JP2000091212A - Method and apparatus for removing edge part of substrate coating - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to remove a coating film with almost the same removing width even at an orientation flat part in a simple step, by flowing a treatment solution up to the surface of an edge part thereof while the treatment solution is fed from below. SOLUTION: In a coating removing method for removing the surface of an edge part out of a coating film (F) formed on a substrate (W), a treatment solution (LQ) is fed from below the substrate (W). Then, the treatment solution is flown up to the surface of an edge of the substrate (W) while the substrate (W) is rotated at low speed. In this way the coating film (F) even at an orientation flat part can be removed in a width of D from its edge.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a coating film formed on the surface of a semiconductor substrate, a glass substrate of a liquid crystal display, a glass substrate for a photomask, a substrate for an optical disk, etc. (hereinafter simply referred to as a substrate). The present invention relates to a technique for removing a film on a surface of an edge portion.

[0002]

2. Description of the Related Art In a spin coating method in which a coating liquid is spread over the entire surface by rotating a substrate to form a coating film, the coating liquid wraps around the back surface of the substrate, so that the particles adhere together with particles originally attached to the back surface. Back washing process (also called back rinsing process) to remove
In order to suppress the generation of particles due to peeling, edge removal processing (also referred to as edge rinse processing) for removing only the edge surface of the coating film is generally performed.

[0003] This edge removal processing is generally performed by a method described below.

[0004] "Method using treatment solution" (EBR (Edge Bead Re
mover) is a method in which a nozzle is moved to the surface of the edge of the substrate, and a processing liquid is supplied from the nozzle to dissolve and remove only the coating film on the edge.

[0005] The "exposure method" (also called edge exposure) is used only when the coating film is photosensitive such as a photoresist film, and after exposing the edge of the substrate using an edge exposure unit, The development removes the coating film on the edge.

[0006]

However, such a conventional example has the following problems. That is, there is a problem that it is difficult to process an orientation flat (hereinafter, referred to as an orientation flat) portion formed on a semiconductor substrate in the “method using a treatment liquid”. For example, when the edge removal processing is performed with a removal width of 2 mm, the processing liquid does not come into contact with the orientation flat section, so that the coating on this section cannot be removed. In order to remove the film on the orientation flat portion, for example, in the case of a 6-inch diameter semiconductor substrate, a removal width of 3.5 mm or more is required. The number of chips that can be collected from one semiconductor substrate decreases. Further, in the processing by this method, the processing liquid viewed from the substrate draws a circle, so that the removal width of the orientation flat portion and other portions cannot be made constant.

In the "method by exposure", the film can be removed with a constant width, but an edge exposure unit is required and the number of steps increases, so that the throughput decreases. If the coating to be removed is non-photosensitive, after forming a photosensitive coating on it,
It is necessary to perform development and etching to remove the coating film on the edge, which complicates the process.

The present invention has been made in view of such circumstances, and removes a coating on an orientation flat portion by a simple process by circulating a processing solution supplied from below onto the edge surface of a substrate. It is an object of the present invention to provide a method and an apparatus for removing an edge portion of a substrate coating capable of removing the coating with a substantially constant removal width.

[0009]

The present invention has the following configuration in order to achieve the above object. That is, according to the method of the present invention, in the method of removing the edge of the substrate coating from among the coating films formed on the surface of the substrate, the rotation of the substrate is reduced at a low speed. In this state, the processing liquid is supplied from below the substrate to the rear surface, and the processing liquid is caused to flow around the edge surface of the substrate.

Note that the flow rate of the processing liquid is set slightly larger than that during the back rinsing processing so that the processing liquid easily wraps around the surface of the substrate, and the supply direction is obliquely upward from the rotation center side to the circumferential side. It is preferred to point.

According to a second aspect of the present invention, in the method for removing an edge of a substrate film according to the first aspect, any one of methanol, ethanol, and IPA (isopropyl alcohol) is used as the treatment liquid. It is characterized in that it is used.

According to a third aspect of the present invention, in the method for removing an edge portion of a substrate film according to the first aspect, any one of methanol, ethanol, and IPA (isopropyl alcohol) is used as the treatment liquid. (N-methyl
-2-pyrrolidone).

According to a fourth aspect of the present invention, in the method for removing an edge portion of a substrate film according to the first aspect, any one of methanol, ethanol, and IPA (isopropyl alcohol) is used as the treatment liquid. (N-methyl
-2-pyrrolidone), followed by treatment using any one of methanol, ethanol, and IPA (isopropyl alcohol) as a treatment liquid. .

According to a fifth aspect of the present invention, in the method for removing an edge portion of a substrate film according to any one of the first to fourth aspects, the processing is performed subsequent to a coating processing for forming a coating film on the surface of the substrate. The present invention is characterized in that it is carried out by

According to a sixth aspect of the present invention, there is provided an apparatus for removing an edge portion of a substrate film from among the coating films formed on the surface of the substrate, which removes the film on the edge surface of the substrate.
Rotation support means for rotatably supporting the substrate, processing liquid supply means for supplying a processing liquid from below the substrate toward the back surface,
Control means for controlling the supply of the processing liquid from the processing liquid supply means so that the processing liquid flows around the edge surface of the substrate while the rotation of the substrate is reduced at a low speed by the rotation support means. It is characterized by having.

[0016]

The operation of the first aspect of the invention is as follows. In a state where the substrate is rotated at a low speed, the processing liquid supplied from below toward the rear surface moves along the rear surface in the outer peripheral direction by weak centrifugal force, and moves upward at the edge rear surface. At this time, the surface tension acts to cause the treatment liquid to once wrap around the edge surface of the substrate, so that the treatment liquid also wraps around the orifice portion of the semiconductor substrate, and the coating can be removed.

According to the second aspect of the present invention, by using any one of methanol, ethanol and IPA as the processing liquid, the processing liquid can easily flow around the edge surface of the substrate.

According to the third aspect of the present invention, when a similar alcohol-based solvent is used as a treatment liquid for a coating film using an alcohol-based solvent as a solvent, the penetrating power to the film is strong. A phenomenon occurs in which the removed end portion of the coating swells up. When the film swells like this,
In particular, a coating made of a silica-based coating material or a ferroelectric material is subjected to a subsequent high-temperature heat treatment process. Therefore, by using a mixed solution in which NMP is mixed, penetration into the film can be suppressed, and swelling of the film can be prevented.

According to the fourth aspect of the present invention, when treated with a mixed solution of an alcohol solvent and NMP,
While the swelling of the coating film can be prevented, the coating can be easily wrapped around the surface of the substrate. On the other hand, NMP has a property that it is very difficult to dry, so that a long time is required for the drying process. Therefore, by treating the mixed solution with any one of methanol, ethanol, and IPA, it is possible to replace the hard-to-dry NMP with an easy-to-dry alcohol-based solvent to make it easier to dry.

According to the fifth aspect of the present invention, since the method is an edge removing method for supplying a processing liquid from the back surface of the substrate, it can be carried out in the same apparatus following the coating processing.
Processing can be performed efficiently.

According to the present invention, when the control means controls the rotation support means and supplies the processing liquid from the processing liquid supply means in a state where the rotation of the substrate is slowed, the processing liquid is directed toward the back surface. The processing liquid supplied from below is directed toward the outer periphery by weak centrifugal force and upwards on the back surface of the edge. At this time, since the treatment liquid once wraps around the edge surface of the substrate due to the surface tension, the treatment liquid also wraps around the orifice portion of the semiconductor substrate, and the film can be removed.

[0022]

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 longitudinal sectional view showing a schematic configuration of a substrate coating apparatus for forming a photoresist film on a semiconductor substrate and performing an edge removing method of the substrate film according to the present invention.

In the drawing, reference numeral 1 denotes a vacuum suction type spin chuck corresponding to the rotation support means of the present invention, which suction-supports the semiconductor substrate W in a horizontal posture. The spin chuck 1 is driven to rotate by an electric motor 5 via a hollow rotary shaft 3. Around the spin chuck 1,
A scatter prevention cup 7 for preventing scatter of a photoresist solution for forming a film and a processing solution for removing an edge portion of the film is provided. When transferring the semiconductor substrate W between the substrate transporting means (not shown) and the spin chuck 1, the lifting means (not shown) raises and lowers the rotating shaft 3 and the scattering prevention cup 7 so that the spin chuck 1 is prevented from scattering. It is designed to be moved above the cup 7 (two-dot chain line in the figure). On the side of the scattering prevention cup 7, a nozzle 9 for moving to a supply position near the center of rotation of the semiconductor substrate W and supplying a photoresist liquid is provided.

The above-mentioned scattering prevention cup 7 is composed of the upper cup 1
1, a circular current plate 13, a rinsing butt 15, and a lower cup 17. The upper cup 11 has an opening at an upper portion, and further has an inclined surface for guiding the photoresist liquid scattered around the semiconductor substrate W and the processing liquid for edge rinsing or back rinsing downward. The upper cup 11 is fitted into the upper end paragraph surface of the outer peripheral wall of the lower cup 17.

The circular current plate 13 is fitted into the rinsing butt 15 and is fitted and attached to the lower cup 17 together therewith. In the upper part, the airflow flowing from the opening of the upper cup 11 and flowing down along the peripheral edge of the semiconductor substrate W is rectified and guided to the lower cup 17, and is guided downward by the inclined surface of the upper cup 11. A rectifying surface is formed that guides the droplets of the photoresist liquid and the processing liquid to the lower cup 17 by placing the droplets on the airflow.

The lower cup 17 has a ring-shaped drain zone 17a inscribed in the lower part of the outer peripheral wall, and a drain zone 17a.
And a ring-shaped exhaust zone 17b formed inside. The drainage zone 17a is connected to a drainage tank via a drainage port at the bottom. The bottom of the exhaust zone 17b is connected to an exhaust pump via a cup exhaust port.

The rinsing butt 15 has a rotating shaft 3 in plan view.
The two rinsing nozzles 21 are provided upright at symmetrical positions with respect to the rectifier plate 13, and their tips protrude above the circular rectifying plate 13. The processing liquid is supplied to these rinsing nozzles 21 corresponding to the processing liquid supply means of the present invention from a processing liquid supply source 27 via a pipe joint 23 attached to one part of the rinse vat 15 and a supply pipe 25. . The rinsing nozzle 21 is formed with a discharge port 21a so that the processing liquid can be supplied obliquely upward from below the rotation center side of the semiconductor substrate W toward the rear surface on the circumferential side thereof.
(A)).

The supply pipe 25 is provided with a flow control valve 29 having the functions of an on-off valve and a flow control valve, and a flow sensor 31. These are connected to a control unit 33 corresponding to the control means of the present invention. The opening / closing timing and the opening degree of the flow rate control valve 29 are adjusted according to a processing program described later, and the actual flow rate detected by the flow rate sensor 31 is adjusted. The opening is finely adjusted according to the difference between the flow rate and the flow rate set in the processing program. The memory 35 connected to the control unit 33 stores the above-described processing program and the like in advance. Further, the control unit 33 controls the rotation drive of the electric motor 5 described above, the supply of the photoresist liquid from the nozzle 9, the relative vertical drive between the scattering prevention cup 7 and the spin chuck 1 when the semiconductor substrate W is delivered, and the like. ing.

Next, the operation of the substrate coating apparatus configured as described above will be described with reference to FIG. 2, which is a time chart of a processing program. The semiconductor substrate W has already been suction-held by the spin chuck 1 as shown in FIG. 1, and the nozzle 9 has been moved to a supply position below the position shown in FIG. It is assumed that

[0030] First, the control unit 33, prior to rotating the electric motor 5, in particular between t ₂ time from time point t ₁ (feed time T _SU), a substantially constant flow rate of the photoresist solution from the nozzle 9 And a required amount of photoresist liquid is supplied to the surface of the semiconductor substrate W. The photoresist liquid supplied at this time is in a substantially circular state in plan view at the center of the semiconductor substrate W.

At the same time when the supply of the photoresist solution from the nozzle 9 is completed, the control unit 33 starts the rotation driving of the electric motor 5. The rotation drive, the rotation speed of the semiconductor substrate W at t ₃ time point is performed at an acceleration that reaches R1 (e.g., 500 rpm). Rotary driving by the rotary speed R1 is maintained until t ₄ time. Then, as shown in FIG. 3A, the photoresist liquid R at the center of the semiconductor substrate W spreads toward the edge by centrifugal force, and finally the entire surface of the semiconductor substrate W becomes thick. Cover and
It covers the peripheral edge or wraps around the back of the edge.

[0032] Then, at t ₄ when beginning to rise the rotation speed, the rotation speed of the semiconductor substrate W at t ₅ when the R2 (e.g.,
(3,000 rpm). The rotation speed R2 is maintained until time t _6. As a result, the surplus of the photoresist liquid R covering the semiconductor substrate W is shaken off, the volatilization of the solvent contained in the photoresist liquid R is promoted, and the photoresist liquid R is thinned over the entire surface. A photoresist film F is formed (FIG. 3A). Although not shown in the figure, the photoresist liquid shaken off by the high-speed rotation R2 becomes a mist and adheres to the back surface of the semiconductor substrate W.

[0033] Then, the rotational speed at t ₇ point R3 (e.g., 300 rpm) to start decelerating at t ₆ time to reach. This low speed is maintained until time t _9, after decelerating the rotation number R3, between the control unit 33 from t ₈ time until t ₉ point, while measuring the actual flow at a flow rate sensor 31 which process flow ( For example, the flow control valve 29 is adjusted so as to coincide with 200 cc / min). Thus, the processing liquid from the processing liquid supply source 27 is supplied from the rinse nozzle 21 toward the back surface of the semiconductor substrate W for the supply time _TER . Then, as shown in FIG. 3B, the processing liquid LQ moves toward the edge of the semiconductor substrate W, dissolves and removes the mist of the photoresist liquid adhering to the back surface, and wraps around the surface by surface tension to remove the photo. The edge portion of the resist film F is scattered around while dissolving and removing it.

Since the rotation speed R3 is low, the centrifugal force is weak and the processing liquid LQ easily enters the rotation center, so that the diameter of the spin chuck 1 is smaller than that of the conventional spin chuck. Is preferred. Specifically, in the case of the above-described apparatus for a 6-inch diameter, the diameter of the spin chuck 1 is φ
It is as small as 54 mm. As a result, it is possible to prevent the occurrence of suction failure and transport failure.

The rotation speed R3 is 100 to 500 rpm.
Is preferable. If the rotation speed R3 is lower than 100 rpm, the processing liquid is too weak to reach the edge portion due to too weak centrifugal force, and the amount of wraparound to the surface of the edge portion is small. On the other hand, if the rotation speed R3 exceeds 500 rpm, the centrifugal force is too strong and the amount of wraparound to the edge surface is also reduced.

[0036] In t ₉ time, the flow regulating valve 29 is increased to R2 speed again while being closed, by maintaining the rotation number R2 to the t ₁₁ time, the drying process is performed. Finally, as shown in FIG. 3C, the photoresist film F is removed from the edge with the removal width D. The removal width D can be adjusted by the rotation speed R3 and the set flow rate of the processing liquid.

As described above, since the processing liquid is supplied from the back surface of the semiconductor substrate W and is wrapped around the semiconductor substrate W to remove the edge of the photoresist film F, as shown in FIG. In the orientation flat portion of the substrate W, the processing liquid similarly flows around and the photoresist film F can be removed. Therefore, even in a simple process, the photoresist film F on the orientation flat portion of the semiconductor substrate W is formed.
Can be removed. Moreover, the removal width D 'can be made substantially the same as the removal width D because the amount of the processing liquid flowing around is almost the same in any part.

The following are examples of the processing solution for the "photoresist film F" described above.

That is, generally, a solvent having the same component as the solvent contained in the photoresist film F can be used as the processing liquid. Specifically, there are methanol, ethanol, IPA (isopropyl alcohol) and the like, and any one of these is used as a processing liquid. As a result of actually processing a 6-inch diameter semiconductor substrate using methanol as a processing liquid under the above-described conditions, the removal width D = 5 mm
(The removal width D 'of the orientation flat portion is also substantially the same).

However, at the removed end F _BD (see FIG. 4), a phenomenon occurred greatly from the surface (film thickness = 0) of the semiconductor substrate W as shown in the film thickness distribution of FIG. This is because the penetration of the processing solution into the photoresist coating is too strong. However, in the case of a photoresist film, there is little problem as compared with a film made of a silica-based film-forming material or a ferroelectric material which generates particles when peeled during a high-temperature process.

In addition, PEGMIA (propylene glycol monomethyl ether acetate), EEP
(Ethyl-3-ethosine propionate), GBR
(Γ-butyl lactone), NBA (n-butyl acetate) and the like or a mixture thereof can be used.

When the coating film is not the photoresist film F but a “ferroelectric thin film” formed of lead zirconate titanate Pb (Zr, Ti) O ₃ , It is suitable as.

NMP (N-methyl-2-pyrrolidone) NMP used as a solvent for polyimide resin and the like
When is used as a processing liquid, it is possible to prevent a problem caused when an alcohol-based solvent is used as a processing liquid for the photoresist film described above. Indeed, the film thickness distribution of the removal end F _BD at the orientation flat portion of the processed semiconductor substrate is as shown in FIG. 6, it can be seen that not at all occur swelling caused by the alcohol-based solvent. However, because NMP has a high viscosity, it is difficult for the NMP to move from the back surface to the front surface, and conditions must be adjusted to increase the removal width D.

A solution of a mixture of NMP and a solvent is to solve the above-mentioned inconvenience that occurs in the processing solution of the solvent and the NMP. In fact, methanol
When treated semiconductor substrate in a mixed solution of MP, the film thickness distribution of the removal end F _BD in orientation flat portion is as shown in FIG. 7, it can be seen that not at all occur protrusion of the coating. In other words, the treatment liquid can easily flow from the back surface to the front surface of the semiconductor substrate by such a mixed solution, and furthermore, the occurrence of swelling at the removed end can be prevented, and the removed end can be finely finished.

When the solvent and NMP are mixed in this way, the removal width and the state of the removal edge can be controlled by adjusting the mixing ratio.

Further, the coating film is a photoresist film F
Instead, when the coating is a “silica-based coating (SOG)”, cyclohexanone, GBR (γ-butyl lactone), ethyl lactate, ethyl pyruvate, or a mixture thereof is suitable as the treatment liquid.

While the above-mentioned NMP has the above-mentioned advantages, it is very difficult to dry. Doing edges removed with a processing solution containing Accordingly NMP, it becomes the subsequent drying process can take a long time (t ₉ ~t ₁₂ point in FIG. 2). Therefore, as shown in FIG.
And a second rinsing nozzle 24. Then, first, a mixed solution of ethanol and NMP is supplied as a processing liquid from the first rinse nozzle 22 to remove the edge of the photoresist film, and then the number of revolutions is slightly increased (for example, 1,500 rpm). Then, ethanol is supplied from the second rinse nozzle 24 as a processing liquid. This makes it possible to replace the hard-to-dry NMP adhering to the back surface with the quick-drying ethanol, thereby shortening the time required for the subsequent drying process.

The rinsing nozzle 21 and the first rinsing nozzle 22, which are processing liquid supply means, are configured to be able to supply the processing liquid obliquely upward toward the back surface of the semiconductor substrate W. This is for making it easy to go around the edge of the surface of W, and when the removal width is small, a structure for supplying the processing liquid directly above may be adopted.

In the above-described embodiment, the edge of the photoresist solution was removed following the application of the photoresist solution in the same apparatus. After being transported to the edge removing device, the edge may be removed using the above-described method.

In the above description, the semiconductor substrate having a substantially circular shape has been described as an example. However, the processing liquid can be substantially uniformly wrapped around the entire periphery of the substrate to remove the coating on the edge. Therefore, even on a rectangular substrate such as a glass substrate of a liquid crystal display, it is possible to remove the coating on the edge surface without causing unevenness at the four corners.

[0051]

As is apparent from the above description, according to the first aspect of the present invention, the processing liquid which is directed upward from the back surface to the edge at the edge is once applied to the edge surface of the substrate by surface tension. Since the treatment liquid is wrapped around, the processing liquid also wraps around the orientation flat portion of the semiconductor substrate, and the coating film can be removed. Therefore, even in a simple process, the film on the orientation flat portion can be removed from the semiconductor substrate, and the removal width can be made substantially constant since the amount of the processing liquid flowing around is almost the same in every portion. As a result, the number of chips that can be formed on a semiconductor substrate can be increased as compared with the related art.

In addition, since the processing solution is circulated almost uniformly over the entire periphery of the substrate to remove the coating on the edge, even if the glass substrate of the liquid crystal display is used, the surface of the edge is not uneven at the four corners. Can be removed.

According to the second aspect of the present invention, by using any one of methanol, ethanol, and IPA as the processing liquid, the processing liquid can easily flow to the edge surface of the substrate. The coating on the edge surface can be removed stably.

According to the third aspect of the present invention, a mixed solution obtained by mixing NMP with an alcoholic solvent is used as a processing liquid, so that the processing liquid easily wraps around the edge surface. It is possible to stably remove the coating on the surface and to prevent swelling of the removed end of the coating. Therefore, the removed end portion of the coating film can be finely finished.

According to the fourth aspect of the present invention, by treating the mixed solution containing NMP with any one of methanol, ethanol and IPA after the mixed solution containing NMP, NMP which is difficult to dry can be removed with an alcohol solvent which is easy to dry. It can be replaced to make it easier to dry. Therefore, the swelling of the film can be prevented and the throughput can be improved.

According to the fifth aspect of the present invention, the coating can be performed in the same apparatus after the coating, and the edge of the substrate film can be efficiently removed.

Further, according to the apparatus invention described in claim 6, the method invention described in claim 1 can be suitably implemented.

[Brief description of the drawings]

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

FIG. 2 is a time chart illustrating an example of a processing program.

FIG. 3 is a schematic diagram illustrating a process of removing an edge portion of a photoresist film.

FIG. 4 is a diagram for explaining a state where an edge portion of a photoresist film is removed.

FIG. 5 is a graph showing a film thickness distribution at a removed end when methanol is used as a processing liquid.

FIG. 6 is a graph showing a film thickness distribution at a removed end when NMP is used as a processing liquid.

FIG. 7 is a graph showing a film thickness distribution at a removed end when a mixed solution of NMP and methanol is used as a processing solution.

FIG. 8 is a longitudinal sectional view of a main part showing a modification.

[Explanation of symbols]

W ... Semiconductor substrate 1 ... Spin chuck (rotation support means) 3 ... Rotating shaft 5 ... Electric motor 7 ... Splash prevention cup 15 ... Rinse butt 21 ... Rinse nozzle (treatment liquid supply means) 21a ... Discharge port 29 ... Flow control valve 31 ... flow sensor 33 ... controller (control means) R ... photoresist liquid F ... photoresist film D ... removed width D '... removed width F _BD ... removal end of the orientation flat portion

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H096 AA25 CA14 FA10 LA13 4J038 RA02 RA04 RA16 5F046 JA02 JA06 JA09 JA13 JA15

Claims (6)

[Claims] In a method of removing an edge of a substrate coating from among coatings formed on a surface of the substrate, the coating on the edge of the substrate is removed. A method for removing an edge from a substrate film, comprising: supplying a processing liquid from below to a back surface; and allowing the processing liquid to flow around the edge of the substrate. 2. The substrate edge removing method according to claim 1, wherein any one of methanol, ethanol, and IPA (isopropyl alcohol) is used as the treatment liquid. Method for removing the edge of the coating. 3. The method according to claim 1, wherein one of methanol, ethanol, and IPA (isopropyl alcohol) and NMP (N-methyl-2-pyrrolidone) are used as the treatment liquid. A method for removing an edge portion of a substrate film, wherein a mixed solution is used. 4. The method for removing an edge portion of a substrate film according to claim 1, wherein any one of methanol, ethanol, and IPA (isopropyl alcohol) and NMP (N-methyl-2-pyrrolidone) are used as the treatment liquid. A method for removing an edge from a substrate film, wherein the method is performed by using one of methanol, ethanol, and IPA (isopropyl alcohol) as a processing liquid after processing using the mixed solution. 5. The method according to claim 1, wherein said processing is performed subsequent to a coating process for forming a coating film on the surface of the substrate. To remove the edge of the substrate coating. 6. An apparatus for removing an edge portion of a substrate coating from a coating film formed on a surface of the substrate, the rotation supporting means for rotatably supporting the substrate, A processing liquid supply means for supplying a processing liquid from below the substrate toward the rear surface, and an end of the substrate which supplies the processing liquid from the processing liquid supply means while the rotation of the substrate is reduced by the rotation support means. Control means for controlling the processing liquid to flow around the edge surface; and a device for removing the edge of the substrate film.