Frame cleaning mechanism and frame cleaning method

Abstract

The present invention provides a frame cleaning mechanism and frame cleaning method that can suppress the scattering of cleaning solution when cleaning the frame. [Solution] The frame cleaning mechanism 100, which cleans an annular frame 18 on which a workpiece 12 with a coating film formed on it via tape 16 is fixed, comprises a table 14 on which the frame 18 is placed, a table rotating device 10 for rotating the table 14, a nozzle 40 for discharging cleaning liquid onto the table 14, and a nozzle swinging mechanism 30 for swinging the nozzle 40 within the width of the frame 18 while the table 14 is rotating by the table rotating device 10, and is configured so that cleaning liquid does not splash onto the coating film.

Description

[Technical Field]

[0001] The present invention relates to a frame cleaning mechanism and a frame cleaning method for cleaning a frame that holds a wafer. [Background technology]

[0002] In the manufacturing of semiconductor devices, wafers (workpieces) are fixed to an annular frame using dicing tape, and while fixed to the frame, the wafers are transported to various processing machines, where various films are formed on the surface of the wafers while they are being processed. For example, during exposure, a resist film is formed on the surface of the wafer, and during grooving, a protective film is formed to protect the device layer.

[0003] Various coating devices are used to form these films. For example, in a rotary coating device, the coating liquid is supplied to the vicinity of the center of the wafer surface, and the wafer is rotated around its central axis (the central axis of the rotary table) as the axis of rotation, thereby using centrifugal force to coat the entire surface of the wafer. Since the frame is located on the outer periphery of the wafer, the coating liquid may splatter onto the frame when the coating liquid is applied to the wafer with a rotary coating device. Also, dirt may adhere to the frame during wafer transport.

[0004] If the frame is contaminated with coating liquid or other substances and proceeds to subsequent processing steps, problems may arise such as defects in the chips formed on the wafer due to the contamination, or the frame becoming difficult to detach from the suction pad during wafer transport due to the stickiness of the contamination. To avoid these problems, a frame cleaning process is sometimes performed during the processing steps.

[0005] For example, Patent Document 1 discloses a water-soluble resin coating method that includes a frame cleaning step. In the frame cleaning step described in Patent Document 1, while the wafer, which is integrated with the frame, is held on a spinner table (rotating table), cleaning water is sprayed from a cleaning water nozzle provided above the frame toward the upper surface of the frame, and the spinner table is rotated to clean the coating liquid or coating film that adheres to the upper surface of the frame when the resin coating is formed. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2007-073670 [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] However, in the frame cleaning process described in Patent Document 1, the cleaning water sprayed from the nozzle toward the frame may spill from the frame and scatter onto the wafer (water splashing), potentially degrading the quality of the coating film formed on the wafer (contamination by the cleaning water).

[0008] To minimize contamination from the cleaning water, one might consider reducing the flow rate of the cleaning water or lowering the rotation speed of the table. However, this could increase the time it takes to complete the cleaning of the entire frame, potentially reducing cleaning efficiency.

[0009] This invention has been made in view of these circumstances, and aims to provide a frame cleaning mechanism and frame cleaning method that can efficiently clean a frame while suppressing the scattering of cleaning solution. [Means for solving the problem]

[0010] To achieve the above objective, a frame cleaning mechanism according to a first aspect of the present invention is a frame cleaning mechanism for cleaning an annular frame on which a workpiece is fixed with tape interposed, comprising: a table on which the frame is placed; a table rotating device for rotating the table; a nozzle for discharging cleaning fluid onto the table; and a nozzle oscillating mechanism for oscillating the nozzle within the width of the frame while the table is rotating by the table rotating device.

[0011] In the first embodiment of the frame cleaning mechanism, the table is rotated by a table rotation device, cleaning liquid is discharged onto the frame from a cleaning nozzle, and the cleaning nozzle is oscillated within the width of the substantially annular frame by a cleaning nozzle oscillating mechanism. This allows the cleaning liquid to be efficiently applied to the entire frame by shifting the position at which it is discharged onto the frame surface. Therefore, the frame can be efficiently cleaned even while discharging the cleaning liquid at a low flow rate and low table rotation speed to suppress contamination of the coating film.

[0012] According to a second aspect of the present invention, in the frame cleaning mechanism according to the first aspect of the present invention, the nozzle comprises an arm having a straight rod shape and provided substantially horizontally with respect to the table, a discharge pipe holder provided at one end of the arm, and a discharge pipe held by the discharge pipe, wherein, when viewed from the rotation center of the table, the discharge pipe is inclined with respect to the table such that the discharge direction of the cleaning liquid has a component in the same direction as the rotation direction of the table.

[0013] In the frame cleaning mechanism according to the second embodiment, since the discharge direction of the cleaning solution includes a component in the same direction as the rotation direction of the table, the relative discharge speed of the cleaning solution to the table can be slowed down by the amount of the component in the same direction as the rotation direction of the table. This makes it possible to suppress contamination of the coating film even more effectively.

[0014] To achieve the above objective, a third aspect of the present invention provides a frame cleaning method for cleaning an annular frame on which a workpiece is fixed via a table, comprising: a rotation step of rotating the table on which the frame is placed; and a discharge step of discharging a cleaning solution from a nozzle onto the frame while the rotation step is being performed, with the nozzle oscillating within the width of the frame.

[0015] In the third embodiment of the frame cleaning method, the cleaning nozzle is oscillated within the width of the annular frame while the table is rotated and cleaning fluid is discharged onto the frame from the cleaning nozzle. This allows the cleaning fluid to be efficiently applied to the entire frame by shifting the position at which it is discharged onto the frame surface. Therefore, the frame can be efficiently cleaned even while discharging the cleaning fluid at a low flow rate and low table rotation speed to suppress contamination of the coating film.

[0016] According to a fourth aspect of the present invention, in the discharge step of the frame cleaning method according to the third aspect of the present invention, the table is rotated multiple times, and the nozzle is oscillated so that the trajectory of the nozzle projected onto the frame does not form a single closed curve. This allows the cleaning liquid to be discharged evenly onto the frame without any stuffing.

[0017] According to a fifth aspect of the present invention, a frame cleaning method according to a third or fourth aspect of the present invention further comprises a standing step of leaving the frame for a certain period of time after a discharge step, and a cleaning liquid removal step of rotating a table after the standing step to remove the cleaning liquid from the frame by centrifugal force.

[0018] In the frame cleaning method according to the fifth embodiment, contaminants adhering to the frame during the standing time can be dissolved in the cleaning water, thus enabling effective cleaning. [Effects of the Invention]

[0019] According to the present invention, it is possible to efficiently clean a frame while suppressing the scattering of cleaning solution. Brief Description of the Drawings

[0020] [Figure 1] This is a perspective view showing an example of a spin coater to which a frame cleaning mechanism according to the present embodiment is applied. [Figure 2] This is a plan view of the spin coater shown in FIG. 1. [Figure 3] This is a schematic configuration diagram of a cleaning nozzle. [Figure 4] This is a diagram for explaining the inclination direction of the discharge pipe relative to the surface of the table. [Figure 5] This is a functional block diagram of the frame cleaning mechanism. [Figure 6] This is a flowchart showing the procedure of the frame cleaning method according to the present embodiment. [Figure 7] This is a diagram for explaining the swinging motion of the cleaning nozzle. [Figure 8] This is a table showing the results of performing frame cleaning under different conditions. Modes for Carrying Out the Invention

[0021] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the following description, a workpiece to be processed is taken as a wafer by way of example, and this is not intended to limit the type of the workpiece to be processed.

[0022] First, the configuration of the frame cleaning mechanism 100 will be described. FIG. 1 and FIG. 2 are a perspective view and a plan view showing an example of the spin coater 1 to which the frame cleaning mechanism 100 according to the present embodiment is applied. The X-axis direction, Y-axis direction, and Z-axis direction are directions orthogonal to each other, the X-axis direction is the horizontal direction, the Y-axis direction is the horizontal direction orthogonal to the X-axis direction, and the Z-axis direction is the up-down direction (vertical direction). The spin coater 1 shown in FIG. 1 and FIG. 2 applies a coating liquid onto a wafer 12, and after the application, cleans the coating liquid scattered onto the frame 18 with a cleaning liquid.

[0023] As shown in Figures 1 and 2, the rotary coating apparatus 1 comprises a table 14 (see Figures 3 and 5), a table rotation device 10 (see Figures 3 and 5), a shielding plate 19, a coating nozzle 20, a coating nozzle drive unit 30, a cleaning nozzle 40, a cleaning nozzle drive unit 50, and a control unit 60. In Figures 1 and 2, the table 14, the table rotation device 10, the cleaning nozzle 40, the cleaning nozzle drive unit 50, and the control unit 60 constitute the frame cleaning mechanism 100 according to this embodiment.

[0024] Since the frame cleaning mechanism 100 can be applied to the rotary coating device 1 simply by adding a cleaning nozzle 40, a cleaning nozzle drive unit 50, and a control unit 60, the frame cleaning mechanism 100 can be realized at a relatively low cost.

[0025] Table 14 has a surface (holding surface) parallel to the horizontal direction and holds the wafer 12 (frame 18) by suction using a suction device (not shown). For example, a roughly disc-shaped wafer 12 is fixed to a roughly annular frame 18 with a dicing tape (tape) 16 in between, and placed on the table 14 such that the center of the wafer 12 coincides with the center of the table 14. That is, the frame 18 is held on the table 14 via the dicing tape 16. Note that in Figures 1 and 2, the state in which the wafer 12 is placed on the table 14 is shown, so the table 14 is hidden beneath the wafer 12, dicing tape 16, and frame 18.

[0026] The table rotation device 10 rotates the table 14 around a rotation axis parallel to the Z-axis using a motor (not shown).

[0027] The shielding plate 19 is erected around the table 14, for example, perpendicular to the Z-axis direction. The shielding plate 19 may also be curved to cover the top of the table 14. The shielding plate 19 shields the coating liquid and cleaning liquid that splashes from the table 14 during coating and cleaning, and prevents the coating liquid and cleaning liquid from splashing outside the rotary coating device 1.

[0028] The coating nozzle 20 supplies the coating liquid to the area near the center of the wafer 12 surface. The coating liquid is appropriately and arbitrarily selected depending on the type of film to be formed. For example, when forming a resist film, a resist solution (photosensitive resin solution) is used as the coating liquid, and when forming a protective film for a device layer, a resin solution for forming a protective film is used as the coating liquid. The coating nozzle 20 comprises a discharge port 21, an arm 22, and a rotating shaft 23. The arm 22 is, for example, a straight rod shape and is positioned substantially horizontally with respect to the table 14. The discharge port 21 is provided at one end of the arm 22 and discharges the coating liquid supplied via piping (not shown) toward the surface of the wafer 12. The rotating shaft 23 is erected substantially parallel to the Z-axis direction, the upper end of the rotating shaft 23 is connected to the other end of the arm 22, and the lower end of the rotating shaft 23 is connected to the coating nozzle drive unit 30.

[0029] The coating nozzle drive unit 30 includes a motor and a transmission mechanism (not shown). The coating nozzle drive unit 30 rotates the coating nozzle 20 around the rotating shaft 23, thereby moving the discharge port 21 of the coating nozzle 20 to near the center of the surface of the table 14 (wafer 12) or retracting it from the table 14.

[0030] When dispensing the coating solution via rotation, once the coating solution is discharged from the coating nozzle 20 to near the center of the wafer 12's surface, the table rotation device 10 rotates the table 14 at a relatively high speed (for example, several hundred to several thousand mins). -1 (or rpm)) The coating liquid is diffused throughout the wafer 12 by centrifugal force. During coating, the movement of the coating nozzle 20 by the coating nozzle drive unit 30 and the rotation of the table 14 by the table rotation device 10 are performed based on control by the control unit 60.

[0031] The cleaning nozzle 40 is an example of the nozzle of the present invention and discharges cleaning fluid onto the surface of the frame 18. The configuration of the cleaning nozzle 40 will be described below with reference to Figure 3. Figure 3 is a schematic diagram showing an example of the cleaning nozzle 40. As shown in Figure 3, the cleaning nozzle 40 comprises a discharge pipe holder 41, an arm 42, a rotating shaft 43, and a discharge pipe 44.

[0032] The arm 42 is, for example, a straight rod shape and is mounted substantially horizontally to the table 14. The discharge pipe holder 41 is mounted at one end of the arm 42 and holds the discharge pipe 44. The rotating shaft 43 is erected substantially parallel to the Z-axis direction, the upper end of the rotating shaft 43 is connected to the other end of the arm 42, and the lower end of the rotating shaft 43 is connected to the cleaning nozzle drive unit 50. The discharge pipe 44 is, for example, a straight pipe shape and discharges cleaning fluid supplied via piping (not shown) toward the frame 18. The cleaning fluid is appropriately and arbitrarily selected depending on the type of coating film, but if the coating film is made of a water-soluble resin, for example, water is used as the cleaning fluid.

[0033] The inner diameter of the discharge pipe 44 is preferably smaller than the width of the substantially annular frame 18 (the difference between the inner and outer diameters of the frame 18). Specifically, the diameter (inner diameter) of the discharge pipe 44 is preferably 1 mm or less. In this embodiment of the frame cleaning mechanism 100, the cleaning nozzle 40 is oscillated within the width of the frame 18 while the cleaning liquid is discharged onto the frame 18 at a sufficiently low flow rate from the small-diameter discharge pipe 44. In other words, the frame cleaning mechanism 100 efficiently discharges the cleaning liquid over the entire frame 18 by oscillating the cleaning nozzle 40 to shift the position where the cleaning liquid is discharged (dropped) onto the surface of the frame 18. The cleaning nozzle 40 (or discharge pipe 44) may also be moved onto the wafer 12 coated with a coating film to clean the coating film.

[0034] Furthermore, it is preferable that the flow rate (discharge flow rate) of the cleaning liquid discharged from the discharge pipe 44 is low enough so that the cleaning liquid discharged from the discharge pipe 44 does not spill from the frame 18 or splash onto the wafer 12 and contaminate or dissolve (hereinafter simply referred to as contamination) the coating film formed on the wafer 12. According to experimental results described later, the desirable flow rate (discharge flow rate) of the cleaning liquid is 0.1 L / min or less. In addition, in order to easily achieve a sufficiently low flow rate, it is preferable that the inner diameter of the discharge pipe 44 be relatively small, for example, 1 mm.

[0035] Thus, the frame cleaning mechanism 100 can efficiently clean the frame by oscillating the cleaning nozzle 40 while suppressing contamination of the coating film by discharging the cleaning fluid at a low flow rate.

[0036] Furthermore, it is preferable that the distance D between the tip of the discharge pipe 44 and the surface of the frame 18 placed on the table 14 is relatively short (distance in the Z-axis direction). A suitable distance D can be determined experimentally or empirically. For example, the distance D is set to 10 mm or less, and more preferably to half that distance or less (i.e., 5 mm or less). The rotary coating device 1 may also be equipped with a height adjustment mechanism that changes the relative height of the tip of the discharge pipe 44 to the frame 18 so that the distance D can be varied according to the flow rate of the cleaning liquid discharged from the discharge pipe 44 or the inner diameter of the discharge pipe 44. By shortening the distance D as described above, it is possible to effectively prevent the cleaning liquid discharged from the discharge pipe 44 from colliding with the frame 18 and scattering into the surroundings.

[0037] Furthermore, the discharge pipe 44 held by the discharge pipe holder 41 may be substantially parallel to the Z-axis direction (vertical direction), that is, substantially perpendicular to the surface of the table 14 (frame 18), but it is preferable that the discharge pipe 44 is inclined with respect to the surface of the table 14. The direction of inclination of the discharge pipe 44 with respect to the surface of the table 14 will be explained below using Figure 4. In Figure 4, reference numeral 4A is a perspective view showing the positional relationship between the rotating table 14 (frame 18) and the cleaning nozzle 40, and reference numeral 4B is a view of the tip of the cleaning nozzle 40 from the center of rotation of the table 14. For the purposes of the explanation below, we will assume that the rotation direction of the table 14 is clockwise (direction of arrow A in Figures 2 to 4 and Figure 7).

[0038] As shown by reference numerals 4A and 4B in Figure 4, when the discharge pipe 44 is inclined with respect to the surface of the table 14, it is preferable that the inclination direction of the discharge pipe 44 has a component in the same direction as the rotation direction of the table 14. In the positional relationship between the cleaning nozzle 40 and the table 14 as shown by reference numeral 4A, when viewing the tip of the cleaning nozzle 40 from the rotation center of the table 14, the rotation direction of the table 14 is in the positive direction of the X axis (from left to right in Figure 4), as shown by arrow A, as shown by reference numeral 4B.

[0039] When the discharge pipe 44 is inclined with respect to the surface of the table 14, the discharge direction of the cleaning fluid immediately after discharge is approximately the same as the inclination direction of the discharge pipe 44 (arrow C in reference numeral 4B). Strictly speaking, the discharge direction of the cleaning fluid is slightly affected by the oscillation of the cleaning nozzle 40. However, the oscillation speed of the cleaning nozzle 40 is low, and the effect of the oscillation on the discharge direction of the cleaning fluid is small (almost nonexistent), so here we will explain it as if the effect of oscillation is practically negligible.

[0040] When the discharge pipe 44 is inclined with respect to the surface of the table 14, the discharge velocity of the discharged cleaning fluid can be decomposed into a component parallel to the surface of the table 14 (horizontal direction) and a component perpendicular to the surface. For example, in the case of reference numeral 4B, since the rotation direction of the table 14 is in the positive direction of the X-axis, it is desirable that the inclination direction of the discharge pipe 44 is in the positive direction of the X-axis. In other words, it is preferable that the discharge pipe 44 is inclined such that the discharge direction of the cleaning fluid has a component in the same direction as the rotation direction of the table 14.

[0041] If the discharge direction of the cleaning solution includes a component in the same direction as the rotation direction of the table 14, the relative discharge speed of the cleaning solution to the table 14 can be slowed down by the amount of the component in the same direction as the rotation direction of the table 14. By slowing down the relative discharge speed of the cleaning solution to the table 14, it is possible to further suppress the cleaning solution from spilling over from the frame 18 or splashing onto the wafer 12 and contaminating the coating film formed on the wafer 12.

[0042] Returning to Figures 1 and 2, the cleaning nozzle drive unit 50 is an example of the nozzle oscillation mechanism of the present invention and includes a motor and transmission mechanism (not shown). The cleaning nozzle drive unit 50 rotates the cleaning nozzle 40 around the rotating shaft 43, thereby moving the discharge pipe 44 of the cleaning nozzle 40 to a predetermined cleaning position so as to face the frame 18, or retracting it from the cleaning position.

[0043] Furthermore, when cleaning the frame 18, while the table 14 is rotated by the table rotating device 10, cleaning liquid is discharged from the cleaning nozzle 40 onto the frame 18, and the cleaning nozzle drive unit 50 oscillates the cleaning nozzle 40 within the width of the substantially annular frame 18. In other words, when cleaning the frame 18, while rotating the table 14 (indicated by arrow A in Figures 2 to 4 and Figure 7), the cleaning nozzle 40 is moved back and forth between the inner and outer diameters of the frame 18 (indicated by arrow B in Figures 2, 3 and 7). The oscillation of the cleaning nozzle 40 during cleaning will be described in more detail later. The movement (and oscillation) of the cleaning nozzle 40 by the cleaning nozzle drive unit 50 and the rotation of the table 14 by the table rotating device 10 during cleaning are performed based on control by the control unit 60.

[0044] The control unit 60 provides integrated control of the table rotation device 10, the coating nozzle 20, the coating nozzle drive unit 30, the cleaning nozzle 40, and the cleaning nozzle drive unit 50. The control unit 60 is connected to the rotary coating device 1 (frame cleaning mechanism 100) by wire or wireless.

[0045] The control unit 60 is composed of an arithmetic unit such as a personal computer, and includes an arithmetic circuit composed of various processors and memory. Examples of various processors include CPUs (Central Processing Units), GPUs (Graphics Processing Units), ASICs (Application Specific Integrated Circuits), and programmable logic devices. Examples of programmable logic devices include SPLDs (Simple Programmable Logic Devices), CPLDs (Complex Programmable Logic Devices), and FPGAs (Field Programmable Gate Arrays). The various functions of the control unit 60 may be implemented by a single processor, or by multiple processors of the same or different types.

[0046] The functional configuration of the control unit 60 will be described below using Figure 5. As shown in Figure 5, the control unit 60 includes a coating control unit 61, a table rotation control unit 62, a nozzle drive control unit 63, a flow rate control unit 64, and an interface 65.

[0047] The coating control unit 61 controls the flow control valve (not shown) and the coating nozzle drive unit 30 to adjust the flow rate of the coating nozzle 20 and drive the coating nozzle 20 when applying the coating liquid. Rotary coating in the rotary coating apparatus 1 is a known technique, so a detailed explanation is omitted. The table rotation control unit 62 controls the table rotation device 10 to rotate the table 14 at an appropriate rotation speed when applying the coating liquid and when cleaning the frame 18.

[0048] The nozzle drive control unit 63 oscillates the cleaning nozzle 40 within the width of the frame 18 when cleaning the frame 18. The flow rate control unit 64 adjusts the flow rate of the cleaning liquid when cleaning the frame 18 by controlling a flow rate control valve (not shown). The interface 65 exchanges information with the user and the rotary coating device 1 via an input / output unit (not shown).

[0049] The following describes the procedure for coating the coating solution and cleaning the frame 18 in the rotary coating apparatus 1, using Figure 6. First, the wafer 12 is placed on the table 14 by a transport arm (not shown) (step S10). Next, the coating solution is discharged from the coating nozzle 20 to the vicinity of the center of the wafer 12, and then the table 14 is rotated by the table rotation device 10 to diffuse the coating solution throughout the wafer 12 (step S12). The rotation speed of the table 14 when diffusing the coating solution is relatively high. Although it varies depending on the type of coating solution, the thickness of the coating film to be formed, and the size of the wafer 12, the rotation speed of the table 14 is, for example, several hundred to several thousand min⁻¹. -1 That is the case.

[0050] After coating is performed in step S12, the frame 18 is cleaned. In cleaning the frame 18, first, the table 14 is rotated at a sufficiently low speed by the table rotating device 10 so that the cleaning liquid discharged from the cleaning nozzle 40 does not spill (step S14). The rotation speed of the table 14 is, for example, 10 min -1 The following is true: By keeping the rotation speed of the table 14 sufficiently low, it is possible to suppress the cleaning solution from spilling from the frame 18 or splashing onto the wafer 12 and contaminating the coating film formed on the wafer 12.

[0051] Next, the cleaning nozzle drive unit 50 moves the cleaning nozzle 40 to the cleaning position (cleaning start position) (step S16). Furthermore, while discharging cleaning fluid from the cleaning nozzle 40 onto the frame 18, the cleaning nozzle drive unit 50 swings the cleaning nozzle 40 within the width of the substantially annular frame 18, and the table rotation device 10 rotates the table 14 by one or more rotations (step S18).

[0052] The oscillation of the cleaning nozzle 40 when cleaning the frame 18 will be explained in more detail below using Figure 7. Figure 7 is a diagram illustrating the oscillation of the cleaning nozzle 40 when cleaning the frame 18. In Figure 7, the black circles indicate the positions of both ends of the range in which the tip of the discharge pipe 44 oscillates.

[0053] As shown in Figure 7, one of the black circles indicating the range of oscillation of the tip of the discharge pipe 44 is located on the inner circumference of the frame 18, and the other black circle is located on the outer circumference of the frame 18. In other words, the tip of the discharge pipe 44 oscillates (reciprocates) between the inner and outer circumferences of the frame 18, or in other words, within the width of the frame 18.

[0054] In the frame cleaning mechanism 100, the inner diameter of the discharge pipe 44 is small so that cleaning fluid can be discharged from the discharge pipe 44 at a sufficiently low flow rate, and is therefore smaller than the width of the frame 18 (the difference between the inner and outer diameters of the frame 18). Therefore, by oscillating the cleaning nozzle 40 within the width of the frame 18 (between the inner and outer diameters of the frame 18), cleaning fluid is discharged across the entire width of the frame 18.

[0055] By shifting the position at which the cleaning solution is discharged (dropped) onto the surface of the frame 18, the cleaning solution can be efficiently applied to the entire frame 18, thereby improving cleaning efficiency even when discharging the cleaning solution at a low flow rate.

[0056] In the frame cleaning mechanism 100, the inner diameter of the discharge pipe 44 is small and the discharge flow rate is also small, so when the cleaning liquid is discharged, it is possible to prevent the cleaning liquid from spilling out of the frame 18 and to suppress contamination of the coating film formed on the wafer 12.

[0057] Furthermore, while rotating the table 14, the cleaning nozzle 40 is oscillated (reciprocated) within the width of the frame 18. This makes it possible to discharge the cleaning fluid around the entire circumference of the frame 18. As a result, the entire frame 18 can be cleaned without the cleaning fluid splashing from the frame 18.

[0058] Here, the discharge flow rate of the cleaning solution and the rotation speed of the table 14 can be set arbitrarily, but it is preferable to set the discharge flow rate of the cleaning solution and the rotation speed of the table 14 to be sufficiently low so that the cleaning solution does not splash from the frame 18. Specifically, it is preferable to set the discharge flow rate of the cleaning solution and the rotation speed of the table 14 to be sufficiently low so that the discharged cleaning solution does not spill off the surface of the frame 18 but remains on the surface of the frame 18 due to surface tension.

[0059] Furthermore, when discharging the cleaning solution, it is preferable to rotate the table 14 multiple times and to oscillate the cleaning nozzle 40 so that the trajectory of the cleaning nozzle 40 projected onto the frame 18 does not form a single closed curve. Because the trajectory of the cleaning nozzle 40 projected onto the frame 18 does not form a single closed curve, for example, when the table 14 is rotated twice, the trajectory of the cleaning nozzle 40 during the first rotation of the table 14 does not completely overlap with the trajectory of the cleaning nozzle 40 during the second rotation of the table 14. Since the position at which the cleaning solution is discharged onto the surface of the frame 18 during the second rotation of the table 14 can be shifted from that during the first rotation of the table 14, it becomes possible to discharge the cleaning solution onto the frame 18 more evenly and uniformly.

[0060] In step S18, after discharging the cleaning solution around the entire circumference of the frame 18, the rotation of the table 14 is stopped (step S20), and the frame is left to stand for a certain period of time (step S22). During this standing time, any contaminants (resist solution or resin solution for protective film formation) adhering to the frame 18 are dissolved in the cleaning water. If the solubility of the contaminants adhering to the frame 18 in the cleaning solution is relatively high, step S22 may be omitted.

[0061] Next, the table 14 is rotated at high speed by the table rotation device 10, and the cleaning solution is scattered from the surface of the frame 18 by centrifugal force (step S24). The rotation speed of the table 14 can be set arbitrarily, for example, from several hundred to several thousand min⁻¹. -1 That is the case.

[0062] After removing the cleaning solution, the frame 18 is visually inspected or photographed with a camera (not shown) to confirm whether the frame 18 has been properly cleaned, and a decision is made whether to repeat the cleaning or terminate the process (step S26). This decision may be made by the user, or it may be made automatically by the control unit 60 based on the camera's observation image.

[0063] If it is determined in step S26 to repeat the cleaning (step S26: NO), the process returns to step S14. If it is determined in step S26 to finish the cleaning (step S26: YES), the wafer 12 is removed from the table 14 (step S28), and the process ends.

[0064] Thus, according to this embodiment, the cleaning liquid is discharged from the tip of the discharge pipe 44 across the entire width direction of the frame 18 by the oscillation of the cleaning nozzle 40, and also discharged across the entire circumferential direction of the frame 18 by the 360-degree rotation (one revolution) of the table 14. At this time, the discharge flow rate of the cleaning liquid and the rotation speed of the table 14 are kept sufficiently low so that the discharged cleaning liquid does not spill off the surface of the frame 18 but remains on the surface of the frame 18 due to surface tension. This makes it possible to suppress the cleaning liquid from spilling off the frame 18 or splashing onto the wafer 12 and contaminating the coating film formed on the wafer 12.

[0065] The preferred cleaning conditions will be described below using Figure 8. Figure 8 shows the results of cleaning the frame 18 in Experimental Examples 1 to 11, where the inner diameter of the discharge pipe 44 is 1 mm and the distance D between the tip of the discharge pipe 44 and the surface of the frame 18 is 4 mm, by changing the rotation speed of the table 14, the discharge flow rate of the cleaning water, and the standing time.

[0066] In Figure 8, a rating of A indicates excellent cleaning results, a rating of B indicates good results, a rating of C indicates partially poor results, and a rating of F indicates poor results. In Experimental Example 1, the rotation speed was 20 min. -1 The discharge flow rate was 0.5 L / min, and the cleaning solution was removed immediately after discharge without being left standing. In Experimental Example 1, the discharged cleaning solution immediately spilled off the surface of the frame 18, and the evaluation result was F.

[0067] In Experimental Example 2 and Experimental Example 3, the discharge flow rate in Experimental Example 1 was changed to 0.2 L / min and 0.1 L / min, respectively. Also in Experimental Example 2 and Experimental Example 3, the discharged cleaning liquid immediately spills off the surface of the frame 18, so the evaluation result is F. From Experimental Example 1 to Experimental Example 3, the rotation speed of the table 14 is 20min -1 , it is found that the rotation speed is too high to perform favorable cleaning.

[0068] In Experimental Example 4 to Experimental Example 6, among the conditions of Experimental Example 1 to Experimental Example 3, the rotation speed was set to 15min -1 was changed. In Experimental Example 4 and Experimental Example 5, the discharged cleaning liquid immediately spills off the surface of the frame 18, so the evaluation result is F. In Experimental Example 6, the cleaning water tends to accumulate on the surface of the frame 18, but the frequency at which the cleaning liquid spills off the surface of the frame 18 is still high, so the evaluation result is F. According to Experimental Example 4 to Experimental Example 6, the rotation speed of the table 14 is 15min -1 Even in this case, it is found that the rotation speed is still too high to perform favorable cleaning.

[0069] In Experimental Example 7 to Experimental Example 9, among the conditions of Experimental Example 1 to Experimental Example 3, the rotation speed was set to 10min -1 was changed. In Experimental Example 7, the discharged cleaning liquid immediately spills off the surface of the frame 18, and the evaluation result is F. In Experimental Example 8, the cleaning water tends to accumulate on the surface of the frame 18, but the frequency at which the cleaning liquid spills off the surface of the frame 18 is still high, so the evaluation result is F. On the other hand, in Experimental Example 9, the cleaning water accumulates on the surface of the frame 18 and no longer spills off, but the contaminant (coating liquid) remains on the surface of the frame 18, so the evaluation result is C. According to Experimental Example 7 to Experimental Example 9, the rotation speed of the table 14 is 10min -1 , it is found that there is a prospect of obtaining good cleaning results by changing other cleaning conditions.

[0070] In Experimental Example 10, the cleaning solution was dispensed under the same conditions as in Experimental Example 9, left for 30 seconds, and then removed. In Experimental Example 10, the contaminants were considerably dissolved, and the cleaning results were improved, so the evaluation result is B. Furthermore, in Experimental Example 11, the cleaning solution was dispensed under the same conditions as in Experimental Example 9, left for 45 seconds, and then removed. In Experimental Example 11, almost all of the contaminants were dissolved, and the cleaning results were further improved, so the evaluation result is A.

[0071] The results of these experiments showed that the cleaning results were good if the rotation speed of table 14 and the discharge flow rate of the cleaning solution were sufficiently low, and the standing time was extended. Specifically, in the experimental example shown in Figure 8, the rotation speed of table 14 was 10 min -1 It was found that effective cleaning could be achieved by setting the discharge flow rate to 0.1 L / min and the standing time to 30 seconds or more. Note that the specific numerical values ​​in the above experimental results are merely examples and are not intended to limit the parameters used during cleaning. Naturally, the optimal rotation speed of the table 14, the discharge flow rate of the cleaning solution, and the standing time will vary depending on the inner diameter of the discharge pipe 44, the distance D between the tip of the discharge pipe 44 and the surface of the frame 18, the type of contaminant (coated film), and the type of cleaning solution.

[0072] <Effects> As described above, according to the frame cleaning mechanism 100 of this embodiment, the table 14 is rotated by the table rotating device 10, while cleaning liquid is discharged onto the frame 18 from the cleaning nozzle 40, and furthermore, the cleaning nozzle drive unit 50 swings the cleaning nozzle 40 within the width of the substantially annular frame 18. In this way, the position from which the cleaning liquid is discharged onto the surface of the frame 18 is shifted, allowing the cleaning liquid to be efficiently applied to the entire frame 18. Therefore, the frame 18 can be efficiently cleaned even while discharging the cleaning liquid at a low flow rate and low table rotation speed to suppress contamination of the coating film.

[0073] Furthermore, when the discharge pipe 44 is viewed from the rotation center of the table 14, it is preferable that the discharge pipe 44 is inclined with respect to the table 14 such that the discharge direction of the cleaning liquid has a component in the same direction as the rotation direction of the table 14. When the discharge direction of the cleaning liquid includes the same direction as the rotation direction of the table 14, the relative discharge speed of the cleaning liquid with respect to the table 14 can be slowed down by the component in the same direction as the rotation direction of the table 14. This further suppresses contamination of the coating film.

[0074] Furthermore, it is preferable to let the cleaning solution stand for a certain period of time after discharging it before removing the cleaning water. During this standing time, any contaminants adhering to the frame 18 can be dissolved in the cleaning water, thus enabling effective cleaning.

[0075] Furthermore, since the frame cleaning mechanism 100 can be applied to the rotary coating device 1 simply by adding a cleaning nozzle 40, a cleaning nozzle drive unit 50, and a control unit 60, the frame cleaning mechanism 100 can be realized at a relatively low cost. <Variation> In the embodiment described above, the discharge pipe 44 was described as being a straight pipe. However, when viewed from the rotation center of the table 14, the discharge pipe 44 only needs to be able to discharge the cleaning liquid such that the discharge direction of the cleaning liquid has a component in the same direction as the rotation direction of the table 14, so the discharge pipe 44 may be a curved pipe.

[0076] In the above embodiment, the case in which the frame cleaning mechanism 100 is applied to the rotary coating apparatus 1 was described. However, it is also possible to realize the frame cleaning mechanism 100 according to this embodiment using an existing frame cleaning mechanism. In this case, the frame cleaning mechanism 100 can be realized relatively inexpensively simply by changing the control program of the nozzle drive control unit 63 so that the cleaning nozzle drive unit 50 oscillates the cleaning nozzle 40.

[0077] Although embodiments of the present invention have been described above, the present invention is not limited to the above examples, and various improvements and modifications may be made without departing from the spirit of the present invention.

[0078] For example, in the above description, we explained the case where the frame 18 with the wafer 12 fixed to it is placed on the table 14 and the frame 18 is cleaned. However, it is also possible to clean the frame 18 by placing only the frame 18 on the table 14. [Explanation of symbols]

[0079] 1...Rotating coating device, 100...Frame cleaning mechanism, 10...Table rotating device, 12...Wafer, 14...Table, 16...Dicing tape, 18...Frame, 20...Coating nozzle, 21...Discharge port, 22...Arm, 23...Rotating shaft, 30...Coating nozzle drive unit, 40...Cleaning nozzle, 41...Discharge pipe holder, 42...Arm, 43...Rotating shaft, 44...Discharge pipe, 50...Cleaning nozzle drive unit, 60...Control unit, 61...Coating control unit, 62...Table rotation control unit, 63...Nozzle drive control unit, 64...Flow rate control unit, 65...Interface

Claims

1. A frame cleaning mechanism for cleaning an annular frame in which a workpiece on which a coated film has been formed with tape interposed is fixed, A table on which the aforementioned frame is placed, A table rotating device for rotating the aforementioned table, The table is equipped with a nozzle for dispensing cleaning solution, A nozzle swinging mechanism that swings the nozzle within the width of the frame while the table is rotating by the table rotating device, Equipped with, A frame cleaning mechanism configured to prevent the cleaning solution from splashing onto the coating film.

2. The aforementioned nozzle is An arm having a straight rod shape and positioned substantially horizontally with respect to the table, A discharge pipe holder is provided at one end of the aforementioned arm, The discharge pipe held in the discharge pipe holder, Equipped with, The frame cleaning mechanism according to claim 1, wherein, when viewed from the rotation center of the table, the discharge pipe is inclined with respect to the table such that the discharge direction of the cleaning liquid has a component in the same direction as the rotation direction of the table.

3. The frame cleaning mechanism according to claim 2, wherein the table rotating device and the nozzle are configured to set the discharge flow rate of the cleaning liquid and the rotation speed of the table so that the cleaning liquid does not splash from the frame onto the coating film.

4. A frame cleaning method for cleaning an annular frame in which a workpiece on which a coated film has been formed is fixed via a table, A rotation step of rotating the table on which the frame is placed, While the rotation step is being performed, a discharge step is performed in which the nozzle is oscillated within the width of the frame and the cleaning liquid is discharged from the nozzle to the frame, Includes, A frame cleaning method comprising setting the discharge flow rate of the cleaning liquid and the rotation speed of the table in the rotation step and the discharge step so that the cleaning liquid does not splash from the frame onto the coating film.

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