JPH08299878A - Rotary coating apparatus and rotary coating method - Google Patents

Abstract

PURPOSE: To reduce the use amt. of a coating soln. without generating coating irregularity. CONSTITUTION: A treatment chamber 5 is filled with a gas containing solvent vapor supplied from a solvent vapor supply source 12 through a diffusion passage 13. A substrate 1 is held to a horizontal posture in the treatment chamber 5 by a chuck 2. A nozzle 9 supplies a photoresist liquid to the center of rotation of the substrate 1 and the chuck 2 is rotated and the gas containing solvent vapor is sprayed on the peripheral part of the substrate from a vapor nozzle 17 along the rotary radius of the substrate 1. The photoresist soln. is spread over the surface of the substrate 1 by the centrifugal force by the rotation of the substrate 1 and spread over the surface of the substrate 1 by the pressure of the sprayed gas and spread over the entire surface of the substrate 1 rapidly and uniformly by the centrifugal force and the pressure of the gas. The treatment chamber 5 is filled with the gas containing the solvent vapor and the sprayed gas contains solvent vapor and the generation of coating irregularity is suppressed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION This invention relates to, for example, ICs and LSs.
I. In the process of forming a fine pattern in the process of manufacturing electronic components such as liquid crystal display devices, a semiconductor substrate typified by a silicon wafer, or a substrate such as a dielectric, metal, or insulator is rotated to produce a photoresist solution or silica. The present invention relates to a rotary coating device and a rotary coating method for coating a coating liquid such as a system coating forming liquid.

[0002]

2. Description of the Related Art Generally, a rotary coating apparatus of this type drops a coating solution on a central portion of a rotatably supported substrate and rotates the substrate to spread the coating solution over the entire substrate.
After that, coating on the substrate is performed by a method of shaking off the excess coating liquid. By the way, since this type of coating liquid is generally very expensive, it is desired to reduce the amount of the coating liquid used. However, by simply reducing the supply amount of the coating liquid to the substrate in the above process, when the coating liquid dropped on the substrate spreads to the peripheral portion of the substrate by rotation, the coating liquid reaching the peripheral portion is There is a problem that since the drying is advanced to some extent and the viscosity is high, the spread is poor only by centrifugal force, it is difficult to apply a uniform thickness, and uneven application occurs.

As disclosed in Japanese Utility Model Laid-Open No. 58-91473, it has been proposed that the coating liquid is spread in a non-contact manner by blowing a gas onto the coating liquid supplied onto the substrate. On the contrary, it results in promoting the drying of the coating liquid, which induces the occurrence of coating unevenness. As described in Japanese Patent Application Laid-Open No. 2-122519, it has been proposed that the gas sprayed on the coating liquid contains the vapor of the solvent of the coating liquid, but the surrounding air is also entrained when the gas is sprayed. The drying of the coating solution was promoted, and the occurrence of coating unevenness was unavoidable.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and provides a rotary coating apparatus and a rotary coating method capable of reducing the amount of coating liquid used without causing coating unevenness. The purpose is to provide.

[0005]

An invention of a rotary coating apparatus according to a first aspect of the present invention includes a processing chamber constructing body which constitutes a processing chamber,
Holding and rotating means for holding and rotating the substrate in the processing chamber;
A coating solution supplying means for supplying a coating solution near the center of rotation of the substrate held by the holding and rotating means; a first solvent vapor supplying means for supplying a gas containing a solvent vapor into the entire processing chamber; Second solvent vapor supply means for spraying a gas containing solvent vapor to the peripheral portion of the substrate held by the means.

According to a second aspect of the present invention, in the rotary coating apparatus according to the first aspect, the second solvent vapor supply means is a gas containing a solvent vapor along a radius of gyration of the substrate held by the holding and rotating means. Is what is blown. A third aspect of the present invention is the rotary coating apparatus according to the first or second aspect, wherein the first and second solvent vapor supply means are connected to the same solvent vapor supply source.

In the rotary coating method according to the fourth aspect, a gas containing a solvent vapor is supplied into the processing chamber to fill the inside of the processing chamber, the substrate is rotatably held in the processing chamber, and the substrate is coated near the center of rotation. It is characterized in that while supplying a liquid and rotating the substrate held by the holding and rotating means, a gas containing a solvent vapor is sprayed on the peripheral portion of the substrate to spread the supplied coating liquid on the substrate surface. .

[0008]

According to the first aspect of the present invention, the coating liquid is supplied from the coating liquid supply means to the vicinity of the center of rotation of the substrate and is spread on the substrate surface by the centrifugal force generated by the rotation of the substrate. At this time, the second
Since the solvent vapor supply means of (3) blows the gas containing the solvent vapor to the peripheral portion of the substrate, the coating liquid can be spread on the substrate surface by the pressure of the blown gas. The centrifugal force and the gas pressure combine to spread the coating liquid quickly and uniformly over the entire surface of the substrate. At this time, the processing chamber is filled with the gas containing the solvent vapor by the first solvent vapor supply means, and the gas supplied from the second solvent vapor supply means is also the gas containing the solvent vapor. Moreover, the evaporation of the solvent of the coating liquid is not excessively accelerated, and the occurrence of coating unevenness is significantly suppressed.

According to the second aspect of the present invention, the second solvent vapor supply means blows the gas containing the solvent vapor along the radius of rotation of the substrate held by the holding and rotating means. The coating liquid can be efficiently spread on the substrate surface. According to the third aspect of the invention, the first and second solvent vapor supply means are connected to the same solvent vapor supply source, and the device configuration does not become complicated.

In the invention of claim 4, the coating liquid is supplied to the vicinity of the center of rotation of the substrate and is spread on the surface of the substrate by the centrifugal force due to the rotation of the substrate, and at this time, a gas containing solvent vapor is generated in the peripheral portion of the substrate. The coating liquid is sprayed and spread on the substrate surface by the pressure of the gas. Since the processing chamber is filled with a gas containing solvent vapor, and the gas sprayed on the peripheral portion of the substrate is also a gas containing solvent vapor,
The evaporation of the solvent of the coating liquid is not excessively accelerated, and the occurrence of coating unevenness is significantly suppressed.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A rotary coating apparatus which is an embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic diagram showing a rotary coating apparatus according to an embodiment of the present invention. Reference numeral 1 is a substantially circular semiconductor wafer (hereinafter referred to as a substrate), 2 is a chuck for adsorbing the center of the substrate 1 and holding it in a horizontal posture, 3 is a chuck 2
Is a motor for rotating and driving. Reference numeral 4 denotes a processing chamber constituting body which constitutes a processing chamber 5 which is substantially sealed when the chuck 2 holding the substrate 1 is housed therein, and 6 is a guide plate which is disposed in the processing chamber 5 and which guides an air flow therein. , 7 are exhaust paths connected to an exhaust source (not shown) to exhaust the atmosphere in the processing chamber 5,
Reference numeral 8 denotes a photoresist liquid supply source that stores the photoresist liquid to be applied to the substrate 1 and sends the photoresist liquid by pressurizing, and 9 is connected to the photoresist supply source 8 by a pipe 11 having a valve 10 and is attached to the chuck 2. It is a nozzle that supplies a photoresist liquid to the center of rotation of the held substrate 1.

Reference numeral 12 stores a solvent which is the same as the solvent component of the photoresist liquid stored in the photoresist liquid supply source 8. The vapor of the solvent is generated and mixed with an arbitrary gas. A solvent vapor supply source for supplying a gas containing a solvent vapor, 13 is opened at a position just above the center of rotation of the substrate 1 of the processing chamber constituting body 4 and communicates with the processing chamber 5, and the solvent is entirely distributed in the processing chamber 5. A diffusion passage 14 for diffusing and supplying a gas containing vapor, a flow meter 15 and a valve 16 for connecting the upper end position of the diffusion passage 13 and the solvent vapor supply source 12 to each other.
Piping 17 connected to the substrate 1, 17 is a vapor nozzle provided in the processing chamber 5 so as to face the peripheral portion of the substrate 1 held by the chuck 2 away from the center of rotation, and 18 is the vapor nozzle 1
7 and solvent vapor supply source 12 to a flow meter 19 and a valve 2
Pipes connected via 0, 21 is provided on the side of the chuck 2, a cleaning nozzle that blows the solvent toward the lower surface of the substrate 1 to remove the photoresist liquid that has flowed to the lower surface, and 22 is the cleaning Piping 23 and valve 24 on nozzle 21
It is a solvent supply source for supplying a solvent via the. The steam nozzle 17 is, as shown in the bottom view of FIG.
The slit 25 is formed in the lower portion formed in a hollow hemisphere, and the slit 25 is formed so that the longitudinal direction of the slit 25 is along the rotation radius direction of the substrate 1 held by the chuck 2.
It is provided so as to face the peripheral portion of the. And piping 1
The gas containing the solvent vapor that has entered the vapor nozzle 17 from 8 is blown out from the slit 25, and is blown to the peripheral portion of the substrate along the radial direction of rotation of the substrate 1.

The operation of this device, such as the opening / closing of the valves 10, 16, 20, 24 and the rotation of the motor 3, is controlled by a control device such as a microcomputer (not shown). Further, the processing chamber structure 4 is provided with an unillustrated loading / unloading port for loading / unloading the substrate 1 into / from the processing chamber 5 and a shutter for opening / closing the loading / unloading port. Next, the spin coating method of the present invention will be described together with the operation of the above apparatus.

When the apparatus is operated, the valve 16 is normally opened so that the solvent vapor supply source 12 constantly supplies the gas containing the solvent vapor into the diffusion passage 13. The supplied gas diffuses in the diffusion passage 13, is introduced into the processing chamber 5 in a uniform state, and fills the processing chamber 5. At this time, the exhaust source communicating with the exhaust passage 7 is also driven, and the processing chamber 5
A downward airflow is formed in the interior by the gas containing the solvent vapor.

The substrate 1 to be processed is carried into the processing chamber 5 through the loading / unloading port, and the center of the substrate 1 is chucked by the chuck 2.
The substrate 1 is adsorbed and held so as to coincide with the center of rotation, the loading / unloading port is closed, and the coating process on the substrate 1 is started. FIG. 3 is a time chart showing the number of revolutions of the chuck 2 by the motor 3 and the timing of discharging the photoresist liquid and supplying gas containing solvent vapor to the processing chamber 5. The valve 16 is normally open, and the supply of the gas containing the solvent vapor from the solvent vapor supply source 12 to the processing chamber 5 through the diffusion passage 13 is always performed.

When the substrate 1 is loaded into the processing chamber 5, first,
With the chuck 2 stopped, the valve 10 is opened and the photoresist liquid is dripped and supplied near the rotation center of the substrate 1. Although the open state of the valve 10 is continued for 3.5 seconds, the rotational driving of the motor 3 is started during the open state,
The chuck 2 starts to rotate. Rotation speed of chuck 2 is 1
The speed is increased to 000 rpm and kept at that rotational speed for 4 seconds, and then further increased to 3000 rpm, but when the rotational speed reaches 1000 rpm for about 1.5 seconds, the valve 20 is opened. The gas containing the solvent vapor is blown out from the slit 25 of the vapor nozzle 17 and is blown to the peripheral portion of the substrate along the rotation radius of the substrate 1. As a result, the supplied photoresist liquid is
The centrifugal force caused by the rotation of the substrate 1 not only spreads on the surface of the substrate 1 by the centrifugal force but also spreads on the surface of the substrate 1 by the pressure of the blown gas. The liquid can be spread quickly and uniformly over the entire surface of the substrate. At this time, the periphery of the substrate 1 is filled with the gas containing the solvent vapor supplied from the diffusion passage 13, and the gas sprayed on the photoresist solution on the substrate 1 is also the gas containing the solvent vapor. The evaporation of the solvent of the photoresist solution is not excessively promoted, and the occurrence of coating unevenness is significantly suppressed. The valve 20 is opened for 3 seconds, and only during that time, the gas containing the solvent vapor is sprayed from the vapor nozzle 17 to the peripheral portion of the substrate 1.

The valve 20 is closed while the rotation speed of the chuck 2 is increasing from 1000 rpm to 3000 rpm, and the blowing of the gas containing the solvent vapor from the vapor nozzle 17 is stopped. After that, the chuck 2 is rotationally driven at a speed of 3000 rpm for about 20 seconds. By the high speed rotation of the chuck 2, the excess photoresist liquid on the substrate 1 is shaken off and removed, the photoresist liquid on the substrate 1 is formed into a film having a desired thickness, and the formed film is dried. Then, the rotation speed of the chuck 2 is reduced to about 1200 rpm, during which,
The valve 24 is opened, the solvent is sprayed from the cleaning nozzle 21 toward the lower surface of the substrate 1, and the back surface of the substrate 1 is cleaned. Then, after the valve 24 is closed, the chuck 2
The rotation speed of is increased to about 2000 rpm, and the solvent attached to the back surface of the substrate 1 is shaken off and dried. When the drying is completed, the rotation of the chuck 2 is stopped, the coating process of the substrate 1 is completed, and the substrate 1 is carried out from the loading / unloading port of the processing chamber constituting body 4 and the next substrate is loaded into the processing chamber 5. Of.

[Experimental Example] The inventor has found that the substrate 1 has a diameter of 8 mm.
Inch semiconductor wafer is used, and a photoresist solution containing ethyl lactate as a solvent and having a viscosity of 18 cP is about 1.2 μm.
Experiments were carried out for the case of applying the same thickness. As the apparatus of the present invention, a processing chamber 5 having a volume of about 15 liters above the substrate 1 is formed, and the processing chamber 5 is radially separated from the center of rotation of the substrate 1 by about 70 mm and above the surface of the substrate 1 by about 15 mm. The vapor nozzle 17 having such a structure was installed so that the slit 25 thereof was aligned with the radial direction of the substrate 1. Then, saturated vapor of ethyl lactate, which is the solvent of the photoresist solution, is supplied from the pipe 14 into the processing chamber 5 through the diffusion passage 13 at a flow rate of 1 liter / min, and according to the timing of the time chart of the method of the present invention described above. An experiment of coating was conducted by supplying by blowing from the steam nozzle 17 at a flow rate of 10 to 50 cc / min for about 3 seconds. As a result of this experiment, even if the amount of photoresist solution supplied from the nozzle 9 was reduced to about 1.2 cc, a sufficiently uniform coating result was obtained in which the film thickness uniformity was within a range of about ± 20 Å. Moreover, the same result could be stably obtained even when a plurality of substrates were continuously processed.

In the above embodiment, the steam nozzle 17
Although the same solvent as the solvent of the photoresist solution to be applied was used as the solvent supplied from the above, the solvent does not necessarily have to be the same. Further, the shape of the vapor nozzle 17 and the timing of supply of the solvent vapor from the vapor nozzle 17 are not limited to those in the above-described embodiment, but can be variously changed. In addition,
In the above embodiment, the chuck 2 and the motor 3 serve as the holding and rotating means, the nozzle 9 serves as the coating liquid supply means, the diffusion passage 13 serves as the first solvent vapor supply means, and the vapor nozzle 17 serves as the second solvent vapor. Each corresponds to a supply means.

[0020]

According to the first aspect of the present invention, the coating liquid is supplied from the coating liquid supply means to the vicinity of the rotation center of the substrate and is spread on the substrate surface by the centrifugal force due to the rotation of the substrate, and further the second solvent vapor is supplied. Since the pressure of the gas blown from the supply means can spread it over the substrate surface, the centrifugal force and the pressure of the gas combine to spread the coating liquid quickly and uniformly over the entire surface of the substrate even if the coating liquid supplied is small. To be Further, the processing chamber is filled with the gas containing the solvent vapor by the first solvent vapor supply means, and the gas supplied from the second solvent vapor supply means is also the gas containing the solvent vapor. The evaporation of the solvent is not excessively accelerated, and the occurrence of coating unevenness is significantly suppressed. As a result, the usage amount of the coating liquid can be reduced without causing uneven coating.

According to the second aspect of the present invention, the second solvent vapor supply means blows the gas containing the solvent vapor along the radius of rotation of the substrate held by the holding and rotating means. Together, the coating liquid can be efficiently spread on the surface of the substrate, and the coating unevenness and the consumption of the coating liquid can be further reduced. According to the invention of claim 3, since the first and second solvent vapor supply means are connected to the same solvent vapor supply source, it is not necessary to separately provide the solvent vapor supply means, and the apparatus configuration can be simplified. it can.

According to the invention of claim 4, the coating liquid is supplied to the vicinity of the center of rotation of the substrate and is spread on the surface of the substrate by the centrifugal force due to the rotation of the substrate. Furthermore, a gas containing solvent vapor is generated in the peripheral portion of the substrate. The coating liquid is sprayed and spread on the substrate surface by the pressure of the gas. Since the processing chamber is filled with a gas containing solvent vapor, and the gas sprayed on the peripheral portion of the substrate is also a gas containing solvent vapor, it may accelerate the evaporation of the solvent of the coating liquid excessively. However, the occurrence of coating unevenness is significantly suppressed. As a result, the usage amount of the coating liquid can be reduced without causing uneven coating.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing a configuration of a main part of a rotary coating apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram showing a structure of a steam nozzle.

FIG. 3 is a timing chart showing control of the apparatus.

[Explanation of symbols]

 1 Substrate 2 Chuck 3 Motor 4 Processing Chamber Construct 5 Processing Chamber 9 Nozzle 12 Solvent Vapor Supply Source 13 Diffusion Passage 17 Vapor Nozzle

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location H01L 21/30 564D

Claims (4)

[Claims] 1. A processing chamber constituting body which constitutes a processing chamber, a holding and rotating means for holding and rotating a substrate in the processing chamber, and a coating liquid supplied to the vicinity of the center of rotation of the substrate held by the holding and rotating means. A coating liquid supply means, and a gas supplying solvent vapor to the entire processing chamber
And a second solvent vapor supply means for spraying a gas containing solvent vapor onto the peripheral portion of the substrate held by the holding and rotating means. 2. The rotary coating apparatus according to claim 1, wherein the second solvent vapor supply means blows a gas containing a solvent vapor along a radius of rotation of the substrate held by the holding and rotating means. 3. The rotary coating apparatus according to claim 1, wherein the first and second solvent vapor supply means are connected to the same solvent vapor supply source. 4. A gas containing solvent vapor is supplied into the processing chamber to fill the inside of the processing chamber, a substrate is rotatably held in the processing chamber, and a coating liquid is supplied near the center of rotation of the substrate. A rotary coating method, wherein the supplied coating liquid is spread on the surface of the substrate by spraying a gas containing a solvent vapor onto the peripheral portion of the substrate while rotating the held substrate.