JPH09134873A - Rotary substrate coating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent resist solution from concentrating to adhere to a certain spot of a fly stop cup by a method wherein a substrate held by a substrate holding means is set different in phase from a preceding substrate to receive resist liquid. SOLUTION: An electric motor 11 by outputting KN pieces of starting pules from a preliminary rotating means 25, and a substrate holding means which holds a substrate W is previously rotated so as to be different in phase from a preceding substrate to receive resist liquid. Thereafter, the number of starting pulses to output next is increased by a number of pulses equivalent to a turning angle of 1 deg. of a substrate W through an adding means 26. Thereafter, judging the elapse of a set time, resist solution is discharged from a resist solution feed nozzle after a time which is enough for finishing the rotation of the substrate W by the preliminary rotating means 25 elapses, and the electric motor 11 is rotated by the set number of rotations at the same time. The orientation flats OF of the substrates are shifted in phase from each other by an angle of 1 deg. respectively, so that resin solution flies to adhere to spots on the upper vertical wall 3a of the fly stop cup 3, which are located distant from each other by an angle of 1 deg., and is prevented from concentrating on a certain spot on the cup 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention applies a coating solution such as a photoresist, a photosensitive polyimide, or a dopant material to the surface of a substrate such as a semiconductor substrate or a substrate for an optical disk, which has a notch such as an orientation flat or a notch. The present invention relates to a rotary substrate coating device.

[0002]

2. Description of the Related Art Heretofore, in this type of rotary substrate coating apparatus, a scatter preventive cup for receiving a sprayed coating solution when the coating solution is spin-coated on a substrate and an exhaust flow in the scatter preventive cup are provided. A straightening sloping plate for adjustment is provided. When the coating liquid that has been scattered during spin coating adheres to the splash prevention cup or straightening sloping plate, and when it dries and solidifies, it is suspended as fine powder dust due to vibration during rotation, etc. It is known that they adhere to cause defective products. Therefore, as a rotary substrate coating apparatus provided with a mechanism for cleaning the coating liquid adhering to the scattering prevention cup and the rectifying inclined plate, for example, there is one disclosed in Japanese Utility Model Publication No. 6-28223. Hereinafter, the configuration of the rotary substrate coating apparatus will be briefly described with reference to the partially cutaway side view of FIG. 7.

In FIG. 7, reference numeral 1 denotes a substrate holding means for sucking and holding a substrate W and rotating it around an axis in the vertical direction. A coating liquid supply nozzle 2 for supplying a coating liquid such as photoresist onto the substrate W is provided above the substrate holding means 1. A scatter preventive cup 3 for receiving the sprayed coating solution at the time of spin coating is provided around the substrate holding means 1, and an exhaust duct 4 is provided at the bottom of the scatter preventive cup 3.
Are connected to communicate with each other and configured to exhaust air from the scattering prevention cup 3. In order to rectify the exhaust flow in the scattering prevention cup 3, a rectifying tilting plate 5 is provided below the substrate W and is tilted so as to be positioned downward toward the outer peripheral side in a circular shape in plan view. Reference numeral 6 in the drawing denotes a drain for draining the excess coating liquid.

An annular inner peripheral surface cleaning conduit 7 is integrally formed on the outer side of the scattering prevention cup 3, and the cleaning liquid supplied to the inner peripheral surface cleaning conduit 7 is supplied to the upper vertical wall 3a of the scattering prevention cup 3. The coating liquid adhered to the inner peripheral surface of the scattering prevention cup 3 is washed away by flowing down from a large number of discharge holes 8 opened on the back side. Further, an annular inclined surface cleaning conduit 9 is integrally formed inside the rectifying inclined plate 5, and the cleaning liquid supplied to the inclined surface cleaning conduit 9 is provided with a large number of discharge holes 10 formed in the rectifying inclined plate 5. It is configured such that the coating liquid adhering to the inclined surface of the rectifying inclined plate 5 is washed away by flowing it down from above.

[0005]

However, according to the conventional rotary substrate coating apparatus, when processing a substrate having a notch such as an orientation flat or a notch, the upper vertical portion of the scattering prevention cup 3 to which the cleaning liquid is not supplied is processed. The coating liquid adheres to some part of the inner peripheral surface of the wall 3a,
Since the concentrated and adhered coating liquid is washed and removed, there has been a drawback that the maintenance cycle is shortened and the processing efficiency is lowered.

The present invention has been made in view of the above circumstances, and by rational improvement, it is possible to prevent the coating liquid from being concentrated and attached to a part of the splash prevention cup and to perform maintenance. The purpose is to be able to extend the cycle.

[0007]

The invention according to claim 1 is
In order to achieve the above object, a substrate holding means for holding a substrate having a notch, a rotation driving means for rotationally driving the substrate holding means, and a position corresponding to the center of rotation of the substrate held by the substrate holding means. In a rotary substrate coating apparatus equipped with a coating liquid supply means for supplying a coating liquid and a scattering prevention cup for receiving and collecting the coating liquid scattered from the substrate during coating, before supplying the coating liquid by the coating liquid supply means. A rotation control means for rotating the substrate holding means is provided so that the substrate processed immediately before the holding substrate has a phase different from that when receiving the coating liquid.

In order to achieve the above-mentioned object, the invention according to claim 2 holds the substrate having the notch, the substrate holding means, the rotation driving means for rotationally driving the substrate holding means, and the substrate. Rotating substrate coating apparatus provided with a coating liquid supply unit that supplies the coating liquid to a position corresponding to the center of rotation of the substrate held by the holding unit, and a splash prevention cup that receives and collects the coating liquid scattered from the substrate during coating. In the above, the cleaning liquid supply means for supplying the cleaning liquid is provided to the portion of the scattering prevention cup where the coating liquid scattered from the notch of the substrate is attached.

[0009]

[Function] As a result of studying the cause of the application liquid being concentrated and attached to a part of the scattering prevention cup, it has been found that it is affected by the notch. That is, the coating liquid supplied onto the substrate spreads over the entire upper surface of the substrate as the substrate rotates, but since the end face of the notch intersects the rotation direction of the substrate, Air currents are generated in the vertical direction, and the coating liquid that has reached the notch is blown off by the upward air flow. On the other hand, when the substrate is held by the substrate holding means, the position of the notch of the substrate is almost specified, and as a result, the coating liquid is concentrated and attached to a part of the splash prevention cup.

Based on the result of the above consideration, according to the configuration of the rotary substrate coating apparatus of the invention according to claim 1, a holding substrate,
The position of the notch when receiving the coating liquid by the coating liquid supply unit is made different from that of the substrate processed immediately before that, and the position where the coating liquid is attached to the scattering prevention cup is changed to concentrate on a part of the place. You can avoid that.

According to the structure of the rotary type substrate coating apparatus of the second aspect of the present invention, based on the above-mentioned consideration result, the cleaning liquid is supplied to the location where the coating liquid is concentrated and adhered, and the adhered coating liquid is successively applied. It is possible to remove by washing and to prevent the coating liquid from adhering and growing.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described in detail with reference to the drawings. 1 is a partial cutaway side view showing a first embodiment of a rotary substrate coating apparatus according to the present invention, and FIG. 2 is a plan view showing an electric motor 1 as a rotation driving means.
A rotary table 13 for vacuum-holding a substrate W on an upper end of a rotary shaft 12 that rotates around a vertical axis P by the drive of 1.
Is integrally rotatably attached, and the substrate holding means 1 is configured to hold the substrate W rotatably around the vertical axis P.

A coating liquid supply nozzle 2 is provided above the substrate holding means 1 as a coating liquid supply means for supplying a coating liquid such as a photoresist onto the substrate W, and around the substrate holding means 1. An anti-scattering cup 3 is provided for receiving the application liquid that has been scattered during spin coating.

An exhaust duct 4 is provided at the bottom of the scattering prevention cup 3.
Are connected to communicate with each other and configured to exhaust air from the scattering prevention cup 3. In order to rectify the exhaust flow in the scattering prevention cup 3, a rectifying tilting plate 5 is provided below the substrate W and is tilted so as to be positioned downward toward the outer peripheral side in a circular shape in plan view. Reference numeral 6 in the drawing denotes a drain for draining the excess coating liquid.

An annular inner peripheral surface cleaning conduit 7 is integrally formed on the outer side of the scattering prevention cup 3, and the cleaning liquid supplied to the inner peripheral surface cleaning conduit 7 is supplied to the upper vertical wall 3a of the scattering prevention cup 3. The coating liquid adhered to the inner peripheral surface of the scattering prevention cup 3 is washed away by flowing down from a large number of discharge holes 8 opened on the back side. Further, an annular inclined surface cleaning conduit 9 is integrally formed inside the rectifying inclined plate 5, and the cleaning liquid supplied to the inclined surface cleaning conduit 9 is provided with a large number of discharge holes 10 formed in the rectifying inclined plate 5. It is configured such that the coating liquid adhering to the inclined surface of the rectifying inclined plate 5 is washed away by flowing it down from above.

The rotary shaft 12 is projected below the electric motor 11, a first ventilation passage 14 is formed in the rotation shaft 12, and a second ventilation passage 15 is formed in the rotary base 13.
And a third ventilation path 17 formed in the housing 16 on the lower end side of the rotary shaft 12 are connected via the first ventilation path 14, and the third ventilation path 17 and a vacuum suction source (not shown). No)
Is an air filter 18 and an electromagnetic switching operation type three-way valve 19
Are connected via an air pipe 20 which is interposed.
A communication pipe 21 for opening to the atmosphere is connected to the three-way valve 19,
When the vacuum suction of the substrate W is released, the state where the substrate W is connected to the vacuum suction source is switched to the state where the vacuum suction source is not connected so that the outside air is introduced into the second ventilation passage 15 to eliminate the suction force.

A pressure sensor 22 for detecting the internal pressure of the air pipe 20 is attached between the three-way valve 19 of the air pipe 20 and the third ventilation passage 17, and the pressure sensor 22 is connected to a microcomputer 23 as a rotation control means. And a microcomputer 23 and an electric motor (pulse motor) 11
Is connected.

As shown in the block diagram of FIG. 3, the microcomputer 23 has a substrate detecting means 24 for detecting the presence or absence of the substrate W, a pre-rotating means 25, an adding means 26, a delaying means 27, a motor starting means 28 and a coating. Means 29 are provided.

In the substrate detecting means 24, the pressure sensor 22 is
A substrate holding signal is output in response to the output of a signal indicating that the substrate W is held by the substrate holding means 1 by sensing a pressure drop caused by the substrate W being held by the turntable 13. Has become.

The pre-rotation means 25 is the substrate detection means 2 described above.
In response to the substrate holding signal from 4, the starting pulse of a predetermined kN is output to the electric motor 11.
Here, k is an integer greater than or equal to 0, and is 0 every time it exceeds 359.
Is the value returned to. N is the number of pulses required to rotate the substrate W by 1 °. The adding means 26 is configured to add the value of k by 1 each time one substrate W is processed.

The delay means 27 delays the transition to the normal substrate coating processing by the time when the rotation of the substrate W by the pre-rotation means 25 is finished, and then gives command signals to the motor starting means 28 and the coating means 29, respectively. Is output, the nozzle opening / closing valve 30 for the coating liquid supply nozzle 2 is opened to discharge the resist liquid onto a portion corresponding to the center of rotation of the substrate W, and the substrate W is rotated at a set rotational speed.

Next, the processing operation of the microcomputer 23 will be described with reference to the flowchart of FIG. First, whether or not the substrate W is held is determined by the substrate detection means 24 (S1), and when the holding of the substrate W is detected, the pre-rotation means 25 outputs kN starting pulses to output the electric motor. 11 is driven, and the substrate holding means 1 is rotated in advance so that the substrate processed immediately before the holding substrate W has a different phase from that when the substrate receives the coating liquid (S2). After that, the adding means 26 adds the number of startup pulses to be output next by the rotation angle of the substrate W of 1 ° (S3).

After that, the process proceeds to step S4, it is judged whether or not the set time T has elapsed, and after the delay means 27 delays by a time sufficient to complete the rotation of the substrate W by the pre-rotation means 25 described above, , Coating liquid supply nozzle 2
Further, the resist solution is discharged (S5) and the electric motor 11 is rotated at the set number of revolutions (S6), and the application process of the application liquid on the substrate W is completed.

With the above configuration, when the substrate W is processed, the phase of the orientation flat OF is moved by 1 ° at the time of starting the normal coating process, and the upper vertical wall 3a of the shatterproof cup 3 is accordingly moved. On the other hand, the spots to which the coating liquid is scattered and attached are also moved by 1 °, so that the coating liquid can be prevented from being concentrated and concentrated on a part of the upper vertical wall 3a.

In order to rotate the substrate holding means 1 in advance so that the substrate processed immediately before the holding substrate W has a phase different from that when receiving the coating liquid, the number of pulses output for starting is changed. However, for example, the rotation angle of the rotary base 13 may be detected by a rotary encoder, and based on the detected rotation angle, the rotary base 13 may be rotated while being sequentially varied by a predetermined phase. Alternatively, the phase may be changed by a random number without changing the phase for each set angle such as 1 °. Further, the frequency of pre-rotating the substrate holding means 1 so as to be different from the phase when the substrate processed immediately before the holding substrate W receives the coating liquid may be set for each substrate to be processed. However, a certain interval such as every two sheets or every three sheets may be provided.

FIG. 5 is a partially cutaway side view of the essential part showing the second embodiment, and FIG. 6 is a plan view showing the position of the orientation flat OF when the substrate W is held on the turntable 13. The vertical wall cleaning conduit 31 is provided at a predetermined position on the upper vertical wall 3a of the splash prevention cup 3 to which the coating liquid scattered due to the influence of the orientation flat OF is concentrated.
And a discharge hole 32 for supplying a cleaning liquid such as acetone to the coating liquid adhering portion on the lower surface of the vertical wall cleaning conduit 31.

The vertical wall cleaning conduit 31 and the cleaning liquid container 34 containing the cleaning liquid stored in the pressure container 33 are provided with a first pipe 36 and a first pipe 36 with a first electromagnetic opening / closing valve 35 interposed therebetween. The connection is completed through the joint 37, the intermediate pipe 38, the second pipe joint 39, and the second pipe 41 having the second electromagnetic opening / closing valve 40, and the application of the coating liquid to one substrate W is completed. Each time the cleaning liquid is supplied, the cleaning liquid is supplied, and the cleaning liquid supply means is configured to clean and remove the coating liquid adhering to the upper vertical wall 3a.

A third pipe 4 in which the second pipe joint 39 and the inner peripheral surface cleaning conduit 7 are provided with a third electromagnetic opening / closing valve 42 interposed therebetween.
3, the second pipe joint 39 and the inclined surface cleaning conduit 9 are connected via a fourth pipe 45 having a fourth electromagnetic opening / closing valve 44 interposed therebetween, and the shatterproof cup 3 The coating liquid adhering to each of the inner peripheral surface and the rectifying inclined plate 5 can be washed and removed.

A pressurized air source is connected to the first pipe joint 37 via a fifth pipe 47 having a fifth electromagnetic opening / closing valve 46 interposed therebetween, and a coating liquid is applied to the next substrate. Before cleaning, the cleaning liquid remaining in each of the inner peripheral surface cleaning conduit 7, the inclined surface cleaning conduit 9 and the vertical wall cleaning conduit 31 is discharged to prevent the vapor of the residual cleaning liquid from causing a film thickness variation or the like. It is designed to improve quality.

In the second embodiment, as shown in FIG. 6, the range in which the vertical wall cleaning conduit 31 can be cleaned is set to a range slightly longer than half the linear length of the orientation flat OF. It may be set to a predetermined range, such as a range of about 1/4 of the circumference of the prevention cup 3. Further, the mounting position of the vertical wall cleaning conduit 31 to the scattering prevention cup 3 may be changed and adjusted in the circumferential direction of the scattering prevention cup 3.

In the above embodiment, the case of processing the substrate W having the orientation flat OF has been described. However, the present invention can be applied to the case of processing a substrate having a notch, and the orientation flat OF, the notch, etc. can be formed. Collectively called a notch.

In the above embodiment, the case where the coating liquid is discharged and the substrate W is rotated after the substrate W is stopped is described. However, the relative relationship between the rotation timing of the substrate W and the discharge timing of the coating liquid is shown. The position of the notch at the time when the coating liquid is discharged from can be specified, and it can also be applied to the case where the coating liquid is discharged onto the substrate W in the rotating state after the rotation of the substrate W is started.

[0033]

As is apparent from the above description, according to the rotary substrate coating apparatus of the first aspect of the present invention, the substrate held by the substrate holding means is rotated before the application of the coating liquid to hold the substrate. And the substrate processed immediately before that, by the rational improvement that the position of the notch when receiving the coating liquid by the coating liquid supply means is made different, the position where the coating liquid adheres to the splash prevention cup, Since the holding substrate and the substrate processed immediately before that are changed, it is possible to prevent the coating liquid from being concentrated and attached to a part of the scattering prevention cup.
For example, you can remove the shatterproof cup once a week and wash it once a month, so you can extend the maintenance cycle and shorten the processing time for maintenance and reduce the processing efficiency. Can be improved.

Further, according to the rotary type substrate coating apparatus of the second aspect of the present invention, based on the above consideration result, the cleaning liquid is supplied to the portion where the coating liquid is concentrated and adhered, and the adhered coating liquid is sequentially cleaned and removed. With the rational improvement that prevents the coating liquid from adhering and growing, it is possible to avoid the coating liquid from concentrating and adhering to a part of the splash prevention cup, and to extend the maintenance cycle. The processing time interrupted for maintenance is shortened and the processing efficiency can be improved.

[Brief description of the drawings]

FIG. 1 is a partially cutaway overall side view showing a first embodiment of a rotary substrate coating apparatus according to the present invention.

FIG. 2 is a plan view of the first embodiment.

FIG. 3 is a block diagram.

FIG. 4 is a flowchart.

FIG. 5 is a partially cutaway side view of an essential part showing a second embodiment.

FIG. 6 is a plan view of the second embodiment.

FIG. 7 is a partially cutaway side view showing a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Substrate holding means 2 ... Coating liquid supply nozzle as coating liquid supply means 3 ... Scattering prevention cup 11 ... Electric motor 31 as rotation driving means 31 ... Vertical wall cleaning conduit 32 ... Discharge hole P ... Rotation axis core OF substrate ... Orientation flat W ... Substrate

Claims (2)

[Claims] 1. A substrate holding means for holding a substrate having a notch, a rotation driving means for rotationally driving the substrate holding means, and a coating liquid at a position corresponding to a rotation center of the substrate held by the substrate holding means. A rotary substrate coating apparatus comprising: a coating liquid supply means for supplying; and a scattering prevention cup for receiving and collecting the coating liquid scattered from the substrate during coating, before supplying the coating liquid by the coating liquid supplying means. A rotation type substrate coating apparatus is provided, which is provided with rotation control means for rotating the substrate holding means so that the substrate processed immediately before the holding substrate has a phase different from that when receiving the coating liquid. 2. A substrate holding means for holding a substrate having a notch, a rotation driving means for rotationally driving the substrate holding means, and a coating liquid at a position corresponding to a rotation center of the substrate held by the substrate holding means. In a rotary substrate coating apparatus comprising: a coating liquid supply means for supplying; and a scattering prevention cup that receives and collects the coating liquid scattered from the substrate during coating, from the cutout of the substrate of the scattering prevention cup. A rotary substrate coating apparatus, characterized in that cleaning liquid supply means for supplying a cleaning liquid is provided at a position where the scattered coating liquid adheres.