Substrate processing method and substrate processing device

Abstract

To provide a substrate processing method and a substrate processing device, capable of forming a coating film having a uniform and small width.SOLUTION: A coating nozzle 30 that discharges a coating liquid is moved to above a notch 90 which is a cutout portion of a substrate W that is held in a stationary state. While discharging the coating liquid from the coating nozzle 30, the substrate W is rotated only once in a horizontal plane to form a coating film 80 on the upper surface at the peripheral portion of the substrate W. When the coating nozzle 30 is again positioned above the notch 90, the coating nozzle 30 retreats. Since the application of the coating liquid is started from the notch 90 of the substrate W and ended at the notch 90, the coating liquid is applied to the peripheral portion of the substrate W only once, and the coating film 80 with a small width can be formed. Moreover, the coating liquid is not applied again over the notch 90, and the coating film 80 with a uniform width can be formed.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The present invention relates to a substrate processing method and a substrate processing apparatus for forming a coating film on the peripheral edge of a disk-shaped substrate having a cutout such as a notch. Substrates to be processed include, for example, semiconductor wafers, substrates for liquid crystal display devices, substrates for flat panel displays (FPDs), substrates for optical disks, substrates for magnetic disks, and substrates for solar cells. [Background technology]

[0002] In photolithography, an important technique for forming patterns in the manufacturing process of semiconductor devices, a resist film is formed on a substrate such as a semiconductor wafer, and the resist film is exposed to a pattern and then developed. If a transfer arm or a positioning unit comes into contact with the edge of a substrate on which a resist film has been formed over the entire surface in each process, the resist film may be damaged and generate dust, which may contaminate the transfer arm. For this reason, a solvent is supplied to the peripheral portion of the substrate to remove the resist film from the peripheral portion. As a result, the silicon base material is exposed at the peripheral portion of the substrate.

[0003] When a DRIE (Deep Reactive Ion Etching) process is performed using a resist film on which a pattern has been formed as a mask, damage occurs to the peripheral portion of the substrate where the base material is exposed. This causes a decrease in strength of the peripheral portion of the substrate, and may also generate particles. For this reason, Patent Documents 1 and 2 disclose a technique for forming a protective film to prevent the peripheral portion of the substrate from being etched. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 7-130703 [Patent Document 2] JP 2002-334879 A Summary of the Invention [Problem to be solved by the invention]

[0005] To form a protective film on the peripheral edge of a substrate, a coating liquid is typically supplied from a nozzle onto the upper surface of the peripheral edge of the rotating substrate, and then the coating liquid is dried to form a coating film. It is desirable for the width of the coating film to be as uniform and narrow as possible around the entire peripheral edge of the substrate.

[0006] However, when the nozzle for discharging the coating liquid is moved to a predetermined position above the periphery of the rotating substrate and the substrate is rotated once, the width of the coating film gradually widens from the start of coating, and it is difficult to obtain a uniform width. For this reason, it is necessary to adjust the width of the coating film to be uniform by rotating the substrate multiple times while holding the nozzle at the above-mentioned predetermined position. However, in this case, the coating liquid is repeatedly applied to the periphery of the substrate over multiple revolutions, and the amount of the coating liquid supplied to the substrate increases, and as a result, the width of the coating film also becomes correspondingly wider. Although it is possible to narrow the width of the coating film by holding the nozzle as close to the edge of the substrate as possible, the force of the coating liquid spreading toward the center of the substrate due to surface tension is strong, and it is difficult to narrow the width of the coating film below a certain value.

[0007] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a substrate processing method and a substrate processing apparatus capable of forming a coating film that is uniform and has a narrow width. [Means for solving the problem]

[0008] In order to solve the above problems, a first aspect of the present invention is a substrate processing method for forming a coating film on a peripheral portion of a disk-shaped substrate having a cutout portion, the method comprising: a nozzle advancing step of moving a nozzle that ejects coating liquid for forming the coating film to a discharge position where a liquid flow of the coating liquid ejected from the nozzle passes through the cutout portion of the substrate held in a horizontal position; and a substrate rotation step of rotating the substrate once in a horizontal plane around a central axis of the substrate while ejecting the coating liquid from the nozzle at the discharge position, thereby starting application of the coating liquid from the cutout portion and finishing application of the coating liquid at the cutout portion.

[0009] In addition, a second aspect is a substrate processing method according to the first aspect, further comprising a nozzle retraction step of moving the nozzle after the substrate rotation step to a position where the flow of the coating liquid ejected from the nozzle passes outside the substrate.

[0010] In a third aspect, in the substrate processing method according to the second aspect, the nozzle advancing step and the nozzle retracting step are performed in a state in which rotation of the substrate is stopped.

[0011] In a fourth aspect, in the substrate processing method according to the second aspect, the nozzle advancing step and the nozzle retracting step are performed in a state in which the substrate is rotated.

[0012] In addition, according to a fifth aspect, in the substrate processing method according to any one of the first to fourth aspects, the nozzle starts discharging the coating liquid before the nozzle reaches the discharging position.

[0013] In addition, a sixth aspect is a substrate processing apparatus for forming a coating film on a peripheral portion of a disk-shaped substrate having a cutout portion, the apparatus comprising: a rotating holding unit for rotating the substrate around a central axis of the substrate while holding the substrate in a horizontal position; a nozzle for ejecting a coating liquid for forming the coating film; a nozzle drive unit for moving the nozzle between above the substrate and outside the substrate; and a control unit for controlling the rotating holding unit and the nozzle drive unit, wherein the control unit controls the nozzle drive unit to move the nozzle to a discharge position where a flow of the coating liquid ejected from the nozzle passes through the cutout portion of the substrate held by the rotating holding unit, and the control unit controls the rotating holding unit to eject the coating liquid from the nozzle at the discharge position while rotating the substrate once in a horizontal plane around the central axis of the substrate, thereby starting application of the coating liquid from the cutout portion and ending application of the coating liquid at the cutout portion.

[0014] In addition, a seventh aspect is a substrate processing apparatus according to the sixth aspect, wherein the control unit controls the nozzle drive unit to move the nozzle to a position where the flow of the coating liquid ejected from the nozzle passes outside the substrate after the coating liquid is applied.

[0015] In an eighth aspect, in the substrate processing apparatus according to the seventh aspect, the control unit controls the nozzle drive unit to move the nozzle to the discharge position while the rotation of the substrate is stopped, and to move the nozzle from the discharge position.

[0016] In addition, a ninth aspect is a substrate processing apparatus according to the seventh aspect, wherein the control unit moves the nozzle to the discharge position while the substrate is rotating, and controls the nozzle drive unit to move the nozzle from the discharge position.

[0017] In addition, according to a tenth aspect, in the substrate processing apparatus according to any one of the sixth to ninth aspects, the nozzle starts discharging the coating liquid before reaching the discharging position. Effect of the Invention

[0018] According to the substrate processing methods of the first to fifth aspects, while the coating liquid is being discharged from the nozzle at the discharge position, the substrate is rotated once in a horizontal plane around the central axis of the substrate, so that the application of the coating liquid starts from the cutout portion of the substrate and ends at the cutout portion. Therefore, the coating liquid is applied only once without overlapping, and a coating film with a uniform and narrow width can be formed.

[0019] In particular, according to the substrate processing method of the fifth aspect, the ejection of the coating liquid from the nozzle begins before the nozzle reaches the ejection position, so that the coating can be started in a state where the ejection of the coating liquid is stable, and a more uniform coating film can be formed.

[0020] According to the substrate processing apparatus of the sixth to tenth aspects, while the coating liquid is ejected from the nozzle at the ejection position, the substrate is rotated once in a horizontal plane around the central axis of the substrate, so that the application of the coating liquid starts from the cutout portion of the substrate and ends at the cutout portion. Therefore, the coating liquid is applied only once without overlapping, and a coating film with a uniform and narrow width can be formed.

[0021] In particular, according to the substrate processing apparatus of the tenth aspect, the ejection of the coating liquid begins before the nozzle reaches the ejection position, so that the coating can be started in a stable state of ejection of the coating liquid, and a more uniform coating film can be formed. [Brief description of the drawings]

[0022] [Figure 1] 1 is a diagram showing a schematic configuration of a substrate processing apparatus according to the present invention; [Diagram 2] 4 is a flowchart showing a procedure of a processing operation in the substrate processing apparatus. [Diagram 3] 1 is a plan view of a substrate to be processed in a substrate processing apparatus; [Figure 4] FIG. 13 is a plan view showing a state in which the application nozzle moves onto a notch in the substrate. [Diagram 5]FIG. 2 is a plan view showing the formation of a coating film on a substrate. [Figure 6] FIG. 2 is a side view showing the formation of a coating film. [Figure 7] 13 is a plan view showing a state in which the application nozzle is retracted from above the notch of the substrate. FIG. [Figure 8] FIG. 2 is a diagram illustrating the drying of a coating film. [Figure 9] 1A and 1B are diagrams illustrating cleaning of the rear surface of a substrate. [Figure 10] 13 is a diagram showing a trajectory of relative movement of a coating nozzle with respect to a substrate in a second embodiment. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] Hereinafter, the embodiments of the present invention will be described in detail with reference to the drawings. In the following, expressions indicating relative or absolute positional relationships (e.g., "in one direction," "along one direction," "parallel," "orthogonal," "center," "concentric," "coaxial," etc.) not only strictly indicate the positional relationship, but also indicate a state in which the relative angle or distance is displaced within a range in which a tolerance or similar function is obtained, unless otherwise specified. Furthermore, expressions indicating an equal state (e.g., "same," "equal," "homogeneous," etc.) not only indicate a state in which the relative position is strictly equal quantitatively, but also indicate a state in which there is a difference in which a tolerance or similar function is obtained, unless otherwise specified. Furthermore, expressions indicating a shape (e.g., "circular," "square," "cylindrical," etc.) not only indicate a geometrically strict shape, but also indicate a shape within a range in which a similar effect is obtained, and may have, for example, unevenness or chamfering. Furthermore, each expression such as "comprises," "includes," "has," "includes," and "has" for a component is not an exclusive expression that excludes the presence of other components. In addition, the expression "at least one of A, B, and C" includes "A only," "B only," "C only," "any two of A, B, and C," and "all of A, B, and C."

[0024] First Embodiment Fig. 1 is a diagram showing a schematic configuration of a substrate processing apparatus 1 according to the present invention. The substrate processing apparatus 1 in Fig. 1 is a coating apparatus (spin coater) that rotates a disk-shaped substrate W and supplies a predetermined coating liquid to the peripheral edge of the substrate W to form a coating film. The substrate W to be processed is, for example, a silicon semiconductor wafer. The size of the semiconductor wafer is not particularly limited, but is, for example, φ300 mm or φ450 mm (φ300 mm in this embodiment).

[0025] The substrate processing apparatus 1 includes, as its main components, a spin holder 10 and a coating nozzle 30. The substrate processing apparatus 1 also includes a control unit 50 that controls various operating mechanisms provided inside the apparatus to cause the processing of the substrate W to proceed.

[0026] The spin holder 10 includes a spin chuck 11 and a spin motor 12. The spin chuck 11 is a substrate holder that holds the substrate W in a horizontal position (a position in which the normal to the main surface of the substrate W is aligned vertically). The spin chuck 11 is, for example, a vacuum suction type chuck. The spin chuck 11 has a disk shape with a diameter smaller than the diameter of the substrate W. The spin chuck 11 suction-holds the center of the lower surface of the substrate W. When the lower surface of the substrate W is suction-held by the spin chuck 11, the peripheral edge of the substrate W protrudes outward beyond the outer circumferential end of the spin chuck 11. The spin chuck 11 may be another type of chuck, such as a clamping type mechanical chuck.

[0027] The spin chuck 11 is connected to the spin motor 12 via a motor shaft. That is, an upper end of the motor shaft of the spin motor 12 is connected to the center of the lower surface of the spin chuck 11. When the spin motor 12 rotates the motor shaft while the substrate W is attracted and held by the spin chuck 11, the substrate W and the spin chuck 11 rotate in a horizontal plane around the central axis X of the substrate W aligned in the vertical direction.

[0028] A cup 40 is provided so as to surround the periphery of the spin chuck 11. The cup 40 can be raised and lowered by a lifting mechanism (not shown). The cup 40 has a cylindrical shape, and the upper part of the cup 40 is inclined so as to approach the spin chuck 11 as it goes upward. However, the inner diameter of the upper end part of the cup 40 is larger than the diameter of the substrate W. When the substrate W is processed, the upper end of the cup 40 is higher than the height position of the substrate W held by the spin chuck 11. Therefore, liquid scattered by centrifugal force from the substrate W rotated by the spin motor 12 is received and collected by the cup 40. The liquid collected by the cup 40 is discharged from a drainage pipe provided at the bottom of the cup 40. The cup 40 may have a multi-stage structure in which a plurality of collection ports are provided for different purposes.

[0029] The coating nozzle 30 discharges a coating liquid onto the substrate W held by the spin chuck 11. In this embodiment, the coating nozzle 30 discharges the coating liquid vertically downward. The coating nozzle 30 is connected to a coating liquid supply unit 31 via a pipe. The coating liquid supply unit 31 delivers the coating liquid to the coating nozzle 30. The coating liquid in this embodiment is a processing liquid that forms a coating film that functions as a protective film having resistance to etching processes such as DRIE by drying, and for example, a liquid for forming a photoresist or an underlayer film is used. Examples of the liquid for forming the underlayer film include SOG liquid (Spin-on-Glass) containing a silicon-containing polymer and SOC liquid (Spin-on-Carbon) containing a carbon-containing polymer.

[0030] The coating nozzle 30 can be moved between above the substrate W held by the spin chuck 11 and outside the substrate W (inside the cup 40) by a nozzle drive mechanism 32 conceptually shown in FIG. 1. The nozzle drive mechanism 32 can also move the coating nozzle 30 to a standby position outside the cup 40. The nozzle drive mechanism 32 can also reciprocate the coating nozzle 30 between above the center and above the peripheral edge of the substrate W held by the spin chuck 11. The nozzle drive mechanism 32 may be a mechanism that moves the coating nozzle 30 along an arc-shaped trajectory (a mechanism that rotates a nozzle arm), or a mechanism that moves the coating nozzle 30 linearly along the radial direction of the substrate W (a linear drive mechanism).

[0031] An encoder 33 is attached to the nozzle drive mechanism 32. The encoder 33 detects the position of the coating nozzle 30 moved by the nozzle drive mechanism 32. Note that a rotary encoder is used as the encoder 33 when the nozzle drive mechanism 32 is a mechanism that rotates the coating nozzle 30, and a linear encoder is used when the nozzle drive mechanism 32 is a linear drive mechanism.

[0032] The substrate processing apparatus 1 also includes a notch detection mechanism 20. The notch detection mechanism 20 is provided above or below the peripheral portion of the substrate W held by the spin chuck 11. The notch detection mechanism 20 detects a notch formed in the substrate W by, for example, emitting a laser beam and detecting the reflected light.

[0033] The substrate processing apparatus 1 further includes a back-rinse nozzle 60. The back-rinse nozzle 60 is fixedly installed below the substrate W held by the spin chuck 11. The back-rinse nozzle 60 is provided at an incline such that the discharge direction is obliquely upward from the center side to the edge side of the substrate W. The back-rinse nozzle 60 discharges, as a rinsing liquid, a liquid containing, for example, PGMEA (propylene glycol monomethyl ether acetate) or PGME (propylene glycol monomethyl ether), or cyclohexane.

[0034] The control unit 50 controls various operating mechanisms provided in the substrate processing apparatus 1. The hardware configuration of the control unit 50 is similar to that of a general computer. That is, the control unit 50 includes a CPU, which is a circuit that performs various arithmetic processing, a ROM, which is a read-only memory that stores basic programs, a RAM, which is a readable and writable memory that stores various information, and a storage unit (magnetic disk or SSD) that stores control software, data, and the like. The CPU of the control unit 50 executes a predetermined processing program to control the operation of the spin holder 10 and the coating nozzle 30, whereby the processing of the substrate W in the substrate processing apparatus 1 proceeds.

[0035] Next, the processing operation in the substrate processing apparatus 1 will be described. FIG. 2 is a flow chart showing the procedure of the processing operation in the substrate processing apparatus 1. FIG. 3 is a plan view of a substrate W to be processed in the substrate processing apparatus 1. The substrate W is a substantially disk-shaped silicon semiconductor wafer. In this embodiment, the diameter of the substrate W is φ300 mm. As shown in FIG. 3, a notch 90, which is a V-shaped groove for indicating a crystal orientation, is engraved in the substrate W. The notch 90 is a cutout portion provided in the substrate W. Note that the size of the notch 90 is exaggerated in FIG. 3 for ease of understanding, but the depth of the notch 90 (the distance from the outer peripheral edge of the substrate W to the V-shaped tip of the notch 90) is about 1.5 mm while the diameter of the substrate W is 300 mm.

[0036] Prior to being carried into the substrate processing apparatus 1, a resist film is formed on the substrate W by a coating and developing apparatus (coater developer) provided separately from the substrate processing apparatus 1, and the resist film after the pattern exposure is subjected to a developing process to form a pattern. In addition, in order to prevent dust generation due to contact between the edge of the substrate W on which the resist film is formed and the transport arm or the positioning unit, the resist film is removed from the peripheral portion of the substrate W immediately after the resist film is formed. Therefore, the silicon base material is exposed at the peripheral portion of the substrate W. The peripheral portion of the substrate W is the region outside (on the edge side) of the region where the pattern is formed, and more specifically, the region 3 mm or less from the edge of the substrate W toward the center. Therefore, the notch 90 is provided at the peripheral portion of the substrate W and does not affect the region where the pattern is formed.

[0037] The substrate W, on which a pattern has been formed and from which the resist film has been removed from its peripheral portion, is carried into the substrate processing apparatus 1 by a transfer robot (not shown) and held by the spin holder 10 (step S1). The spin chuck 11 of the spin holder 10 adsorbs the central portion of the lower surface of the substrate W and holds the substrate W in a horizontal position.

[0038] Next, the spin holder 10 rotates the substrate W by a certain angle less than 360° to adjust the orientation of the substrate W (step S2). Specifically, the position where the trajectory of the coating nozzle 30 moved by the nozzle driving mechanism 32 and the edge of the substrate W intersect as viewed from above is obtained in advance and stored, for example, in a memory unit of the control unit 50. Based on the detection result of the notch detection mechanism 20, the control unit 50 controls the spin holder 10 to rotate the substrate W so that the notch 90 moves to the intersecting position, thereby adjusting the orientation of the substrate W. In the first embodiment, when the notch 90 reaches the intersecting position and the adjustment of the orientation of the substrate W is completed, the spin holder 10 stops the rotation of the substrate W and holds the substrate W in a stationary state.

[0039] Next, the coating nozzle 30 starts discharging the coating liquid (step S3). The coating nozzle 30 starts discharging the coating liquid while stopped at an initial position inside the cup 40 and outside the substrate W held by the spin chuck 11. The coating nozzle 30 discharges a liquid for forming a photoresist or an underlayer film as the coating liquid. The coating nozzle 30 also discharges the coating liquid at a constant flow rate vertically downward. At this time, since the coating nozzle 30 is waiting at the initial position outside the substrate W, the coating liquid discharged from the coating nozzle 30 is collected by the cup 40 without landing on the substrate W.

[0040] After the discharge state of the coating liquid from the coating nozzle 30 becomes stable, the coating nozzle 30 moves above the notch 90 of the substrate W held in a stationary state by the spin chuck 11 (step S4). FIG. 4 is a plan view showing the state in which the coating nozzle 30 moves above the notch 90 of the substrate W. The coating nozzle 30, which discharges the coating liquid downward, is moved by the nozzle driving mechanism 32 from an initial position outside the substrate W to a discharge position above the notch 90 of the substrate W. More specifically, for example, the coordinates of the discharge position are stored in advance in the storage unit of the control unit 50, and the control unit 50 controls the nozzle driving mechanism 32 so that the coating nozzle 30 moves to the discharge position based on the detection result of the encoder 33. The coating nozzle 30 stops at the discharge position. At this time, the rotation of the substrate W is stopped, and the coating liquid discharged vertically downward from the coating nozzle 30 that has moved to the discharge position passes through the notch 90 and falls into the cup 40. Strictly speaking, the discharge position is the position of the coating nozzle 30 where the flow of the coating liquid discharged from the coating nozzle 30 passes through the notch 90 of the substrate W whose direction has been adjusted in step S2, and is a position that is a predetermined distance away from the edge of the substrate W toward the center.

[0041] After the coating nozzle 30 that discharges the coating liquid stops at the discharge position, the rotation of the substrate W held in a horizontal position by the spin holder 10 begins. The spin motor 12 of the spin holder 10 rotates the substrate W in a horizontal plane around the central axis X of the substrate W. In the first embodiment, the spin holder 10 rotates the substrate W one rotation (360°) in the horizontal plane (step S5).

[0042] While discharging the coating liquid vertically downward from the coating nozzle 30 stopped at the discharging position, the substrate W is rotated in a horizontal plane around the central axis X, whereby the coating liquid is supplied to the peripheral portion of the substrate W, forming a coating film. FIG. 5 is a plan view showing the formation of a coating film on the substrate W. FIG. 6 is a side view showing the formation of a coating film. When the substrate W starts to rotate from the state shown in FIG. 4 while discharging the coating liquid from the coating nozzle 30 at the discharging position, the coating of the coating liquid on the peripheral portion of the substrate W is started starting from the notch 90 as shown in FIG. The coating liquid that has landed on the peripheral portion of the substrate W flows so as to spread toward the edge portion of the substrate W due to the centrifugal force caused by the rotation of the substrate W, and a part of the coating liquid flows around from the edge portion of the substrate W to the peripheral portion of the lower surface. In addition, a part of the coating liquid that has landed on the peripheral portion of the substrate W also spreads toward the center side of the substrate W due to surface tension. As a result, on the upper surface of the peripheral edge of the substrate W, the coating liquid is applied to an area of ​​a certain width from the edge, so that a coating film 80 is formed in a circular ring shape.

[0043] When the substrate W rotates once in the horizontal plane, the coating nozzle 30 is again positioned above the notch 90. At this point, the rotary holder 10 stops the rotation of the substrate W. This ends the application of the coating liquid to the peripheral portion of the substrate W, with the notch 90 as the end point, and a coating film 80 of a constant width is formed on the upper surface of the peripheral portion of the substrate W, excluding the location of the notch 90. Furthermore, the coating liquid discharged from the coating nozzle 30 that has returned to above the notch 90 passes through the notch 90 and falls into the cup 40, just as before coating.

[0044] Next, the coating nozzle 30 moves from the discharge position to the initial position. That is, the coating nozzle 30 retreats from above the notch 90 of the substrate W, whose rotation has been stopped (step S6). FIG. 7 is a plan view showing the state in which the coating nozzle 30 retreats from above the notch 90 of the substrate W. The coating nozzle 30 is returned from above the notch 90 of the substrate W to an initial position outside the substrate W by the nozzle drive mechanism 32. The initial position is a position where the coating liquid discharged from the coating nozzle 30 passes outside the substrate W. The coating nozzle 30 stops at the initial position. Note that even when the coating nozzle 30 retreats from above the notch 90 of the substrate W, the coating liquid continues to be discharged from the coating nozzle 30, and the coating liquid is collected by the cup 40.

[0045] After the coating nozzle 30 returns to the initial position, the discharge of the coating liquid is stopped (step S7). Next, the coating film 80 formed on the peripheral portion of the substrate W is dried (step S8). FIG. 8 is a diagram showing a schematic diagram of drying of the coating film 80. Specifically, the control unit 50 controls the operation of the spin motor 12 so that the rotation speed of the substrate W becomes significantly high. The high speed rotation of the substrate W executes so-called spin drying, and the coating film 80 is dried. As a result, a circular coating film 80 having a constant width d1 is formed on the upper surface of the peripheral portion of the substrate W.

[0046] After the drying process, the back surface of the substrate W is cleaned (step S9). FIG. 9 is a diagram showing the back surface cleaning of the substrate W. When the coating liquid is supplied to the peripheral portion of the rotating substrate W in step S5, a part of the coating liquid flows from the edge portion of the substrate W to the peripheral portion of the lower surface. The coating liquid that flows to the lower surface of the substrate W is dried in the drying process of step S8 and adheres to the lower surface as a coating film. In step S9, such a coating film adhered to the lower surface of the substrate W is washed away. Specifically, while rotating the substrate W, a rinsing liquid is discharged from the back rinse nozzle 60 onto the lower surface of the substrate W. The rinsing liquid supplied to the lower surface of the substrate W flows along the lower surface of the substrate W toward the edge portion due to centrifugal force. This flow of the rinsing liquid washes away and removes the coating film adhered to the lower surface of the substrate W.

[0047] Thereafter, the substrate W on which the coating film 80 has been formed is carried out from the substrate processing apparatus 1 by a transfer robot (not shown) (step S10). The substrate W carried out from the substrate processing apparatus 1 is subjected to a post-process, such as a DRIE process. In the DRIE process, the upper surface of the peripheral portion of the substrate W is protected by the coating film 80.

[0048] In the first embodiment, the coating nozzle 30 that discharges the coating liquid is moved above the notch 90 of the substrate W held in a stationary state, and the substrate W is rotated only once in a horizontal plane to form a coating film 80 on the upper surface of the peripheral portion of the substrate W. That is, the application of the coating liquid is started from the notch 90 of the substrate W and ends at the notch 90. As a result, the coating liquid is applied only once to the upper surface of the peripheral portion of the substrate W in a single stroke (single coating). Since the substrate W is rotated only once to apply the coating liquid to the peripheral portion only once, the amount of coating liquid supplied is kept to a minimum, and the coating liquid that has landed on the substrate is prevented from spreading in the radial direction of the substrate W, so that a coating film 80 with a narrow width can be formed. Furthermore, if the amount of coating liquid supplied to the substrate W is small, partial swelling of the coating film 80, which is a peculiar phenomenon that occurs when coating the peripheral portion, can also be prevented.

[0049] Furthermore, in the first embodiment, the coating nozzle 30 starts discharging the coating liquid before it reaches the discharge position, and the coating liquid is applied to the peripheral portion of the substrate W in a stable state of discharge. That is, the coating liquid is supplied at a constant flow rate to the peripheral portion of the substrate W rotating at a constant speed, and a coating film 80 of a uniform width can be formed.

[0050] However, even if the substrate W is rotated at a constant speed and the coating liquid is ejected from the coating nozzle 30 at a constant flow rate, if the application of the coating liquid is started from a location other than the notch 90 and then ended at that location, some of the coating liquid will be reapplied at that location, which will hinder the formation of a uniform coating film 80.

[0051] In the first embodiment, application of the coating liquid starts from the notch 90 of the substrate W and ends at the notch 90. At the start and end of application, the coating liquid discharged from the coating nozzle 30 passes through the notch 90 and is collected in the cup 40. Therefore, the coating liquid is not applied over at the notch 90, and it is possible to form a coating film 80 of a more uniform width. That is, by following the first embodiment, a coating film 80 of a uniform and narrow width can be formed.

[0052] <Second embodiment> Next, a second embodiment of the present invention will be described. The configuration of the substrate processing apparatus of the second embodiment is the same as that of the first embodiment (FIG. 1). In the first embodiment, the coating nozzle 30 is advanced and retreated relative to the stationary substrate W, whereas in the second embodiment, the coating nozzle 30 is moved relative to the rotating substrate W.

[0053] In the second embodiment, the substrate W to be processed is a disk-shaped silicon semiconductor wafer having a notch 90 formed therein (FIG. 3). A pattern is formed on the substrate W by photolithography, and the resist film is removed from the peripheral portion of the substrate W to expose the silicon base material. The substrate W is loaded into the substrate processing apparatus 1 and held by the rotating holder 10.

[0054] Next, in the second embodiment, the spin holder 10 starts to rotate the substrate W held in a horizontal position. The spin motor 12 of the spin holder 10 rotates the substrate W in a horizontal plane around the central axis X of the substrate W. The spin holder 10 rotates the substrate W at a constant rotation speed set in advance. In the second embodiment, the rotation speed of the substrate W is 100 rpm or less, and typically 20 rpm or more and 30 rpm or less.

[0055] The position of the notch 90 of the rotating substrate W is derived based on the detection result by the notch detection mechanism 20. Specifically, the notch detection mechanism 20 detects the notch 90 when the notch 90 of the rotating substrate W passes directly below (or directly above) the notch detection mechanism 20. Since the substrate W rotates at a constant speed, the notch detection mechanism 20 detects the notch 90 periodically at constant intervals. The control unit 50 calculates the position of the notch 90 based on the time elapsed from the point in time when the notch detection mechanism 20 detected the notch 90 and the rotational speed of the substrate W.

[0056] Meanwhile, the coating nozzle 30 starts discharging the coating liquid. The coating nozzle 30 starts discharging the coating liquid while stopped at an initial position inside the cup 40 and outside the substrate W held by the spin chuck 11. As in the first embodiment, the coating nozzle 30 discharges the coating liquid vertically downward at a constant flow rate.

[0057] In the second embodiment, after the discharge state of the coating liquid from the coating nozzle 30 becomes stable, the coating nozzle 30 moves above the notch 90 of the rotating substrate W. The position of the notch 90 of the rotating substrate W is obtained based on the detection result by the notch detection mechanism 20 as described above. The position of the coating nozzle 30 is detected by the encoder 33. The control unit 50 controls the nozzle drive mechanism 32 so that the coating nozzle 30 also reaches the intersecting position at the timing when the notch 90 reaches the position where the trajectory of the coating nozzle 30 moved by the nozzle drive mechanism 32 and the edge portion of the substrate W intersect when viewed from above. The notch 90 of the substrate W and the coating nozzle 30 discharging the coating liquid reach the intersecting position at the same time, and the coating nozzle 30 moves above the notch 90, and the liquid flow of the coating liquid discharged from the coating nozzle 30 enters between the V-shaped grooves of the notch 90. Then, the coating nozzle 30 moves to a discharge position above the notch 90 and stops. As in the first embodiment, the discharge position is, strictly speaking, the position of the coating nozzle 30 where the liquid flows of the coating liquid discharged from the coating nozzle 30 pass through the notch 90 at the position where they intersect.

[0058] In the first embodiment, the coating nozzle 30 advances toward the notch 90 of the stationary substrate W, whereas in the second embodiment, the coating nozzle 30 must move in synchronization with the notch 90 of the rotating substrate W. For this reason, it is preferable that the nozzle driving mechanism 32 moves the coating nozzle 30 as fast as possible (for example, 20 mm / sec or faster). The higher the rotation speed of the substrate W, the greater the need to move the coating nozzle 30 at high speed.

[0059] 10 is a diagram showing the trajectory of the relative movement of the coating nozzle 30 with respect to the substrate W in the second embodiment. When the notch 90 of the rotating substrate W reaches the above-mentioned intersection position, the coating nozzle 30 moves to the discharge position and stops, whereby the coating nozzle 30 moves above the notch 90 and the flow of the coating liquid enters between the V-shaped grooves of the notch 90.

[0060] The substrate W continues to rotate even after the coating nozzle 30 that discharges the coating liquid stops at the discharge position. The coating liquid is discharged vertically downward from the coating nozzle 30 stopped at the discharge position, while the substrate W rotates in a horizontal plane around the central axis X, so that the coating liquid is supplied to the peripheral portion of the substrate W and the coating film 80 is formed. In the second embodiment, the liquid flow of the coating liquid first enters the notch 90, so that the coating of the coating liquid on the peripheral portion of the substrate W starts from the notch 90 as a starting point. The coating liquid that has landed on the peripheral portion of the substrate W flows so as to spread toward the edge portion of the substrate W due to the centrifugal force caused by the rotation of the substrate W, and a part of the coating liquid flows around from the edge portion of the substrate W to the peripheral portion of the lower surface. In addition, a part of the coating liquid that has landed on the peripheral portion of the substrate W also spreads toward the center side of the substrate W due to surface tension. As a result, the coating liquid is applied to a region of a certain width from the edge portion on the upper surface of the peripheral portion of the substrate W, and a circular coating film 80 is formed.

[0061] When the substrate W rotates once in the horizontal plane, the coating nozzle 30 is again positioned above the notch 90. In the second embodiment, the coating nozzle 30 moves from the discharge position to the initial position at the timing when the coating nozzle 30 is again positioned above the notch 90. That is, the coating nozzle 30 retreats from above the notch 90 of the substrate W. As a result, the application of the coating liquid to the peripheral portion of the substrate W is completed with the notch 90 as the end point, and a circular coating film 80 of a certain width is formed on the upper surface of the peripheral portion of the substrate W except for the notch 90. The initial position is a position where the coating liquid discharged from the coating nozzle 30 passes outside the substrate W. The substrate W continues to rotate even when the coating nozzle 30 retreats from above the notch 90. The coating nozzle 30 stops at the initial position.

[0062] Thereafter, as in the first embodiment, the discharge of the coating liquid from the coating nozzle 30 is stopped. Then, the substrate W is rotated at high speed to dry the coating film 80 formed on the peripheral portion of the substrate W. As a result, a coating film 80 of a certain width is formed on the upper surface of the peripheral portion of the substrate W. Finally, while rotating the substrate W, a rinsing liquid is discharged from the back rinse nozzle 60 onto the lower surface of the substrate W to wash away and remove the coating film adhered to the lower surface.

[0063] In the second embodiment, the coating nozzle 30 that discharges the coating liquid is moved above the notch 90 of the rotating substrate W, and the substrate W is continuously rotated only once in a horizontal plane to form a coating film 80 on the upper surface of the peripheral portion of the substrate W. That is, as in the first embodiment, the application of the coating liquid is started from the notch 90 of the substrate W and ends at the notch 90. As a result, the coating liquid is applied only once to the upper surface of the peripheral portion of the substrate W in a single stroke. Since the coating liquid is applied only once to the peripheral portion of the substrate W, the supply amount of the coating liquid is kept to a minimum, and the applied coating liquid is prevented from spreading in the radial direction of the substrate W, thereby forming a coating film 80 with a narrow width.

[0064] Moreover, the coating nozzle 30 starts discharging the coating liquid before it reaches the discharge position, and the coating liquid is applied to the peripheral portion of the substrate W in a stable state. That is, the coating liquid is supplied at a constant flow rate to the peripheral portion of the substrate W rotating at a constant speed, and a coating film 80 of a uniform width can be formed.

[0065] Furthermore, in the second embodiment, the application of the coating liquid is started from the notch 90 of the substrate W and ends at the notch 90. At the start and end of the application, the coating liquid discharged from the coating nozzle 30 passes through the notch 90 and is collected in the cup 40. Therefore, the coating liquid is not applied over the notch 90, and it is possible to form a coating film 80 with a more uniform width. In addition, in the second embodiment, the coating nozzle 30 moves at high speed and suddenly stops at the discharge position, so that the coating nozzle 30 vibrates at the moment of stopping, causing disturbances in the liquid flow of the coating liquid, but the disturbed liquid flow passes through the notch 90 and does not land on the substrate W, so it does not affect the formation of the coating film 80 with a uniform width. In other words, if the second embodiment is performed, a coating film 80 with a uniform and narrow width can be formed.

[0066] <Modification> Although the embodiments of the present invention have been described above, various modifications can be made to the present invention without departing from the spirit of the present invention. For example, in each of the above embodiments, a notch 90 is formed in the substrate W, but instead, an orientation flat (orientation flat) may be provided in the substrate W. The orientation flat is also a flat cutout portion that indicates the crystal orientation, like the notch 90. Typically, an orientation flat is formed in a relatively small substrate W having a diameter of 200 mm. In this case, application of the coating liquid starts from the orientation flat and ends at the orientation flat. Both the notch 90 and the orientation flat are cutout portions provided in the substrate W.

[0067] In addition, in each of the above embodiments, the coating liquid is started to be discharged before the coating nozzle 30 reaches the discharge position, but instead, the coating liquid may be started to be discharged after the coating nozzle 30 reaches the discharge position. In this way, the consumption amount of the coating liquid can be reduced, but if the coating liquid is started to be discharged before the coating nozzle 30 reaches the discharge position as in the above embodiment, the coating can be started in a stable state, and the coating film 80 with a more uniform width can be formed.

[0068] In the first embodiment, the orientation of the substrate W is adjusted in the substrate processing apparatus 1, but instead, the orientation of the substrate W may be adjusted in a separate apparatus before being carried into the substrate processing apparatus 1. The adjusted orientation of the substrate W is maintained unless the substrate W is rotated during the transport process.

[0069] In addition, in each of the above embodiments, a resist film or an underlayer film is formed as the coating film 80, but this is not limited to this, and any film that functions as a protective film that is resistant to etching processes such as DRIE may be used.

[0070] In addition, in each of the above embodiments, the coating liquid is discharged vertically downward from the coating nozzle 30, but instead, the coating liquid may be discharged obliquely downward (toward the edge portion of the substrate W) from the coating nozzle 30. In this case, the discharge position of the coating nozzle 30 may be different from above the notch 90. [Explanation of symbols]

[0071] 1. Substrate Processing Equipment 10 Rotational support part 11 Spin chuck 12 Spin motor 20 Notch detection mechanism 30 Application nozzle 32 Nozzle drive mechanism 33 Encoder 40 cups 50 Control section 60 Back rinse nozzle 80 Coating film 90 notches W substrate

Claims

1. A substrate processing method for forming a coating film on a peripheral portion of a disk-shaped substrate having a cutout portion, comprising the steps of: a nozzle advancing step of moving a nozzle that ejects a coating liquid for forming the coating film to a ejection position where a liquid flow of the coating liquid ejected from the nozzle passes through the cutout portion of the substrate that is held in a horizontal position; a substrate rotation process in which the substrate is rotated once in a horizontal plane around a central axis of the substrate while the coating liquid is being discharged from the nozzle at the discharge position, thereby starting application of the coating liquid from the cutout portion and ending application of the coating liquid at the cutout portion; A substrate processing method comprising:

2. 2. The substrate processing method according to claim 1, The substrate processing method further includes, after the substrate rotating step, a nozzle retracting step of moving the nozzle to a position where a liquid flow of the coating liquid discharged from the nozzle passes outside the substrate.

3. 3. The substrate processing method according to claim 2, The nozzle advancing step and the nozzle retracting step are performed in a state where rotation of the substrate is stopped.

4. 3. The substrate processing method according to claim 2, The nozzle advancing step and the nozzle retracting step are performed in a state in which the substrate is rotated.

5. 5. The substrate processing method according to claim 1, A substrate processing method comprising: starting to discharge the coating liquid from the nozzle before the nozzle reaches the discharge position.

6. A substrate processing apparatus for forming a coating film on a peripheral portion of a disk-shaped substrate having a cutout portion, comprising: a rotation holder that holds the substrate in a horizontal position and rotates the substrate around a central axis of the substrate; a nozzle for ejecting a coating liquid for forming the coating film; a nozzle driving unit that moves the nozzle between above the substrate and outside the substrate; a control unit for controlling the rotation holding unit and the nozzle driving unit; Equipped with the control unit controls the nozzle driving unit to move the nozzle to a discharge position where a liquid flow of the coating liquid discharged from the nozzle passes through the notch portion of the substrate held by the spin holding unit; The control unit controls the rotating and holding unit to eject the coating liquid from the nozzle at the ejection position while rotating the substrate once in a horizontal plane around the central axis of the substrate, thereby starting application of the coating liquid from the cutout portion and ending application of the coating liquid at the cutout portion.

7. 7. The substrate processing apparatus according to claim 6, The control unit controls the nozzle drive unit to move the nozzle to a position where a flow of the coating liquid discharged from the nozzle passes outside the substrate after the coating liquid is applied.

8. 8. The substrate processing apparatus according to claim 7, The control unit controls the nozzle drive unit to move the nozzle to the discharge position while rotation of the substrate is stopped, and to move the nozzle from the discharge position.

9. 8. The substrate processing apparatus according to claim 7, The control unit controls the nozzle drive unit to move the nozzle to the discharge position while the substrate is rotating, and to move the nozzle from the discharge position.

10. 10. The substrate processing apparatus according to claim 6, The substrate processing apparatus starts discharging the coating liquid before the nozzle reaches the discharging position.

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