Protective film formation method, protective film formation device, and substrate processing system

Abstract

To appropriately form a protective film in a peripheral part of a substrate having a plurality of patterning layers on a front surface.SOLUTION: A method for forming a protective film in a peripheral part of a substrate having a plurality of patterning layers on a front surface includes the steps of: (A) forming the protective film in the peripheral part of the substrate by supplying a coating liquid for forming the protective film from a front surface side coating part located on the front surface side of the substrate to the front surface of the substrate while rotating the substrate; (B) after the step (A), cleaning a rear surface and a peripheral end surface of the substrate by supplying a cleaning liquid from a cleaning liquid supply part located on the rear surface side of the substrate to the rear surface of the substrate while rotating the substrate; and (C) after the step (B), forming the protective film in the rear surface and the peripheral end surface of the peripheral part of the substrate by supplying the coating liquid from a rear surface side coating part located on the rear surface side of the substrate to the rear surface of the substrate while rotating the substrate.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present disclosure relates to a protective film forming method, a protective film forming apparatus, and a substrate processing system. [Background technology]

[0002] Patent Document 1 discloses a coating and developing method including the steps of applying a metal-containing resist to the surface of a substrate to form a resist film and exposing the resist film to light, and supplying a developer to the surface of the substrate to develop the resist film. This coating and developing method further includes the step of forming a protective film, prior to the developing step, on the peripheral portion of the substrate on which the resist film is not formed, that prevents at least the peripheral end face and the peripheral edge on the back side from contacting the developer. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2018-49987 Summary of the Invention [Problem to be solved by the invention]

[0004] The technique according to the present disclosure appropriately forms a protective film around the periphery of a substrate having multiple patterned layers on its front surface. [Means for solving the problem]

[0005] One aspect of the present disclosure is a method for forming a protective film on a peripheral portion of a substrate having multiple patterning layers on its surface, the method comprising the steps of: (A) supplying a coating liquid for forming the protective film from a front-side coating unit located on the front side of the substrate to the front surface of the substrate while rotating the substrate, thereby forming the protective film on the peripheral portion of the substrate; (B) after step (A), supplying a cleaning liquid from a cleaning liquid supply unit located on the back side of the substrate to the back surface of the substrate while rotating the substrate, thereby cleaning the back surface and peripheral edge surface of the substrate; and (C) after step (B), supplying the coating liquid from the back-side coating unit located on the back side of the substrate to the back surface of the substrate while rotating the substrate, thereby forming the protective film on the back surface and peripheral edge surface of the substrate. [Effects of the Invention]

[0006] According to the present disclosure, a protective film can be appropriately formed around the periphery of a substrate having a plurality of patterned layers on its front surface. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 illustrates a substrate having multiple patterned layers. [Figure 2] 1 is a diagram schematically illustrating an outline of the configuration of a wafer processing system as a substrate processing system including a protective film forming apparatus according to a first embodiment. [Figure 3] 1 is an explanatory diagram showing a schematic side view of the configuration of a protective film forming apparatus according to a first embodiment. [Figure 4] 1 is an explanatory diagram showing a schematic plan view of the configuration of a protective film forming apparatus according to a first embodiment. [Figure 5] FIG. 4 is an explanatory diagram showing the discharge angle of the front surface side coating nozzle relative to the substrate in a plan view. [Figure 6] FIG. 10 is an explanatory diagram showing the discharge angle of the front surface coating nozzle relative to the substrate in a side view. [Figure 7] 1 is a flowchart illustrating the main steps of a processing sequence performed by a wafer processing system. [Figure 8]FIG. 2 is a perspective view showing the state of the surroundings of the substrate during the processing sequence. [Figure 9] 10A and 10B are partially enlarged cross-sectional views showing the state of the vicinity of the periphery of the substrate during the processing sequence. [Figure 10] 10A to 10C are diagrams for explaining a protective film forming method according to a comparative example. [Figure 11] 10A and 10B are diagrams showing other examples of the number and positions of rear surface coating and cleaning nozzles. [Figure 12] FIG. 10 is a diagram showing another example of a back surface coating nozzle. [Figure 13] FIG. 10 is a diagram showing another example of a back surface coating nozzle. [Figure 14] FIG. 10 is a diagram showing another example of a back surface coating nozzle. [Figure 15] FIG. 10 is an explanatory diagram showing a schematic side view of the configuration of a protective film forming apparatus according to a second embodiment. [Figure 16] FIG. 10 is an explanatory diagram showing a schematic plan view of the configuration of a protective film forming apparatus according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] In the photolithography process in the manufacturing process of multilayer semiconductor devices such as 3D NAND flash memory, various processes are performed, such as a coating process in which a coating liquid is applied to a substrate such as a semiconductor wafer (hereinafter referred to as "wafer") to form a resist film, an exposure process in which the resist film is exposed to a predetermined pattern, and a development process in which the exposed substrate is developed to form a resist pattern. Furthermore, the resist pattern is used as a mask to perform an etching process on the substrate, thereby forming a patterned layer on the substrate. Furthermore, the sequence of forming a patterned layer on the substrate as described above is repeated multiple times until a multilayer semiconductor device is formed, resulting in a substrate Su having multiple patterned layers PL on its surface, as partially shown in FIG. 1.

[0009] Incidentally, a substrate Su having multiple patterning layers PL on its surface has an exposed peripheral edge Su1, which may be damaged in a subsequent process for the substrate Su. For example, if the substrate Su having multiple patterning layers PL on its surface is made of silicon, the peripheral edge Su1 of the substrate Su may be damaged during a cleaning process in which a layer PL1 made of amorphous silicon, a material similar to silicon, in the substrate Su is removed by batch processing using a cleaning solution. Specifically, the layer PL1 is a layer that fills holes H in the patterning layers PL.

[0010] Because the peripheral edge Su1 of the substrate Su may be damaged as described above, it has been considered to form a protective film on the peripheral edge Su1. Specifically, it has been considered to supply a coating liquid for forming a protective film to the substrate Su while rotating the substrate Su, and form a protective film on the peripheral edge Su1 of the substrate Su against the above-mentioned cleaning process. However, depending on the formation method, it is not possible to form an appropriate protective film. Specifically, for example, the following is described.

[0011] That is, the front surface of the peripheral portion Su1 of the substrate Su is damaged not only by processes after the formation of the multiple patterned layers PL but also by the etching used to form the patterned layers PL, resulting in a step during the formation of the protective film. If the rotation speed of the substrate Su is reduced during the protective film formation in order to prevent the shoulders of the step on the surface of the peripheral portion Su1 from being exposed, defects may occur in the protective film formed on the back surface of the peripheral portion Su1 of the substrate Su. Furthermore, the surface of the peripheral portion Su1 of the substrate Su may accumulate damage during the cleaning process in batch processing or the etching used to form the patterned layer PL. This accumulation can cause defects such as chipping and particle generation, which is why a protective film is necessary. Furthermore, if the back surface and peripheral edge of the peripheral portion Su1 of the substrate Su are damaged during the cleaning process in batch processing, the damaged portion may chip when it comes into contact with a substrate processing device or substrate transport mechanism, such as a device for removing the protective film, resulting in cross-contamination. Therefore, a protective film is also required on the back surface and peripheral edge of the peripheral portion Su1 of the substrate Su.

[0012] Therefore, the technique according to the present disclosure appropriately forms a protective film on the peripheral edge of a substrate having multiple patterning layers on its front surface.

[0013] Hereinafter, the configuration of a protective film forming apparatus and a substrate processing system according to this embodiment will be described with reference to the drawings. In this specification, elements having substantially the same functional configuration are designated by the same reference numerals, and redundant description will be omitted.

[0014] (First embodiment) <Wafer processing system> FIG. 2 is a diagram schematically illustrating the configuration of a wafer processing system as a substrate processing system including a protective film forming apparatus according to the first embodiment.

[0015] The wafer processing system 1 in FIG. 2 includes a coating system 2, a cleaning system 3, and a removal system 4.

[0016] The coating system 2 includes a carrier station 2a and a processing station 2b.

[0017] Wafers as substrates are carried in and out of the carrier station 2a in units of carriers. A carrier is a container that can accommodate a plurality of wafers at once.

[0018] The processing station 2b includes a protective film forming device 11, a heat treatment device 12, and a transfer mechanism 13. The protective film forming device 11 and the heat treatment device 12 each process wafers one by one. The protective film forming apparatus 11 forms a protective film on the peripheral edge of a wafer having multiple patterned layers on its front surface, such as the substrate Su in FIG. 1. The patterned layer is formed on the front surface of the wafer through a coating process in which a coating liquid is supplied onto the wafer to form a resist film, an exposure process in which the resist film is exposed to a predetermined pattern, a development process in which the exposed wafer is developed to form a resist pattern, and an etching process in which the wafer is etched using the resist pattern as a mask. This series of processes is repeated multiple times to form multiple patterned layers on the front surface of the wafer. The substrate of the wafer is, for example, silicon. The peripheral edge of the wafer on which the protective film forming apparatus 11 forms the protective film is an area outside the device effective area of the wafer, specifically, an area outside the area on the wafer where the patterned layer is formed. The heat treatment device 12 performs a heat treatment such as heating on the wafer on which the protective film is formed. The heat treatment by the heat treatment device 12 vaporizes the solvent contained in the coating liquid for forming the protective film remaining on the protective film, thereby hardening the protective film. The transfer mechanism 13 transfers wafers one by one between devices within the processing station 2b.

[0019] The cleaning system 3 includes a carrier station 3a and a processing station 3b.

[0020] Like the carrier station 2a, the carrier station 3a carries wafers in and out in carrier units.

[0021] The processing station 3b includes a cleaning device 21 and a transfer mechanism 22. The cleaning device 21 processes wafers in batches. That is, the cleaning device 21 processes wafers in lots, each of which includes a group of multiple wafers. Specifically, the cleaning device 21 uses a cleaning liquid to batch-process and remove a layer made of the same material as the base material of a wafer on which a protective film has been formed. For example, when the base material of the wafer is silicon, the cleaning device 21 uses a cleaning liquid to batch-process and remove an amorphous silicon layer (see symbol PL1 in FIG. 1) that fills holes in a patterned layer of a wafer having multiple patterned layers on its front surface. The cleaning liquid for removing the amorphous silicon layer is, for example, an aqueous choline solution (choline concentration 4%) at 80°C. The transfer mechanism 22 transfers wafers in lots, such as to the cleaning device 21, within the processing station 3b. In addition, the cleaning system 3 and cleaning device 21 can be, for example, a substrate liquid processing system and an etching processing device disclosed in Japanese Patent Application Laid-Open No. 2021-40162.

[0022] The removal system 4 includes a carrier station 4a and a processing station 4b.

[0023] Like the carrier station 2a, the carrier station 4a carries wafers in and out in carrier units.

[0024] The processing station 4 b includes a removal device 31 and a transport mechanism 32 . The removal device 31 removes the protective film from the wafer on which the protective film is formed. Specifically, the removal device 31 removes the protective film from the wafer one by one. The transfer mechanism 32 transfers wafers one by one within the processing station 3b, such as transferring wafers to the removal device 31. The removal device 31 may be, for example, the liquid treatment device disclosed in Japanese Patent Application Laid-Open No. 2014-86639.

[0025] Although not shown, the wafer processing system 1 also includes an overhead hoist transport (OHT) that transports wafers W between the systems constituting the system 1 on a carrier-by-carrier basis.

[0026] The wafer processing system 1 further includes at least one controller 5. The controller 5 processes computer-executable instructions that cause the wafer processing system 1 to perform the various processes described in this disclosure. The controller 5 may be configured to control each element of the wafer processing system 1 to perform the various processes described herein. In one embodiment, some or all of the controller 5 may be included in the wafer processing system 1. The controller 5 may include a processing unit, a storage unit, and a communication interface. The controller 5 may be implemented, for example, by a computer. The processing unit may be configured to read from the storage unit a program that provides logic or routines that enable various control operations and execute the read program to perform the various control operations. This program may be stored in the storage unit in advance or may be acquired via a medium when needed. The acquired program is stored in the storage unit and read from the storage unit by the processing unit for execution. The medium may be various computer-readable storage media or a communication line connected to the communication interface. The storage medium may be temporary or non-temporary. The processing unit may be a CPU (Central Processing Unit) or one or more circuits. The storage unit may include a RAM (Random Access Memory), a ROM (Read Only Memory), a HDD (Hard Disk Drive), an SSD (Solid State Drive), or a combination thereof. The communication interface may communicate with the wafer processing system 1 via a communication line such as a LAN (Local Area Network).

[0027] <Protective film forming device 11> Fig. 3 is an explanatory diagram showing a schematic side view of the configuration of the protective film forming apparatus 11, and Fig. 4 is an explanatory diagram showing the same configuration from a plan view. Figs. 5 and 6 are explanatory diagrams showing the discharge angle of the front surface side coating nozzle, which will be described later, relative to the wafer in a plan view and a side view, respectively.

[0028] As described above, the protective film forming apparatus 11 forms a protective film on the peripheral edge of a wafer having multiple patterned layers on its surface. Specifically, the protective film is a film that is resistant to a cleaning solution used in a process for removing a specific layer from the front surface of the wafer W by the cleaning apparatus 21, and more specifically, an SoG film that is resistant to an 80°C choline aqueous solution (choline concentration: 4%). As shown in FIGS. 3 and 4, the protective film forming apparatus 11 includes a spin chuck 111, which is a rotary holder that holds and rotates the wafer W, in a processing chamber 100. Specifically, the spin chuck 111 holds the wafer W horizontally and rotates it around a vertical axis by vacuum-suctioning the central portion of the back surface of the wafer W.

[0029] The spin chuck 111 is connected to a chuck driving mechanism 113 via a shaft 112. The chuck driving mechanism 113 has a rotation driving source (not shown) such as a motor that generates a driving force for rotating the spin chuck 111 around a vertical axis. The rotation of the spin chuck 111 by the chuck driving mechanism 113 causes the wafer W to rotate around the vertical axis.

[0030] Furthermore, the chuck driving mechanism 113 may be provided with a driving source such as a cylinder that generates a driving force for raising and lowering the spin chuck 111. The spin chuck 111 is raised and lowered by the chuck driving mechanism 113, whereby the wafer W is raised and lowered. The chuck driving mechanism 113 is controlled by the control device 5, for example.

[0031] A circular plate 114 is provided below the spin chuck 111 so as to surround the shaft portion 112 with a gap therebetween. Three or more through holes (not shown) are formed in the circular plate 114 along the circumferential direction, and lift pins (not shown) can be inserted into each of the through holes. These lift pins can be raised and lowered by a lift mechanism (not shown). By raising and lowering the lift mechanism, the lift pins can lift the wafer W from the spin chuck 111 after it has been released from suction and hold by the spin chuck 111, or can lower the wafer W received from the transfer mechanism 13 and place it on the spin chuck 111.

[0032] A cup 120 is provided in the processing vessel 100 so as to surround the wafer W held on the spin chuck 111. The cup 120 receives the processing liquid (e.g., a coating liquid for forming a protective film) that has been shaken off or dropped from the wafer W held on the spin chuck 111, and guides the processing liquid to be discharged to the outside.

[0033] More specifically, cup 120 has a mountain-shaped guide portion 121 that is provided around the circular plate 114 and has a ring-shaped cross section with a mountain-shaped cross section, and an annular vertical wall 122 that extends downward from the outer circumferential edge of mountain-shaped guide portion 121. Mountain-shaped guide portion 121 guides the processing liquid that has dropped from wafer W to the outside and below wafer W.

[0034] Furthermore, cup 120 has a vertical cylindrical portion 123 outside mountain-shaped guide portion 121 so as to surround mountain-shaped guide portion 121, and an upper guide portion 124 extending obliquely inward and upward from a portion of cylindrical portion 123 above vertical wall 122. Upper guide portion 124 is provided with a plurality of openings 125 in the circumferential direction. The upper end portion of cylindrical portion 123 extends above spin chuck 111, and an inclined body 123a extending inward and upward is provided on the inner edge of the end portion.

[0035] A ring-shaped liquid receiving portion 126 having a recessed cross section is formed below the mountain-shaped guide portion 121 and the cylindrical portion 123 on the lower side of the cylindrical portion 123. A drainage path 127 is connected to the outer periphery of this liquid receiving portion 126. Two exhaust pipes 128 are provided on the inner periphery of the liquid receiving portion 126 relative to the drainage path 127.

[0036] 4, a rail 130 extending in the Y direction (left and right direction in FIG. 4) is formed on the negative X direction side (downward direction in FIG. 4) of cup 120. Rail 130 is located, for example, from the outside of cup 120 on the negative Y direction side (left direction in FIG. 2) to the outside of cup 120 on the positive Y direction side (right direction in FIG. 4). An arm 131 is provided on rail 130 so as to be movable along rail 130.

[0037] A front surface side coating nozzle 132 serving as a front surface side coating unit is supported on the arm 131. The front surface side coating unit supplies a protective liquid (specifically, for example, a material for an SoG film, i.e., an SoG material) which is a coating liquid for forming a protective film, from the front surface side of the wafer W held on the spin chuck 111 to the front surface of the wafer W. A plurality of front surface side coating nozzles 132 may be provided for one arm 131. In this case, a front surface side coating nozzle 132 is provided for each type or concentration of protective liquid, for example.

[0038] The front surface application nozzle 132 is connected to a protective liquid supply mechanism 133. The supply mechanism 133 has, for example, a supply pipe 135 having one end connected to a protective liquid supply source 134. This supply pipe 135 is provided with a supply device group 136 for controlling the supply of protective liquid from the supply source 134. The supply device group 136 has, for example, a supply valve that switches between supply and stop of the protective liquid and a flow rate adjustment valve that adjusts the flow rate of the protective liquid. The supply equipment group 136 is controlled by the control device 5, for example.

[0039] The arm 131 is movable along the Y direction on the rail 130 by the nozzle drive unit 137. This allows the front surface side coating nozzle 132 to move from a waiting unit 138 installed outside the cup 120 on the positive Y direction side to above the peripheral edge of the wafer W held by the spin chuck 111 inside the cup 120. The arm 131 is also movable up and down by the nozzle drive unit 137, thereby adjusting the height of the front surface side coating nozzle 132. The nozzle drive unit 137 has, for example, a motor or a cylinder as a drive source that generates a drive force for driving the movement of the arm 131 along the rail 130 and the lifting and lowering of the arm 131.

[0040] 5, the discharge angle θ1 of the front surface side coating nozzle 132 relative to the wafer W in a plan view is set to an acute angle, specifically set to an acute angle of 10° or more, and more specifically set to, for example, 25° to 45°. Specifically, the discharge angle θ1 is the angle formed between the rotation direction D1 of the wafer W at the impact point W1 of the protective liquid from the front surface side coating nozzle 132 on the wafer W and the discharge direction D2 of the protective liquid from the front surface side coating nozzle 132 in a plan view.

[0041] By setting the discharge angle θ1 of the front surface side application nozzle 132 in a planar view relative to the wafer W as described above, the protective liquid discharged from the front surface side application nozzle 132 is less likely to move inward after reaching the surface of the wafer W, and therefore the position of the inner peripheral edge of the protective film on the front surface side of the wafer W can be kept constant in the circumferential direction of the wafer W. Furthermore, by setting the discharge angle θ1 of the front-side coating nozzle 132 relative to the wafer W as described above, the following effect can be achieved: When multiple nozzles are provided on the arm 131, it is possible to prevent the protective liquid discharged from the front-side coating nozzle 132 and bounced off the surface of the wafer W from contaminating nozzles other than the front-side coating nozzle 132 provided on the arm 131.

[0042] The front surface side coating nozzle 132 is configured to eject the protective liquid obliquely downward from the inside to the outside of the wafer W so that the protective liquid that has landed on the wafer W from the front surface side coating nozzle 132 is directed toward the outside of the wafer W. For example, the ejection angle θ2 of the front surface side coating nozzle 132 relative to the wafer W in a side view (i.e., the depression angle of the front surface side coating nozzle 132) is set to 15° to 35°. This makes it possible to weaken the impact force of the protective liquid from the front surface side coating nozzle 132 on the wafer W.

[0043] 3, a cleaning nozzle 141 serving as a cleaning liquid supply unit is disposed on the inner periphery of the mountain-shaped guide portion 121. The cleaning liquid supply unit supplies a cleaning liquid to the back surface of the wafer W held by the spin chuck 111 from the back surface side of the wafer W. The cleaning liquid is a solvent capable of dissolving the protective liquid. Examples of this cleaning liquid include a mixed solution of propylene glycol monomethyl ether (PGME) and propylene glycol monomethyl ether acetate (PGMEA) (mixing ratio 7:3) and cyclohexane.

[0044] Unlike the front surface-side application nozzle 132, the cleaning nozzle 141 is fixed. The cleaning nozzle 141 is connected to a cleaning liquid supply mechanism 142. The supply mechanism 142 has, for example, a supply pipe 144 having one end connected to a cleaning liquid supply source 143. This supply pipe 144 is provided with a supply device group 145 for controlling the supply of the cleaning liquid from the supply source 143. The supply device group 145 has, for example, a supply valve that switches between supply and stop of the cleaning liquid and a flow rate adjustment valve that adjusts the flow rate of the cleaning liquid. The supply equipment group 145 is controlled by the control device 5, for example.

[0045] Furthermore, a back surface side coating nozzle 151 serving as a back surface side coating unit is arranged on the inner circumferential side of the mountain-shaped guide portion 121, outside the cleaning nozzle 141. The back surface side coating unit supplies the protective liquid to the back surface of the wafer W held by the spin chuck 111 from the back surface side of the wafer W. The protective liquid supplied by the back surface side coating nozzle 151 and the front surface side coating nozzle 132 is the same.

[0046] The back surface coating nozzle 151 is fixed, similar to the cleaning nozzle 141. The back surface coating nozzle 151 is connected to a protective liquid supply mechanism 152. The supply mechanism 152 has, for example, a supply pipe 154 having one end connected to a protective liquid supply source 153. The supply pipe 154 is provided with a supply device group 155 for controlling the supply of the protective liquid from the supply source 153. The supply device group 155 has, for example, a supply valve that switches between supply and stop of the protective liquid and a flow rate adjustment valve that adjusts the flow rate of the protective liquid. The supply equipment group 155 is controlled by the control device 5, for example.

[0047] At least one of the cleaning nozzle 141 and the back surface side coating nozzle 151 may have the same discharge angle as the front surface side coating nozzle 132 in a plan view relative to the wafer W. Furthermore, at least one of the cleaning nozzle 141 and the back surface side coating nozzle 151 may have the same discharge angle as the front surface side coating nozzle 132 in a side view relative to the wafer W.

[0048] <Example of processing sequence> Next, an example of a processing sequence executed by the wafer processing system 1 will be described with reference to Figs. 7 to 9. Fig. 7 is a flowchart showing main steps of the processing sequence executed by the wafer processing system 1. Fig. 8 is a perspective view showing the state around the wafer W during the processing sequence. Fig. 9 is a partially enlarged cross-sectional view showing the state near the periphery of the wafer W during the processing sequence.

[0049] (Step S1: Forming a protective film) As shown in FIG. 7, first, a protective film is formed by the coating system 2 on the peripheral edge of the wafer W having a plurality of patterned layers. This step S1 includes, for example, the following steps S1a to S1h.

[0050] (Step S1a: Loading of wafer W) In step S1a, the wafer W is carried into the coating system 2, specifically, into the protective film forming apparatus 11. More specifically, a carrier containing a plurality of wafers W is loaded into the carrier station 2a of the coating system 2. Thereafter, the wafers W in the carrier are loaded into the processing vessel 100 of the protective film forming apparatus 11 in the processing station 2b via the transfer mechanism 13 or the like, and placed on the spin chuck 111. The placed wafers W are held by suction on the spin chuck 111.

[0051] (Step S1b: Cup cleaning) In step S1b, the wafer W is rotated, and a cleaning liquid is supplied to the rear surface of the wafer W from the cleaning nozzle 141 located on the rear surface side of the wafer W, thereby cleaning the cup 120. Specifically, the wafer W held by the spin chuck 111 is rotated at a predetermined rotation speed, and a cleaning liquid is supplied from the cleaning nozzle 141 toward the rear surface of the wafer W. This allows the cup 120 to be cleaned with the cleaning liquid scattered from the rear surface of the wafer W. This also allows the rear surface of the wafer W to be cleaned. The cup cleaning in step S1b may be omitted.

[0052] (Step S1c: Applying protective liquid from the surface side) In step S1c, the wafer W is rotated, and a protective liquid is supplied to the front surface of the wafer W from the front surface application nozzle 132 located on the front surface side of the wafer W, thereby forming a protective film on the peripheral edge of the wafer W. 8(a), for example, the front surface-side coating nozzle 132 is moved to a discharge start position Pb outside the peripheral edge of the wafer W, and then the discharge of the protective liquid HL from the front surface-side coating nozzle 132 begins, and the wafer W held by the spin chuck 111 is rotated at a predetermined rotation speed ω1. Then, while the discharge of the protective liquid HL and the rotation of the wafer W are continued, the front surface-side coating nozzle 132 is moved from the discharge start position Pb to a return position Pe on the peripheral edge of the wafer W, and then returned to the discharge start position Pb.

[0053] 9(a), a protective film F is formed on the peripheral edge of the wafer W, including the bevel portion Wb. The bevel portion Wb is composed of an inclined portion Wb1 on the front side, an inclined portion Wb2 on the back side, and a side edge surface (i.e., peripheral edge surface) Wb3. Specifically, in step S1, the protective film F is formed so as to cover all of the horizontal surface Wf on the front side, the horizontal surface Wr on the back side, the inclined portion Wb1 on the front side, the inclined portion Wb2 on the back side, and the side edge surface Wb3 of the peripheral edge of the wafer W.

[0054] The rotation speed ω1 of the wafer W in step S1c is lower than the rotation speed of the wafer W in step S1e (cleaning the back surface and peripheral edge surface) and step S1f (supplying the protective liquid from the back surface side), and is, for example, 50 rpm to 500 rpm, preferably 150 rpm to 200 rpm. By lowering the rotation speed ω1 in this manner, even if a step occurs on the front surface side of the peripheral edge of the wafer W during patterning layer formation, the shoulder of the step can be covered with the protective film F.

[0055] Furthermore, in step S1c, the front surface coating nozzle 132 is moved only to the outside of the protective film formation position set on the front surface of the wafer W. This makes it possible to prevent the protective liquid from the front surface coating nozzle 132 from reaching an area on the front surface of the wafer W that is inside the set protective film formation position. In particular, in step S1c, since the rotation speed of the wafer W is low as described above, the centrifugal force acting on the protective liquid on the wafer W is weak and the protective liquid from the front surface coating nozzle 132 is likely to move inward, so it is effective to limit the inward movement position of the front surface coating nozzle 132 as described above. On the surface of the wafer W, the position where the protective film is formed is set outside the region where the patterning layer is formed.

[0056] In step S1c, the discharge time of the protective liquid HL from the front surface-side coating nozzle 132 and the movement speed of the front surface-side coating nozzle 132 are set to be constant, for example, regardless of the formation width of the protective film. This makes it possible to simplify the setting of the processing conditions for forming the protective film. Note that when set to be constant as described above, for example, by lengthening the discharge time at the discharge start position Pb, the supply time of the protective liquid to the peripheral portion of the wafer W can be shortened and the formation width of the protective film can be narrowed. Furthermore, by shortening the discharge time at the discharge start position Pb, the supply time of the protective liquid to the peripheral portion of the wafer W can be lengthened and the formation width of the protective film can be widened.

[0057] (Step S1d: Drying the protective film) In step S1d, the wafer W is rotated without the protective liquid being supplied to the wafer W, and the protective film F formed in step S1c is dried. Specifically, in a state where the protective liquid and the cleaning liquid are not supplied to the wafer W, the wafer W held by the spin chuck 111 is rotated for a predetermined time.

[0058] In this step S1d, the rotation speed of the wafer W may be increased over time. Specifically, the rotation speed of the wafer W may be increased stepwise. More specifically, for example, the rotation speed of the wafer W may be increased by 100 rpm once every few seconds from 150 rpm to 200 rpm to 1500 rpm. Alternatively, the rotation speed of the wafer W may be increased at a relatively low constant acceleration (for example, 100 rpm / s). By adjusting the rotation speed in this manner, it is possible to dry the protective film F while maintaining the thickness of the protective film F, particularly the thickness of the protective film F covering the front surface side of the peripheral edge of the wafer W. In other words, it is possible to prevent the step formed on the front surface side of the peripheral edge of the wafer W from being exposed through the protective film F in this step S1.

[0059] In step S1d, the wafer W may be rotated at a low rotation speed (e.g., 150 rpm to 200 rpm) for a long time, and then rotated at a high rotation speed (e.g., 1500 rpm) for a short time. This also allows the protective film F to dry while maintaining its thickness.

[0060] (Step S1e: Cleaning the back surface and peripheral edge surface) In step S1e, the wafer W on which the protective film F is formed is rotated, and a cleaning liquid is supplied to the back surface of the wafer W from a cleaning nozzle 141 located on the back surface side of the wafer W, thereby cleaning the back surface and peripheral edge surface of the wafer W. Specifically, the wafer W held by the spin chuck 111 is rotated at a predetermined rotational speed ω2, and the cleaning liquid CL is supplied from the cleaning nozzle 141 toward the back surface of the wafer W, as shown in FIG. 8(b). As a result, as shown in FIG. 9(b), the entire portion of the protective film F covering the horizontal surface Wr on the back surface side of the peripheral edge of the wafer W, the inclined portion Wb2 on the back surface side, and the side end surface Wb3 is removed. Furthermore, if droplets or clumps of the protective liquid supplied to the front surface of the wafer W in the aforementioned step S1c are attached to the back surface of the wafer W, these droplets and clumps of the protective liquid are also removed by the cleaning liquid supplied in step S1e. The reason why the portion of the protective film F covering the inclined portion Wb1 on the front surface side of the wafer W is not removed in step S1e is because it is difficult to cover the entire inclined portion Wb1 on the front surface side of the wafer W with the protective film F in the later step S1f. However, if it is possible to cover the lower part of the inclined portion Wb1 on the front surface side of the wafer W with the protective film F in the later step S1f, the lower part of the portion of the protective film F that covers the inclined portion Wb1 on the front surface side of the wafer W may be removed in this step S1e.

[0061] The rotation speed ω2 of the wafer W in step S1e is higher than the rotation speed of the wafer W in step S1c (supply of protective liquid from the front side) and step S1f (supply of protective liquid from the back side), and is, for example, 2000 rpm or higher, specifically 2000 rpm. By increasing the rotation speed ω2 in this manner, it is possible to prevent the portion of the protective film F that is formed thickly and covers the front-side horizontal surface Wf of the peripheral edge of the wafer W from being removed by the cleaning liquid.

[0062] After step S1e and before step S1f (supplying protective liquid from the back surface side), a process may be performed in which the wafer W is rotated to remove the cleaning liquid and then dried without the cleaning liquid being supplied to the wafer W.

[0063] (Step S1f: Applying protective liquid from the back side) In step S1f, the wafer W is rotated and a protective liquid is supplied to the back surface of the wafer W from a back surface application nozzle 151 located on the back surface side of the wafer W, and a protective film F is formed on the back surface and peripheral edge surface of the peripheral portion of the wafer W. Specifically, the wafer W held by the spin chuck 111 is rotated at a predetermined rotation speed ω3, and at the same time, as shown in Fig. 8(c), a protective liquid HL is supplied from the back surface coating nozzle 151 toward the back surface of the wafer W. As a result, as shown in Fig. 9(c), a protective film F is formed at least on the portion of the peripheral edge of the wafer W that was exposed from the protective film F in step S1e. Specifically, in step S1f, the protective film F is formed so as to entirely cover the horizontal surface Wr on the back surface side of the peripheral edge of the wafer W, the inclined portion Wb2 on the back surface side, and the side end surface Wb3.

[0064] The position on the back surface of the wafer W to which the back surface coating nozzle 151 supplies the protective liquid in step S1f is outside the position on the back surface of the wafer W to which the cleaning nozzle 141 supplies the cleaning liquid in step S1e. In other words, the position on the back surface of the wafer W to which the cleaning liquid is supplied is inside the position to which the protective liquid is supplied. Therefore, the area on the back surface of the wafer W where the protective film is formed can be reliably cleaned with the cleaning liquid.

[0065] Furthermore, the rotation speed ω3 of the wafer W in step S1f is higher than the rotation speed ω1 of the wafer W in step S1c (supplying the protective liquid from the front side) and lower than the rotation speed ω2 of the wafer W in step S1e (cleaning the back surface and peripheral edge surface), and is, for example, 750 rpm to 1750 rpm, preferably 1250 to 1500 rpm. According to repeated tests conducted by the inventors, by setting the rotation speed ω3 to 1750 rpm or less, the protective film F can be formed up to the above-mentioned position on the peripheral edge of the wafer W, and by setting the rotation speed ω3 to 750 rpm or more, the position of the inner peripheral edge of the protective film F on the back surface of the wafer W can be made constant in the circumferential direction of the wafer.

[0066] After step S1f and before step S1g (heat treatment), a step of rotating the wafer W without supplying the protective liquid to the wafer W and drying the protective film F formed in step S1f may be performed.

[0067] (Step S1g: Heat treatment) After step S1f, the wafer W is subjected to a heat treatment. Specifically, the wafer W is transferred from the protective film forming device 11 to the heat treatment device 12 in the processing station 2b by the transfer mechanism 13. Thereafter, the heat treatment device 12 performs a heat treatment on the wafer W, and the protective film on the wafer W is hardened.

[0068] (Step S1h: Unloading the wafer W) In step S1h, the wafer W is carried out from the coating system 2. Specifically, the wafer W is returned from the heat treatment device 12 in the treatment station 2b to the original carrier in the carrier station 2a via the transfer mechanism 13 or the like.

[0069] Step S1, which includes steps S1a to S1h, is performed for all wafers W in the carrier.

[0070] (Step S2: Batch removal with cleaning solution) After step S1, the layer made of the same material as the base material of the wafer W on which the protective film has been formed is removed by the cleaning system 3 through batch processing using a cleaning liquid. Specifically, a carrier containing wafers W on which a protective film has been formed is carried into the carrier station 3a of the cleaning system 3. Next, the wafers W in the carrier are carried into the cleaning device 21 of the processing station 3b in units of lots via the transfer mechanism 22 or the like. Then, in the cleaning device 21, the amorphous silicon layer (see symbol PL1 in FIG. 1) of the wafers W is removed in units of lots using a cleaning solution. Thereafter, the wafers W are returned to their original carrier in the carrier station 3a via the transfer mechanism 22 or the like. Step S2 is performed for all wafers W in the carrier.

[0071] (Step S3: Removal of protective film) After step S2, the protective film F is removed by the removal system 4 from the wafer W on which the protective film F is formed. Specifically, the carrier containing the wafer W after step S2 is loaded into the carrier station 4a of the removal system 4. Next, the wafer W in the carrier is loaded into the removal device 31 of the processing station 4b via the transfer mechanism 32 or the like. Then, in the removal device 31, the protective film F is removed from the peripheral edge of the wafer W. Thereafter, the wafer W is returned to the original carrier in the carrier station 4a via the transfer mechanism 32 or the like. Step S3 is performed for all wafers W in the carrier.

[0072] This completes the processing sequence of this example.

[0073] <Major Effects of This Embodiment> As described above, the protective film forming method according to this embodiment includes step S1c (first protective film forming step) of supplying a protective liquid onto the front surface of the wafer W from the front surface-side coating nozzle 132 located on the front surface side of the wafer W while rotating the wafer W, thereby forming a protective film on the peripheral edge of the wafer W. Furthermore, the protective film forming method according to this embodiment includes, after step S1c (first protective film forming step), step S1e (cleaning step) of supplying a coating liquid onto the back surface of the wafer W from the cleaning nozzle 141 located on the back surface side of the wafer W while rotating the wafer W, thereby cleaning the back surface and peripheral edge of the wafer W. Furthermore, the protective film forming method according to this embodiment includes, after step S1e (cleaning step), step S1f (second protective film forming step) of supplying a protective liquid onto the front surface of the wafer W from the back surface-side coating nozzle 151 located on the back surface side of the wafer W while rotating the wafer W, thereby forming a protective film on the back surface and peripheral edge of the wafer W.

[0074] A protective film forming method different from the protective film forming method according to this embodiment (hereinafter referred to as a protective film forming method according to a comparative embodiment) includes the following steps X1 and X2. Step X1 is a process in which a protective liquid is supplied to the front surface of the wafer W from a back surface coating nozzle 151 located on the back surface side of the wafer W while rotating the wafer W, thereby forming a protective film from the back surface of the peripheral edge of the wafer W to the side edge faces. By this process, a protective film F is formed so as to entirely cover the horizontal surface Wr on the back surface side of the peripheral edge of the wafer W, the inclined portion Wb2 on the back surface side, and the side edge faces Wb3, for example, as shown in FIG. 10(a). Step X2 is a process in which, after step X1, while rotating the wafer W, a protective liquid is supplied onto the surface of the wafer W from the front surface-side application nozzle 132 located on the front surface side of the wafer W, thereby forming a protective film on the front surface side of the peripheral edge of the wafer W. By this process, as shown in FIG. 10(b), for example, a protective film F is formed so as to cover the entire front surface-side horizontal surface Wf and front surface-side inclined portion Wb1 of the peripheral edge of the wafer W, which are not covered in step X1.

[0075] If a step is formed on the peripheral surface of the wafer W, the rotation speed of the wafer W needs to be reduced in both step S1c (first protective film formation process) of the protective film formation method according to this embodiment and step X2 of the protective film formation method according to the comparative embodiment. Furthermore, if the rotation speed of the wafer W is reduced in step X2 of the protective film forming method according to the comparative embodiment, poor coating of the protective film may occur on the rear surface of the wafer W. For example, protrusions due to lumps of protective liquid may occur on the protective film on the rear surface of the peripheral portion of the wafer W, or droplets of the protective liquid may adhere to the protective film near a notch (not shown) on the rear surface of the peripheral portion of the wafer W.

[0076] In contrast, in the protective film forming method according to this embodiment, the rotation speed of the wafer W is reduced in step S1c (first protective film forming process), so that even if droplets or clumps of the protective liquid adhere to the rear surface of the peripheral edge of the wafer W, these can be removed in step S1e (cleaning process). Then, in step S1f (second protective film forming process) after step S1e (cleaning process), a protective film is again formed on the rear surface of the peripheral edge of the wafer W. Therefore, there is no problem with the application of the protective film on the rear surface of the wafer W, as occurs in the protective film forming method according to the comparative embodiment. In other words, according to this embodiment, a protective film can be appropriately formed on the peripheral edge of the wafer W.

[0077] Another method for forming a protective film on the peripheral edge of the wafer W is a CVD method. However, when a protective film is formed on the peripheral edge of the wafer W by the CVD method, it is difficult to fill the recesses that form the steps on the surface of the peripheral edge, and it is also difficult to form a protective film on the back surface of the peripheral edge.

[0078] Furthermore, in the protective film forming method according to this embodiment, multiple patterning layers are already formed when the protective film is formed on the peripheral edge of the wafer W. Therefore, the protective film does not affect the formation of the patterning layers, as occurs when multiple patterning layers are formed after the protective film is formed. This is true even when the protective film is thick.

[0079] Incidentally, when a protective film is formed by supplying a protective liquid from the front side of the wafer W, as in step S1c (first protective film formation step) of the protective film formation method according to this embodiment and step X2 of the protective film formation method according to the comparative embodiment, the portion of the protective film covering the inclined portion Wb2 on the back side of the wafer W is likely to become thicker than other portions due to gravity and other factors. In particular, in the protective film formation method according to the comparative embodiment, after the protective film is formed to cover the inclined portion Wb2 on the back side of the wafer W in step X1, the protective liquid supplied from the front side of the wafer W is supplied to the inclined portion Wb2 in step X2, so the portion of the protective film covering the inclined portion Wb2 on the back side of the wafer W becomes thick. If the protective film becomes too thick, the thick portion of the protective film may separate from the wafer W (i.e., film lifting) or cracks may occur in the thick portion of the protective film during a heat treatment after the protective film formation. In the protective film formation method according to the comparative embodiment, the portion of the protective film covering the inclined portion Wb2 on the back side of the wafer W remains thick. In contrast, even if the portion of the protective film covering the inclined portion Wb2 on the back surface of the wafer W becomes thick in step S1c (first protective film formation process) of the protective film formation method according to this embodiment, this portion is temporarily removed in step S1e (cleaning process). Then, in the subsequent step S1f (second protective film formation process), a protective film covering the inclined portion Wb2 on the back surface of the wafer W is formed by supplying a protective liquid to the back surface of the wafer W. Therefore, it is possible to prevent the portion of the protective film covering the inclined portion Wb2 on the back surface of the wafer W from becoming thick.

[0080] According to tests conducted by the inventors, in the protective film forming method according to the comparative embodiment, the portion of the protective film covering the inclined portion Wb2 on the back surface of the wafer W was approximately 2.5 to 5 times thicker than the other portions. In contrast, in the protective film forming method according to the present embodiment, the portion of the protective film covering the inclined portion Wb2 on the back surface of the wafer W can be made approximately the same thickness as the other portions or thinner than the other portions.

[0081] Furthermore, in this embodiment, the cup cleaning process of step S1b may be omitted. Even in this case, the cup 120 can also be cleaned with cleaning liquid in the process of cleaning the back surface and peripheral edge surface of step S1e. That is, the process of cleaning the back surface and peripheral edge surface of step S1e can also serve as the process of cleaning the cup 120. This can improve the throughput of the protective film formation sequence, including cleaning of the cup 120, and also reduce the amount of cleaning liquid consumed.

[0082] <Another Example of Discharge Time of Protection Liquid from Front-Side Application Nozzle 132> In the above example, the ejection time of the protective liquid from the front surface side coating nozzle 132 in step S1c was set to a constant value regardless of the formation width of the protective film, i.e., regardless of the coating width of the protective liquid from the front surface side coating nozzle 132 onto the wafer W. Alternatively, the discharge time of the protective liquid may be changed and set in accordance with the coating width of the protective liquid from the front surface-side coating nozzle 132 onto the wafer W. This change is made, for example, by the control device 5 based on correlation data between the coating width and the discharge time, which is acquired and stored in advance in the storage unit, and the set coating width. This shortens the time it takes for the protective liquid from the front surface side coating nozzle 132 to be supplied outside the peripheral edge of the wafer W, thereby preventing the protective liquid from adhering to the mountain-shaped guide portion 121.

[0083] <Other Examples of the Number and Position of the Back Side Coating Nozzles 151 and the Cleaning Nozzles 141> FIG. 11 is a diagram showing another example of the number and positions of the rear surface side coating nozzles 151 and cleaning nozzles 141. 11, there may be provided a plurality (two in the illustrated example) of back surface coating nozzles 151. In the example of Fig. 11, the two back surface coating nozzles 151 are provided at positions facing each other with the spin chuck 111 interposed therebetween in a plan view. Furthermore, the back surface side coating nozzle 151 may be provided upstream in the rotation direction of the wafer W from the supply position of the protective liquid from the front surface side coating nozzle 132. This makes it possible to prevent the back surface side coating nozzle 151 from being contaminated by the protective liquid from the front surface side coating nozzle 132. The back-side coating nozzle 151, which is located downstream in the rotation direction of the wafer W from the supply position of the protective liquid from the front-side coating nozzle 132, may be located at a position shifted by 90° or more in the rotation direction of the wafer W from the supply position of the protective liquid from the front-side coating nozzle 132. This also makes it possible to prevent the back-side coating nozzle 151 from being contaminated by the protective liquid from the front-side coating nozzle 132.

[0084] Similar to the back surface side coating nozzle 151, a plurality of cleaning nozzles 141 may be provided. The cleaning nozzle 141 may also be provided upstream in the rotation direction of the wafer W from the supply position of the protective liquid from the front surface side coating nozzle 132. The cleaning nozzle 141 located downstream in the rotation direction of the wafer W from the supply position of the protective liquid from the front surface side coating nozzle 132 may be provided at a position shifted by 90° or more in the rotation direction of the wafer W from the supply position of the protective liquid from the front surface side coating nozzle 132.

[0085] <Another example of the back surface side coating nozzle 151> 12 to 14 are diagrams showing other examples of the back surface coating nozzle 151. FIG. The back surface coating nozzle 151 in FIG. 12 has a nozzle head 500, which is provided with a protective liquid discharge port 500a and a solvent discharge port 500b. The protective liquid outlet 500a is an example of a coating liquid outlet that discharges a coating liquid for forming a protective film, that is, a protective liquid. The solvent outlet 500b is provided separately from the protection liquid outlet 500a and discharges a solvent, for example, the same processing liquid as the cleaning liquid discharged from the cleaning nozzle 141.

[0086] For example, the nozzle head 500 has a vertical surface 501, on which a protective liquid outlet 500a is formed. The nozzle head 500 also has an outlet surface 502 extending perpendicularly from the vertical surface 501 in the direction in which the protective liquid is ejected from the protective liquid outlet 500a, and a solvent outlet 500b is formed above the outlet surface 502. The solvent outlet 500b ejects the solvent toward the vertical surface 501. Specifically, the solvent outlet 500b ejects the solvent toward the portion of the vertical surface 501 where the protective liquid outlet 500a is formed. That is, the angle at which the solvent is ejected from the solvent outlet 500b is such that the solvent directly hits the protective liquid outlet 500a. This allows for more reliable cleaning of the protective liquid outlet 500a and its surroundings. The solvent outlet 500b is also larger than the protective liquid outlet 500a. Therefore, a large amount of solvent can be discharged from the solvent discharge port 500b, and the protection liquid discharge port 500a and its surroundings can be cleaned in a short time.

[0087] The solvent discharge port 500b is formed on the discharge surface 502 closer to the spin chuck 111, i.e., closer to the inside, than the protective liquid discharge port 500a. The discharge surface 502 may be inclined downward from the inside to the outside. This allows the solvent or the like that is discharged from the solvent discharge port 500b, collides with the vertical surface 501, and then reaches the discharge surface 502 to flow downward and outward along the discharge surface 502 and be discharged from above the nozzle head 500.

[0088] The protective liquid ejection port 500a is connected to the protective liquid supply mechanism 133 described above via a protective liquid flow path (not shown) provided in the nozzle head 500. The solvent discharge port 500b is connected to a solvent supply mechanism (not shown) via a solvent flow path (not shown) provided in the nozzle head 500. The solvent supply mechanism has, for example, a supply pipe connected at one end to a solvent supply source. This supply pipe is provided with a group of supply devices for controlling the supply of solvent from the solvent supply source. The group of supply devices has, for example, a supply valve that switches between supplying and stopping the solvent and a flow rate adjustment valve that adjusts the flow rate of the solvent. The group of supply devices of the solvent supply mechanism is controlled by, for example, a control device 5.

[0089] 12 is used, a step is performed in which the protective liquid outlet 500a is cleaned with a solvent from the solvent outlet 500b. Specifically, a step is performed in which the protective liquid outlet 500a is cleaned with a solvent discharged from the solvent outlet 500b toward the vertical surface 501. In this step of cleaning the protective liquid outlet 500a, a dummy discharge of protective liquid may be performed from the protective liquid outlet 500a while cleaning with the solvent discharged from the solvent outlet 500b. This allows the solidified protective liquid to be removed if the protective liquid outlet 500a is clogged due to solidification, and also prevents the solvent from entering the protective liquid outlet 500a.

[0090] This cleaning process of the protective liquid discharge port 500a is performed after the wafer W, which has been subjected to steps S1a to S1g of step S1, is separated from the spin chuck 111. This is because if the solvent is discharged from the solvent discharge port 500b while the wafer W, on which a protective film has been formed on the back surface of the wafer W, is positioned on the spin chuck 111, the solvent may come into contact with the protective film on the back surface of the wafer W, causing unevenness in the protective film. Furthermore, if the protective liquid is also discharged during solvent discharge, the protective liquid may come into contact with the protective film on the back surface of the wafer W, causing unevenness in the film thickness or unevenness in the film thickness. In other words, by performing the above-described cleaning process of the protective liquid discharge port 500a while the wafer W is separated from the spin chuck 111, i.e., when the wafer W is not positioned on the spin chuck 111, it is possible to prevent unevenness in the protective film on the back surface of the wafer W due to the solvent or protective liquid, and unevenness in the film thickness of the protective film on the back surface of the wafer W.

[0091] Specifically, the cleaning process of the protective liquid discharge port 500a is performed after the wafer W, which has been subjected to steps S1a to S1g of step S1, is separated from the spin chuck 111 and before step S1e of step S1 (cleaning of the back surface and peripheral edge surface) is performed on the next wafer W. Therefore, after the wafer W, which has been subjected to steps S1a to S1g of step S1, is separated from the spin chuck 111, the cleaning process of the protective liquid discharge port 500a may be performed in parallel with step S1c of step S1 (supply of the protective liquid from the front surface side) on the next wafer W.

[0092] Furthermore, the cleaning process of the protective liquid discharge port 500a described above when the wafer W is separated from the spin chuck 111, i.e., when the wafer W is not positioned on the spin chuck 111, is performed, for example, every time n wafers W (n is an integer greater than or equal to 1) are processed. Furthermore, before and after steps S1a to S1g of step S1 are performed on multiple wafers W belonging to the same lot, the above-mentioned cleaning process of the protective liquid discharge port 500a may be performed in a state where no wafer W is positioned on the spin chuck 111.

[0093] 13 has a nozzle head 600. A protective liquid discharge port 500a and a solvent discharge port 500b are provided on the side of the nozzle head 600 opposite to the spin chuck 111 side, i.e., on an outer portion 610. Note that a connection port 600a to which a protective liquid supply pipe is connected and a connection port 600b to which a solvent supply pipe is connected are provided on the spin chuck 111 side of the nozzle head 600, i.e., on an inner portion 620.

[0094] The nozzle head 600 has a notch 611 in the outer portion 610, downstream in the protective liquid ejection direction from the protective liquid ejection port 500a. The protective liquid from the protective liquid ejection port 500a can reach this portion, but the solvent ejected from the solvent ejection port 500b (specifically, the solvent ejected from the solvent ejection port 500b and bounced off the vertical surface 501) is unlikely to reach this portion. Therefore, there is a risk that the protective liquid will remain in this portion. Providing the notch 611 can prevent this.

[0095] Furthermore, the nozzle head 600 has a surface 612 that extends from below the protective liquid ejection port 500a in the protective liquid ejection direction and is an inclined surface facing downward in the protective liquid ejection direction. Therefore, even if protective liquid lands on the surface 612 when ejection from the protective liquid ejection port 500a is stopped, the protective liquid can be guided along the inclined surface 612 to the outside of the nozzle head 600. Furthermore, the solvent ejected from the solvent ejection port 500b and bounced off the vertical surface 501 can be guided along the surface 612. Therefore, it is possible to prevent protective liquid from remaining on the surface 612. Furthermore, the protective liquid that has reached the underside of the nozzle head 600 through the surface 612 or the like can also be removed by the solvent that has similarly reached the underside of the nozzle head 600 through the surface 612 .

[0096] In the nozzle head 600, part of the solvent that is discharged from the solvent discharge port 500b and reaches the vertical surface 501 is bounced off the vertical surface 501 as described above and then flows along the surface 612, while the other part flows downward along the outer end surface 613 of the nozzle head 600 after reaching the vertical surface 501. The solvent flowing downward along the outer end surface 613 of the nozzle head 600 can also remove the protective liquid adhering to the underside of the nozzle head 600.

[0097] In the example shown in the figure, the surface 612 extends in the protective liquid ejection direction from the lower end of the vertical surface 501 where the protective liquid ejection port 500a is provided to the lower end of the nozzle head 600, and is formed by the above-mentioned inclined surface up to the outer end of the nozzle head 600.

[0098] 14 has a nozzle head 700. A protective liquid discharge port 500a and a solvent discharge port 500b are provided on the side of the nozzle head 700 opposite to the spin chuck 111 side, that is, on an outer portion 710 thereof.

[0099] The nozzle head 700, like the nozzle head 600 in FIG. 13, has a notch 611 in the outer portion 710 at the downstream side in the protective liquid ejection direction from the protective liquid ejection port 500a.

[0100] The nozzle head 700 also has a wall portion 711 that extends from a portion of the vertical surface 501 on which the protective liquid outlet 500a is provided, downstream of the protective liquid outlet 500a in the solvent outlet direction from the solvent outlet 500b, so as to face the solvent outlet 500b. Therefore, the wall portion 711 can block the solvent that is ejected from the solvent outlet 500b and bounced off the vertical surface 501, allowing the blocked solvent to flow in the protective liquid ejection direction to a portion 712 that extends from below the protective liquid outlet 500a in the protective liquid ejection direction. Therefore, even if the protective liquid lands on the portion 712 when ejection from the protective liquid outlet 500a is stopped, the protective liquid can be removed by the solvent.

[0101] Furthermore, the protective liquid that has reached the bottom surface of the nozzle head 700 through the portion 712 and the side surface 713 downstream in the protective liquid ejection direction can also be removed by the solvent that has similarly reached the bottom surface of the nozzle head 700 through the portion 712 and the side surface 713.

[0102] In the nozzle head 700, part of the solvent discharged from the solvent discharge port 500b and reaching the vertical surface 501 is blocked by the wall portion 711 and then flows along the portion 712, while the other part passes over the wall portion 711 and flows downward along the outer surface 711a of the wall portion 711. The solvent flowing downward along the outer surface 711a of the wall portion 711 can also remove the protective liquid adhering to the underside of the nozzle head 700.

[0103] In the example shown in the figure, the wall portion 711 is formed so as to extend vertically from the outer end of the vertical surface 501 on which the protective liquid outlet 500a is provided, and also to extend vertically upward from the outer end of the outlet surface 502.

[0104] Furthermore, the aforementioned portion 712 may be formed as an inclined surface like the surface 612 of the nozzle head 600 in FIG.

[0105] (Second embodiment) <Protective film forming device> FIG. 15 is an explanatory diagram showing the outline of the configuration of a protective film forming apparatus according to the second embodiment from a side view, and FIG. 16 is an explanatory diagram showing the outline from a plan view.

[0106] 15 and 16, a front-side cleaning nozzle 161 serving as a front-side cleaning liquid supply unit is supported on an arm 131 in addition to a front-side application nozzle 132. The front-side cleaning liquid supply unit supplies a cleaning liquid from the front side of the wafer W held by the spin chuck 111, and more specifically, supplies the cleaning liquid from the front side of the wafer W to outside the periphery of the wafer W. The front surface cleaning nozzle 161 and the front surface application nozzle 132 are arranged to be aligned along the direction in which the front surface application nozzle 132 moves, that is, the extension direction of the rail 130 (Y direction).

[0107] The cleaning liquid supplied by the front surface side cleaning nozzle 161 is the same as that supplied by the cleaning nozzle 141. The front surface side cleaning nozzle 161 is connected to a cleaning liquid supply mechanism 162. The supply mechanism 162 has, for example, a supply pipe 164 having one end connected to a cleaning liquid supply source 163. The supply pipe 164 is provided with a supply equipment group 165 for controlling the supply of the cleaning liquid from the supply source 163. The supply equipment group 165 has, for example, a supply valve that switches between supply and stop of the cleaning liquid and a flow rate adjustment valve that adjusts the flow rate of the cleaning liquid. The supply equipment group 165 is controlled by the control device 5, for example.

[0108] Furthermore, the discharge angle of the front surface side cleaning nozzle 161 in a plan view is set to be the same as the discharge angle of the front surface side application nozzle 132 in a plan view. Similarly, the discharge angle of the front surface side cleaning nozzle 161 in a side view (i.e., depression angle) is set to be the same as the discharge angle of the front surface side application nozzle 132 in a side view.

[0109] 15 and 16 is used, a process is performed in which the cup 120 to which the protective liquid has adhered is cleaned with the cleaning liquid from the front surface side cleaning nozzle 161. Specifically, in step S1c (first protective film forming process), a process is performed in which the mountain-shaped guide portion 121 to which the protective liquid, which has been supplied from the front surface side application nozzle 132 to the outside of the periphery of the wafer W, is cleaned with the cleaning liquid from the front surface side cleaning nozzle 161.

[0110] The cleaning process for the cup 120 (mountain-shaped guide portion 121) is performed, for example, during the cleaning process for the back surface and peripheral end surface in step S1e. The cleaning process for the mountain-shaped guide portion 121 may also be performed during the protective film drying process in step S1d.

[0111] Specifically, in the cleaning process of the mountain-shaped guide portion 121, for example, the front surface side cleaning nozzle 161 is moved to the aforementioned discharge start position Pb outside the periphery of the wafer W, and then the cleaning liquid is discharged from the front surface side cleaning nozzle 161 for a predetermined time while the position of the front surface side cleaning nozzle 161 is kept fixed at the discharge start position Pb. When the front surface side cleaning nozzle 161 is moved to the discharge start position Pb, a part of the front surface side cleaning nozzle 161 may overlap the wafer W in a plan view, as long as the cleaning liquid from the nozzle 161 does not hit the wafer W held by the spin chuck 111.

[0112] By cleaning the mountain-shaped guide portion 121 as described above, it is possible to prevent the protective liquid adhering to the mountain-shaped guide portion 121 from adversely affecting the processing of the wafer in the protective film forming apparatus 11 . Furthermore, by making the discharge angle of the front surface side cleaning nozzle 161 in a plan view and the discharge angle in a side view the same as those of the front surface side application nozzle 132, the protective liquid discharged from the front surface side application nozzle 132 and adhering to the mountain-shaped guide portion 121 can be more reliably removed by the cleaning liquid from the front surface side cleaning nozzle 161.

[0113] <Modification> In the above example, the protective film forming device 11 is provided in a coating system 2 that is different from the coating and developing device to which the exposure device is connected, but the protective film forming device 11 may be provided in the coating and developing device. That is, the protective film may be formed on the peripheral edge of the wafer W as described above by the protective film forming device 11 provided in the coating and developing device.

[0114] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The above-described embodiments may be omitted, substituted, or modified in various ways without departing from the scope and spirit of the appended claims. For example, the components of the above-described embodiments may be arbitrarily combined. Such an arbitrary combination naturally provides the functions and effects of each of the components involved in the combination, and also provides other functions and effects that are apparent to those skilled in the art from the description of this specification.

[0115] Furthermore, the effects described herein are merely descriptive or exemplary and are not limiting. In other words, the technology according to the present disclosure may achieve other effects that are apparent to those skilled in the art from the description of this specification, in addition to or in place of the above-described effects.

[0116] The following configurations also fall within the technical scope of the present disclosure. (1) A method for forming a protective film on the peripheral portion of a substrate having a plurality of patterning layers on its surface, comprising: (A) supplying the protective film-forming coating liquid from a front surface-side coating unit located on the front surface side of the substrate to the front surface of the substrate while rotating the substrate, thereby forming the protective film on the peripheral edge of the substrate; (B) after the step (A), supplying a cleaning liquid from a cleaning liquid supply unit located on the back surface side of the substrate to the back surface of the substrate while rotating the substrate, thereby cleaning the back surface and peripheral edge surface of the substrate; (C) after the step (B), supplying the coating liquid to the back surface of the substrate from a back surface coating unit located on the back surface side of the substrate while rotating the substrate, thereby forming the protective film on the back surface and peripheral edge surface of the peripheral portion of the substrate. (2) The protective film forming method described in (1), wherein the position on the back surface of the substrate from which the cleaning liquid supply unit supplies the cleaning liquid in step (B) is inside the position on the back surface of the substrate from which the back surface coating unit supplies the coating liquid in step (C). (3) The method for forming a protective film according to (1) or (2), wherein the rotation speed of the substrate in step (A), the rotation speed in step (C), and the rotation speed in step (B) are in decreasing order. (4) The method for forming a protective film according to any one of (1) to (3), wherein the process (A) moves the surface-side coating unit from outside the periphery of the substrate onto the periphery of the substrate, and also moves it from the periphery of the substrate to outside the periphery of the substrate, when the coating liquid is supplied. (5) (D) after the step (A) and before the step (B), the method further comprises a step of rotating the substrate in a state in which the coating liquid is not supplied to the substrate, and drying the protective film; The method for forming a protective film according to any one of (1) to (4), wherein the rotation speed of the substrate in the step (D) is increased stepwise. (6) The method for forming a protective film according to any one of (1) to (5), wherein during the step (D), the cleaning liquid is supplied from a front-side cleaning liquid supply unit located on the front side of the substrate to a position outside the periphery of the substrate, and a cup that receives the processing liquid dropped from the substrate is cleaned. (7) The method for forming a protective film according to any one of (1) to (6), wherein during the step (B), the cleaning liquid is supplied from a front-side cleaning liquid supply unit located on the front side of the substrate to a position outside the periphery of the substrate, and a cup that receives the processing liquid dropped from the substrate is cleaned. (8) The protective film forming method according to (6) or (7), wherein the ejection direction of the cleaning liquid from the front surface side cleaning liquid supply unit in a plan view and the ejection direction in a side view are the same as the ejection direction of the coating liquid from the front surface side coating unit in a plan view and the ejection direction in a side view, respectively. (9) The method for forming a protective film according to any one of (1) to (8), wherein the angle formed by the rotation direction of the substrate at the point of impact of the coating liquid from the front surface side coating unit on the substrate and the ejection direction of the coating liquid from the front surface side coating unit in a planar view is an acute angle. (10) (E) The method for forming a protective film according to any one of (1) to (9), further comprising, before the step (A), a step of supplying the cleaning liquid from the cleaning liquid supply unit located on the back side of the substrate to the back side of the substrate while rotating the substrate, thereby cleaning a cup surrounding the periphery of the substrate. (11)(F) The method for forming a protective film according to any one of (1) to (10), further comprising a step of cleaning the coating liquid discharge port of the backside coating part, which discharges the coating liquid, with a solvent from a solvent discharge port provided separately from the coating liquid discharge port of the backside coating part. (12) The method for forming a protective film according to (11), wherein the substrate on which steps (A) to (C) have been performed is separated from a rotary holder that rotatably holds the substrate, and then step (F) is performed. (13) The method for forming a protective film according to (11) or (12), wherein the step (F) includes cleaning the coating liquid outlet of the backside coating unit with the solvent while the coating liquid is being discharged from the coating liquid outlet. (14) The method for forming a protective film according to any one of (11) to (13), wherein in the step (F), a solvent is ejected from the solvent ejection port toward a wall surface on which the coating liquid ejection port of the back side coating section is provided. (15) The method for forming a protective film according to any one of (11) to (14), wherein the step (F) is carried out before and after the steps (A) to (C) are carried out on a plurality of substrates belonging to the same lot. (16) The method for forming a protective film according to any one of (1) to (15), further comprising a step of changing the ejection time in step (A) based on correlation data, previously acquired, between the coating width of the coating liquid from the front-side coating unit onto the substrate and the ejection time of the coating liquid from the front-side coating unit, and the set coating width. (17) The method for forming a protective film according to any one of (1) to (16), wherein the protective film is a protective film against a cleaning solution that removes a layer made of the same material as the base material of the substrate by batch processing. (18) A protective film forming apparatus for forming a protective film on a peripheral portion of a substrate having a plurality of patterning layers on its surface, comprising: a rotation holder that holds and rotates the substrate; a front surface side coating unit that supplies the coating liquid for forming the protective film to the surface of the substrate from the front surface side of the substrate; a cleaning liquid supply unit that supplies a cleaning liquid to the rear surface of the substrate from the rear surface side of the substrate; a back surface side coating unit that supplies the coating liquid to the back surface of the substrate from the back surface side of the substrate; a control unit, The control unit (A) supplying the coating liquid from the front-side coating unit onto the surface of the substrate while rotating the substrate, thereby forming the protective film on the peripheral edge of the substrate; (B) after the step (A), supplying a cleaning liquid from the cleaning liquid supply unit to the back surface of the substrate while rotating the substrate, thereby cleaning the back surface and peripheral edge surface of the substrate; (C) after the step (B), supplying the coating liquid from the back surface coating unit to the back surface of the substrate while rotating the substrate, thereby forming the protective film on the back surface and peripheral edge surface of the peripheral portion of the substrate. (19) The protective film forming apparatus described in (18), wherein the position on the back surface of the substrate from which the cleaning liquid supply unit supplies the cleaning liquid in step (B) is inside the position on the back surface of the substrate from which the back surface coating unit supplies the coating liquid in step (C). (20) The control unit is configured to further execute, after the step (A) and before the step (B), a step of rotating the substrate and drying the protective film without supplying the coating liquid to the substrate; The protective film forming apparatus according to (18) or (19) above, wherein the rotation speed of the substrate in the step (D) is increased stepwise. (21) The protective film forming device according to any one of (18) to (20), wherein the angle formed by the rotation direction of the substrate at the point of impact of the coating liquid from the front surface side coating unit on the substrate and the ejection direction of the coating liquid from the front surface side coating unit in a planar view is an acute angle. (22) The apparatus further includes a cup provided to surround the substrate held by the rotary holder, The protective film forming apparatus according to any one of (18) to (21), wherein the control unit is configured to further execute a step (E) before the step (A), in which the control unit supplies a cleaning liquid from the cleaning liquid supply unit located on the back side of the substrate to the back side of the substrate while rotating the substrate, thereby cleaning the cup. (23) The back side coating unit is a coating liquid discharge port that discharges the coating liquid; a solvent discharge port that is provided separately from the coating liquid discharge port and that discharges a solvent, The protective film forming apparatus according to any one of (18) to (22), wherein the control unit is configured to further execute (F) a step of cleaning a coating liquid discharge port with the solvent from the solvent discharge port. (24) The protective film forming device according to (23), wherein a notch is provided in a portion of the back side coating unit on the side of the coating liquid discharge port, downstream in the direction of discharge of the coating liquid from the coating liquid discharge port. (25) The protective film forming apparatus according to (23) or (24), wherein the surface of the backside coating unit extending from below the coating liquid discharge port in the direction of discharging the coating liquid is an inclined surface facing downward in the discharging direction. (26) The protective film forming device according to any one of (23) to (25), wherein the back surface coating unit has a wall portion extending from a portion downstream of the coating liquid discharge port in the discharge direction of the solvent from the solvent discharge port on the surface where the coating liquid discharge port is provided, so as to face the solvent discharge port. (27) A coating system having the protective film forming device according to any one of (18) to (25) above, a cleaning system including a cleaning device that removes a layer made of the same material as the base material of the substrate on which the protective film is formed by batch processing using a cleaning liquid; a removal system having a removal device that removes the protective film from the substrate. [Explanation of symbols]

[0117] 5. Control device 11 Protective film forming device 111 Spin Chuck 132 Surface application nozzle 141 Cleaning nozzle 151 Back side application nozzle CL cleaning solution F Protective film HL protection liquid PL patterning layer W wafer Wb3 Side end face (peripheral end face)

Claims

1. A method for forming a protective film on a peripheral edge of a substrate having a plurality of patterned layers on its surface, comprising: (A) while rotating the substrate, supplying a coating liquid for forming the protective film from a surface-side coating portion located on the surface side of the substrate onto the surface of the substrate to form the protective film on the peripheral edge of the substrate; (B) after the step (A), while rotating the substrate, supplying a cleaning liquid from a cleaning liquid supply portion located on the back side of the substrate onto the back surface of the substrate to clean the back surface and the peripheral end surface of the substrate; (C) after the step (B), while rotating the substrate, supplying the coating liquid from a back-side coating portion located on the back side of the substrate onto the back surface of the substrate to form the protective film on the back surface and the peripheral end surface of the peripheral edge of the substrate.

2. The position where the cleaning liquid supply portion supplies the cleaning liquid in the step (B) on the back surface of the substrate is inside the position where the back-side coating portion supplies the coating liquid in the step (C) on the back surface of the substrate. The method for forming a protective film according to Claim 1.

3. The rotation speed of the substrate in the step (A), the rotation speed in the step (C), and the rotation speed in the step (B) are low in this order. The method for forming a protective film according to Claim 1 or 2.

4. In the step (A), the surface-side coating portion is moved from outside the peripheral edge of the substrate onto the peripheral edge portion of the substrate and then moved from the peripheral edge portion of the substrate to outside the peripheral edge of the substrate when supplying the coating liquid. The method for forming a protective film according to Claim 1 or 2.

5. (D) further comprising, after the step (A) and before the step (B), rotating the substrate without supplying the coating liquid to dry the protective film; The rotation speed of the substrate in the step (D) is increased step by step. The method for forming a protective film according to Claim 1 or 2.

6. During the step (B) or the step (D), the cleaning liquid is supplied from a surface-side cleaning liquid supply portion located on the surface side of the substrate outside the peripheral edge of the substrate to clean a cup for receiving the processing liquid dropped from the substrate. The method for forming a protective film according to Claim 5.

7. The discharge direction in plan view and the discharge direction in side view of the cleaning liquid from the surface-side cleaning liquid supply portion are the same as the discharge direction in plan view and the discharge direction in side view of the coating liquid from the surface-side coating portion, respectively. The method for forming a protective film according to Claim 6.

8. The method for forming a protective film according to claim 1 or 2, wherein an angle formed by a rotation direction of the substrate at an impact point of the coating liquid from the surface-side coating portion on the substrate and a discharge direction of the coating liquid in a plan view from the surface-side coating portion is an acute angle.

9.

9. The method for forming a protective film according to claim 1 or 2, further comprising a step (F) of cleaning a coating liquid discharge port that discharges the coating liquid of the back surface-side coating portion with a solvent from a solvent discharge port provided separately from the coating liquid discharge port in the back surface-side coating portion.

10. The method for forming a protective film according to claim 9, wherein in the step (F), while discharging the coating liquid from the coating liquid discharge port of the back surface-side coating portion, the coating liquid discharge port is cleaned with the solvent.

11. The method for forming a protective film according to claim 9, wherein in the step (F), the solvent is discharged from the solvent discharge port toward a wall surface provided with the coating liquid discharge port of the back surface-side coating portion.

12. The method for forming a protective film according to claim 1 or 2, further comprising a step of changing the discharge time in the step (A) based on correlation data of a coating width of the coating liquid from the surface-side coating portion on the substrate and a discharge time of the coating liquid from the surface-side coating portion, which are acquired in advance, and the set coating width.

13. A protective film forming apparatus for forming a protective film on a peripheral portion of a substrate having a plurality of patterned layers on a surface, comprising: a rotary holding portion that holds and rotates the substrate; a surface-side coating portion that supplies a coating liquid for forming the protective film onto the surface of the substrate from the surface side of the substrate; a cleaning liquid supply portion that supplies a cleaning liquid onto the back surface of the substrate from the back surface side of the substrate; a back surface-side coating portion that supplies the coating liquid onto the back surface of the substrate from the back surface side of the substrate; a control portion, and the control portion is configured to execute: a step (A) of rotating the substrate and supplying the coating liquid from the surface-side coating portion onto the surface of the substrate to form the protective film on the peripheral portion of the substrate; a step (B) of, after the step (A), rotating the substrate and supplying the cleaning liquid from the cleaning liquid supply portion onto the back surface of the substrate to clean the back surface and the peripheral end surface of the substrate; and a step (C) of, after the step (B), rotating the substrate and supplying the coating liquid from the back surface-side coating portion onto the back surface of the substrate to form the protective film on the back surface and the peripheral end surface of the peripheral portion of the substrate.

14. In the film forming apparatus according to claim 13, the position on the back surface of the substrate where the cleaning liquid supply unit supplies the cleaning liquid in the step (B) is inside the position on the back surface of the substrate where the back surface side coating unit supplies the coating liquid in the step (C).

15. The control unit is configured to further execute a step of rotating the substrate in a state where the coating liquid is not supplied to the substrate after the step (A) and before the step (B) to dry the protective film. In the film forming apparatus according to claim 13 or 14, the rotation speed of the substrate in the step (D) is increased step by step.

16. The back surface side coating unit has a coating liquid discharge port for discharging the coating liquid, and a solvent discharge port for discharging a solvent provided separately from the coating liquid discharge port. In the film forming apparatus according to claim 13 or 14, the control unit is configured to further execute a step of cleaning the coating liquid discharge port with the solvent from the solvent discharge port.

17. In the film forming apparatus according to claim 16, a notch is provided in a portion on the coating liquid discharge port side of the back surface side coating unit and on the downstream side in the discharge direction of the coating liquid from the coating liquid discharge port.

18. In the film forming apparatus according to claim 16, the surface extending in the discharge direction of the coating liquid from below the coating liquid discharge port in the back surface side coating unit is an inclined surface facing downward in the discharge direction.

19. In the film forming apparatus according to claim 16, the back surface side coating unit has a wall portion extending so as to face the solvent discharge port from a portion on the surface where the coating liquid discharge port is provided and on the downstream side in the discharge direction of the solvent from the solvent discharge port with respect to the coating liquid discharge port.

20. A coating system having the film forming apparatus according to claim 13 or 14, a cleaning system having a cleaning apparatus for removing, by batch processing with a cleaning liquid, a layer made of the same material as the base material of the substrate on the substrate on which the protective film is formed, and a substrate processing system including a removing system having a removing apparatus for removing the protective film from the substrate.

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