Coating film removal device, coating film removal method and storage medium

Abstract

The present invention provides a coating film removal device, a coating film removal method and a storage medium for suppressing the generation of bulges (protuberances) at the ends of the coating film when the peripheral portion of the coating film formed on the surface of a wafer as a substrate is removed by using a removal liquid. When the removal liquid is sprayed from a removal liquid nozzle (3) to the peripheral portion of a wafer (W) rotating by a rotating chuck (11) to remove unnecessary films at the peripheral portion of the coating film, the supply position of the removal liquid is moved from the peripheral position to a cutting position on the inner side of the peripheral position while the wafer is rotated at a first rotation speed of more than 2300 rpm. Then, after the supply position reaches the cutting position, the supply position is moved from the cutting position to the peripheral side of the wafer within 1 second. By rotating the wafer at such a large rotation speed of more than 2300 rpm, a large centrifugal force is applied to the flow of the removal liquid on the surface of the wafer, and the removal liquid is pushed toward the outside of the wafer.

Description

Technical Field

[0001] The present invention relates to a coating film removal device, a coating film removal method and a storage medium for removing a peripheral portion of a coating film formed on a surface of a circular substrate using a removal liquid. Background Art

[0002] One of the processes performed in the photolithography process of forming a coating film pattern on a semiconductor wafer (hereinafter referred to as a wafer) as a substrate is an edge coating film removal (EBR) process in which a solvent is supplied to a wafer having a coating film formed on its surface to remove an unnecessary film at the edge of the coating film in a ring shape. In the EBR process, a solvent of the coating film is locally sprayed from a solvent nozzle to the edge of a wafer placed on a spin chuck and rotating.

[0003] In the above-mentioned EBR process, when removing the film at the peripheral portion of the coating film, in order to ensure the formation area of ​​the circuit pattern and improve the yield of the semiconductor device, it is required to suppress the generation of bulges (protuberances) near the boundary with the film removal area, that is, at the end of the coating film. As the number of photolithography steps increases with the refinement of the circuit, it is expected that the requirements for defects in the EBR process will become stricter, and therefore it is expected to develop a technology to suppress the generation of protuberances.

[0004] Patent Document 1 describes a technique in which a solvent is ejected from a solvent nozzle to dissolve a thin film at the edge of a substrate, and a gas is ejected from a gas nozzle to a portion after the solvent is ejected, thereby blowing the solvent outward from the edge of the substrate to remove the solvent. In this example, the gas nozzle is used to eject the gas toward the solvent from the upper and rear side. Therefore, when this method is applied to EBR processing, there is a possibility that the solvent of the coating film is scattered and the coating film other than the peripheral edge of the wafer is also removed, resulting in a deterioration in the shape of the end of the coating film.

[0005] In addition, Patent Document 2 discloses a technique in which a gas ejection unit is provided at a position inside the peripheral portion of the substrate relative to the processing liquid supply unit to correct the warping of the substrate that occurs when the processing liquid is supplied from the processing liquid supply unit to the peripheral portion of the substrate. When this method is applied to the EBR process, since the gas is ejected to a position closer to the outer edge of the wafer than the solvent of the coating film, it is not possible to expect to improve the shape of the coating film end near the solvent supply area.

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 6-196401 ( Figure 3 wait)

[0007] Patent Document 2: Japanese Patent Application Publication No. 2012-99833 (paragraph 0031 etc.) Summary of the invention

[0008] Problem that the invention aims to solve

[0009] The present invention is completed in view of such a situation, and its purpose is to provide a technology that can suppress the generation of bulges near the boundary with the removal area of ​​the coating film, that is, at the end of the coating film when the peripheral portion of the coating film formed on the surface of a circular substrate is removed using a removing liquid.

[0010] Solutions for solving problems

[0011] The coating film removal device of the present invention uses a removal liquid to remove the peripheral portion of a coating film formed by supplying a coating liquid to the surface of a circular substrate. The coating film removal device is characterized in that it comprises: a rotating holding portion that holds the substrate and rotates; a removing liquid nozzle that sprays the removing liquid to the peripheral portion of the surface of the substrate held by the rotating holding portion in a manner that the removing liquid is toward the downstream side of the rotation direction of the substrate; and a control portion that outputs a control signal so that the substrate rotates at a rotation speed of more than 2300 rpm when the removing liquid is sprayed.

[0012] In addition, the coating film removal method of the present invention is used to remove the peripheral portion of the coating film formed by supplying the coating liquid to the surface of a circular substrate using a removal liquid. The coating film removal method is characterized in that it includes the following steps: holding the substrate horizontally on a holding portion; and then rotating the substrate at a rotation speed of more than 2300 rpm, spraying the removal liquid from a removal liquid nozzle to the peripheral portion of the surface of the substrate in a manner toward the downstream side of the rotation direction of the substrate.

[0013] Furthermore, a storage medium of the present invention stores a computer program used in a coating film removal apparatus, and the storage medium is characterized in that steps for executing the coating film removal method of the present invention are incorporated into the program.

[0014] Effects of the Invention

[0015] According to the present invention, when removing the peripheral portion of the coating film on the surface of the substrate by using the removal liquid, the removal liquid is sprayed from the removal liquid nozzle toward the peripheral portion of the substrate surface, and the substrate is rotated at a speed of more than 2300 rpm when spraying the removal liquid. By rotating the substrate at such a large speed of more than 2300 rpm, a large centrifugal force is applied to the flow of the removal liquid on the surface of the substrate, and the removal liquid is pushed toward the outside of the substrate. Thus, the removal liquid is prevented from penetrating into the end of the coating film, thereby preventing the generation of bulges at the end of the coating film. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a longitudinal sectional side view showing one embodiment of a coating device to which the coating film removal device is applied.

[0017] Figure 2 It is a top view showing the coating device.

[0018] Figure 3 It is a top view showing a removing liquid nozzle provided in the coating device.

[0019] Figure 4 It is a longitudinal sectional side view showing the removal liquid nozzle.

[0020] Figure 5 It is a longitudinal sectional side view showing the operation of the coating device.

[0021] Figure 6 It is a longitudinal sectional side view showing the operation of the coating device.

[0022] Figure 7 It is a characteristic diagram showing the results of the evaluation test.

[0023] Figure 8 It is a characteristic diagram showing the results of the evaluation test.

[0024] Fig. 9 It is a characteristic diagram showing the results of the evaluation test.

[0025] Fig.10 It is a characteristic diagram showing the results of the evaluation test.

[0026] Fig.11 It is a characteristic diagram showing the results of the evaluation test.

[0027] Fig.12 It is a characteristic diagram showing the results of the evaluation test.

[0028] Fig.13 It is a characteristic diagram showing the results of the evaluation test.

[0029] Fig.14 It is a characteristic diagram showing the results of the evaluation test.

[0030] Fig.15 It is a characteristic diagram showing the results of the evaluation test.

[0031] Fig.16 It is a characteristic diagram showing the results of the evaluation test.

[0032] Fig.17 It is a characteristic diagram showing the results of the evaluation test.

[0033] Fig.18 It is a characteristic diagram showing the results of the evaluation test.

[0034] Fig.19 It is a characteristic diagram showing the results of the evaluation test.

[0035] Fig. 20It is a longitudinal cross-sectional side view of the wafer.

[0036] Fig.21 It is a characteristic diagram showing the results of the evaluation test.

[0037] Fig. 22 It is a characteristic diagram showing the results of the evaluation test.

[0038] Fig.23 is a top view of the wafer and the removal liquid nozzle.

[0039] Fig.24 Characteristic diagram showing the results of the evaluation test.

[0040] Fig.25 Characteristic diagram showing the results of the evaluation test.

[0041] Description of Reference Numerals

[0042] 1: coating device; 11: rotary chuck; 21: rotating mechanism; 3: removal liquid nozzle; 30: ejection outlet; 7: control unit; W: wafer; P: supply position. DETAILED DESCRIPTION

[0043] Reference Figure 1 The longitudinal section and Figure 2 An embodiment of a coating device 1 to which the coating film removal device of the present invention is applied is described in a top view. The coating device 1 is configured to be capable of performing a process of applying a coating liquid to a wafer W as a substrate to form a coating film and an EBR process. The wafer W is circular, and its diameter is, for example, 300 mm. In addition, a notch N is formed on the peripheral edge of the wafer W as a cutout indicating the direction of the wafer W.

[0044] 11 in the figure is a rotary chuck constituting a rotating holding portion for holding and rotating a wafer W. The rotary chuck 11 is configured to hold the wafer W horizontally by adsorbing the central portion of the back side of the wafer W, and is freely rotatable in a clockwise direction along a vertical axis when viewed from above by a rotating mechanism 21. The rotary chuck 11 is connected to the rotating mechanism 21 by a shaft 211, and a cup 22 is provided around the wafer W held by the rotary chuck 11. The cup 22 is exhausted via an exhaust pipe 23, and liquid spilled from the wafer W into the cup 22 is discharged by a drain pipe 24.

[0045] The exhaust pipe 23 is connected to an exhaust mechanism 232, which is an exhaust path in a factory, for example, via an exhaust volume adjustment unit 231 formed of a buffer, and the exhaust pipe 23 can adjust the pressure in the cup 22. Reference numeral 25 in the figure denotes a lifting pin, which is configured as follows: the lifting pin is lifted by the lifting mechanism 26, thereby transferring the wafer W between the transfer mechanism of the wafer W (not shown) and the spin chuck 11.

[0046] The coating device 1 includes a coating liquid nozzle 41 for spraying a coating liquid toward vertically downward, and a solvent nozzle 42 for spraying a solvent as a solvent of the coating liquid toward vertically downward. The coating liquid nozzle 41 is connected to a coating liquid supply mechanism 44 for supplying the coating liquid to the nozzle 41 via a flow path 43 having an on-off valve V1. The solvent nozzle 42 is a nozzle used in a pre-treatment before spraying the coating liquid onto the wafer W, and is connected to a solvent supply mechanism 46 for supplying the solvent to the nozzle 42 via a flow path 45 having an on-off valve V2. Figure 2 As shown, the coating liquid nozzle 41 and the solvent nozzle 42 are supported by an arm 48 and are movable between a central portion of the wafer W and a retracted position outside the cup 22. The arm 48 is raised and lowered by a moving mechanism 47 and is movable in the horizontal direction. Reference numeral 49 in the figure denotes a guide portion for moving the moving mechanism 47 in the horizontal direction as described above.

[0047] Furthermore, the coating device 1 is provided with a removal liquid nozzle 3 for performing the above-mentioned EBR treatment. The removal liquid nozzle 3 sprays the removal liquid toward the peripheral edge of the surface of the wafer W held by the spin chuck 11 in a manner that the removal liquid is directed toward the downstream side in the rotation direction of the wafer W. The removal liquid nozzle 3 is formed, for example, in a straight tube shape, and its front end opening is a spray port 30 for the removal liquid.

[0048] The removal liquid in this example is a solvent that is a solvent of the coating liquid, and the removal liquid nozzle 3 is configured such that: it is connected to the above-mentioned solvent supply mechanism 46 via a flow path 31 having an on-off valve V3, and the solvent (removal liquid) is independently supplied from the common solvent supply mechanism 46 to the solvent nozzle 42 and the removal liquid nozzle 3. In addition, the removal liquid nozzle 3 is configured as follows: Figure 2 As shown, the arm 33 is supported by the arm 33 and can be moved freely between a processing position for spraying the removal liquid toward the periphery of the wafer and a retreat position outside the cup 22. The arm 33 is configured to be able to be raised and lowered freely and to be able to be moved freely in the horizontal direction by the moving mechanism 32. Figure 2 In the figure, the moving direction of the removal liquid nozzle 3 is represented as the Y direction, and the horizontal direction perpendicular to the Y direction is represented as the X direction. In the figure, 34 is a guide for moving the moving mechanism 32 in the horizontal direction as described above.

[0049] like Figure 3 As shown in FIG. 1 , when the removal liquid nozzle 3 is viewed from above, the angle θ formed by the straight line connecting the ejection outlet 30 of the removal liquid nozzle 3 and the supply position P and the tangent line of the wafer W at the supply position P is set to, for example, 0 degrees. From the viewpoint of suppressing splashing, the angle θ is preferably small. That is, it is preferred that the tangent line L at the supply position P is consistent with the ejection direction of the removal liquid, but it is more preferably within 6 degrees. The so-called supply position P of the removal liquid is the landing position of the removal liquid ejected from the removal liquid nozzle 3 when it reaches the wafer surface. Figure 3 In FIG. 1 , a part of the outer edge Lw of the wafer W is indicated by a solid line, and a tangent line L of the wafer W at the supply position P and a discharge direction of the removal liquid are indicated by a dotted line.

[0050] In addition, if Figure 4 As shown, when the removal liquid nozzle 3 is observed in a vertical plane, the angle Z formed by the straight line connecting the removal liquid nozzle 3 and the supply position P and the surface of the wafer W is set to, for example, 10 degrees. From the viewpoint of suppressing splashing, the angle Z is preferably small. Therefore, it is preferably 20 degrees or less, but more preferably 15 degrees or less. In addition, the diameter A of the ejection port 30 of the removal liquid nozzle 3 is set to, for example, 0.15 mm to 0.35 mm, preferably 0.15 mm to 0.25 mm.

[0051] Furthermore, the coating device 1 is provided with a control unit 7. The control unit 7 is constituted by, for example, a computer and has a program storage unit (not shown). In the program storage unit, a program is stored in which commands (step groups) are compiled in such a manner that the coating film forming process and the EBR process described later can be performed. Furthermore, by using the program, control signals are output from the control unit 7 to each part of the coating device 1 to control the operation of each part of the coating device 1. Specifically, the following operations are controlled: opening and closing control of the opening and closing valves V1 to V3; movement of the removal liquid nozzle 3, the coating liquid nozzle 41, and the solvent nozzle 42 by the moving mechanisms 32 and 47; rotation of the rotary chuck 11 by the rotating mechanism 21; adjustment of the pressure in the cup 22 by the exhaust volume adjustment mechanism 231; and lifting and lowering of the lifting pin 25 by the lifting mechanism 26. The program is stored in the program storage unit in a storage medium such as a hard disk, an optical disk, a magneto-optical disk, or a memory card.

[0052] In addition, the control unit 7 of this example is configured to output a control signal for executing the first step and the second step in the EBR process. The so-called first step is a step of ejecting the removal liquid from the removal liquid nozzle 3 while moving the supply position P of the removal liquid from the peripheral position of the surface of the wafer W to the cutting position of the coating film closer to the center of the wafer W than the peripheral position while rotating the wafer W at a first rotation speed of more than 2300 rpm. A bevel portion W1 is provided at the periphery of the wafer W, but in this example, the peripheral position is a flat surface portion closer to the inner side than the bevel portion W1 and a position 0.1 mm to 0.3 mm closer to the inner side from the edge of the flat surface portion (the boundary between the bevel portion). In addition, the second step is a step of causing the removal liquid nozzle 3 to leave the cutting position to the peripheral side of the wafer W within 1 second, preferably within 0.5 seconds, after the supply position P reaches the cutting position.

[0053] Furthermore, the control unit 7 is configured to output a control signal for executing the following steps: after the second step, the supply position P is set between the cutting position and the peripheral position or at the peripheral position, and the wafer W is rotated at a second rotation speed lower than the first rotation speed while the removal liquid is ejected from the removal liquid nozzle 3. The second rotation speed is set, for example, to 500 rpm to 2000 rpm.

[0054] Next, the coating film formation process (coating film formation step) and the EBR process (EBR step) performed by the coating device 1 are described. First, the wafer W is transported and placed on the spin chuck 11 by a transport mechanism not shown in the figure. Then, the cup 22 is evacuated at an exhaust pressure of, for example, 65 Pa. Then, the solvent is sprayed from the solvent nozzle 42 onto the center of the wafer W. On the other hand, the wafer W is started to rotate, and the solvent is applied to the entire surface of the wafer W by centrifugal force, so that the wettability of the surface of the wafer W with respect to the coating liquid is improved. Thereafter, the coating liquid, in this example, the anti-etching liquid, is sprayed from the coating liquid nozzle 41 onto the center of the wafer W while the wafer W is rotated, and the coating liquid is applied to the entire surface of the wafer W by centrifugal force. Thereafter, the wafer W is rotated for a specified time to dry the liquid film, thereby forming a coating film 10.

[0055] Next, the EBR step is performed. In this process, for example, the exhaust volume in the cup 22 is set to be larger than the exhaust volume in the coating film forming step, and the exhaust pressure is set to be 50Pa or more, for example, 75Pa. Figure 5 As shown in (a), the first step is performed by moving the removal liquid nozzle 3 from the retreat position outside the wafer so that the supply position of the removal liquid becomes the peripheral position. Then, while the wafer W is rotated at a first rotation speed of 2300 rpm or more, the supply position P of the removal liquid is moved from the peripheral position to the first position as the cutting position, and the removal liquid is ejected from the removal liquid nozzle 3 at a flow rate of, for example, 20 ml / min to 60 ml / min, preferably at a flow rate of 55 ml / min or more ( Figure 5 (b)). The first position (cutting position) in this example is, for example, a position 2 mm from the outer edge of the wafer W toward the center of the wafer W. In addition, in the drawings, the ratio of dimensions is not necessarily accurate for the sake of technical understanding.

[0056] In the first step, in order to prevent the formation of bulges (protuberances) at the ends of the coating film, the wafer W needs to be rotated at a speed of 2300 rpm or more, but more preferably 2500 rpm or more, and more preferably 3000 rpm or more. For example, it is very preferably set to 4000 rpm. In addition, the upper limit of the rotation speed of the wafer W in the first step is, for example, 5000 rpm.

[0057] Next, the second step is performed. That is, after the supply position P of the removal liquid reaches the cutting position, the removal liquid nozzle 3 is immediately moved from the first position to the peripheral side of the wafer W, for example, without a waiting time. No waiting time means: for example, when there is no waiting time designed in the moving process of the removal liquid nozzle 3, the removal liquid nozzle 3 also stops at the cutting position for, for example, about 0.1 to 0.5 seconds, or 0.1 seconds in this example, from the action of the driving mechanism. After the supply position of the removal liquid reaches the first position, it is necessary to move the removal liquid nozzle 3 to the peripheral side immediately, and the so-called immediately means, for example, within 1 second. Therefore, for example, this step is the following steps: after the supply position P of the removal liquid reaches the cutting position, the removal liquid nozzle 3 leaves the peripheral side of the wafer W without substantially stopping.

[0058] The removing liquid is ejected from the removing liquid nozzle 3 toward the downstream side in the rotation direction of the wafer W and in a manner such that the extension line of the ejection trajectory of the removing liquid is toward the outside of the peripheral portion of the coating film. In addition, the wafer W is rotated at a high speed of more than 2300 rpm, so a large centrifugal force is generated, so that the liquid flow of the removing liquid flows rapidly in a manner such that it is pushed outward from the wafer W. Thus, in the supply area of ​​the removing liquid, the coating film 10 is softened and dissolved by the removing liquid, and the removing liquid including the components of the dissolved coating film is pushed outward from the wafer W and removed by the large centrifugal force.

[0059] After the second step is performed in this way, a step of cleaning the beveled portion W1 of the wafer end face is performed. This step is as follows: the supply position P of the removal liquid is set between the first position and the peripheral position or is set to the peripheral position, and the wafer W is rotated at a second rotation speed, i.e., 500 rpm to 2000 rpm, for example, 1000 rpm, while the removal liquid is sprayed from the removal liquid nozzle 3 ( Figure 5 (c)). For example Figure 5 As shown in (c), the supply position (second position) of the removal liquid in this step is 0.5 mm inward of the wafer W from the outer edge of the wafer W. In this step, the removal liquid is continuously supplied to the second position for, for example, more than 1 second, in this example, 5 seconds.

[0060] The second rotation speed when the removal liquid is sprayed to the second position is lower than the first rotation speed when the removal liquid is sprayed to the first position. Therefore, the flow of the removal liquid is pushed toward the outer side of the wafer W at a slower speed than the speed when sprayed to the first position by centrifugal force, thereby suppressing the splashing phenomenon of the removal liquid sprayed to the wafer W from the rotating wafer W, and flowing in a manner of going around from the outer edge of the wafer W to the back side. In this way, in the beveled portion W1 of the end face of the wafer W, the removal liquid also spreads to the back side, so that the components attached to the beveled portion W1 are cleaned by the removal liquid.

[0061] After removing the unnecessary peripheral edge portion of the coating film and cleaning the bevel portion W1, the exhaust volume is restored to the exhaust volume when the coating film is formed, for example, the ejection of the removing liquid from the removing liquid nozzle 3 is stopped, and the removing liquid nozzle 3 is moved to the standby position ( Figure 5 (d)). Then, the rotation of the wafer W is stopped, and the wafer W is carried out of the coating device 1 by a transport mechanism (not shown).

[0062] According to the above-mentioned embodiment, when a removal liquid is supplied to the peripheral portion of the coating film on the surface of the wafer to remove the unnecessary coating film on the peripheral portion, the wafer W is rotated at a rotation speed of more than 2300 rpm when the removal liquid is sprayed. Therefore, a large centrifugal force is generated, and the flow of the removal liquid flows in a manner of being pushed out toward the outer side of the wafer W. Thus, it is possible to suppress the removal liquid at the cutting position from penetrating the end of the coating film, thereby suppressing the generation of a force to lift the end of the coating film. In this way, the unnecessary peripheral portion of the coating film can be removed while suppressing the generation of a bulge (protuberance) at the end of the coating film. In addition, as will be clear from the evaluation test described later, the height of the protuberance caused by the EBR process can be reduced regardless of the type of the removal liquid.

[0063] In addition, after the supply position P of the removal liquid reaches the cutting position, the supply position P is immediately moved from the cutting position to the peripheral side, for example, within 1 second, so that the removal liquid supplied to the cutting position flows rapidly from the cutting position toward the peripheral side of the wafer W due to a large centrifugal force. Therefore, it is possible to suppress the removal liquid at the cutting position from penetrating the end of the coating film, and the formation of ridges can be further suppressed. In addition, after the supply position P of the removal liquid reaches the cutting position, the supply position P is moved from the cutting position to the peripheral side within 1 second, thereby shortening the time required for the EBR process, which helps to improve productivity.

[0064] In addition, when the rotation speed of the wafer W during the EBR step is high, there is a possibility that the bevel portion W1 may not be sufficiently cleaned, but by performing a cleaning step of spraying the removal liquid to a position outside the cut position of the coating film, the cleanliness at the bevel portion W1 can be improved. In this cleaning step, the second rotation speed is lower than the first rotation speed, and the supply time of the removal liquid at the second position is long, but since the second position is closer to the peripheral side of the wafer W than the first position, it is possible to suppress the removal liquid from penetrating the end of the coating film. In this way, in the cleaning step, the size of the second rotation speed, the second position, and the stop time when the supply position is set to the second position are determined in a manner that can suppress the generation of ridges and can fully clean the bevel portion W1.

[0065] On the other hand, it can be recognized that when the rotation speed of the wafer W is increased when the removal liquid is supplied, splashing occurs, and the mist of the removal liquid scattered by the splashing reattaches to the wafer W to form mist-like defects (wet particles), and the number of defects on the peripheral edge of the wafer increases. Therefore, in the above-mentioned embodiment, the occurrence of the splashing phenomenon is suppressed by optimizing the angle of the removal liquid nozzle 3, resulting in a reduction in the number of defects. That is, the removal liquid nozzle 3 of this embodiment is set to form the angle θ within 6 degrees and the angle Z below 20 degrees. Thus, the removal liquid is sprayed from the removal liquid nozzle 3 slightly inclined upward relative to the horizontal plane to the surface of the wafer W in a general direction of rotation. Therefore, when the removal liquid is supplied to the wafer W rotating at a high speed, the impact force when the removal liquid hits the surface of the wafer W becomes smaller, and the removal liquid is easily compatible with the wafer W, thereby preventing splashing. In addition, since splashing can be prevented, the attachment of wet particles to the peripheral edge of the wafer can also be reduced.

[0066] Furthermore, in the EBR step, the wet particles can be improved by setting the inside of the cup 22 to a high pressure exhaust state of, for example, 50 Pa or more. This is because the removal liquid in the form of mist caused by splashing is quickly exhausted from the exhaust path.

[0067] It can also be recognized that when the rotation speed of the wafer W when the removal liquid is supplied is increased, the cutting accuracy of the cut surface of the coating film (the end surface at the cutting position of the coating film) decreases, and when viewed from above, the cut surface is rough and the smoothness decreases. Therefore, in this embodiment, the diameter A of the ejection port 30 of the removal liquid nozzle 3 is reduced, that is, it is set to 0.15mm~0.35mm. As a result, the ejection pressure of the removal liquid becomes larger, and the cutting force of the removal liquid at the cutting position of the coating film increases, so the cutting accuracy of the cut surface is improved. In addition, in this example, the ejection flow rate of the removal liquid when the supply position P is moved from the peripheral position to the first position (cutting position) is set to 20ml / min~60ml / min. As a result, the ejection pressure of the removal liquid becomes larger, and the cutting accuracy of the cut surface is further improved.

[0068] (Second Embodiment)

[0069] This embodiment is different from the above-mentioned embodiment in that the control unit 7 is configured to output a control signal for repeating the first step and the second step a plurality of times. Figure 6 As shown in (a), the removal liquid nozzle 3 is moved from the retreat position outside the wafer to the peripheral position. Then, while the wafer W is rotated at a first rotation speed of 2300 rpm or more, the supply position P of the removal liquid is moved from the peripheral position of the surface of the wafer W to the cutting position, i.e., the first position, and the removal liquid is ejected from the removal liquid nozzle 3 at a flow rate of, for example, 20 ml / min to 60 ml / min (the first step, Figure 6Next, after the supply position P of the removal liquid reaches the cutting position, the supply position P is immediately moved from the first position to the peripheral position, for example, within 1 second (the second step, Figure 6 (c)). In the second step, the removal liquid is ejected from the removal liquid nozzle 3 at a flow rate of 20 ml / min to 60 ml / min while the wafer W is rotated at a first rotation speed of 2300 rpm or more. In this way, the first step and the second step are repeated multiple times, for example, five times.

[0070] By performing the first step and the second step in this way, as described above, the generation of ridges can be suppressed and the unnecessary peripheral portion of the coating film can be removed. In addition, by repeating the first step and the second step, the cutting force of the removal liquid at the cut position of the coating film is increased, so as can be clearly seen from the evaluation test described later, the cutting accuracy of the cut surface is improved. In addition, by repeating the first step and the second step, the removal liquid can easily go around from the end of the wafer W to the back side, and the bevel portion W1 can be cleaned. In addition, the cleaning step of the first embodiment can also be implemented after repeating the first step and the second step as in the second embodiment.

[0071] As already mentioned, by rotating the wafer W at a high speed when the removal liquid is sprayed, the generation of ridges can be suppressed, and the unnecessary peripheral portion of the coating film can be removed. As can be clearly seen from the evaluation test described later, the higher the rotation speed of the wafer W, the lower the height of the ridge at this time. On the other hand, when the rotation speed of the wafer W becomes higher, there is a tendency for splashing to occur, resulting in defects, or reducing the smoothness of the cut surface. Based on this situation, the inventors of the present invention have found that by rotating the wafer W at a rotation speed of more than 2300 rpm when the removal liquid is sprayed, the generation of ridges can be suppressed compared to the past, and the unnecessary peripheral portion of the coating film can be removed.

[0072] [Example]

[0073] Next, through Figures 7 to 19 The evaluation test of the present invention will be described.

[0074] (Evaluation Test 1: Evaluation of Height of Protrusion)

[0075] The coating film forming step and the EBR step were performed while the wafer W was rotated at 1000rpm, 2000rpm, 3000rpm, and 4000rpm, and the height of the bulge at the end of the processed coating film was evaluated. The coating film was set to the liquid A as the SOC (Spin On Carbon) material, the removal liquid was set to the OK-73 diluent, and the cutting position was set to the position 2.5mm inside from the outer edge of the wafer. The height of the bulge at each rotation speed was measured when the stop time of the supply position at the cutting position was 5 seconds and when the stop time was 0 seconds. The bulge height was calculated using a step measuring instrument, and the height from the coating film was set as the bulge height. The bulge height was evaluated similarly for multiple wafers W.

[0076] exist Figure 7 The result is shown in . In the figure, the vertical axis is the ridge height (nm), and the horizontal axis records the stop time and rotation speed of the supply position of the removal liquid at the cut-off position. Regarding the average value of the ridge height when the stop time is 5 seconds, the average value is 724.92nm when the rotation speed is 1000rpm, the average value is 481.31nm when the rotation speed is 2000rpm, the average value is 302.48nm when the rotation speed is 3000rpm, and the average value is 256.49nm when the rotation speed is 4000rpm. In addition, regarding the average value of the ridge height when the stop time is 0 seconds, the average value is 512.99nm when the rotation speed is 1000rpm, the average value is 312.97nm when the rotation speed is 2000rpm, the average value is 240.76nm when the rotation speed is 3000rpm, and the average value is 209.35nm when the rotation speed is 4000rpm.

[0077] It was confirmed that in both cases when the stop time was 5 seconds and 0 seconds, the higher the rotation speed, the lower the ridge height. In addition, it was also confirmed that when the rotation speed was the same, the unnecessary film could be removed even when the stop time was 0 seconds, and the ridge height became lower. Therefore, it can be understood that when the rotation speed is high, the force of pushing the removal liquid supplied to the cutting position toward the outer edge of the wafer W is increased by the large centrifugal force, and the cutting force at the cutting position increases. Therefore, even if the stop time is 0 seconds, the unnecessary film can be fully removed.

[0078] In addition, after the same evaluation was performed by changing the coating film to the chemical solution B as the resist solution, the chemical solution C as the SOC material, the chemical solution D as the resist, and the chemical solution E as the SiARC material, and changing the removal liquid to the OK-73 diluent and cyclohexanone, it was confirmed that the higher the rotation speed, the lower the ridge height, and when the rotation speed is the same, the ridge height is low when the stop time is 0 seconds. Therefore, it can be understood that the method of the present invention can reduce the ridge height without depending on the type of coating film and removal liquid.

[0079] As such, the higher the rotation speed of the wafer W, the lower the ridge height. However, from the perspective of the ridge height transition, the change in the ridge height becomes smaller when it exceeds 3000 rpm, so it is found that a rotation speed of 2300 rpm or more can fully contribute to the reduction of the ridge height. In addition, regarding the stop time at the supply position, it is found that the average value of the ridge height when the stop time is 5 seconds and the rotation speed is 3000 rpm is lower than the average value of the ridge height when the stop time is 0 seconds and the rotation speed is 2000 rpm, so if the stop time is within 1 second, the ridge height can be reduced.

[0080] (Evaluation Test 2: Liquid Splashing Evaluation)

[0081] The coating film forming step and the EBR step are performed, and the presence or absence of splashing is evaluated by taking a moving image of the processing state. At this time, regarding the removal liquid nozzle 3, the angle θ formed is changed to 0 degrees and 8.5 degrees, the angle Z formed is changed to 10 degrees, 20 degrees, and 30 degrees, and the ejection flow rate of the removal liquid is changed to 13 ml / min, 20 ml / min, and 30 ml / min, respectively, and the same evaluation is performed. The maximum rotation speed without splashing is calculated for each case. The coating film is set to the chemical solution A, the removal liquid is set to the OK-73 diluent, the cutting position is set to a position 2.5 mm inward from the outer edge of the wafer, and the stop time of the supply position at the cutting position is set to 10 seconds.

[0082] exist Figure 8The result is shown in . In the figure, the horizontal axis is the maximum rotation speed (rpm) without splashing, and the vertical axis represents the angle of the removal liquid nozzle 3 (the angle θ, Z formed) and the discharge flow rate (ml / min). As a result, it can be recognized that when the angle θ formed by the removal liquid nozzle 3 and the tangent is compared, the maximum rotation speed is large when the angle θ is 0 degrees, and when the angle Z formed with the wafer surface is compared, the maximum rotation speed is larger when the angle Z is 10 degrees and 20 degrees than when the angle Z is 30 degrees. Therefore, it can be understood that by adjusting the angle θ formed and the angle Z formed, splashing can be reduced. In addition, it can be recognized that even if the angle θ and the angle Z formed by the removal liquid nozzle 3 are the same, the maximum rotation speed will change according to the discharge flow rate. In addition, after forming a coating film on a wafer W with ±300μm unevenness and performing EBR treatment using a removal liquid nozzle 3 with a formed angle θ of 8.5 degrees and a formed angle Z of 30 degrees and a removal liquid nozzle 3 with a formed angle θ of 0 degrees and a formed angle Z of 10 degrees, it was confirmed that the cutting accuracy was improved in the removal liquid nozzle 3 with a formed angle θ of 0 degrees and a formed angle Z of 10 degrees.

[0083] As a result of the above processing, it was confirmed that when the angle θ formed was 8.5 degrees, if the angle Z formed was less than 20 degrees, the maximum rotation speed exceeded 2300 rpm. Based on this, it was found that if the angle θ formed was within 6 degrees, the spray flow rate and the angle Z formed could reduce splashing even if the maximum rotation speed was above 2300 rpm, and if the angle Z formed was within 20 degrees, the spray flow rate and the angle θ formed could reduce splashing even if the maximum rotation speed was above 2300 rpm.

[0084] (Evaluation Test 3: Defect Evaluation)

[0085] After the coating film formation step, the wafer W is rotated at 4000 rpm, and the removing liquid is sprayed from the removing liquid nozzle 3 while the removing liquid nozzle 3 is reciprocated once between the peripheral position and the cutting position of the wafer W to perform the EBR step. The number of defects (wet particles) is evaluated by extracting mist-like defects using an SEM (scanning electron microscope).

[0086] At this time, the removal liquid nozzle 3 with the angle θ formed being 0 degrees, the angle Z formed being 10 degrees, and the diameter A of the discharge port 30 being 0.2 mm and the removal liquid nozzle 3 with the angle θ formed being 8.5 degrees, the angle Z formed being 30 degrees, and the diameter A of the discharge port 30 being 0.3 mm were used. The coating film was formed using the chemical solution A, the removal liquid was formed using the OK-73 thinner, the exhaust pressure in the coating film formation step was 65 Pa, and the exhaust pressure in the cup 22 in the EBR step was 75 Pa. In addition, the stop time of the supply position at the cutting position was set to 0 seconds, and the cutting position (cutting width) was changed for evaluation.

[0087] exist Fig. 9 The results of the same evaluation of three wafers W under various conditions are shown in FIG. The horizontal axis in the figure represents the conditions of the cutting width and the removal liquid nozzle 3, and the vertical axis represents the number of mist defects with a size of 50 nm or more. As a result, it can be confirmed that the number of mist defects is greatly reduced by using a removal liquid nozzle 3 with an angle θ of 0 degrees and an angle Z of 10 degrees. Through evaluation test 2, it can be recognized that splashing is reduced by optimizing the angle θ formed by the removal liquid nozzle 3, so it can be inferred that the mist defects are reduced because the splashing is suppressed.

[0088] (Evaluation Test 4-1: Exhaust Pressure Evaluation)

[0089] After the coating film formation step, the wafer W is rotated at 4000 rpm, and the removal liquid is sprayed from the removal liquid nozzle 3 while the removal liquid nozzle 3 is reciprocated 60 times between the peripheral position of the wafer W and the cutting position to perform the EBR step, and the number of defects is evaluated using SEM. At this time, the removal liquid nozzle 3 with a formed angle θ of 0 degrees, a formed angle Z of 10 degrees, and a diameter A of the nozzle 30 of 0.2 mm is used. Assuming that the coating film uses the resist, that is, the chemical solution B, the removal liquid uses the OK-73 diluent, the stop time of the supply position at the cutting position is 0 seconds, the cutting width is 2 mm, and the spray flow rate is 25 ml / min, the exhaust pressure of the cup 22 during the EBR step is changed to perform the treatment and evaluation. In addition, the removal liquid nozzle 3 is rotated 60 times because: the number of defects increases due to the increase in the number of treatments, so increasing the number of defects can more accurately grasp the occurrence of defects.

[0090] exist Fig.10 The results of the same evaluation of three wafers W under different conditions are shown in FIG. The horizontal axis in the figure represents the exhaust pressure in the cup 22, and the vertical axis represents the number of defects with a size of 50 nm or more. As a result, it can be confirmed that the number of defects decreases when the exhaust pressure in the cup 22 becomes higher, and defects occur below 50 Pa when the rotation speed is 4000 rpm.

[0091] (Evaluation Test 4-2: Exhaust Pressure Evaluation)

[0092] The rotation speed of the wafer W was changed to 3500 rpm, and the other conditions were kept the same, and the evaluation was performed in the same manner as in (Evaluation Test 4-1). Fig.11 2 shows the results of the same evaluation of three wafers W under various conditions. The horizontal axis in the figure represents the exhaust pressure in the cup 22, and the vertical axis represents the number of defects with a size of 50 nm or more. As a result, it can be confirmed that defects occur below 30 Pa when the rotation speed is 3500 rpm.

[0093] (Evaluation Test 4-3: Exhaust Pressure Evaluation)

[0094] The rotation speed of the wafer W was changed to 3000 rpm, and the other conditions were kept the same, and the evaluation was performed in the same manner as in (Evaluation Test 4-1). Fig.12 2 shows the results of the same evaluation of three wafers W under different conditions. The horizontal axis in the figure represents the exhaust pressure in the cup 22, and the vertical axis represents the number of defects with a size of 50 nm or more. As a result, it can be confirmed that defects are generated at an exhaust pressure of 23 Pa when the rotation speed is 3000 rpm.

[0095] (Evaluation Test 4-4: Exhaust Pressure Evaluation)

[0096] After the coating film formation step, the rotation speed of the wafer W was set to 3000 rpm, 3500 rpm, and 4000 rpm, and the removal liquid was sprayed from the removal liquid nozzle 3 while the removal liquid nozzle 3 was moved from the peripheral position of the wafer W to the cutting position at one time to perform the EBR step, and the other conditions were kept the same and the evaluation was performed in the same manner as (Evaluation Test 4-1). Fig.13 The results of the same evaluation of three wafers W under various conditions are shown in the figure. In the figure, the horizontal axis represents the exhaust pressure in the cup 22, and the vertical axis represents the number of mist defects with a size of 50nm or more. As a result, it can be recognized that defects are likely to occur when the rotation speed of the wafer W becomes higher, but the number of defects can be reduced by increasing the exhaust pressure in the cup 22. In addition, it can be confirmed that when compared under the same exhaust pressure (75Pa, 90Pa), the number of mist defects is small at high rotation speed. It is speculated that the reason is that when the rotation speed is reduced, splashing is likely to occur in the notch portion of the wafer W, and the number of mist defects increases due to this reason.

[0097] (Evaluation Test 5-1: Evaluation of Cleaning of Beveled Areas)

[0098] After the coating film formation step, the wafer W is rotated at 4000 rpm, and the stop time at the first position (cutting position) is set to 0 seconds to perform the EBR step. Then, the supply position is moved to the second position, and the wafer W is rotated at 2000 rpm to perform the cleaning step. The stop time at the second position is changed between 1 second and 5 seconds, and the bevel inspection device is used to confirm the cleanliness of the bevel portion W1. The removal liquid nozzle 3 uses a nozzle with a formed angle θ of 0 degrees, a formed angle Z of 10 degrees, and a nozzle with a diameter A of 0.2 mm of the nozzle 30. The coating film is set to liquid B, the removal liquid is OK-73 diluent, the cutting position is 2 mm inward from the outer edge of the wafer, and the second position is 0.5 mm inward from the outer edge of the wafer.

[0099] As a result, it was confirmed that the cleanliness of the beveled portion W1 was improved by performing the cleaning step after the EBR step, and the cleanliness of the beveled portion W1 was improved by extending the supply time of the removal liquid at the second position. It was confirmed that if the supply time of the removal liquid at the second position was 3 seconds or more, the contamination of the beveled portion W1 could be improved.

[0100] (Evaluation Test 5-2: Evaluation of Cleaning of Beveled Areas)

[0101] The EBR step and the cleaning step were performed in the same manner as in (Evaluation Test 5-1). The stop time at the second position was set to 5 seconds, the rotation speed of the wafer W (second rotation speed) and the exhaust pressure in the cup 22 in the cleaning step were changed, and the cleanliness of the beveled portion was confirmed. The coating film was set to be the chemical solution B, the removal liquid was set to be the OK-73 diluent, the cutting position was set to be 2 mm inward from the outer edge of the wafer, and the second position was set to be 0.5 mm inward from the outer edge of the wafer. In addition, the same evaluation was performed for the case where the cleaning step was not performed.

[0102] exist Fig.14 The results of the same evaluation of three wafers W under various conditions are shown in FIG. The horizontal axis in the figure represents the processing conditions such as the exhaust pressure and the rotation speed, and the vertical axis represents the number of defects with a size of 50 nm or more. The stop time at the second position and the condition of the second rotation speed not recorded are the cases where the cleaning step is not performed. As a result, under the conditions of the exhaust pressure of 90Pa and the second rotation speed of 1000rpm, although there are wafers W with a large number of defects, the number of defects of the remaining wafers W under this condition is small, so it can be said that even if the cleaning step is performed, no deterioration in the number of defects is confirmed.

[0103] In addition, in (Evaluation Test 5-2), the number of mist-like defects with a size of 50 nm or more was evaluated by defect review-SEM (Defect Review-Scanning Electron Microscope). Fig.15 The results are shown in . In this case as well, it was confirmed that the number of defects did not deteriorate by performing the cleaning step.

[0104] (Evaluation Test 6-1: Cut Surface Evaluation)

[0105] After the coating film forming step, the EBR step was performed with the stop time at the cutting position set to 0 seconds. At this time, the removal liquid nozzle 3 with the angle θ formed being 0 degrees, the angle Z formed being 10 degrees, and the diameter A of the ejection port 30 being 0.3 mm and the removal liquid nozzle 3 with the angle θ formed being 8.5 degrees, the angle Z formed being 30 degrees, and the diameter A of the ejection port 30 being 0.3 mm were used. The coating film was set to the chemical solution A, the removal liquid was set to the OK-73 diluent, and the cutting width was set to 2.5 mm. The EBR step was performed by changing the ejection flow rate and the rotation speed, and the evaluation was performed. The smoothness of the cut surface was evaluated using a bevel inspection device.

[0106] exist Fig.16 The results of the same evaluation of three wafers W under various conditions are shown in FIG. The horizontal axis in the figure represents the processing conditions such as the ejection flow rate and the rotation speed, and the vertical axis represents the smoothness of the cut surface (mm), showing that the smaller the value, the less rough the cut surface is and the higher the smoothness is. As a result, it can be confirmed that when the removal liquid nozzle 3 with a formed angle θ of 0 degrees and a formed angle Z of 10 degrees is used, the smoothness of the cut surface is poor, and when the rotation speed is increased, the smoothness is still poor, but the smoothness can be improved by increasing the ejection flow rate.

[0107] (Evaluation Test 6-2: Cut Surface Evaluation)

[0108] The smoothness of the cut surface was evaluated by using a removal liquid nozzle 3 with an angle θ of 0 degrees and an angle Z of 10 degrees, setting the diameter A of the nozzle 30 to 0.3 mm and 0.2 mm, and keeping other conditions the same as (Evaluation Test 6-1). Fig.17 The results are shown in FIG. The horizontal axis in the figure represents the processing conditions such as the ejection flow rate and the rotation speed, and the vertical axis represents the smoothness of the cut surface (mm). As a result, it can be confirmed that in the removal liquid nozzle 3 where the angle θ formed is 0 degrees and the angle Z formed is 10 degrees, the smoothness of the cut surface is improved by reducing the diameter A of the ejection port 30. In addition, it can be confirmed that the smoothness can also be improved by increasing the ejection flow rate.

[0109] When the diameter A of the removal liquid nozzle 3 is 0.3 mm, when the discharge flow rate is 27 ml / min, the smoothness at the rotation speeds of 3500 rpm and 4000 rpm is roughly the same, so it is found that the diameter A of the discharge port 30 of the removal liquid nozzle 3 is 0.15 mm to 0.35 mm. In addition, in the comparison of the diameters A of 0.3 mm and 0.2 mm when the discharge flow rate is 20 ml / min, the smoothness at 0.2 mm is good when the rotation speed is 2900 rpm or more, so it can be said that if the diameter A of the discharge port 30 of the removal liquid nozzle 3 is 0.15 mm to 0.25 mm, the smoothness of the cut surface can be fully improved.

[0110] (Evaluation Test 6-3: Cut Surface Evaluation)

[0111] After the coating film formation step, the wafer W is rotated at 4000 rpm, and the stop time at the cutting position is set to 0 seconds to perform the EBR step. Next, the supply position is moved to the second position, the stop time at the second position is set to 5 seconds, and the wafer W is rotated at 2000 rpm to implement the cleaning step. The smoothness of the cut surface is confirmed by changing the ejection flow rate of the removal liquid in the EBR step and the cleaning step. Assume that the coating film is liquid A, the removal liquid is OK-73 diluent, the diameter A of the ejection port 30 is 0.2 mm, the cutting position is 2 mm inward from the outer edge of the wafer, and the second position is 0.5 mm inward from the outer edge of the wafer.

[0112] exist Fig.18 The result is shown in . In the figure, the horizontal axis is the ejection flow rate, the vertical axis is the smoothness of the cut surface (mm), and Ref is the data when the removal liquid nozzle 3 with a formed angle θ of 8.5 degrees and a formed angle Z of 30 degrees is used, the stop time at the cutting position is 5 seconds, and the rotation speed of the wafer W is 2000rpm. As a result, it can be recognized that in the removal liquid nozzle 3 with a formed angle θ of 0 degrees and a formed angle Z of 10 degrees, the smoothness of the cut surface is improved by increasing the ejection flow rate. When the ejection flow rate is 40ml / min or more, the smoothness can be greatly improved. Therefore, it was found that if the ejection flow rate is 40ml / min to 70ml / min, the smoothness of the cut surface can be fully improved.

[0113] (Evaluation Test 7: Discharge Flow Rate Evaluation)

[0114] Regarding the wafer W processed in the same manner as in (Evaluation Test 6-3), the protrusion height was checked using a step measuring instrument. Fig.19 The results are shown in FIG. 1 . The horizontal axis in the figure is the ejection flow rate, and the vertical axis is the ridge height (nm). As a result, it can be recognized that there is no possibility that the ridge height increases due to an increase in the ejection flow rate.

[0115] In the above description, in order to reduce the height of the protrusion, the coating apparatus 1 of the present invention only needs to rotate the wafer W at a rotation speed of 2300 rpm or more when the removal liquid is ejected from the removal liquid nozzle 3. In the coating apparatus 1, the following (a) to (g) can be appropriately combined.

[0116] (a) Execute the first and second steps

[0117] (b) Perform a cleaning step

[0118] (c) Repeat the first and second steps multiple times

[0119] (d) The angle θ formed by the removal liquid nozzle 3 and the tangent line is set within 6 degrees.

[0120] (e) The angle Z formed between the removal liquid nozzle 3 and the wafer surface is set to be less than 20 degrees.

[0121] (f) The diameter A of the discharge port 30 of the removal liquid nozzle 3 is set to 0.15 to 0.35 mm

[0122] (g) The flow rate of the removal liquid ejected from the removal liquid nozzle 3 is set to 20 ml / min to 60 ml / min.

[0123] In the above description, regarding the coating device 1, the wafer W having the coating film formed thereon can also be subjected to EBR treatment in an external device. That is, the coating device 1 described above can be configured as a dedicated device that only performs EBR treatment, in which case it is not necessary to provide the coating liquid nozzle 41 and the solvent nozzle 42. As the coating liquid, it can be applied to various coating films obtained by dissolving the components of the coating film in a solvent, such as a resist, SOD material, SOC material, SiARC material, BARC material, an organic film having carbon as a main component, and the coating film softened by a solvent.

[0124] In order to form a NAND flash memory in which wiring is formed in multiple layers, such as a 3D NAND, a coating film such as a resist film is sometimes formed by a coating device on a wafer W having multiple films stacked thereon. Each wafer W conveyed to the coating device in a state in which multiple films are formed thereon may be warped and have different shapes due to the influence of the previously performed processes and the stress received from each film.

[0125] Furthermore, the rotating chuck 11 of the coating device 1 only attracts the center of the wafer W, so the warped wafer W is processed while being transported in a warped state. Due to such a situation, it is preferred that the removal liquid nozzle 3 of the coating device 1 is configured so that the accuracy of the EBR process will not be reduced due to the warping. Specifically, in order to suppress the warping from the end of the wafer W to the supply position P (see FIG. 1 ) when the wafer W is warped, Figure 3 ) to prevent the deviation between the cutting width and the set value. Figure 3 The angle θ of the removal liquid nozzle 3 described in the figure is set to a value close to 0°, specifically, for example, 0° to 5°, and more preferably, for example, 0° to 3°. In addition, the cutting width is supplemented, and the cutting width is the width of the annular area on the surface of the wafer W where the coating film is removed by the removal liquid ejected from the removal liquid nozzle 3.

[0126] in addition, Figure 4 The closer the angle Z described in the figure is to 90°, the more the deviation between the set ejection position and the actual ejection position caused by the warping of the wafer W can be suppressed, and the less likely the cutting width is to be affected by the warping. However, when the removal liquid is ejected onto the wafer W rotating at a relatively high speed as described above, the closer the angle Z is to 0°, the more the pressure of the removal liquid when it lands on the wafer W can be suppressed, thereby improving the effect of suppressing the splashing of the removal liquid on the surface of the wafer W. Therefore, when the angle θ is set to 0° to 5° as described above, it is preferred that the angle Z be set to 5° to 20°.

[0127] The evaluation test performed to confirm the appropriate values ​​of the angle θ and the angle Z will be described in detail later. In this evaluation test, the warpage of the wafer W is measured before the test. Fig. 20 The measurement of the warpage is described below. Fig. 20 In the figure, W1 represents the surface of the wafer W, and W2 represents the back surface. Reference numeral 51 in the figure denotes a placement portion for the wafer W, which places the wafer W in a manner that only the peripheral portion of the wafer W is supported from below. Reference numeral 52 in the figure denotes a laser displacement meter, which is configured to be freely movable laterally above the wafer W relative to the wafer W, so as to measure the height of each portion of the upper surface of the wafer W placed on the placement portion 51.

[0128] In such Fig. 20 As shown in (a) of FIG. 1 , the wafer W is placed on the placement portion 51 with the surface W1 facing upward, the height of each portion in the surface W1 of the wafer W is obtained, and the warpage amount (referred to as the surface side warpage amount) is obtained based on the obtained height of each portion. Fig. 20When the wafer W is placed with the back side W2 facing upward as shown in (b), the height of each part in the back side W2 of the wafer W is obtained, and the warpage amount (set as the back side warpage amount) is obtained based on the height of each part obtained. Then, the average value of the surface side warpage amount and the back side warpage amount is set as the warpage amount of the wafer W. Since the loading part 51 only supports a part of the surface of the wafer W, the wafer W is deformed due to its own weight. Therefore, by calculating the warpage amount of the wafer W based on the surface side warpage amount and the back side warpage amount in this way, the measurement error caused by the self-weight can be eliminated. Regarding the above-mentioned surface side warpage amount, for example, the height of multiple points in the surface W1 is measured, and the height of the reference plane is calculated based on the height of all the points obtained and the least squares method is used to calculate the sum of the distance between the height of the highest point among the measured points and the reference plane and the distance between the height of the lowest point among the measured points relative to the reference plane. Regarding the back side warpage amount, the calculation is performed using the same method as the method for calculating the surface side warpage amount.

[0129] In the evaluation test described below, Fig. 20 As shown in FIG. 1 , a wafer W whose height of the peripheral edge of the entire circumference of the wafer W is higher than that of the center when the surface of the wafer W is directed upward is recorded as a concave wafer W. In addition, a wafer W whose height of the peripheral edge of the entire circumference of the wafer W is lower than that of the center when the surface of the wafer W is directed upward is recorded as a convex wafer W. In addition, a wafer W that is warped in such a manner that the height of the peripheral ends of the wafer W is respectively located above and below the center of the wafer W when viewed along the circumferential direction of the wafer W is recorded as a concave-convex wafer W.

[0130] (Evaluation Test 8)

[0131] As evaluation test 8, EBR treatment is performed on wafers W with different warpage amounts by setting the cutting width to 1 mm. After the treatment, the cutting widths at multiple locations in the circumferential direction of the wafer W are measured, and the average value of the cutting widths is calculated. The EBR treatment is performed using any one of the three removal liquid nozzles 3 set in different combinations of angles θ and angles Z. One of the three removal liquid nozzles 3 is set to θ=0° and Z=10°, and this nozzle is set to 3-1. One of the three removal liquid nozzles 3 is set to θ=8.5° and Z=30°, and this nozzle is set to 3-2. The remaining one of the removal liquid nozzles 3 is set to θ=30° and Z=30°, and this nozzle is set to 3-3. Using a wafer without warpage, i.e., a wafer with a warpage amount of 0 μm, and the above-mentioned Fig. 20 The test was conducted using a concave wafer W with a warpage of 196 μm and a convex wafer W with a warpage of 232 μm.

[0132] Fig.21The graph shows the results of evaluation test 8. The horizontal axis of the graph represents the warpage amount of wafer W (unit: μm), and the warpage amount of concave wafer W is marked with a symbol +, and the warpage amount of convex wafer W is marked with a symbol -. The vertical axis of the graph represents the average value of the cutting width (unit: mm). As shown in the graph, when nozzle 3-3 is used, when wafer W has warpage, there is a relatively large deviation between the average value of the cutting width and 1mm as the set value. When nozzle 3-2 is used, the deviation is suppressed compared to the case of using nozzle 3-3. However, the deviation between the average value of the cutting width when the warpage amount is +196mm and the set value of 1mm is slightly larger than the practically effective level. When nozzle 3-1 is used, in all cases when the warpage amount is 0mm, +196mm, and -232mm, the average value of the cutting width is roughly consistent with the set value of the cutting width. Therefore, according to the evaluation test 8, it was confirmed that the accuracy of the cut width can be effectively improved by using the nozzle 3 - 1 when the warpage amount of the wafer W is in the range of +196 μm to −232 μm.

[0133] According to the results obtained by using nozzles 3-2 and 3-3 in which only the value of θ is different in angle θ and Z, it can be seen that by changing the angle θ, the change in the average value of the cut width caused by the warping of the wafer W can be suppressed. Moreover, when the nozzle 3-1 with θ=0 is used, the deviation between the average value of the cut width and the set value of the cut width can be fully suppressed. In addition, when θ=8.5°, as described above, the amount of the deviation is slightly large. Therefore, it is considered that if it is a value of 0° or more to a value slightly lower than 8.5°, the deviation can be fully suppressed. Specifically, for example, if θ=0° to 5° as described above, the deviation can be fully suppressed. In addition, when the nozzle 3-1 is used, the value of Z is 10°, which suppresses the deviation between the average value of the cut width and the warping amount, but considering that the deviation is relatively large when the nozzles 3-2 and 3-3 with the value of angle Z of 30° are used, it is considered that it is preferable to set the angle Z to about 10°, for example, it is preferable to set it to 5° to 20° as described above.

[0134] (Evaluation Test 9)

[0135] As evaluation test 9, the EBR process was performed on the concavoconvex wafer W with a warpage of 428 μm using the nozzle 3-1, 3-2 or 3-3 used in evaluation test 8, and the EBR cutting width at each position in the circumferential direction of the wafer W was measured, and the maximum value-minimum value was calculated as the deviation about the cutting width. In this evaluation test 9 as well, the setting value of the cutting width was set to 1 mm.

[0136] Fig. 22The graph depicts the results of evaluation test 9, and the vertical axis of the graph represents the cutting width (unit: mm). Regarding the deviation of the cutting width (maximum value - minimum value), when using nozzle 3-1, the deviation is 0.041mm, when using nozzle 3-2, the deviation is 0.099mm, and when using nozzle 3-3, the deviation is 0.205mm. In this way, when using nozzle 3-1, the deviation of the cutting width can be most suppressed. Therefore, according to evaluation tests 8 and 9, it can be confirmed that when processing any of the concave wafers W, convex wafers W, and concave-convex wafers W, the accuracy of the cutting width can be improved by using nozzle 3-1.

[0137] (Evaluation Test 10)

[0138] As evaluation test 10-1, a plurality of concave wafers W with a warpage of 150 μm were subjected to EBR treatment by changing the angle θ of the removal liquid nozzle 3, and the deviation of the cut width was measured. In addition, as evaluation test 10-2, a plurality of convex wafers W with a warpage of 250 μm were subjected to EBR treatment by changing the angle θ of the removal liquid nozzle 3, and the deviation of the cut width was measured. In evaluation tests 10-1 and 10-2, as described above, Figure 3 , Fig.23 The removal liquid arrangement 3 is arranged as shown by the solid line in FIG. 1 , and the test is performed by setting the angle θ so that the removal liquid is sprayed from the inner side to the outer side of the wafer W when viewed from above. Fig.23 The removal liquid nozzle 3 is arranged as shown by the single-dot chain line in FIG. 1 , and the angle θ is set so that the removal liquid is ejected from the outside to the inside of the wafer W. In the evaluation test 10, when θ is set so that the ejection direction of the removal liquid is from the inside to the outside of the wafer W, the numerical value of the angle θ is marked with a symbol +, and when the ejection direction of the angle θ is set so that the ejection direction is from the outside to the inside of the wafer W, the numerical value of θ is marked with a symbol -. In addition, Fig.23 In FIG. 1 , L1 denotes a tangent line to the wafer W, and L denotes a line L that passes through the supply position P (the landing position of the liquid ejected from the removing liquid nozzle 3 on the wafer W) and is parallel to the tangent line L1 .

[0139] Fig.24 , Fig.25The graphs show the results of evaluation tests 10-1 and 10-2, respectively. The vertical axis of each graph represents the deviation of the cutting width (unit: mm), and the horizontal axis of the graph represents the angle θ. As shown in the graph, as the absolute value of the angle θ increases, the deviation of the cutting width increases. In practice, it is particularly preferred to suppress the deviation of the cutting width to less than 0.1 mm. In both evaluation tests 10-1 and 10-2, in the range of angle θ of -3° to +3°, the deviation of the cutting width is 0.1 mm. Therefore, it can be confirmed that the warpage amount of wafer W is in the range of +150μm to -250μm, and the deviation of the cutting width can be suppressed by setting the angle θ within such a range. When the angle θ is -, there is a possibility that the removal liquid moves to a position closer to the center side of the wafer W than the supply position P, so that there is a deviation between the cutting width and the desired value, so the angle θ is preferably greater than 0°. Therefore, it is preferred to set the angle θ to 0° to +3°.

Claims

1. A coating film removal device for removing a peripheral portion of a coating film formed by supplying a coating liquid to a surface of a circular substrate using a removal liquid, the coating film removal device comprising: A rotation holding part that holds the substrate and rotates it; a removing liquid nozzle configured to eject the removing liquid toward a peripheral portion of a surface of the substrate held by the rotation holding portion so that the removing liquid is directed toward a downstream side in a rotation direction of the substrate; and a control unit that outputs a control signal so that the substrate rotates at a rotation speed of 2300 rpm or more when the removal liquid is ejected, The control unit outputs a control signal for executing the first step and the second step, wherein: In the first step, while the substrate is rotated at a first rotation speed of 2300 rpm or more, the supply position of the removing liquid is moved from a peripheral position on the surface of the substrate to a cutting position of the coating film closer to the center of the substrate than the peripheral position, and the removing liquid is ejected from the removing liquid nozzle. In the second step, after the supply position reaches the cutting position, the supply position is moved away from the cutting position toward the peripheral edge of the substrate within 1 second.

2. The coating film removal device according to claim 1, characterized in that: The control unit outputs a control signal for executing the following steps: after the second step, the supply position is set between the cutting position and the peripheral position or to the peripheral position, and the removal liquid is sprayed from the removal liquid nozzle while the substrate is rotated at a second rotational speed lower than the first rotational speed.

3. The coating film removal device according to claim 2, characterized in that: The second rotation speed is set to 500 rpm to 2000 rpm.

4. The coating film removal device according to claim 1, characterized in that: The control unit is configured to output a control signal for repeating the first step and the second step a plurality of times.

5. The coating film removal device according to any one of claims 1 to 4, characterized in that: The angle formed by a straight line connecting the discharge port of the removing liquid nozzle and the supply position and a tangent line of the substrate at the supply position is set to be within 6 degrees in a plan view.

6. The coating film removal device according to any one of claims 1 to 4, characterized in that: When viewed in a vertical plane, an angle formed between a straight line connecting the removal liquid nozzle and the supply position and the surface of the substrate is set to be 20 degrees or less.

7. The coating film removal device according to any one of claims 1 to 4, characterized in that: The diameter of the discharge port of the removal liquid nozzle is set to 0.15 mm to 0.25 mm.

8. The coating film removal device according to any one of claims 1 to 4, characterized in that: The discharge flow rate of the removal liquid when the supply position is moved from the peripheral portion to the cut-off position is set to 55 ml / min or more.

9. The coating film removal device according to any one of claims 1 to 4, characterized in that: A cup is further provided around the substrate held by the rotation holding portion, wherein the pressure in the cup is set to be 50 Pa or more when the removing liquid is ejected from the removing liquid nozzle.

10. A coating film removal method for removing a peripheral portion of a coating film formed by supplying a coating liquid to a surface of a circular substrate using a removal liquid, the coating film removal method comprising the following steps: holding the substrate horizontally on the holding portion; Then, while the substrate is rotated at a rotation speed of 2300 rpm or more, the removing liquid is ejected from the removing liquid nozzle toward the peripheral edge of the surface of the substrate in a manner that the removing liquid is directed toward the downstream side in the rotation direction of the substrate; In a first step, the substrate is rotated at a first rotation speed of 2300 rpm or more, and a supply position of the removal liquid nozzle is moved from a peripheral position on the surface of the substrate to a cutting position of the coating film closer to the center of the substrate than the peripheral position, while the removal liquid is ejected from the removal liquid nozzle; as well as In the second step, after the supply position reaches the cutting position, the supply position is moved away from the cutting position toward the peripheral edge of the substrate within 1 second.

11. The coating film removal method according to claim 10, characterized in that: Including the following processes: After the second step, the supply position is set between the cutting position and the peripheral position or at the peripheral position, and the removing liquid is ejected from the removing liquid nozzle while the substrate is rotated at a second rotation speed lower than the first rotation speed.

12. The coating film removal method according to claim 11, characterized in that: The second rotation speed is 500 rpm to 2000 rpm.

13. The coating film removal method according to claim 10, characterized in that: The first step and the second step are repeated multiple times.

14. A storage medium storing a computer program used in a coating film removal device for removing a peripheral portion of a coating film formed by supplying a coating liquid to a surface of a circular substrate using a removal liquid, the storage medium being characterized in that: The program is compiled into a step group to execute the coating film removal method according to any one of claims 10 to 13.

15. A computer program product comprising a computer program for use in a coating film removal device for removing a peripheral portion of a coating film formed by supplying a coating liquid to a surface of a circular substrate using a removal liquid, wherein the computer program product is characterized in that: The program is compiled into a step group to execute the coating film removal method according to any one of claims 10 to 13.

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