Spin coater and spin coating method

Abstract

The present invention provides a spin coater and a spin coating method capable of suppressing the incorporation of air bubbles in the formed coating layer. The spin coater (1) forms a coating layer on a substrate by coating a liquid onto the substrate, wherein the spin coater has: a rotating stage (30) including a holding surface (31) that holds the substrate for rotation; a liquid supply nozzle (50) having an outlet (51) that sprays liquid onto the substrate held by the rotating stage (30); and a oscillating motor (60) that moves the liquid supply nozzle (50) between a position where the outlet (51) faces the substrate held by the rotating stage (30) and a position where the outlet (51) is located outside the substrate held by the rotating stage (30), wherein the start and stop of liquid spraying are performed when the outlet (51) is located outside the substrate held by the rotating stage (30).

Description

Technical Field

[0001] The present invention relates to a spin coater and a spin coater method for forming a coating layer on a substrate by coating a liquid onto the substrate. Background Technology

[0002] To prevent debris generated during laser processing from adhering to the front side of the wafer, a protective film made of water-soluble resin is formed on the front side of the wafer beforehand. Furthermore, spin coating machines have been widely used in the formation of this protective film (see, for example, Patent Document 1).

[0003] Patent Document 1: Japanese Patent Application Publication No. 2017-216291

[0004] When air bubbles remain in the formed protective film, it becomes difficult to detect the pattern during subsequent alignment processes, potentially leading to alignment errors. Furthermore, the air bubbles may also prevent adequate protection of the devices on the wafer.

[0005] On the other hand, spin coaters are also widely used in the manufacture of photomasks for coating resist films. When residual bubbles are present, uneven coating and foaming during baking become problems. Summary of the Invention

[0006] The purpose of this invention is to provide a spin coater and spin coater method capable of suppressing the incorporation of air bubbles into the formed coating layer.

[0007] To address the aforementioned issues and achieve the objective, the spin coater of the present invention is a spin coater that forms a coating layer on a substrate by applying a liquid onto the substrate. The spin coater is characterized by comprising: a rotating worktable including a holding surface that holds the substrate for rotational movement; a liquid supply nozzle having an outlet that sprays the liquid onto the substrate held by the rotating worktable; and a moving unit that moves the liquid supply nozzle between a position where the outlet faces the substrate held by the rotating worktable and a position where the outlet is located outside the substrate held by the rotating worktable, wherein the start and stop of liquid spraying are performed when the outlet is located outside the substrate held by the rotating worktable.

[0008] The spin coating method of the present invention is a spin coating method for forming a coating layer on a substrate by applying a liquid onto the substrate. The spin coating method is characterized by the following steps: a holding step, in which the substrate is held using a freely rotatable rotary table; a spraying start step, in which the spraying of the liquid is started with the liquid supply nozzle positioned at a position where the spray outlet faces the outer side of the substrate held by the rotary table; a first moving step, in which, after the spraying start step, the liquid supply nozzle is moved towards a position where the spray outlet faces the substrate while spraying the liquid from the spray outlet; a second moving step, in which, after the first moving step, the liquid supply nozzle is retracted towards a position where the spray outlet is located outside the substrate held by the rotary table without stopping the spraying of the liquid; and a spraying stop step, in which the spraying of the liquid is stopped after the second moving step.

[0009] In the spin coating method, the rotary table may rotate at least during the first and second moving steps, and the moving speed of the liquid supply nozzle in the first moving step may be set to be faster than the retraction speed of the liquid supply nozzle in the second moving step.

[0010] The present invention has the effect of suppressing the introduction of air bubbles into the formed coating layer. Attached Figure Description

[0011] Figure 1 This is a perspective view showing a partial cross-section of the structure of the spin coater of Embodiment 1.

[0012] Figure 2 Through Figure 1 The diagram shows a three-dimensional view of a substrate with a coating layer formed by a spin coater.

[0013] Figure 3 This is a flowchart illustrating the spin coating method of Embodiment 1.

[0014] Figure 4 It is shown schematically. Figure 3 A cross-sectional view of the holding step of the spin coating method shown.

[0015] Figure 5 It is shown schematically. Figure 3 A top view of the spraying start step of the spin coating method shown.

[0016] Figure 6 It is shown schematically. Figure 3 A cross-sectional view of the spraying start step of the spin coating method shown.

[0017] Figure 7 It is shown schematically. Figure 3 A top view of the first moving step of the spin coating method shown.

[0018] Figure 8 It is shown schematically. Figure 3 A top view of the second moving step of the spin coating method shown.

[0019] Figure 9 It is shown schematically. Figure 3 A cross-sectional view of the spray-stopping step of the spin coating method shown.

[0020] Label Explanation

[0021] 1: Spin coater; 2: Liquid; 30: Rotary worktable; 31: Holding surface; 50: Liquid supply nozzle; 51: Spray outlet; 60: Oscillating motor (moving unit); 200: Substrate; 210: Coating layer; 1001: Holding step; 1002: Spray start step; 1003: First moving step; 1005: Second moving step; 1006: Spray stop step. Detailed Implementation

[0022] Referring to the accompanying drawings, the embodiments (implementations) for carrying out the present invention will be described in detail. The present invention is not limited to the contents described in the following embodiments. Furthermore, the constituent elements described below include contents that are readily conceived by those skilled in the art and substantially the same. Additionally, the structures described below can be appropriately combined. Furthermore, various omissions, substitutions, or modifications to the structure can be made without departing from the spirit of the present invention.

[0023] [Implementation Method 1]

[0024] The spin coater of Embodiment 1 of the present invention will be described with reference to the accompanying drawings. Figure 1 This is a perspective view showing a partial cross-section of the structure of the spin coater of Embodiment 1. Figure 2 Through Figure 1 The diagram shows a three-dimensional view of a substrate with a coating layer formed by a spin coater.

[0025] Implementation method 1 Figure 1 The spin coater 1 shown is in Figure 2 Liquid 2 is coated on the substrate 200 shown. Figure 5 As shown), a coating layer 210 is formed on a substrate 200 using liquid 2. As... Figure 1 The substrate 200 to which the liquid 2 of the spin coater 1 is coated is a wafer such as a disc-shaped semiconductor wafer with silicon as the base material or an optical device wafer with sapphire, SiC (silicon carbide) or the like as the base material.

[0026] In implementation method 1, such as Figure 2As shown, the substrate 200 has devices 203 formed in each region of the front side 202, which is divided by multiple intersecting predetermined dividing lines 201. The devices 203 are integrated circuits such as IC (Integrated Circuit) or LSI (Large Scale Integration), image sensors such as CCD (Charge Coupled Device) or CMOS (Complementary Metal Oxide Semiconductor).

[0027] The substrate 200 is diced into individual devices 203 by ablation along the predetermined dicing line 201, which is irradiated with a laser beam of a wavelength that is absorbed by the substrate. Furthermore, in this invention, the substrate 200 coated with liquid 2 by the spin coater 1 is not limited to the wafer described above. In Embodiment 1, the substrate 200 is coated with liquid 2 while the back side 204 of the front side 202 is attached to a strip 206 with an annular frame 205 mounted on its outer periphery, and supported by the strip 206 within the opening 208 of the annular frame 205, thus forming a coating layer 210 on the front side 202.

[0028] The spin coater 1 of Embodiment 1 is an apparatus that forms a coating layer 210 of liquid 210 on the front side 202 of substrate 200 by applying liquid 2 on the front side 202 of substrate 200 before performing ablation processing by irradiation with a laser beam or the like. The coating layer 210 is used to prevent debris generated during the ablation processing of substrate 200 from adhering to device 203.

[0029] Furthermore, in Embodiment 1, liquid 2 is, for example, a water-soluble liquid resin formed from polyvinyl alcohol (PVA) or polyvinylpyrrolidone (PVP). Additionally, in this invention, Hogomax (registered trademark) manufactured by Disco Corporation can be used as liquid 2, for example.

[0030] like Figure 1 As shown, the spin coater 1 includes: a housing 10, a motor 20, a rotary worktable 30, multiple clamps 32, a lifting unit 40, a liquid supply nozzle 50, a oscillating motor 60 as a moving unit, a cleaning liquid supply nozzle 70, an oscillating motor 80 for cleaning nozzles, and a control unit 100 (not shown). Additionally, Figure 1 A portion of the housing 10 is shown cut open.

[0031] The housing 10 has: a cylindrical peripheral wall 11; a disc-shaped bottom wall 12 whose outer edge is connected to the lower end of the peripheral wall 11; and a leg 13 extending downward from the lower end of the peripheral wall 11. A drain outlet 15 is provided on the bottom wall 12 for communicating with the drain hose 14 to discharge liquid 2 from the housing 10. Furthermore, the housing 10 has a through hole 16 at the center of the bottom wall 12 for the output shaft 22 of the motor 20 to pass through to the inside, and a cylindrical inner peripheral wall 17 vertically arranged from the inner edge of the through hole 16. The peripheral wall 11, the bottom wall 12, and the inner peripheral wall 17 are arranged coaxially with each other.

[0032] The electric motor 20 provides power to rotate the output shaft 22, which protrudes from the motor body 21, about its axis. In Embodiment 1, the electric motor 20 extends the output shaft 22 into the inner peripheral wall 17, and arranges it parallel to the vertical direction. The output shaft 22 is positioned coaxial with the peripheral wall 11, the bottom wall 12, and the inner peripheral wall 17.

[0033] The rotary stage 30 includes a holding surface 31 that holds the substrate 200 in a rotatable manner. The rotary stage 30 is formed in a disk shape and holds the substrate 200 on the holding surface 31, which is a surface. The holding surface 31 of the rotary stage 30 is formed of a porous ceramic or the like, which is a porous material, and the holding surface 31 is connected to an attraction source (not shown). An output shaft 22 of a motor 20 is mounted at the center of another surface of the rotary stage 30 and is configured coaxially with the output shaft 22.

[0034] The rotary table 30 attracts the holding surface 31 via an attraction source, thereby attracting and holding the substrate 200 placed on the holding surface 31. In Embodiment 1, the rotary table 30 attracts and holds the back side 204 of the front side 202 onto the holding surface 31 through the belt 206, attracting and holding the substrate 200 with the front side 202 exposed. Furthermore, the rotary table 30 rotates around an axis via the output shaft 22 of the motor 20. The rotary table 30, by rotating around an axis via the output shaft 22 of the motor 20, keeps the substrate 200 attracted and held by the holding surface 31 in a rotatable manner.

[0035] Multiple clamps 32 are provided at circumferential intervals at a position closer to the outer periphery of the rotary table 30. The clamps 32 hold the annular frame 205 that supports the substrate 200 inside the opening 208.

[0036] The lifting unit 40 causes the rotary table 30 to move up and down in the vertical direction. The lifting unit 40 has a plurality of cylinders 41. Each cylinder 41 has: a cylinder body 42, which is mounted on the outer peripheral surface of the motor body 21 of the motor 20; and a telescopic rod 43, which is configured to extend and retract freely downward from the cylinder body 42.

[0037] The lifting unit 40 extends the telescopic rod 43 from the cylinder body 42, thereby raising the motor 20 and the rotary table 30. The lifting unit 40 also retracts the telescopic rod 43 into the cylinder body 42, thereby lowering the motor 20 and the rotary table 30. Furthermore, a sealing wall 18 is installed on the output shaft 22 of the motor 20 to seal the opening on the upper side of the inner peripheral wall 17 when the rotary table 30 and the motor 20 are lowered. Figure 4 (As shown).

[0038] The liquid supply nozzle 50 has an outlet 51 for spraying liquid 2 onto the substrate 200 held by the rotary table 30. The liquid supply nozzle 50 has: a vertical extension 52, which is a pipe supplying liquid 2 from a liquid supply source (not shown) extending vertically; and a horizontal extension 53, which extends horizontally from the upper end of the vertical extension 52, the horizontal extension 53 having an outlet 51 facing the substrate 200 held by the rotary table 30 at its front end on the side away from the vertical extension 52. The liquid supply nozzle 50 sprays liquid 2 supplied from the liquid supply source (not shown) from the outlet 51, coating the liquid 2 onto the front surface 202 of the substrate 200 held by the rotary table 30.

[0039] The oscillating motor 60 is powered to rotate an output shaft (not shown) rotatably supported on the motor body 61 about a central axis. The motor body 61 is mounted on the lower surface of the bottom wall 12 of the housing 10, and the output shaft is mounted on the vertical extension 52 of the liquid supply nozzle 50. The oscillating motor 60 rotates the output shaft, causing the liquid supply nozzle 50 to oscillate (move) about the vertical extension 52 between a position where the nozzle 51 faces the substrate 200 held by the rotary table 30 and a position where the nozzle 51 is located on the outer periphery of the substrate 200 held by the rotary table 30.

[0040] The cleaning fluid supply nozzle 70 has a cleaning fluid outlet 71 that supplies cleaning fluid (e.g., pure water) to the substrate 200 held by the rotary table 30. The cleaning fluid supply nozzle 70 has: a vertical extension 72, which is a pipe supplying cleaning fluid from a cleaning fluid supply source (not shown) extending vertically; and a horizontal extension 73, which extends horizontally from the upper end of the vertical extension 72, the horizontal extension 73 having a cleaning fluid outlet 71 facing the substrate 200 held by the rotary table 30 at its front end on the side away from the vertical extension 72. The cleaning fluid supply nozzle 70 sprays the cleaning fluid supplied from the cleaning fluid supply source (not shown) from the cleaning fluid outlet 71, supplying the cleaning fluid to the front surface 202 of the substrate 200 held by the rotary table 30.

[0041] The oscillating motor 80 for cleaning nozzles is powered to rotate an output shaft (not shown) rotatably supported on a motor body 81 about a central axis. Regarding the oscillating motor 80, the motor body 81 is mounted on the lower surface of the bottom wall 12 of the housing 10, and the output shaft is mounted on the vertical extension 72 of the cleaning fluid supply nozzle 70. The oscillating motor 68 for cleaning nozzles rotates the output shaft, causing the cleaning fluid supply nozzle 70 to oscillate (move) about the vertical extension 72 between a position where the cleaning fluid outlet 71 faces the substrate 200 held by the rotary table 30 and a position where the cleaning fluid outlet 71 is located on the outer periphery of the substrate 200 held by the rotary table 30.

[0042] The control unit 100 controls each of the aforementioned components constituting the spin coater 1. Specifically, the control unit 100 causes the spin coater 1 to perform the coating operation of liquid 2 onto the substrate 200. The control unit 100 is a computer, and it includes: an arithmetic processing unit having a microprocessor such as a CPU (central processing unit); a storage unit having a memory such as ROM (read-only memory) or RAM (random access memory); and an input / output interface device.

[0043] The arithmetic processing unit of the control unit 100 performs arithmetic processing according to a computer program stored in a storage device, and outputs control signals for controlling the spin coater 1 to the aforementioned components of the spin coater 1 via an input / output interface device. Furthermore, the control unit 100 is connected to a display unit, such as a liquid crystal display device that displays the status or image of the processing operation, and an input unit used by the operator to register coating conditions, etc. The input unit consists of at least one of a touch panel and a keyboard provided on the display unit.

[0044] Next, the spin coating method of Embodiment 1 will be described with reference to the accompanying drawings. Figure 3 This is a flowchart illustrating the spin coating method of Embodiment 1. The spin coating method of Embodiment 1 is a method of forming a coating layer 210 on the front side 202 of a substrate 200 by applying liquid 2 to the front side 202 of the substrate 200 using a spin coater 1. Figure 3 As shown, the spin coating method of Embodiment 1 includes a holding step 1001, a spray start step 1002, a first moving step 1003, a coating step 1004, a second moving step 1005, and a spray stop step 1006.

[0045] (Keep the steps)

[0046] Figure 4 It is shown schematically. Figure 3A cross-sectional view of the holding step in the spin coating method shown. Holding step 1001 is a step of holding the substrate 200 using a freely rotatable rotary table 30.

[0047] In step 1001, regarding the spin coater 1, the operator registers the coating conditions with the control unit 100. When the control unit 100 receives a start instruction for the coating operation from the operator, it begins the operation. In step 1001, as... Figure 4 As shown, the control unit 100 of the spin coater 1 controls the swing motors 60 and 80 to position the nozzles 50 and 70 so that the spray outlets 51 and 71 are located on the outer periphery of the rotary worktable 30, and controls the lifting unit 40 to extend the telescopic rod 43 of the cylinder 41 to position the rotary worktable 30 above.

[0048] In holding step 1001, the spin coater 1 places the back side 204 of the substrate 200 on the holding surface 31 through the belt 206. In holding step 1001, the control unit 100 of the spin coater 1 controls the suction source to attract and hold the back side 204 of the substrate 200 on the holding surface 31, and uses the clamp 32 to clamp the annular frame 205.

[0049] (Initial spraying steps)

[0050] Figure 5 It is shown schematically. Figure 3 A top view of the spraying start step of the spin coating method shown. Figure 6 It is shown schematically. Figure 3 The spin coating method shown is a cross-sectional view of the spraying start step. The spraying start step 1002 is as follows: the spraying of liquid 2 begins with the liquid supply nozzle 50 positioned so that the spray outlet 51 faces the outer side of the substrate 200 held by the rotary table 30.

[0051] In the spraying start step 1002, the control unit 100 of the spin coater 1 controls the lifting unit 40 to shorten the extension rod 43 of the cylinder 41, thereby positioning the rotary table 30 downwards. In the spraying start step 1002, the control unit 100 of the spin coater 1 controls the motor 20 to rotate the rotary table 30 and the substrate 200 held by the rotary table 30 about an axis. In Embodiment 1, in the spraying start step 1002, the motor 20 of the spin coater 1 rotates the rotary table 30 and the substrate 200 held by the rotary table 30 in one direction 3 about the axis.

[0052] In the initial ejection step 1002, as follows Figure 5As shown, the control unit 100 of the spin coater 1 controls the liquid supply source to supply liquid 2 to the liquid supply nozzle 50 when the liquid supply nozzle 50 is positioned such that the spray outlet 51 faces the outer side of the substrate 200 held by the rotary table 30. In the spray start step 1002, as... Figure 6 As shown, the spin coater 1 begins to spray liquid 2 from the spray outlet 51 of the liquid supply nozzle 50. To this end, in the spraying start step 1002, before the liquid 2 is sprayed from the spray outlet 51, the gas that has entered the liquid supply nozzle 50 is sprayed out from the spray outlet 51 along with the liquid 2 to remove the gas from the liquid supply nozzle 50.

[0053] Furthermore, in Embodiment 1, during the spraying start step 1002, the spin coater 1 rotates the rotating worktable 30 at a speed of 10 rpm or more and 30 rpm or less. However, in this invention, during the spraying start step 1002, the spin coater 1 may not rotate the rotating worktable 30 around its axis.

[0054] (Step 1)

[0055] Figure 7 It is shown schematically. Figure 3 The first moving step of the spin coating method shown is a top view. The first moving step 1003 is as follows: after the spray start step 1002 is performed, the liquid supply nozzle 50 is moved toward a position where the spray outlet 51 faces the front surface 202 of the substrate 200 while spraying liquid 2 from the spray outlet 51.

[0056] In the first moving step 1003, the control unit 100 of the spin coater 1 controls the oscillating motor 60 while liquid 2 is being ejected from the nozzle 51, thereby causing the liquid supply nozzle 50 to move from the point of origin of step 1002. Figure 7 The position indicated by the dashed line is moved to the center of the front surface 202 of the substrate 200 held by the rotary table 30, facing the nozzle 51. Figure 7 The position is shown by the solid line in the figure. In Embodiment 1, in the first moving step 1003, the outlet 51 of the liquid supply nozzle 50 is moved at a speed of 20 mm / sec or more and 30 mm / sec or less.

[0057] (Coating Steps)

[0058] Coating step 1004 is the step of forming a coating layer 210 on the front surface 202 of the substrate 200 held by the rotary table 30. In coating step 1004, the control unit 100 of the spin coater 1 controls the liquid supply source to continuously spray liquid 2 from the nozzle 51 while controlling the motor 20 to rotate the rotary table 30 about its axis. In addition, in the present invention, in coating step 1004, the spin coater 1 can rotate the rotary table 30 about its axis while the oscillating motor 60 oscillates the liquid supply nozzle 50 so that the nozzle 51 moves along the front surface 202 of the substrate 200.

[0059] In coating step 1004, the liquid 2 coated onto the front surface 202 of the substrate 200 is propelled from the center to the outer periphery by the centrifugal force generated by the rotation of the rotary table 30, thereby coating the entire front surface 202 of the substrate 200. Additionally, the liquid 2 falling from the outer edge of the front surface 202 of the substrate 200 flows into the housing 10 and onto the bottom wall 12 of the housing 10, and is discharged through the outlet 15 and the drain hose 14.

[0060] In coating step 1004, the spin coater 1 sprays liquid 2 from the nozzle 51 while rotating the rotary table 30 around its axis for a predetermined time. Alternatively, in embodiment 1, in coating step 1004, the spin coater 1 rotates the rotary table 30 in one direction 3 around its axis.

[0061] (Step 2)

[0062] Figure 8 It is shown schematically. Figure 3 The top view of the second moving step of the spin coating method shown. The second moving step 1005 is the following step: after the first moving step 1003 is performed, without stopping the spraying of liquid 2, the liquid supply nozzle 50 is moved back to the position of the spray outlet 51 on the outer periphery of the substrate 200 held by the rotary table 30.

[0063] In the second moving step 1005, the control unit 100 of the spin coater 1 does not stop spraying liquid 2 from the spray nozzle 51, but controls the oscillating motor 60 to make the liquid supply nozzle 50 spray from the coating step 1004. Figure 8 The position indicated by the dashed line moves towards the position indicated by the solid line. At the position indicated by the solid line, the nozzle 51 is located on the outer periphery of the substrate 200 held by the rotary table 30. In Embodiment 1, in the second moving step 1005, the retraction speed of the nozzle 51 of the liquid supply nozzle 50 is set to a speed of 3 mm / sec or more and 10 mm / sec or less, which is lower than the moving speed of the nozzle 51 in the first moving step 1003.

[0064] Thus, in Embodiment 1, the spin coater 1 rotates the rotary table 30 about its axis at least during the first movement step 1003 and the second movement step 1005. Furthermore, in Embodiment 1, the spin coater 1 sets the moving speed of the outlet 51 of the liquid supply nozzle 50 in the first movement step 1003 to be faster than the retraction speed of the outlet 51 of the liquid supply nozzle 50 in the second movement step 1005.

[0065] Additionally, in the second moving step 1005, the spin coater 1 rotates the rotating table 30 in one direction about the axis, the same direction as in the first moving step 1003. However, in the invention, in the second moving step 1005, the spin coater 1 may also rotate the rotating table 30 in another direction 4 (opposite to one direction 3 of the first moving step 1003) about the axis. Figure 8 Rotate on (as shown).

[0066] In addition, in Embodiment 1, the position of the nozzle 51 in the second moving step 1005 is the same as the position of the nozzle 51 facing the outside of the substrate 200 held by the rotary table 30 at the beginning of the first moving step 1003. However, in this invention, these positions may be different from each other.

[0067] Furthermore, in this invention, if the rotary table 30 is not rotated around the axis in the spraying start step 1002 and the first moving step 1003, the coating step 1004 can be performed by rotating the rotary table 30 around the axis in the second moving step 1005, or the coating step 1004 can be performed by rotating the rotary table 30 around the axis after the second moving step 1005.

[0068] Furthermore, the coating step 1004 can be omitted in this invention. That is, in the spin coater 1 and spin coater method of this invention, the nozzle 51 of the liquid spraying 2 can be moved from the outer periphery of the substrate 200 to the center of the substrate 200 in the first moving step 1003, and then the nozzle 51 can be moved to the outer periphery of the substrate 200 immediately in the second moving step 1005 to complete the coating of the coating layer 210.

[0069] (Ejection Stopping Procedure)

[0070] Figure 9 It is shown schematically. Figure 3 The diagram shows a cross-sectional view of the spray-stopping step of the spin coating method. Spray-stopping step 1006 is the following step: after performing the second moving step 1005, the spraying of liquid 2 is stopped.

[0071] In the spray stop step 1006, after the second movement step 1005 is performed, i.e., when the spray nozzle 51 is positioned on the outer periphery of the substrate 200 held by the rotary table 30, the control unit 100 of the spin coater 1 controls the liquid supply source, such as... Figure 9 As shown, the supply of liquid 2 to the liquid supply nozzle 50 is stopped, thereby stopping the ejection of liquid 2 from the spray outlet 51. Thus, in the spin coater 1, the start and stop of the ejection of liquid 2 are carried out with the spray outlet 51 positioned on the outer periphery of the substrate 200 held by the rotating worktable 30.

[0072] In addition, the liquid 2 coated onto the front side 202 of the substrate 200 is dried to form a coating layer 210 formed of a water-soluble resin contained in the liquid 2 on the front side 202 of the substrate 200.

[0073] Regarding the reasons for the inclusion of air bubbles in the formed coating layer 210, the applicant of this application has discovered the following aspects: when liquid 2 is dripped onto the coating layer 210, air is trapped between the coating layer 210 and the droplet of liquid 2, thus mixing in air bubbles; at the beginning of the ejection of liquid 2, the ejection is unstable, causing the gas in the liquid supply nozzle 50 to be mixed into the liquid 2 as air bubbles.

[0074] Therefore, as described above, in the spin coater 1 of Embodiment 1, the start and stop of liquid 2 spraying are performed with the nozzle 51 positioned on the outer periphery of the substrate 200 held by the rotary table 30. Thus, the liquid 2, which enters as bubbles from the gas in the nozzle 50 at the start of spraying, is sprayed onto the outer periphery of the substrate 200 held by the rotary table 30, and a continuous and stable spray of liquid 2 is provided onto the substrate 200. As a result, the spin coater 1 of Embodiment 1 has the following effects: it can suppress the introduction of bubbles into the liquid 2 sprayed onto the substrate 200, and it can suppress the introduction of bubbles into the formed coating layer 210.

[0075] In the spin coating method of Embodiment 1, liquid 2 is sprayed out in the spray start step 1002 with the spray outlet 51 located on the outer periphery of the substrate 200 held by the rotary table 30, and the spray stop step is taken to stop the spraying of liquid 2 while the spray outlet 51 is still located on the outer periphery of the substrate 200 held by the rotary table 30. As a result, the spin coating method of Embodiment 1 has the following effects: it can provide a continuous and stable spray of liquid 2 onto the substrate 200, it can suppress the mixing of air bubbles into the liquid 2 sprayed onto the substrate 200, and it can suppress the mixing of air bubbles into the formed coating layer 210.

[0076] Furthermore, regarding the spin coater 1 and spin coating method of Embodiment 1, the moving speed of the spray outlet 51 of the liquid supply nozzle 50 in the first moving step 1003 is set to be faster than the retraction speed of the spray outlet 51 of the liquid supply nozzle 50 in the second moving step 1005. Therefore, even though the rotating worktable 30 rotates, the spray outlet 51 can be quickly positioned at the center of the substrate 200, thus enabling the liquid 2 to be coated onto the entire front surface 202 of the substrate 200.

[0077] Furthermore, the present invention is not limited to the embodiments described above. That is, various modifications and implementations can be made without departing from the spirit of the present invention.

Claims

1. A spin coater that coats a liquid onto a substrate to form a coating layer on the substrate using the liquid, wherein, This spin coater has the following features: A rotary table includes a holding surface that holds a substrate in a freely rotatable manner. A liquid supply nozzle having an outlet that sprays the liquid onto a substrate held by a rotary table; and The moving unit moves the liquid supply nozzle between a position where the nozzle outlet faces the substrate held by the rotary table and a position where the nozzle outlet is located outside the substrate held by the rotary table. The liquid is started and stopped when the nozzle is located outside the substrate held by the rotary table.

2. A spin coating method, wherein a liquid is coated on a substrate to form a coating layer on the substrate using the liquid, wherein, The spin coating method has the following steps: The substrate is held in place using a freely rotating rotary table. The ejection start step begins with the liquid supply nozzle positioned so that the outlet faces the outer side of the substrate held by the rotary table. In the first moving step, after the ejection initiation step is performed, the liquid supply nozzle is moved toward the position where the ejection outlet and the substrate face each other while the liquid is ejected from the ejection outlet. The second moving step involves, after the first moving step is performed, not stopping the liquid ejection, but causing the liquid supply nozzle to retract to a position outside the ejection outlet located on the substrate held by the rotating worktable. as well as The ejection stop step stops the ejection of the liquid after the second moving step has been performed.

3. The spin coating method according to claim 2, wherein, The rotary table rotates at least during the execution of the first and second moving steps. The moving speed of the liquid supply nozzle in the first moving step is set to be faster than the retraction speed of the liquid supply nozzle in the second moving step.

Images