JP2000051770A - Film thickness distribution adjusting method and substrate coating apparatus using the same - Google Patents

Abstract

(57) [Problem] To achieve a desired film thickness distribution by adjusting a distance between a supply nozzle and a substrate surface,
The processing efficiency can be improved by shortening the waiting time. SOLUTION: A supply nozzle 7 is moved to a supply position above a substrate W supported on a spin chuck 1 to supply a coating liquid, and the substrate W is rotated by the spin chuck 1 to apply a coating film on the entire surface. The substrate coating apparatus to be formed is provided with an elevating mechanism 21 for adjusting the distance H between the supply nozzle 7 and the surface of the substrate W.
Is adjusted according to a desired film thickness distribution. As a result, the degree of impact when the coating liquid is dropped onto the substrate surface and the behavior when the coating liquid spreads are changed, and a desired film thickness distribution can be adjusted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a film for supplying a coating solution such as a photoresist solution to a substrate such as a semiconductor wafer to adjust the thickness distribution of a coating film formed on the entire surface of the substrate. The present invention relates to a thickness distribution adjusting method and a substrate coating apparatus using the same.

[0002]

2. Description of the Related Art As a conventional film thickness distribution adjusting method of this type, a temperature of a coating solution itself or a temperature before coating is adjusted in accordance with a desired film thickness distribution while an ambient temperature around a substrate is kept constant. The cooling temperature has been changed in the substrate cooling process.

The desired film thickness distribution is generally substantially uniform in the plane of the substrate. The temperature for obtaining such a film thickness distribution varies depending on the type of substrate, its surface condition, the type of coating solution, application conditions such as the number of revolutions, and the like. I am adjusting.

[0004]

However, such a conventional example has the following problems. That is, since the temperature of the coating liquid or the cooling process is changed for adjusting the film thickness distribution, at least the time until the temperature reaches the target value is generated as a wasteful waiting time. Therefore, there is a problem that the waiting time until the coating treatment after the adjustment to the desired film thickness distribution is performed is long, and the treatment efficiency is reduced. In particular, when sequentially processing the substrates in the single-wafer processing, a shift in the tact time may be a problem.

The present invention has been made in view of such circumstances, and while adjusting the distance between the supply nozzle and the substrate surface, it is possible to adjust the film thickness to a desired one, while maintaining the waiting time. It is an object of the present invention to provide a film thickness distribution adjusting method capable of improving the processing efficiency by shortening the thickness, and a substrate coating apparatus using the method.

[0006]

The present invention has the following configuration in order to achieve the above object. That is, according to the first aspect of the present invention, a coating solution is supplied to a substrate from a supply nozzle, and the thickness distribution of the coating film formed on the entire surface is adjusted by rotating the substrate. In the method, the distance between the supply nozzle and the substrate surface when supplying the coating liquid is adjusted according to a desired film thickness distribution.

According to a second aspect of the present invention, the supply nozzle is moved to a supply position above the substrate supported by the rotation supporting means to supply the coating liquid, and the substrate is rotated by the rotation supporting means. A substrate coating apparatus for forming a coating film on the entire surface thereof by adjusting the distance between the supply nozzle and the substrate surface, wherein the distance at the supply position is adjusted according to a desired film thickness distribution. It is characterized by having made it.

According to a third aspect of the present invention, in the substrate coating apparatus according to the second aspect, the adjusting means comprises:
The height of the supply nozzle with respect to the substrate surface is adjusted.

According to a fourth aspect of the present invention, in the substrate coating apparatus according to the third aspect, the apparatus further comprises a rotation speed of the substrate by the rotation supporting means and a desired film thickness distribution. Storage means for previously storing a processing program including film thickness distribution information; and control means for adjusting the height of a supply nozzle via the adjusting means based on the film thickness distribution information when executing the processing program. It is characterized by having.

[0010]

The operation of the method according to the first aspect is as follows. That is, if the distance between the supply nozzle and the substrate surface is adjusted, an impact occurs when the coating liquid reaches the substrate surface, and a change occurs when the supplied coating liquid spreads from the vicinity of the rotation center of the substrate to the peripheral portion. This changes the thickness distribution of the coating film.
Therefore, by adjusting the distance between the supply nozzle and the substrate surface, the coating film can be adjusted to a desired film thickness distribution without changing the temperature of the coating solution itself or the cooling temperature in the substrate cooling process before coating.

For example, FIG. 3 is a graph showing the distance between the supply nozzle and the substrate surface when the conditions such as the number of revolutions during coating are constant.
3 (a), 5 mm in FIG. 3 (b), and FIG.
In (c), the result of measuring the in-plane uniformity of the thickness of a photoresist film formed by supplying a photoresist solution as a coating solution from a supply nozzle to a substrate having an 8-inch diameter by setting it to 10 mm is shown. It is a graph shown.
In these graphs, the position of x = 0 on the horizontal axis is the center of the substrate. From these graphs, it can be seen that the best in-plane uniformity is obtained when the interval is set to 5 mm as shown in FIG. FIG. 3 (a) corresponding to before and after the interval.
At 3 mm, the central portion of the substrate is slightly thinner than the peripheral portion, and at 10 mm in FIG. 3C, the central portion of the substrate is thinner than the peripheral portion. From these graphs, it is clear that the film thickness distribution in the substrate surface can be adjusted by adjusting the distance between the supply nozzle and the substrate surface.

The operation of the device according to the present invention is as follows. When the distance between the supply nozzle and the surface of the substrate supported by the rotation support means is adjusted by the adjustment means, the impact when the coating liquid reaches the substrate surface or the supplied coating liquid flows from the vicinity of the rotation center of the substrate to the periphery. Changes in the behavior of the film when it spreads, and the film thickness distribution of the coating film changes. Therefore, if the distance is adjusted by the adjusting means in accordance with the desired film thickness distribution, the coating film is adjusted to the desired film thickness distribution without changing the temperature of the coating solution itself or the cooling temperature in the substrate cooling process before coating. can do.

According to the third aspect of the present invention, even if the adjusting means is configured to adjust the height of the supply nozzle with respect to the substrate surface, the distance between the supply nozzle and the substrate surface is adjusted. The film thickness distribution can be adjusted.

Further, according to the apparatus described in claim 4, when the control means executes the processing program stored in the storage means, the height of the supply nozzle is controlled via the adjustment means based on the film thickness distribution information. Adjust the length. Therefore, by setting the film thickness distribution information in advance, a desired film thickness distribution can be obtained according to the coating conditions such as the type of the coating liquid set in the processing program.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a schematic configuration of a substrate coating apparatus employing a film thickness distribution adjusting method according to the present invention.

The substrate W is suction-supported in a horizontal posture by, for example, a vacuum chuck-type spin chuck 1. The spin chuck 1 corresponding to the rotation support means of the present invention is configured to be driven to rotate around the rotation axis P1 by the electric motor 3, and around the rotation, the photoresist liquid supplied to the surface of the substrate W, etc. The anti-scattering cup 5 for preventing the application liquid from being scattered is provided to be vertically movable.

A supply nozzle 7 for supplying a coating liquid is provided beside the scattering prevention cup 5. The supply nozzle 7 is in a standby position (a two-dot chain line in the drawing) in which the discharge hole 7a directed downward is on the side of the scattering prevention cup 5.
And a supply position (solid line in the figure) above the rotation axis P1.

The nozzle swinging mechanism 9 swings the supply nozzle 7 in this manner. The hollow member 13 erected from one end of the oscillating arm 11 and into which a pipe (not shown) for feeding the application liquid into the discharge hole 7a is inserted has a top end portion corresponding to the supply nozzle 7 opposite to the discharge hole 7a. It is attached to the base end side. On the other end side of the swing arm 11, an electric motor 15 for swinging the supply nozzle 7 together with the swing arm 11 is provided. The rotating shaft 15a of the electric motor 15 rotates around the pivot axis P2.
A driving pulley 15b is attached to a. A timing belt 19 is bridged between the main pulley 15b and a driven pulley 17a of an encoder 17 arranged in parallel with the electric motor 15, and the amount of swing drive by the electric motor 15 is detected by the encoder 17. It has become.

Next, the elevating mechanism 21 for elevating and lowering the nozzle swing mechanism 9 will be described. The electric motor 15 and the encoder 17 are attached to an extending portion of an elevating arm 23 having an L-shape. A screw shaft 27 and a guide shaft 29 are attached in the vertical direction to a U-shaped frame 25 which is fixedly disposed in the apparatus. The elevating member 31 is screwed to the screw shaft 27 and slidably attached to the guide shaft 29. The screw shaft 2 is provided on the side surface of the frame 25.
A stepping motor 33 for driving the motor 7 is mounted, and a driving pulley 33a is mounted on a rotating shaft thereof. A timing belt 3 is provided between the driving pulley 33a and the driven pulley 27a interlockingly connected to the screw shaft 27.
5, and is configured so that the driving of the stepping motor 33 is interlocked with the screw shaft 27. Therefore, the nozzle swinging mechanism 9 is driven to move up and down by driving the stepping motor 33 to rotate.

The elevating mechanism 21 configured as described above
When the supply nozzle 7 at the standby position is moved to the supply position, the supply nozzle 7 is driven to move over the periphery of the scattering prevention cup 5, and the distance between the supply nozzle 7 and the surface of the substrate W at the supply position (the supply nozzle It is driven to adjust the height H). That is, the elevating mechanism 21 corresponds to the adjusting means of the present invention.

A control unit 37 corresponding to the control means of the present invention
Drives the electric motors 3 and 15 to rotate, and controls the swing drive of the supply nozzle 7 while detecting the drive amount by the encoder 17. Further, the stepping motor 33 controls the up / down drive by outputting a pulse train corresponding to the up / down amount. In addition, the supply timing and supply time of the application liquid from the supply nozzle 7 are controlled.

The control section 37 is connected with a memory 39 corresponding to a storage means and an operation section 41. The memory 39 is
As shown in the schematic diagram of the processing program shown in FIG. 2, the supply nozzle height H corresponding to the film thickness distribution information corresponding to the desired film thickness distribution, the first rotation speed of the electric motor 3, A plurality of processing programs including the application liquid supply time and the second rotation speed of the electric motor 3 are stored in advance. Such a processing program is input and set by an operator of the apparatus through an operation unit 41 including a keyboard or the like.

The above-mentioned film thickness distribution information corresponds to a desired film thickness distribution in the plane of the substrate W. For example, a certain photoresist liquid is used as a coating liquid, and a supply nozzle height H at a supply position is used. An experiment was conducted by applying the same processing program to a substrate having a diameter of 8 inches while changing only the thickness of the supply nozzle. It became so. Each graph shows that the supply nozzle height H is 3 mm, 5 mm, and 10 m in order.
m and the legend represents the five substrates plotted in the graph.

When the supply nozzle height H is 3 mm, the center of the substrate is slightly thinner than the peripheral portion, and when the supply nozzle height H is 5 mm, good uniformity is exhibited. : In the case of 10 mm, the central part is thinner than the peripheral part. As is clear from these graphs, the film thickness distribution can be adjusted by changing the supply nozzle height H. Therefore, the desired film thickness distribution can be adjusted according to the type of the coating liquid or the substrate and the coating conditions set in the processing program. Thus, the supply nozzle height H is set in advance in the processing program as the film thickness distribution information. In the case of this example, the supply nozzle height H: 5 mm is generally set as the film thickness distribution information.

Further, an experiment was conducted in which a certain anti-reflection coating agent was used as a coating liquid, and only the supply nozzle height H at the supply position was changed in the same manner as described above. The thickness distribution was as shown in FIGS. In the case of the supply nozzle height H: 3 mm, coating unevenness (streak-like unevenness and called striation) occurs, the film thickness distribution is extremely deteriorated, and the supply nozzle height H:
In the case of 5 mm, good uniformity is shown, and in the case of the supply nozzle height H: 10 mm, a better film thickness distribution is shown than in H: 5 mm. In the case of such a coating liquid, the supply nozzle height H: 3 mm is generally set as the film thickness distribution information, but in some cases, the supply nozzle height H: 5
Set to mm.

Next, in the first processing program, a photoresist liquid is set as a coating liquid and the supply nozzle height H is set to 5 mm. In the second processing program, an anti-reflection coating agent is set as a coating liquid. Is set and the supply nozzle height H: 3 mm is set as an example, and the operation of the substrate coating apparatus having the above-described configuration will be described.

After the substrate W to be processed is placed on the spin chuck 1 by controlling a transport mechanism (not shown), the controller 37 drives the electric motor 15 of the nozzle swing mechanism 9 to move the supply nozzle 7 to the supply position. Moving. Next, the control unit 37 gives a predetermined pulse train based on the processing program to the stepping motor 33 of the elevating mechanism 21, and the supply nozzle height H: 5 m
Set to m. Then, the electric motor 3 is driven at the first rotation speed specified in the processing program, the photoresist liquid is supplied from the supply nozzle 7, and the electric motor 3 is driven at the second rotation speed. Next, in a state where the supply nozzle 7 is moved to the standby position by the elevating mechanism 21 and the nozzle swing mechanism 9, the substrate W on which the photoresist film is formed is carried out by a carrying mechanism (not shown). The film thickness distribution of the photoresist film formed in this manner depends on the supply nozzle height H: 5 mm specified in the processing program, and has a desired film thickness distribution.

Next, the case of processing by the second processing program will be described. The substrate W to be processed is a spin chuck 1
After that, the control unit 37 sets the supply nozzle height H to 3 mm based on the second processing program. Then, the anti-reflection coating agent is supplied from the supply nozzle 7 while rotating the substrate W at the first rotation speed (different from the above-described supply nozzle 7), and then the electric motor 3 is driven at the second rotation speed. I do. With the supply nozzle 7 moved to the standby position, the substrate W on which the antireflection film is formed is carried out by a carrying mechanism (not shown). The film thickness distribution of the anti-reflection film formed in this manner corresponds to the supply nozzle height H: 3 specified in the processing program.
mm, and a desired film thickness distribution is obtained.

As described above, by adjusting the height H of the supply nozzle 7 with respect to the surface of the substrate W according to the desired film thickness distribution by the elevating mechanism 21, the temperature of the coating solution itself or cooling in the substrate cooling process before coating is performed. The coating film can be adjusted to a desired film thickness distribution without changing the temperature.
Therefore, the waiting time for adjusting the film thickness distribution can be shortened, and the processing efficiency can be improved. In addition, by setting the supply nozzle height H in advance, it is possible to adjust the film thickness distribution according to the application conditions set in the processing program so as to obtain a desired film thickness distribution. Therefore, it is possible to suitably execute the automatic processing of sequentially processing the substrates.

In the embodiment described above, the lifting mechanism 21
Although the distance between the supply nozzle 7 and the surface of the substrate W is adjusted by changing the height of the supply nozzle 7 with respect to the surface of the substrate W, the height of the spin chuck 1 may be changed instead.

In the above description, a photoresist solution and an anti-reflective coating agent are taken as examples of the coating solution. However, other coating solutions include a polyimide resin, a silica-based film forming material, and a ferroelectric material. And the like.

[0032]

As is apparent from the above description, according to the first aspect of the present invention, the supply nozzle and the supply nozzle can be connected without changing the temperature of the coating solution itself or the cooling temperature in the substrate cooling process before coating. Since the coating film is adjusted to a desired film thickness distribution by adjusting the distance from the substrate surface, the waiting time for adjusting the film thickness distribution can be shortened and the processing efficiency can be improved.

According to the second aspect of the present invention, by adjusting the distance between the supply nozzle and the substrate surface in accordance with the desired film thickness distribution by the adjusting means, the temperature of the coating solution itself or the temperature before coating can be improved. The coating film can be adjusted to a desired film thickness distribution without changing the cooling temperature in the substrate cooling process. Therefore, the waiting time for adjusting the film thickness distribution can be shortened, and the processing efficiency can be improved.

According to the third aspect of the present invention, even if the adjusting means is configured to adjust the height of the supply nozzle with respect to the substrate surface, the distance between the supply nozzle and the substrate surface is adjusted. The film thickness distribution can be adjusted. Further, the configuration can be simplified as compared with a configuration in which the height of the rotation support means that normally rotates at a high speed is adjusted.

According to the fourth aspect of the present invention, when the control means executes the processing program stored in the storage means, the height of the supply nozzle is adjusted via the adjustment means based on the film thickness distribution information. Since the thickness is adjusted, by setting the film thickness distribution information in advance, the film thickness can be adjusted to a desired film thickness distribution according to the application conditions set in the processing program. Therefore, it is possible to suitably execute the automatic processing of sequentially processing the substrates.

[Brief description of the drawings]

FIG. 1 is a view showing a schematic configuration of a substrate coating apparatus according to an embodiment.

FIG. 2 is a schematic diagram showing an example of a processing program stored in a memory.

FIG. 3 is a graph showing a film thickness distribution when a photoresist liquid is applied while changing the height of a supply nozzle.

FIG. 4 is a graph showing a film thickness distribution when an antireflection film agent is applied while changing the height of a supply nozzle.

[Explanation of symbols]

 W ... substrate 1 ... spin chuck (rotation support means) 3 ... electric motor 5 ... scattering prevention cup 7 ... supply nozzle 7a ... discharge port 9 ... nozzle swing mechanism 15 ... electric motor 17 ... encoder 21 ... elevating mechanism (adjustment means) 23 ... lifting arm 27 ... screw shaft 29 ... guide shaft 33 ... stepping motor 37 ... control unit (control means) 39 ... memory (storage means)

Continued on front page F term (reference) 2H025 AA00 AB16 EA05 4D075 AC64 AC84 AC88 AC92 AC93 DA08 DC22 4F042 AA07 EB18 EB19 EB29 5F046 JA02 JA13

Claims (4)

[Claims] 1. A method for adjusting a film thickness distribution of a coating film formed on an entire surface by supplying a coating liquid to a substrate from a supply nozzle and rotating the substrate, wherein the coating liquid is supplied. A method for adjusting the distance between the supply nozzle and the surface of the substrate when performing the method according to a desired film thickness distribution. 2. A coating liquid is supplied by moving a supply nozzle to a supply position above a substrate supported by the rotation support means, and the substrate is rotated by the rotation support means to form a coating film on the entire surface thereof. A substrate coating apparatus, comprising: adjusting means for adjusting a distance between the supply nozzle and the substrate surface, wherein the distance at a supply position is adjusted according to a desired film thickness distribution. . 3. The substrate coating apparatus according to claim 2, wherein said adjusting means adjusts a height of said supply nozzle with respect to a substrate surface. 4. The substrate coating apparatus according to claim 3, wherein the apparatus further executes a processing program including a number of rotations of the substrate by the rotation support unit and film thickness distribution information according to a desired film thickness distribution. A substrate comprising: storage means for storing in advance; and control means for adjusting the height of a supply nozzle via the adjustment means based on the film thickness distribution information when executing the processing program. Coating device.