so as to evaporate a solvent in this coating liquid 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating liquid coating method and a coating liquid coating device. In particular, a method for applying a coating solution and a method for applying a coating solution, in which a coating object on which the coating solution is placed is rotated to evaporate a solvent in the coating solution to form a coating film on the surface of the coating object. It relates to the device. INDUSTRIAL APPLICABILITY The present invention can be applied to coating liquid coating in various fields, and can be used, for example, when coating various coating liquids on electronic materials (semiconductor wafers and the like).

[0002]

2. Description of the Related Art Conventionally, as a method for forming a coating liquid film, particularly a thin film having a uniform thickness, on a substrate to be coated such as a semiconductor wafer (hereinafter, this may be simply referred to as a wafer), rotation has been performed. There is application. This is typically done by, for example, rotating a wafer coated with a resist solution at a high speed to perform processing by photolithography, spreading the resist solution on the wafer by centrifugal force, and evaporating the solvent in the resist solution to form a resist. It is used when forming a film (for literature on this, see, for example, Industrial Research Council, December 13, 1988, "Electronic Materials," December 1989, Supplement, P78-83). .

FIG. 2 shows a schematic block diagram of a conventional spin coater of this type. In the figure, reference numeral 1 is an object to be coated such as a wafer, and 2 is a chuck for fixing the object 1 to be coated by a method such as vacuum suction.
Is generally configured to be rotated at a high speed by driving means such as the motor 3. Reference numeral 4 is a coating liquid such as a resist, and 5 is a nozzle for supplying the coating liquid 4 onto the object 1 to be coated. Further, in order to remove the coating liquid in the peripheral portion of the coated object 1, a solvent supply nozzle indicated by reference numeral 6 is provided. By supplying the solvent from the nozzle 6 while rotating the object to be coated 1, the coating film around the object to be coated is dissolved and removed. In addition, a scattering prevention plate 7 for preventing the coating liquid and the solvent from scattering is installed around the object 1 to be coated.

In order to form a thin film such as a resist film on the object to be coated 1 by the conventional spin coater thus constructed, first, the object to be coated 1 is fixed on the chuck 2 and the coating liquid 4 is applied to the nozzle. 5 is dropped onto the article 1 to be coated. Then, the motor 3 is driven to rotate the object to be coated 1 together with the chuck 2 at a high speed for a certain period of time. When the object 1 to be coated is rotated at a high speed in this way, the coating liquid 4 spreads over the entire upper surface of the object 1 to be coated by centrifugal force, and the thickness of the coating liquid 4 is reduced. After that, the film reduction due to the evaporation of the solvent contained in the coating liquid 4 becomes remarkable, but at the same time, the viscosity of the coating liquid 4 increases and the contribution of the centrifugal force to the film reduction further decreases.
Finally, the decrease of the diffusion coefficient in the liquid phase makes it difficult for the solvent to move in the film, and evaporation from the gas-liquid interface becomes impossible, and the decrease in film thickness stops. Generally, the article 1 to be coated is as described above.
It is believed that a thin film is formed on top. At this time, in order to remove the thin film at the edge portion of the object to be coated 1, by dropping the solvent of the object to be coated from the solvent supply nozzle 6, the viscosity of the coating of the edge portion is reduced, and the coating force of the edge portion is reduced by centrifugal force. The coating material 1 is blown to the outer peripheral side.

At this time, most of the sprayed coating liquid 4 collides with the scattering prevention plate 7 and is discharged from a discharge port (not shown).

However, the coating liquid 4 is reflected on the surface of the anti-scattering plate 7, although it is a very small portion, and is reflected on the coated object 1, that is,
The coating liquid adheres on the thin film. The adhesion causes unevenness of the film thickness at that portion. This may cause a defective product, which causes a problem such as a decrease in the yield of semiconductor devices.

In order to solve this problem, the shape and the like of the shatterproof plate 7 have been devised, but it is not perfect and the above problems have occurred to some extent or another.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and prevents unevenness of the film thickness due to re-adhesion of the coating liquid and prevents unevenness of the film thickness. It is an object of the present invention to provide a coating liquid coating method and a coating liquid coating device which prevent a reduction in yield of products to be coated due to uneven thickness.

[0009]

According to the present invention, a coating solution coating method and a coating solution coating apparatus having the following constitution are provided.
The above objective was achieved.

That is, in the coating liquid coating method of the present invention, the coating liquid on which the coating liquid is placed is rotated to evaporate the solvent in the coating liquid to form a coating film on the surface of the coating liquid. In the liquid coating method, the above object is achieved by providing a means for preventing the scattering of the coating liquid and forming a gas flow on the surface of the coating liquid scattering prevention means.

Further, the coating liquid coating apparatus of the present invention rotates the object to be coated on which the coating liquid is placed to evaporate the solvent in the coating liquid to form a coating film on the surface of the object to be coated. In the liquid coating device, the above-mentioned object is achieved by providing a coating liquid scattering prevention means around the object to be coated and providing a gas supply device for producing a gas flow on the surface of the coating liquid scattering prevention means. To do.

The coating liquid coating technique of the present invention is a coating liquid coating process in which a coating liquid dropped onto the coating liquid is rotated to evaporate the solvent in the coating liquid to form a coating liquid film on the surface of the coating liquid. In the technology, a configuration may be provided in which a gas supply device that creates a gas flow is provided on the surface of the coating liquid scattering prevention plate that is installed in the peripheral portion of the object to be coated.

The coating liquid coating apparatus according to the present invention has a configuration including a device for cleaning the peripheral portion of the object to be coated with the solvent of the coating liquid and supplying a coating liquid solvent for removing the coating film on the peripheral portion. Can be implemented in.

The coating liquid coating device of the present invention can be implemented in a mode in which the gas supply device is connected and a gas exhaust port is provided.

Further, the gas supplied by the gas supply device may be embodied in such a manner that it contains the components of the coating liquid.

[0016] Further, in a mode in which an impurity removing device is provided between the gas exhaust port side and the gas supply port, and a gas circulation device for returning the gas discharged from the gas exhaust port to the gas supply side is interposed. It can be carried out.

Further, there are provided a sensor for measuring a gas component in the atmosphere in which the object to be rotated and an atmosphere gas component control device connected to the sensor and the gas supply device for adjusting the component of the atmosphere gas. It can be implemented in the form of a configuration.

[0018]

According to the present invention, when the coating object on which the coating solution is placed is rotated and the solvent in the coating solution is evaporated to form a coating film on the surface of the coating solution, the coating solution scatters. Since the gas flow is formed on the surface of the prevention step, the coating liquid splash can be discharged in a predetermined direction by the gas flow,
It is possible to prevent reattachment to the object to be coated.

[0019]

Embodiments of the present invention will be described below with reference to the drawings. Of course, the present invention is not limited to the embodiments.

Example 1 In this example, the present invention is applied to a case where a semiconductor wafer is used as an object to be coated, and a resist solution is applied thereon as a coating solution to form a resist film.

Referring to FIG. In the present embodiment, the object to be coated 1 (here, the wafer) on which the coating liquid 4 (here, the resist solution) is dropped is rotated, and the solvent in the coating liquid 4 is evaporated to cause the object to be coated. When a coating film (here, a resist film) is formed on the surface of the coating liquid 1, a coating liquid scattering prevention means 7 (specifically, a scattering prevention plate) is provided, and a gas flow (arrow) is formed on the surface of the coating liquid scattering prevention means 7. (Shown by 10) is performed.

Further, in the coating apparatus of this embodiment, as shown in FIG. 1, the coated body 1 on which the coating liquid 4 is placed is rotated,
The solvent in the coating liquid 4 is evaporated to form a coating film on the surface of the coating target 1. The coating liquid scattering prevention means 7 is provided in the peripheral portion of the coating target 1 and the coating liquid scattering is performed. The coating solution coating apparatus is provided with a gas supply device (consisting of a gas supply pipe 8, a gas supply port 9, and a gas supply unit 13) that creates a gas flow (indicated by an arrow 10) on the surface of the prevention means 7.

In the coating liquid coating apparatus of the present embodiment, the coating liquid solvent supply device (solvent supply nozzle 6) for cleaning the peripheral portion of the article to be coated 1 with the solvent of the coating liquid and removing the coating film on the peripheral portion. ) Is provided.

In the coating liquid coating apparatus of the present embodiment, the gas supply apparatus described above is connected and the gas exhaust port 11 is connected.
Is provided.

In the coating liquid coating apparatus of the present embodiment, the gas supplied by the gas supply unit contains the coating liquid component (here, solvent).

In the coating liquid coating apparatus of this embodiment, an impurity removing device was provided between the gas exhaust port 11 side and the circulation system reaching the gas supply port 9 again, and the coating liquid was exhausted from the gas exhaust port. A gas circulation device for returning the gas to the gas supply side may be interposed.

In the coating liquid coating apparatus of the present embodiment, a sensor for measuring the gas component in the atmosphere in which the article to be coated 1 rotates and the sensor and the gas supply apparatus are connected,
A controller is provided to adjust the composition of the ambient gas. Specifically, the illustrated gas adjusting device 12 has a concentration measuring sensor and a gas component adjusting function.

That is, the coating liquid coating device of this embodiment is equipped with a gas supply device for forming a flow of air flow on the surface of the scattering prevention plate which is the coating liquid scattering prevention means 7. According to this configuration, it is possible to prevent the coating material from being redeposited from the anti-scattering plate 7 onto the coated object 1.

The present embodiment will be described in more detail below. FIG. 1 is a schematic configuration diagram showing a coating liquid coating apparatus of this embodiment.

In FIG. 1, reference numeral 1 is an object to be coated which is a wafer, and 2 is a chuck which constitutes an object supporting portion for fixing the object 1 by a method such as vacuum suction, and the chuck 2 is a driving means. It is configured to be rotated at a high speed by a certain motor 3. Reference numeral 4 is a coating liquid such as a resist liquid, and 5 is a nozzle for supplying the coating liquid 4 onto the object 1 to be coated. Further, in order to remove the coating liquid in the peripheral portion of the coated object 1, a solvent supply nozzle indicated by reference numeral 6 is provided.

In this embodiment, the solvent is supplied from the nozzle 6 while rotating the object to be coated 1, so that the coating film on the peripheral portion of the object to be coated 1 is dissolved and removed. A gas supply port 9 is set on the shatter prevention plate 7, and gas is supplied from the gas supply unit 13 through the gas supply pipe 8 to form an air flow in the direction of arrow 10. In addition, a gas discharge port 11 is installed on the downstream side of the air flow so that gas can be discharged.

A gas adjusting device 12 is provided for the discharged gas.
Is connected, and the gas is supplied through the gas supply unit 1
Re-supplied to 3. The gas adjusting device 12 is provided with a sensor having a function of measuring the concentration of the coating liquid solvent in the discharged gas, and also has a function of supplying the solvent as a gas to adjust the concentration. Further, in the present embodiment, an impurity removing device for removing impurities is incorporated in the gas adjusting device 12.

In this embodiment, air is ejected as a gas from the gas supply port 9 to form an air flow in the direction of arrow 10 in the figure.

In this embodiment, specifically, first, the object to be coated 1 is fixed on the chuck 2, and the coating liquid 4 is applied to the nozzle 5.
To the object to be coated 1 from above. Then, the motor 3 is driven to rotate the object to be coated 1 together with the chuck 2 at a high speed for a certain period of time. When the object 1 to be coated is rotated at high speed in this way, the coating liquid 4 spreads over the entire surface of the object 1 to be coated by centrifugal force, and a thin film of the coating liquid can be formed by the mechanism as described above.

At this time, the excess portion of the coating liquid 4 is blown off by the centrifugal force of the object to be coated 1 and collides with the shatterproof plate 7, but due to the flow of the air flow (see arrow 10), it is effectively moved to the downstream side. It is prevented from being washed away and scattered and adhered onto the object to be coated 1 due to the reaction. Further, after forming the coating liquid thin film on the surface, in order to remove the coating film in the peripheral portion of the object to be coated 1, the solvent is dropped from the solvent supply nozzle 6 to the peripheral portion of the object to be coated 1. At this time, the solvent reduces the viscosity of the coating liquid 4 on the edge portion of the object to be coated 1 and the centrifugal force causes centrifugal force.
Is skipped to the outer circumference side.

The coating solution and the solvent that have been blown off collide with the scattering prevention plate which is the scattering prevention means 7, but are effectively pushed down to the downstream side by the flow of the air flow, and are re-attached to the object to be coated 1 due to the reaction. Does not occur.

A part of the solvent flows to the lower portion without entering the gas discharge port 11, but is discharged to the outside of the shatterproof plate 7 through a discharge port (not shown). At this time, by providing a means for exhausting the entire enclosure of the shatterproof plate 7 at the bottom,
It is possible to further enhance the effect.

As described above, according to this embodiment,
A gas supply device (a gas supply port 9, a gas supply pipe 8, a gas supply) that forms a flow of an air flow (arrow 10) along the anti-scattering plate 7 on the anti-scattering plate 7 at the outer peripheral portion of the object 1 to be rotated. 1
Since 3) is provided, the coating liquid that has been blown off from the article to be coated 1 by centrifugal force can be effectively swept down to the downstream side. Therefore, reattachment of the coating liquid can be prevented. Therefore,
There is an effect that the yield can be improved and the processing cost, the material cost, etc. can be kept low.

Second Embodiment A second embodiment of the present invention will be described below with reference to FIG. In the first embodiment described above, air was used as the gas, but in the second embodiment of the present invention, the solvent of the coating liquid was mixed with nitrogen gas and used as the mixed gas.

First, the coating liquid 1 is fixed on the chuck 2, and the coating liquid 4 is dropped from the nozzle 5 onto the coating target 1.
Then, the motor 3 is driven to rotate the object to be coated 1 together with the chuck 2 at a high speed for a certain period of time. When the object 1 to be coated is rotated at a high speed in this way, the coating liquid 4 spreads over the entire surface of the object 1 to be coated by centrifugal force, and a thin film of the coating liquid can be formed by the mechanism as described above.

After forming the thin film on the surface, a solvent is dropped from the solvent supply nozzle 6 to the peripheral portion of the coating object 1 in order to remove the coating film on the peripheral portion of the coating object 1. At this time, the viscosity of the coating body 1 at the edge portion is reduced, and the coating body 1 is blown to the outer peripheral side of the coating body by centrifugal force.

The sprayed coating liquid and the solvent collide with the scattering prevention plate 7, but since nitrogen containing the solvent is jetted from the gas supply port 9, it does not re-adhere to the upper part of the coated object 1. The gas is discharged from the gas discharge port 11 or a discharge port (not shown) to the outside of the system.

In this case, since the nitrogen gas containing the solvent is supplied from the gas supply port 9, the solvent of the coating liquid evaporates in the region where the flow of the air flow is formed in the portion of the shatterproof plate 7. It is possible to prevent the formation of a coating thin film,
It is washed away as a solution. Therefore, it becomes possible to prevent the coating film from being thickly deposited.

Further, in this embodiment, since the solvent concentration of the gas supplied from the gas supply port 9 is controlled by the gas adjusting device 12 (having the concentration measuring function and the concentration adjusting function as in the first embodiment), It became possible to obtain a stable effect. In addition, the gas supply unit 13 can change the gas supply amount from here. Further, it is possible to set the optimum gas supply amount for each coating liquid.

According to the present embodiment, since the gas supplied from the gas supply device contains the solvent of the coating liquid in particular and the function of controlling the concentration is added to the first embodiment, the coating adhered to the anti-scattering plate is applied. It can be flushed downstream before the solution forms a film. Therefore, it is possible to prevent a thin film of the coating liquid from being deposited and forming a thick film. For this reason,
Since the number of maintenances for removing the thin film formed on the shatterproof plate can be reduced, the downtime of the apparatus can be reduced and the productivity can be improved.

[0046]

As described above, according to the coating solution coating method and the coating solution coating apparatus of the present invention, it is possible to prevent nonuniformity of the coating film thickness due to redeposition of the coating solution during coating of the coating solution. It was possible to prevent the occurrence of thickness unevenness and also to prevent the yield of coated products from being reduced due to such thickness unevenness.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing a coating liquid coating apparatus according to the present invention.

FIG. 2 is a schematic cross-sectional view showing a conventional spin coater.

[Explanation of symbols]

 1 Object to be coated (semiconductor wafer) 2 Object to be supported (chuck) 3 Driving means (motor) 4 Coating liquid (resist liquid) 5 Coating liquid supply nozzle 6 Solvent supply nozzle 7 Scattering prevention plate 8 Gas supply pipe 9 Gas supply Port (gas supply device) 10 Arrow indicating the flow of air (gas flow) 11 Gas discharge port (gas supply device) 12 Gas adjustment device 13 Gas supply unit (gas supply device)

Claims (7)

[Claims] 1. An object to be coated on which a coating liquid is placed is rotated,
In the coating liquid coating method for forming a coating film on the surface of an object to be coated by evaporating the solvent in the coating liquid, a means for preventing scattering of the coating liquid is provided, and a gas flow on the surface of the coating liquid scattering prevention means. A method for applying a coating liquid, characterized in that 2. The object to be coated on which the coating liquid is placed is rotated,
In a coating liquid coating apparatus for forming a coating film on the surface of an object to be coated by evaporating the solvent in the coating liquid, the coating liquid scattering prevention means is provided in the peripheral portion of the object to be coated, and the coating liquid scattering prevention means A coating liquid coating device comprising a gas supply device for generating a gas flow on the surface. 3. The coating liquid coating device according to claim 2, further comprising a coating liquid solvent supply device for cleaning the peripheral portion of the object to be coated with the solvent of the coating liquid and removing the coating film on the peripheral portion. A coating liquid coating device characterized by the above. 4. The coating liquid coating apparatus according to claim 2, wherein the gas supply device is connected and a gas exhaust port is provided. 5. The coating liquid coating device according to claim 2, wherein the gas supplied by the gas supply device contains a component of the coating liquid. 6. The coating liquid coating apparatus according to claim 4, further comprising an impurity removing device between the gas exhaust port and the gas supply port, and returning the gas exhausted from the gas exhaust port to the gas supply side. A coating liquid coating device characterized in that a gas circulating device is interposed. 7. The coating liquid coating apparatus according to claim 2, wherein a sensor for measuring a gas component in an atmosphere in which the object to be rotated rotates, and a sensor connected to the sensor and the gas supply device, the atmospheric gas component. And an atmosphere gas component control device for adjusting the temperature.