TWI785626B - Peripheral portion coating apparatus and peripheral portion coating method - Google Patents

Abstract

In the present invention, the substrate is held by the rotation holder to rotate the substrate around the central axis of the substrate. By supplying the coating liquid to the peripheral portion of one side of the substrate by the coating liquid supply unit while the substrate is rotating, a coating film is formed on the peripheral portion of one side of the substrate except for the central region. After the coating film is formed on the peripheral portion of one surface of the substrate, the stirring operation by the rotating holding portion is repeated for a predetermined number of times or more. In each stirring operation, the substrate is accelerated to increase the rotational speed of the substrate. After the substrate is accelerated, the substrate is decelerated to reduce the rotational speed of the substrate. After the substrate is decelerated, the rotational speed of the substrate is maintained.

Description

Peripheral portion coating device and peripheral portion coating method

The present invention relates to a peripheral portion coating device and a peripheral portion coating method for forming a coating film on the peripheral portion of a substrate.

In a lithography step in the manufacture of semiconductor devices, etc., a substrate supported horizontally is rotated by a rotating chuck. In this state, a resist film is formed on the entire surface of the substrate to be processed by spraying the resist liquid toward the substantially central portion of the surface to be processed of the substrate. In addition, the resist film on the peripheral portion is removed by spraying the cleaning liquid toward the peripheral portion of the substrate. Then, by exposing and developing the substrate, a resist pattern is formed on the central region of the substrate except the peripheral portion. In recent years, a ring-shaped coating film has been further formed on the peripheral portion of the substrate (for example, refer to Japanese Patent No. 5682521 and Japanese Patent No. 5779168).

In the coating of the peripheral portion of the substrate, the coating film dries faster at the boundary portion between the resist pattern in the central region of the substrate and the coating film on the inner edge of the peripheral portion. From this, it can be seen that the thickness of the coating film is locally increased, and the coating film is partially raised at the inner edge of the peripheral portion. The coating film on the peripheral portion of the substrate will be removed by etching or the like in a subsequent step. However, when the thickness of the convex part of a coating film is large, this part may remain as a residue. In this case, the substrate is defective. Therefore, it is required to improve the uniformity of coating film thickness.

An object of the present invention is to provide a peripheral portion coating device and a peripheral portion coating method capable of improving the uniformity of thickness of a coating film formed on the peripheral portion of a substrate.

(1) A peripheral portion coating apparatus according to an aspect of the present invention includes: a rotation holding unit that holds a substrate so as to rotate the substrate around a central axis of the substrate; and a coating liquid supply unit that rotates the substrate by the rotation holding unit. , by supplying the coating liquid to the peripheral portion of one side of the substrate, thereby forming a coating film on the peripheral portion of one side of the substrate except for the central region; , controlling the rotation holding part in such a way as to repeatedly perform a predetermined number of times of agitation for more than 2 times; and the agitation action includes: accelerating the substrate to increase the rotation speed of the substrate; decelerating the substrate after accelerating the substrate to reduce the rotation speed of the substrate; and Maintain the rotation speed of the substrate after deceleration.

In this peripheral portion coating device, the substrate is held by the rotation holding unit to rotate the substrate around the central axis of the substrate. By supplying the coating liquid to the peripheral portion of one side of the substrate by the coating liquid supply portion while the substrate is rotated by the rotation holding unit, a coating film is formed on the peripheral portion of one side of the substrate except for the central region. After the coating film is formed on the peripheral edge of one side of the substrate by the coating solution supply unit, the stirring operation by the rotation holding unit is repeated a predetermined number of times or more. In each stirring operation, the substrate is accelerated to increase the rotational speed of the substrate. After the substrate is accelerated, the substrate is decelerated to reduce the rotational speed of the substrate. After the substrate is decelerated, the rotational speed of the substrate is maintained.

In each stirring operation, when the substrate is accelerated, the centrifugal force of the coating liquid applied to the peripheral portion of the substrate increases, and when the substrate is decelerated, the centrifugal force of the coating liquid applied to the peripheral portion of the substrate decreases. Therefore, according to the above configuration, the centrifugal force applied to the coating liquid is repeatedly increased and decreased by repeating the stirring operation. Therefore, the coating liquid is stirred at the peripheral edge of the substrate. In this way, the coating solution on the periphery of the substrate becomes uniform, and the formed coating film is almost flat.

Also, if the substrate is rotated at high speed for a long time, a turbulent flow that promotes drying of the coating liquid will be generated at the periphery of the substrate. In such a case, the thickness of the formed coating film becomes locally large, and the coating film is partially raised. On the other hand, according to the above configuration, by repeating the stirring operation, generation of turbulent flow at the peripheral edge of the substrate is suppressed, and drying of the coating liquid is prevented from being accelerated. As a result, the uniformity of the thickness of the coating film formed on the peripheral portion of the substrate can be improved.

(2) The predetermined number of times may be the number of times the coating film is dried due to loss of fluidity of the coating film formed on the peripheral portion of one side of the substrate by the coating liquid supply unit. In such a case, the uniformity of the thickness of the coating film formed on the peripheral portion of the substrate can be further improved.

(3) The control unit may control the rotation holding unit so as to omit the step of maintaining the rotation speed of the substrate in the last stirring operation among the stirring operations repeated two or more times. In this case, the uniformity of the thickness of the coating film formed on the peripheral portion of the substrate can be improved, and the time required for substrate processing can be shortened.

(4) The control unit may control the rotation holding unit so that the absolute value of the rotational acceleration of the substrate is equal to or greater than the absolute value of the rotational deceleration of the substrate during each stirring operation. In this case, since the rotational acceleration of the substrate is relatively large, the time for the substrate to rotate at a high speed can be shortened. Therefore, acceleration of drying of the coating liquid can be prevented more easily. In this way, the uniformity of the thickness of the coating film formed on the peripheral portion of the substrate can be more easily improved.

(5) The coating liquid supply part may include a coating nozzle for ejecting the coating liquid, and the control part may move the coating nozzle in the first direction so that the supply position of the coating liquid ejected from the coating nozzle is away from the outer edge of the peripheral edge of the substrate. After moving toward the inner edge, the coating nozzle is moved in a second direction opposite to the first direction so that the supply position of the coating liquid ejected from the coating nozzle moves from the inner edge to the outer edge of the peripheral edge of the substrate. In such a case, the coating film can be easily formed on the periphery of one surface of the substrate except for the central region.

(6) The control unit may move the coating nozzle so that the speed in the second direction is higher than the speed in the first direction. When a resist pattern or the like is formed in the central area of the substrate, the coating film dries faster at the interface between the resist pattern and the coating film at the inner edge of the peripheral portion, so that the coating film partially bulges at the inner edge of the peripheral portion. Even in such a case, according to the above constitution, it is possible to increase the thickness of the coating film at the outer edge of the peripheral portion. Therefore, the coating film formed on the peripheral portion of the substrate is almost flat. In this way, the uniformity of the thickness of the coating film formed on the peripheral portion of the substrate can be improved.

(7) A method for coating a peripheral portion of another aspect of the present invention includes the steps of: rotating the substrate around the central axis of the substrate while being held by the rotation holding unit; Use the coating liquid supply part to supply the coating liquid to the peripheral part of one side of the substrate, thereby forming a coating film on the peripheral part of one side of the substrate except the central area; and after using the coating liquid supply part to form the coating film on the peripheral part of one side of the substrate, repeat Stirring action using the rotating holding part for a predetermined number of times or more; and the stirring action includes: accelerating the substrate to increase the rotational speed of the substrate; decelerating the substrate after accelerating the substrate to reduce the rotational speed of the substrate; and maintaining the rotational speed of the substrate after decelerating the substrate Rotating speed.

According to this peripheral portion coating method, the substrate is held by the rotation holding unit to rotate the substrate around the central axis of the substrate. By supplying the coating liquid to the peripheral portion of one side of the substrate by the coating liquid supply portion while the substrate is rotated by the rotation holding unit, a coating film is formed on the peripheral portion of one side of the substrate except for the central region. After the coating film is formed on the peripheral edge of one side of the substrate by the coating solution supply unit, the stirring operation by the rotation holding unit is repeated a predetermined number of times or more. In each stirring operation, the substrate is accelerated to increase the rotational speed of the substrate. After the substrate is accelerated, the substrate is decelerated to reduce the rotational speed of the substrate. After the substrate is decelerated, the rotational speed of the substrate is maintained.

In each stirring operation, when the substrate is accelerated, the centrifugal force of the coating liquid applied to the peripheral portion of the substrate increases, and when the substrate is decelerated, the centrifugal force of the coating liquid applied to the peripheral portion of the substrate decreases. Therefore, according to the above configuration, the centrifugal force applied to the coating liquid is repeatedly increased and decreased by repeating the stirring operation. Therefore, the coating liquid is stirred at the peripheral edge of the substrate. In this way, the coating solution on the periphery of the substrate becomes uniform, and the formed coating film is almost flat.

Also, if the substrate is rotated at high speed for a long time, a turbulent flow that promotes drying of the coating liquid will be generated at the periphery of the substrate. In such a case, the thickness of the formed coating film becomes locally large, and the coating film is partially raised. On the other hand, according to the above configuration, by repeating the stirring operation, generation of turbulent flow at the peripheral edge of the substrate is suppressed, and drying of the coating liquid is prevented from being accelerated. As a result, the uniformity of the thickness of the coating film formed on the peripheral portion of the substrate can be improved.

(8) The predetermined number of times may be the number of times the coating film is dried due to loss of fluidity of the coating film formed on the peripheral portion of one side of the substrate by the coating liquid supply unit. In such a case, the uniformity of the thickness of the coating film formed on the peripheral portion of the substrate can be further improved.

(9) It is also possible to omit the step of maintaining the rotation speed of the substrate in the last stirring operation among the stirring operations repeated more than two times. In this case, the uniformity of the thickness of the coating film formed on the peripheral portion of the substrate can be improved, and the time required for substrate processing can be shortened.

(10) In each stirring operation, the absolute value of the rotational acceleration of the substrate may be greater than or equal to the absolute value of the rotational deceleration of the substrate. In this case, since the rotational acceleration of the substrate is relatively large, the time for the substrate to rotate at a high speed can be shortened. Therefore, it is easier to prevent accelerated drying of the coating liquid. In this way, the uniformity of the thickness of the coating film formed on the peripheral portion of the substrate can be more easily improved.

(11) The step of forming the coating film may also include: after moving the coating nozzle in the first direction so that the supply position of the coating liquid ejected from the coating nozzle of the coating liquid supply part is moved from the outer edge to the inner edge of the peripheral edge of the substrate. and then moving the coating nozzle in a second direction opposite to the first direction so that the supply position of the coating liquid ejected from the coating nozzle moves from the inner edge to the outer edge of the peripheral edge of the substrate. In such a case, the coating film can be easily formed on the periphery of one surface of the substrate except for the central region.

(12) The speed at which the coating nozzle moves in the second direction may be greater than the speed at which the coating nozzle moves in the first direction. When a resist pattern or the like is formed in the central area of the substrate, the coating film dries faster at the interface between the resist pattern and the coating film at the inner edge of the peripheral portion, so that the coating film partially bulges at the inner edge of the peripheral portion. Even in this case, according to the method described above, it is possible to increase the thickness of the coating film at the outer edge of the peripheral portion. Therefore, the coating film formed on the peripheral portion of the substrate is almost flat. In this way, the uniformity of the thickness of the coating film formed on the peripheral portion of the substrate can be improved.

(1) Peripheral coating device Hereinafter, a peripheral portion coating device and a peripheral portion coating method according to an embodiment of the present invention will be described with reference to the drawings. Fig. 1 is a schematic cross-sectional view of a peripheral portion coating device according to an embodiment of the present invention. As shown in FIG. 1 , the peripheral portion coating device 100 includes a rotation holding unit 10 , a cover 20 , a coating liquid supply unit 30 , a cleaning liquid supply unit 40 , and a control unit 50 . The spin holder 10 includes a spin chuck 11 and a motor 12 . The spin chuck 11 is attached to the front end of the rotating shaft 12a of the motor 12, and is driven to rotate around a vertical axis while keeping the substrate W in a horizontal posture.

The shield 20 is provided to surround the substrate W held by the spin chuck 11 , and catches coating liquid or cleaning liquid scattered from the substrate W. As shown in FIG. An opening 21 for introducing the substrate W into the shield 20 is formed on the upper portion of the shield 20 . Also, a waste liquid port 22 and an exhaust port 23 are formed at the lower part of the shield 20 . The waste liquid port 22 and the exhaust port 23 are respectively connected to waste liquid equipment and exhaust equipment in the factory.

The coating solution supply unit 30 includes a coating nozzle 31 , a coating solution storage unit 32 , piping 33 and a valve 34 . The coating nozzle 31 is connected to a coating liquid storage unit 32 via a pipe 33 . A coating liquid is stored in the coating liquid storage unit 32 . In the present embodiment, the coating liquid is a photosensitive resist liquid, but the embodiment is not limited thereto. The coating liquid may also be a non-photosensitive resist liquid or a resin-containing solution. A valve 34 is inserted through the piping 33 .

The coating nozzle 31 is provided movable between a processing position above the peripheral portion of the substrate W and a standby position outside the shield 20, and moves to the processing position when the substrate is processed. In this state, by opening the valve 34 , the coating liquid is supplied from the coating liquid storage part 32 to the coating nozzle 31 through the piping 33 . In this way, the coating liquid is ejected from the coating nozzle 31 toward the peripheral edge of the substrate W. As shown in FIG. Here, the peripheral portion of the substrate W refers to an inner region of the substrate W that is only a certain width away from the outer peripheral portion.

The cleaning liquid supply part 40 includes one or more (two in this example) rear cleaning liquid nozzles 41 , a cleaning liquid storage part 42 , piping 43 and a valve 44 . Each rear cleaning liquid nozzle 41 is provided below the substrate W, and is connected to the cleaning liquid storage part 42 through a pipe 43 . Cleaning liquid is stored in the cleaning liquid storage unit 42 . The cleaning solution includes, for example, PGMEA (propylene glycol monomethyl ether acetate, propylene glycol methyl ether acetate), PGME (propylene glycol monomethyl ether, propylene glycol methyl ether) or cyclohexanone. A valve 44 is inserted through the piping 43 .

When the substrate is processed, the cleaning liquid is supplied from the cleaning liquid storage part 42 to each rear cleaning liquid nozzle 41 through the piping 43 by opening the valve 44 . In this case, the cleaning liquid is sprayed from each rear cleaning liquid nozzle 41 toward the back surface of the substrate W (the surface opposite to the surface to be processed). In this way, the back surface of the substrate W is cleaned.

The control unit 50 includes, for example, a CPU (central processing unit) and controls the movement of the coating nozzle 31 . Moreover, the control unit 50 controls the rotation speed of the substrate W held by the spin chuck 11 by controlling the rotation speed of the motor 12 . Furthermore, the control unit 50 controls the opening and closing of the valves 34 and 44 to respectively control the spraying timings of the coating liquid and the cleaning liquid.

(2) Outline of Substrate Processing 2 to 6 are side views showing substrates in substrate processing steps. As shown in FIG. 2 , the substrate W is held by the spin chuck 11 with the surface to be processed facing upward. Here, a resist pattern (not shown) is formed in the central region of the surface to be processed except for the peripheral portion of the substrate W. As shown in FIG. Then, the substrate W is rotated by the motor 12 shown in FIG. 1 .

Next, when the coating nozzle 31 moves from the standby position to the position outside and above the substrate W, it moves toward the center of the substrate W as shown by arrow A in FIG. 2 . Hereinafter, moving the coating nozzle 31 from the outer side of the substrate W toward the center of the substrate W is referred to as inward scanning. As shown in FIG. 3 , when the coating nozzle 31 reaches the upper position near the outer edge of the peripheral portion of the substrate W during the inward scanning, the coating liquid starts to be sprayed from the coating nozzle 31 .

When the coating nozzle 31 moves to the upper position near the inner edge of the peripheral portion of the substrate W, it moves toward the outer side of the substrate W as shown by arrow B in FIG. 4 . Hereinafter, moving the coating nozzle 31 from the center of the substrate W toward the outside of the substrate W is referred to as outward scanning. As shown in FIG. 5 , when the coating nozzle 31 reaches a position near the upper portion of the peripheral portion of the substrate W during outward scanning, the spraying of the coating liquid from the coating nozzle 31 is stopped. Then, the coating nozzle 31 moves to the standby position.

After the coating film on the peripheral portion of the substrate W is dried, a cleaning solution is sprayed from the rear cleaning solution nozzle 41 to the back surface of the substrate W as shown in FIG. 6 . In this way, the back surface of the substrate W is cleaned, and the coating film on the slope portion of the substrate W is removed. Then, the substrate processing is completed by drying the cleaning solution.

According to the above control, after the inward scanning in which the supply position of the coating liquid ejected from the coating nozzle 31 is moved from the outer edge to the inner edge of the peripheral portion of the substrate W, the supply position of the coating liquid is moved from the inner edge to the inner edge of the peripheral portion of the substrate W. Outward scanning for outer edge movement. In this way, the coating film is formed on the peripheral portion of the surface to be processed of the substrate W except for the central region. In this example, the moving speed of the coating nozzle 31 scanning outward is greater than the moving speed of the coating nozzle 31 scanning inward.

FIG. 7 is a side view showing a substrate W after substrate processing. In the substrate processing described above, the coating film dries quickly at the boundary between the resist pattern in the central region of the substrate W and the coating film on the inner edge of the peripheral portion. In this way, as shown in FIG. 7 , the thickness of the coating film becomes locally large, and the coating film protrudes at the inner edge of the peripheral portion. The raised part in this coating film is called a bump. The coating film on the peripheral portion of the substrate W is removed by etching or the like in a subsequent step performed outside the peripheral portion coating apparatus 100 .

However, when the thickness of the bulge is large, the bulged part may remain as a residue. In this case, the substrate W has defects. Therefore, in the substrate processing, a stirring operation is performed in order to reduce the ratio of the bump thickness h2 to the average film thickness h1 of the coating film (hereinafter referred to as film thickness ratio). In addition, average film thickness h1 means the average value of the thickness of the part except a protrusion in a coating film. Also, the uplift thickness h2 refers to the maximum thickness of the uplift. The details of the substrate processing will be described below.

(3) Details of substrate processing FIG. 8 is a graph showing changes in the rotational speed of the substrate W in the processing steps of the substrate W. As shown in FIG. As shown in FIG. 8 , at the initial time point t0 , the substrate W is stationary. That is, the rotation speed of the substrate W is 0 rpm. Also, the valves 34, 44 of Fig. 1 are closed. Firstly, the rotation speed of the substrate W is increased by starting the rotation of the substrate W, and reaches a fixed rotation speed, such as 100 rpm, at time point t1. The rotation speed of the substrate W is maintained until the time point t2.

Also, the inward scanning and outward scanning of the coating nozzle 31 in FIG. 1 are sequentially performed. Here, at time t1, the discharge of the coating liquid to the peripheral portion of the substrate W is started by opening the valve 34, and at time t2, the discharge of the coating liquid is stopped by closing the valve 34. In this way, a coating film is formed on the peripheral portion of the substrate W. As shown in FIG. The step from the time point t1 to the time point t2 is called a discharge step.

At time t2, the rotation speed of the substrate W increases rapidly. In this way, at the time point t3, the rotation speed of the substrate W reaches, for example, 3000 rpm. The step from time t2 to time t3 is called an acceleration step. Hereinafter, the rotational acceleration of the substrate W in the acceleration step is simply referred to as the rotational acceleration of the substrate W. The rotational acceleration of the substrate W is, for example, 5000 rpm/sec or more, and in this example, it is 25000 rpm/sec.

At time t3, after the rotation speed of the substrate W is maintained for a short period of time (for example, greater than 0 seconds and less than 1 second), the rotation speed of the substrate W decreases sharply. In this way, at the time point t4, the rotation speed of the substrate W reaches below 1000 rpm (500 rpm in this example), for example. At the time point t4, the rotation speed of the substrate W may also be reduced to less than 500 rpm (for example, 0 rpm).

The step from the time point t3 to the time point t4 is called a deceleration step. Hereinafter, the rotational deceleration of the substrate W in the deceleration step is simply referred to as the rotational deceleration of the substrate W. In this example, the absolute value of the rotational deceleration of the substrate W is substantially equal to the absolute value of the rotational acceleration of the substrate W, but the embodiment is not limited thereto. The absolute value of the rotational deceleration of the substrate W may also be smaller than the absolute value of the rotational acceleration of the substrate W.

Next, during the period from time point t4 to time point t5, the rotation speed of the substrate W is maintained at a constant rotation speed. The time interval between the time point t4 and the time point t5 is, for example, from 0.01 second to 10 seconds, and in this example is 0.15 seconds. The step from time t4 to time t5 is called a speed maintaining step. The speed maintaining step is a step for adjusting the thickness of the coating film formed on the peripheral portion of the substrate W. Therefore, the time of the speed maintaining step is determined according to the required thickness of the coating film.

In the acceleration step, the deceleration step and the speed maintenance step, a series of actions of the rotating holding part 10 is a stirring action. After the time point t5, the stirring operation was repeated several times. Here, the number of repetitions of the stirring operation is predetermined as the number of times the coating film formed on the peripheral portion of the substrate W loses fluidity and the coating film dries. In this example, the number of repetitions of the stirring operation is 5 times, but the number of repetitions of the stirring operation may not be 5 times as long as it is more than 2 times. In addition, in this example, the speed maintenance step following the last deceleration step is omitted. In this case, the uniformity of the thickness of the coating film formed on the peripheral portion of the substrate W can be improved, and the time required for substrate processing can be shortened.

In the last (fifth time in this example) stirring operation, after the deceleration step is performed, at time t6, the rotation speed of the substrate W reaches a fixed rotation speed, for example, 400 rpm. In this state, by opening the valve 44, spraying of the cleaning liquid to the back surface of the substrate W starts. In this way, the back surface of the substrate W is cleaned, and the coating film on the slope portion of the substrate W is removed. Then, at the time point t7, the rotation speed of the substrate W increases, and reaches a fixed rotation speed, such as 800 rpm, at the time point t8.

Next, at time t9, the valve 44 is closed to stop spraying of the cleaning liquid. In addition, the rotation speed of the substrate W increases, reaching, for example, 2000 rpm at time t10. In this way, the substrate W is dried. Then, at time t11, the rotation speed of the substrate W decreases. At time t12, the substrate W stops rotating, thereby ending the substrate processing.

(4) Effect In the peripheral portion coating apparatus 100 of this embodiment, the substrate W is held by the rotation holding unit 10 , and the substrate W is rotated around the central axis of the substrate W. As shown in FIG. In the state where the substrate W is rotated by the rotation holding unit 10, by supplying the coating liquid to the peripheral portion of the surface to be processed of the substrate W by the coating liquid supply portion 30, A coating film is formed on the peripheral portion. After the coating film is formed on the peripheral portion of the surface to be processed of the substrate W by the coating liquid supply unit 30 , the stirring operation by the rotation holding unit 10 is repeated a predetermined number of times or more. In each stirring operation, the substrate W is accelerated to increase the rotation speed of the substrate W. After the substrate W is accelerated, the substrate W is decelerated to reduce the rotation speed of the substrate W. After the substrate W is decelerated, the rotation speed of the substrate W is maintained.

In each stirring operation, when the substrate W is accelerated, the centrifugal force of the coating liquid applied to the peripheral portion of the substrate W increases, and when the substrate W decelerates, the centrifugal force of the coating liquid applied to the peripheral portion of the substrate W decreases. Therefore, according to the above configuration, the centrifugal force applied to the coating liquid is repeatedly increased and decreased by repeating the stirring operation. Therefore, the coating liquid is stirred on the peripheral portion of the substrate W. As shown in FIG. In this way, the coating liquid on the peripheral portion of the substrate W becomes uniform, and the formed coating film is almost flat.

Also, if the substrate W is rotated at high speed for a long time, a turbulent flow that promotes drying of the coating liquid will be generated on the peripheral edge of the substrate W. In such a case, the thickness of the formed coating film becomes locally large, and the coating film is partially raised. On the other hand, according to the above configuration, by repeating the stirring operation, generation of turbulent flow in the peripheral portion of the substrate W is suppressed, and drying of the coating liquid is prevented from being accelerated. As a result, the uniformity of the thickness of the coating film formed on the peripheral portion of the substrate W can be improved.

In each stirring operation, the absolute value of the rotational acceleration of the substrate W is equal to or greater than the absolute value of the rotational deceleration of the substrate W. In this case, since the rotational acceleration of the substrate W is high, the time for the substrate W to rotate at a high speed can be shortened. Therefore, it is easier to prevent accelerated drying of the coating liquid. In this way, the uniformity of the thickness of the coating film formed on the peripheral portion of the substrate W can be improved more easily.

Also, the moving speed of the coating nozzle 31 scanning outward is greater than the moving speed of the coating nozzle 31 scanning inward. In this case, the thickness of the coating film at the outer edge of the peripheral portion of the substrate W can be increased. Therefore, the coating film formed on the peripheral portion of the substrate W is nearly flat. In this way, the uniformity of the thickness of the coating film formed on the peripheral portion of the substrate W can be further improved.

(5) Another embodiment (a) In the above-mentioned embodiment, the step of maintaining the speed in the last stirring operation is omitted when the stirring operation is repeated twice or more, but the embodiment is not limited thereto. A speed maintenance step for the final stirring action may also be performed.

(b) In the above embodiment, the absolute value of the rotational deceleration of the substrate W is equal to or less than the absolute value of the rotational acceleration of the substrate W, but the embodiment is not limited thereto. The absolute value of the rotational deceleration of the substrate W may also be greater than the absolute value of the rotational acceleration of the substrate W.

(c) In the above embodiment, although the moving speed of the coating nozzle 31 scanning outward is greater than the moving speed of the coating nozzle 31 scanning inward, the embodiment is not limited thereto. The moving speed of the coating nozzle 31 scanning outward may also be lower than the moving speed of the coating nozzle 31 scanning inward. In addition, when forming the coating film, the coating nozzle 31 may be fixed at the home position without performing inward scanning and outward scanning of the coating nozzle 31 .

(d) In the above-mentioned embodiment, although the coating nozzle 31 is installed in an upright state so that the discharge port of the coating liquid faces downward, embodiment is not limited to this. The coating nozzle 31 may be installed in an inclined state so that the discharge port of the coating liquid faces obliquely downward and outward.

(6) Embodiment In the first embodiment, when the duration of the speed maintaining step was changed, changes in the average film thickness h1, the bump thickness h2, and the film thickness ratio were measured. Fig. 9 is a graph showing the measurement results of the first example. The horizontal axis of FIG. 9 represents the duration of the speed maintaining step, and the vertical axis represents the average film thickness h1, the bump thickness h2, or the film thickness ratio. In addition, in the first embodiment, the repetition procedure of the stirring operation is five times, and the same is true in the third to sixth embodiments described below.

As shown in FIG. 9, when the duration of the speed maintaining step is prolonged, the average film thickness h1 becomes larger, while the bump thickness h2 hardly changes. As a result, when the duration of the speed maintaining step is prolonged, the film thickness ratio becomes smaller. Therefore, it was confirmed that the film thickness ratio can be reduced by extending the duration of the speed maintaining step.

In the second embodiment, changes in the average film thickness h1, the bump thickness h2, and the film thickness ratio were measured when the number of stirring operations performed was changed. Fig. 10 is a graph showing the measurement results of the second example. The horizontal axis of FIG. 10 represents the number of execution times of the stirring operation, and the vertical axis represents the average film thickness h1, the raised thickness h2 or the film thickness ratio.

As shown in FIG. 10, the average film thickness h1 remained almost unchanged even though the number of times the stirring operation was performed was changed. On the other hand, when the number of stirring operations is increased, the raised thickness h2 becomes smaller, and when the number of times of stirring operations exceeds a fixed number, the raised thickness h2 hardly changes. As a result, the film thickness ratio becomes smaller as the number of stirring operations is increased, and the film thickness ratio hardly changes when the number of stirring operations is performed more than a fixed number of times. Therefore, it was confirmed that the average film thickness h1 can be maintained and the film thickness ratio can be reduced by repeating the stirring operation for a fixed number of times.

In the third embodiment, when the rotation speed of the substrate W after the acceleration step was changed, changes in the average film thickness h1, the bump thickness h2, and the film thickness ratio were measured. Fig. 11 is a graph showing the measurement results of the third example. The horizontal axis of FIG. 11 represents the rotational speed of the substrate W after the acceleration step, and the vertical axis represents the average film thickness h1, the bump thickness h2 or the film thickness ratio.

As shown in FIG. 11 , when the rotation speed of the substrate W after the acceleration step is increased, the average film thickness h1 and the bump thickness h2 become smaller. As a result, the film thickness ratio remained almost unchanged even though the rotation speed of the substrate W after the acceleration step was increased. Therefore, it was confirmed that the rotation speed of the substrate W after the acceleration step has little effect on reducing the film thickness ratio.

In the fourth example, when the rotational acceleration of the substrate W was changed, changes in the average film thickness h1, the bump thickness h2, and the film thickness ratio were measured. Fig. 12 is a graph showing the measurement results of the fourth example. The horizontal axis of FIG. 12 represents the rotational acceleration of the substrate W, and the vertical axis represents the average film thickness h1, the bump thickness h2, or the film thickness ratio.

As shown in FIG. 12 , when the rotational acceleration of the substrate W is increased, the average film thickness h1 increases, and when the rotational acceleration exceeds a fixed value, the average film thickness h1 hardly changes. On the other hand, the bump thickness h2 hardly changes despite increasing the rotational acceleration. As a result, when the rotational acceleration is increased, the film thickness ratio becomes small, and when the rotational acceleration exceeds a fixed value, the film thickness ratio hardly changes. Therefore, it was confirmed that the film thickness ratio can be reduced by setting the rotational acceleration of the substrate W to a constant value or more.

In the fifth embodiment, when changing the rotation speed of the substrate W in the speed maintaining step, changes in the average film thickness h1, the bump thickness h2, and the film thickness ratio were measured. Fig. 13 is a graph showing the measurement results of the fifth example. The horizontal axis of FIG. 13 represents the rotational speed of the substrate W in the speed maintaining step, and the vertical axis represents the average film thickness h1, the bump thickness h2, or the film thickness ratio.

As shown in FIG. 13 , when the rotation speed of the substrate W in the speed maintenance step is increased, the average film thickness h1 becomes smaller and the bump thickness h2 becomes larger. As a result, if the rotation speed of the substrate W in the speed maintenance step is increased, the film thickness ratio becomes smaller. Therefore, it was confirmed that the film thickness ratio can be reduced by reducing the rotational speed of the substrate W in the speed maintaining step.

In the sixth embodiment, when the rotation speed of the substrate W in the discharge step was changed, changes in the average film thickness h1, the bump thickness h2, and the film thickness ratio were measured. Fig. 14 is a graph showing the measurement results of the sixth example. The horizontal axis of FIG. 14 represents the rotation speed of the substrate W in the discharge step, and the vertical axis represents the average film thickness h1, the raised thickness h2, or the film thickness ratio.

As shown in FIG. 14, even though the rotation speed of the substrate W in the ejection step was increased, the average film thickness h1 remained unchanged, and the bump thickness h2 hardly changed. As a result, the film thickness ratio remained almost unchanged even though the rotation speed of the substrate W in the ejection step was increased. Therefore, it was confirmed that the rotation speed of the substrate W in the ejection step hardly contributes to reducing the film thickness ratio.

(7) Correspondence between each constituent element of the claim and each element of the embodiment In the above embodiment, the rotation holding unit 10 is an example of a rotation holding unit, the coating liquid supply unit 30 is an example of a coating liquid supply unit, the control unit 50 is an example of a control unit, and the coating nozzle 31 is an example of a coating nozzle.

10: Rotation holding part 11:Rotary suction cup 12: Motor 12a: axis of rotation 20: shield 21: opening 22: Waste liquid port 23: Exhaust port 30: Coating liquid supply part 31: coating nozzle 32: Coating liquid storage part 33: Piping 34: valve 40:Cleaning solution supply part 41: Rear washer fluid nozzle 42: Cleaning solution storage part 43: Piping 44: valve 50: Control Department 100: Peripheral coating device A: arrow B: Arrow h1: average film thickness h2: bump thickness W: Substrate

Fig. 1 is a schematic cross-sectional view of a peripheral portion coating device according to an embodiment of the present invention. Fig. 2 is a side view showing a substrate in a substrate processing step. Fig. 3 is a side view showing a substrate in a substrate processing step. Fig. 4 is a side view showing a substrate in a substrate processing step. Fig. 5 is a side view showing a substrate in a substrate processing step. Fig. 6 is a side view showing a substrate in a substrate processing step. Fig. 7 is a side view showing a substrate after substrate processing. FIG. 8 is a graph showing changes in the rotational speed of a substrate in a substrate processing step. Fig. 9 is a graph showing the measurement results of the first example. Fig. 10 is a graph showing the measurement results of the second example. Fig. 11 is a graph showing the measurement results of the third example. Fig. 12 is a graph showing the measurement results of the fourth example. Fig. 13 is a graph showing the measurement results of the fifth example. Fig. 14 is a graph showing the measurement results of the sixth example.

10: Rotation holding part

11:Rotary suction cup

12: Motor

12a: axis of rotation

20: shield

21: opening

22: Waste liquid port

23: Exhaust port

30: Coating liquid supply part

31: coating nozzle

32: Coating liquid storage part

33: Piping

34: valve

40:Cleaning solution supply part

41: Rear washer fluid nozzle

42: Cleaning solution storage part

43: Piping

44: valve

50: Control Department

100: Peripheral coating device

W: Substrate

Claims (12)

A peripheral portion coating device comprising: a rotation holding unit that holds a substrate and rotates the substrate around a central axis of the substrate; and a coating liquid supply unit that supplies the substrate with A coating liquid is supplied to the peripheral portion of one side to form a coating film on the peripheral portion of one side of the substrate except for the central region; and a control unit controls the rotation after the coating film is formed on the peripheral portion of one side of the substrate by the coating liquid supply portion. The holding part repeats the stirring action for a predetermined number of times more than 2 times; and the stirring action includes: accelerating the substrate to increase the rotational speed of the substrate; after the substrate is accelerated, decelerating the substrate to reduce the rotational speed of the substrate; and after the substrate is decelerated, The rotation speed of the substrate is maintained; and the above-mentioned predetermined number of times is the number of times that the coating film formed on the peripheral portion of one side of the substrate by the above-mentioned coating liquid supply part loses fluidity. The peripheral portion coating device according to claim 1, wherein the predetermined number of times is the number of times of drying the coating film formed on the peripheral portion of one side of the substrate by the coating liquid supply portion. The peripheral portion coating device according to claim 1 or 2, wherein the control unit controls the rotation holding unit so as to omit the step of maintaining the rotation speed of the substrate in the last stirring operation among the stirring operations repeated two or more times. The peripheral portion coating device according to claim 1 or 2, wherein the control unit controls the rotation holding unit so that the absolute value of the rotational acceleration of the substrate is equal to or greater than the absolute value of the rotational deceleration of the substrate during each stirring operation. The peripheral part coating device according to claim 1 or 2, wherein the coating liquid supply part includes a coating nozzle for spraying the coating liquid, and the control part moves the coating nozzle in the first direction so that the coating sprayed by the coating nozzle After the supply position of the liquid is moved from the outer edge to the inner edge of the peripheral edge of the substrate, the coating nozzle is moved to the second direction opposite to the first direction, so that the supply position of the coating liquid ejected from the coating nozzle is moved from the substrate to the second direction opposite to the first direction. The inner edge of the peripheral portion moves toward the outer edge. The peripheral portion coating device according to claim 5, wherein the control unit moves the coating nozzle so that the speed in the second direction is greater than the speed in the first direction. A method for coating a peripheral portion, comprising the steps of: holding a substrate by a rotation holding unit and rotating the substrate around a central axis of the substrate; Supplying the coating liquid to the peripheral portion of one side to form a coating film on the peripheral portion of one side of the substrate except the central region; and after using the coating liquid supply part to form the coating film on the peripheral portion of one side of the substrate, repeat the predetermined number of times for more than 2 times The stirring action using the above-mentioned rotating holding part; and the above-mentioned stirring action includes: accelerating the substrate to increase the rotation speed of the substrate; After the substrate is accelerated, the substrate is decelerated to reduce the rotational speed of the substrate; and after the substrate is decelerated, the rotational speed of the substrate is maintained; Number of times of loss of liquidity. The peripheral portion coating method according to claim 7, wherein the predetermined number of times is the number of times of drying the coating film formed on the peripheral portion of one side of the substrate by the coating liquid supply portion. The method for coating the peripheral edge according to claim 7 or 8, wherein the step of maintaining the rotation speed of the substrate is omitted in the last stirring operation among the stirring operations repeated more than two times. The peripheral portion coating method according to claim 7 or 8, wherein in each stirring operation, the absolute value of the rotational acceleration of the substrate is equal to or greater than the absolute value of the rotational deceleration of the substrate. The peripheral part coating method according to claim 7 or 8, wherein the step of forming the above-mentioned coating film includes: moving the above-mentioned coating nozzle in the first direction so that the supply position of the coating liquid ejected from the coating nozzle of the above-mentioned coating liquid supply part After moving from the outer edge to the inner edge of the peripheral edge of the substrate, the coating nozzle is moved in the second direction opposite to the first direction, so that the supply position of the coating liquid ejected from the coating nozzle is from the inside of the peripheral edge of the substrate. The edge moves toward the outer edge. The peripheral portion coating method according to claim 11, wherein the speed at which the coating nozzle moves in the second direction is greater than the speed at which the coating nozzle moves in the first direction.

Images