Cleaning apparatus and cleaning method

Abstract

To provide a cleaning apparatus capable of eliminating the problem in which, during cleaning of a wafer grinding surface by the cleaning apparatus, cleaning water mixed with contaminants is sucked in from the outer periphery of a spinner table, thereby contaminating the adsorption surface of the wafer.SOLUTION: The cleaning apparatus includes: a spinner table (111) having a holding surface (111b) for holding a wafer (W) by suction; a driving source (116) for rotating the spinner table (111); and a nozzle (112) for supplying cleaning water (L) to the wafer (W) held on the spinner table (111). The outer diameter of the spinner table (111) is configured to be smaller than the outer diameter of the wafer (W). A fan (114) for generating an upward airflow (R10) during rotation of the spinner table (111) is installed below the holding surface (111b) of the spinner table (111). This configuration prevents cleaning water (L) supplied during cleaning of the wafer (W) from flowing around the wafer (W) and being drawn in through the holding surface (111b).SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to a cleaning apparatus for cleaning a wafer. [Background technology]

[0002] A wafer has multiple devices such as ICs and LSIs formed on its surface, separated by planned dividing lines. The back side of the wafer is ground using a grinding machine to form it to a specified thickness, and then the wafer is divided into individual device chips using a dicing machine and laser processing machine. These chips are then used in electrical devices such as mobile phones and personal computers.

[0003] The grinding device is composed of a chuck table that sucks and holds the front surface of the wafer with a protective tape attached, a grinding means having a rotatably mounted grinding wheel with a ring-shaped grinding stone that grinds the back surface of the wafer held by suction on the chuck table, and a cleaning device that sucks and rotates the front surface side of the ground wafer with a spinner table, while supplying cleaning water to the back surface, which is the grinding surface, to clean it, and can process and clean the wafer to the desired thickness with high precision.

[0004] Furthermore, when grinding the back surface of a wafer, there is a problem in that grinding water containing contaminants seeps in from the outer periphery of the chuck table and contaminates the protective tape attached to the front surface of the wafer. To address this problem, the present applicant has proposed a grinding device equipped with an adsorption surface cleaning means for cleaning the surface of the protective tape attached to the front surface of the wafer that has been adsorbed by the chuck table (see Patent Document 1). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2019-054082 Summary of the Invention [Problem to be solved by the invention]

[0006] However, when the grinding surface (back surface) of the wafer is cleaned by the above-mentioned cleaning device, the cleaning water containing contaminants used to clean the back surface is sucked from the outer periphery of the spinner table that holds the wafer in the cleaning device, causing a problem that the chucking surface of the wafer that has been cleaned by the above-mentioned chucking surface cleaning means becomes contaminated again.

[0007] The present invention has been made in consideration of the above-mentioned facts, and its main technical object is to provide a cleaning device that solves the problem that, when the grinding surface (back surface) of a wafer is cleaned by the cleaning device, cleaning water containing contaminants is sucked in from the outer periphery of the spinner table, causing contamination of the adsorption surface of the wafer (the surface on the protective tape side). [Means for solving the problem]

[0008] In order to solve the above-mentioned main technical problem, according to the present invention, there is provided a cleaning apparatus for cleaning wafers, comprising a spinner table having a holding surface that suction-holds the wafer, a drive source that rotates the spinner table, and a nozzle that supplies cleaning water to the wafer held on the spinner table, wherein the outer diameter of the spinner table is smaller than the outer diameter of the wafer, and a fan that rotates as the spinner table rotates and generates an updraft is installed below the holding surface of the spinner table, so that when cleaning the wafer, the cleaning water supplied flows around the wafer and is prevented from being sucked through the holding surface.

[0009] It is preferable that the suction area that sucks the wafer on the holding surface of the spinner table is divided into an outer circumferential area and a central area, and that when the wafer that has been cleaned is transported from the chuck table, a fluid is ejected from the central area. [Effects of the Invention]

[0010] The cleaning apparatus of the present invention comprises a spinner table having a holding surface that suction-holds a wafer, a drive source that rotates the spinner table, and a nozzle that supplies cleaning water to the wafer held on the spinner table. The outer diameter of the spinner table is smaller than the outer diameter of the wafer, and a fan that rotates as the spinner table rotates and generates an ascending air current is installed below the holding surface of the spinner table, preventing the cleaning water supplied when cleaning the wafer from flowing around the wafer and being sucked through the holding surface.Therefore, when cleaning the grinding surface of the wafer in the cleaning apparatus, grinding water supplied from the cleaning nozzle and containing contaminants removed from the grinding surface is prevented from being sucked into the holding surface of the spinner table, preventing the outer periphery of the suction surface of the wafer from becoming contaminated. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is an overall perspective view of a grinding apparatus in which a cleaning apparatus according to an embodiment of the present invention is provided; [Figure 2] 2 is a perspective view of a wafer to be ground by the grinding apparatus shown in FIG. 1. FIG. [Figure 3] 2 is a perspective view of an attraction surface cleaning means disposed in the grinding device shown in FIG. 1. FIG. [Figure 4] FIG. 2 is a perspective view showing a spinner table constituting the cleaning device. [Figure 5] 10 is a conceptual diagram showing the configuration of a fluid path that generates negative pressure on a holding surface of the cleaning device or jets a fluid. FIG. [Figure 6] 10 is a perspective view showing how the suction surface of the wafer is cleaned by the suction surface cleaning means. FIG. [Figure 7] 10 is a side view showing how the ground surface of the wafer is cleaned by the cleaning device. FIG. [Figure 8] FIG. 10 is a side view showing a manner in which fluid is ejected from a central region of a holding surface of the cleaning device. DETAILED DESCRIPTION OF THE INVENTION

[0012] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a cleaning device configured based on the present invention will be described in detail with reference to the accompanying drawings.

[0013] 1 shows a grinding machine 1 equipped with a cleaning device 11 according to this embodiment. The cleaning device of the present invention is not limited to being installed in the grinding machine as in the embodiment described below, but may be independent of the grinding machine.

[0014] The grinding machine 1 shown in Fig. 1 includes a substantially rectangular parallelepiped housing 2. A support wall 21 is erected on the rear end side of the housing 2. Two pairs of guide rails 22, 22 and 23, 23 extending in the vertical direction (Z-axis direction) are provided on the inner surface of the support wall 21. A rough grinding unit 3 serving as rough grinding means is mounted on one of the guide rails 22, 22 so as to be movable in the vertical direction, and a finish grinding unit 4 serving as finish grinding means is mounted on the other guide rails 23, 23 so as to be movable in the vertical direction.

[0015] The rough grinding unit 3 includes a unit housing 31, a wheel mount 33 disposed at the lower end of a rotating shaft 32 rotatably supported by the unit housing 31, a rough grinding wheel 34 mounted on the wheel mount 33 and having a plurality of grinding stones 35 arranged in an annular pattern on its underside, an electric motor 36 mounted on the upper end of the unit housing 31 for rotating the wheel mount 33 in the direction indicated by arrow R1, and a movable base 38 for supporting the unit housing 31 via a support member 37. A grinding water supply means (not shown) is connected to the upper end 32a of the rotating shaft 32, and grinding water L introduced from the upper end 32a is supplied via the rotating shaft 32 from the underside of the rough grinding wheel 34 to the grinding area by the grinding stones 35.

[0016] The movable base 38 is provided with guided grooves that slidably engage with the guide rails 22, 22 provided on the support wall 21, and the rough grinding unit 3 is supported so as to be movable in the vertical direction. The illustrated grinding apparatus 1 is equipped with a grinding feed mechanism 39 that raises and lowers the movable base 38 of the rough grinding unit 3 along the guide rails 22, 22. The grinding feed mechanism 39 is equipped with an externally threaded rod 391 that is rotatably supported and disposed in the vertical direction on the support wall 21 parallel to the guide rails 22, 22, a pulse motor 392 for driving the rotation of the externally threaded rod 391, and an internally threaded block (not shown) that is attached to the movable base 38 and threadably engages with the externally threaded rod 391, and the rough grinding unit 3 is moved in the vertical direction by driving the externally threaded rod 391 in the forward and reverse directions by the pulse motor 392.

[0017] The finish grinding unit 4 is configured in substantially the same manner as the rough grinding unit 3, and includes a unit housing 41, a wheel mount 43 disposed at the lower end of a rotating shaft 42 rotatably supported by the unit housing 41, a finish grinding wheel 44 mounted on the wheel mount 43 and having a plurality of grinding stones 45 arranged in an annular pattern on its underside, an electric motor 46 mounted on the upper end of the unit housing 41 for rotating the wheel mount 43 in the direction indicated by arrow R2, and a movable base 48 supporting the unit housing 41 via a support member 47. A grinding water supply means (not shown) is connected to the upper end 42a of the rotating shaft 42, and grinding water L introduced from the upper end 42a is supplied via the rotating shaft 42 from the underside of the finish grinding wheel 44 to the grinding area by the grinding stones 45.

[0018] The movable base 48 is provided with guided grooves that slidably engage with the guide rails 23, 23 provided on the support wall 21, and the finish grinding unit 4 is supported so as to be movable in the vertical direction. The grinding apparatus 1 is provided with a grinding feed mechanism 49 as elevating means for raising and lowering the movable base 48 of the finish grinding unit 4 along the guide rails 23, 23. The grinding feed mechanism 49 is provided with an externally threaded rod 491 that is rotatably supported and disposed in the vertical direction on the support wall 21 parallel to the guide rails 23, 23, a pulse motor 492 for driving the rotation of the externally threaded rod 491, and an internally threaded block (not shown) that is attached to the movable base 48 and threadably engages with the externally threaded rod 491, and the externally threaded rod 491 is driven to rotate forward and backward by the pulse motor 492, thereby moving the finish grinding unit 4 in the vertical direction.

[0019] The grinding machine 1 is equipped with a turntable 5 disposed on the front side of the support wall 21 so as to be substantially flush with the upper surface of the device housing 2. The turntable 5 is formed in a relatively large disk shape and is rotated appropriately in the direction indicated by arrow R3 by a rotation drive mechanism (not shown) within a drain pan 20 on the upper surface of the device housing 2. The turntable 5 is provided with three chuck tables 6, each of which serves as a holding means for holding a workpiece at an angle of 120 degrees. Each chuck table 6 is equipped with a rotation drive means (not shown) and is configured to be rotatable in the direction indicated by arrow R4. The holding surface of the chuck table 6 is formed in a disk shape using a porous material with air permeability, and is connected to a suction source (not shown).

[0020] The three chuck tables 6 arranged on the turntable 5 are moved sequentially from the workpiece carry-in / out area A → the rough grinding area B → the finish grinding area C → the workpiece carry-in / out area A by rotating the turntable 5 in the direction indicated by the arrow R3. A cleaning water supply nozzle 16 is arranged near the workpiece carry-in / out area A in the drain pan 20, for supplying cleaning water L (which can also be used as the grinding water L) to the upper surface of the chuck table 6 positioned in the workpiece carry-in / out area A.

[0021] The illustrated grinding apparatus 1 includes a first cassette 7 disposed on one side of the workpiece carry-in / out area A and accommodating a plurality of wafers W, which are workpieces before grinding; a second cassette 8 disposed on the other side of the workpiece carry-in / out area A and accommodating a plurality of wafers W after grinding; a temporary placement table 9 disposed between the first cassette 7 and the workpiece carry-in / out area A and on which the wafers W are temporarily placed and centered; a cleaning device 11 configured according to the present invention and disposed between the workpiece carry-in / out area A and the second cassette 8 and for cleaning the grinding surface (upper surface) of the wafer W; and a cleaning device 12 disposed between the chuck table 6 moved to the workpiece carry-in / out area A and the cleaning device 11 and for cleaning the chuck table 6. a workpiece carrying-in / out means 13 for carrying out the wafer W stored in the first cassette 7 to the temporary storage table 9 and carrying out the wafer W cleaned by the cleaning device 11 into the second cassette 8; a carrying-in means 14 for carrying the wafer W held on the temporary storage table 9 to the chuck table 6 positioned in the workpiece carrying-in / out area A; and a carrying-out means 15 for carrying out the ground wafer W placed on the chuck table 6 positioned in the workpiece carrying-in / out area A with the ground surface thereof held by suction to the suction surface cleaning means 12 and the cleaning device 11.

[0022] The cleaning device 11 includes a spinner table 111 that holds the wafer W by suction and is rotated at high speed by a drive motor described later, and a cleaning nozzle 112 that supplies cleaning water to the upper surface (ground surface) of the wafer W held on the spinner table 111. The cleaning device 11 is provided with a mechanism (not shown) that moves up and down in the direction indicated by arrow R7 in the drawing, and when cleaning the wafer W, the entire cleaning device 11 moves down and a blocking member 11a (shown in the drawing) closes the top, and cleaning of the wafer W is carried out within the device housing 2. The cleaning device 11 will be described in detail later.

[0023] Workpiece carry-in / out means 13 is movable up and down in the vertical direction (Z-axis direction) and includes a suction unit 13a at the tip of an articulated arm, as shown in the figure, with multiple suction holes connected to a suction source (not shown). Carry-in means 14 is movable up and down in the vertical direction (Z-axis direction) and includes an arm member 141 that pivots in the direction indicated by arrow R5, and a suction unit 142 formed at the tip of arm member 141 and with multiple suction holes on its underside. Carry-out means 15 is also movable up and down in the vertical direction (Z-axis direction) and includes an arm member 151 that pivots in the direction indicated by arrow R6, and a suction unit 152 formed at the tip of arm member 151 and with multiple suction holes on its underside.

[0024] An operation panel 17 is provided on the front side of the device housing 2, and the operation panel 17 can be used to issue grinding instructions to a control means 100 provided inside the device housing 2. The control means 100 is configured by a computer and includes a central processing unit (CPU) that performs calculations according to a control program, a read-only memory (ROM) that stores the control program, etc., a readable and writable random access memory (RAM) that temporarily stores detected values, calculation results, etc., an input interface, and an output interface (details not shown). Each operating unit of the grinding device 1 described above is connected to the control means 100, and the control means 100 controls each operating unit to perform the grinding process and cleaning described below.

[0025] 2 shows a wafer W to be processed by the grinding apparatus 1. The wafer W is, for example, a silicon wafer, and a plurality of devices D are formed on the front surface Wa of the wafer W, separated by planned division lines WL. A protective tape T is attached to the front surface Wa of the wafer W in advance as shown in the figure, and the wafer W is stored in the first cassette 7 with the back surface Wb, which is the grinding surface, facing upward.

[0026] 3 shows an enlarged view of the suction surface cleaning means 12. The suction surface cleaning means 12 is disposed on the drain pan 20 on a path taken when the wafer W, which is held on the chuck table 6 by the suction unit 152 of the carry-out means 15, is sucked from the chuck table 6 positioned in the workpiece loading / unloading area A and transported to the cleaning device 11. The suction surface cleaning means 12 includes a drive source 121 disposed on the underside of the drain pan 20, a rotary shaft 122 that protrudes above the drain pan 20 and is driven to rotate by the drive source 121, a plurality of sponge holding units 123 (four in the illustrated embodiment) disposed radially from the upper end of the rotary shaft 122, sponge units 124 attached to each sponge holding unit 123, and a cleaning water supply unit 125 that supplies cleaning water L upward.

[0027] Four cleaning water supply units 125 are formed along each sponge holder 123. A plurality of nozzle holes 125a are arranged on the upper surface of each cleaning water supply unit 125 for spraying cleaning water L (which can also serve as the grinding water L) upward. These nozzle holes 125a are connected to a cleaning water supply means (not shown) to spray the cleaning water L. The sponge unit 124 may be made of any material, including, but not limited to, a sponge made from sea sponge, loofah, or cotton; a sponge containing a nonwoven fabric made from a natural material such as cotton, linen, or wool; or a synthetic sponge containing polyurethane, polyester, nylon nonwoven fabric, or melamine. By operating the drive source 121, the sponge holder 123 and the cleaning water supply unit 125 are rotated in the direction indicated by arrow R8. The drive source 121 is an electric motor and is controlled by the control means 100.

[0028] 4 shows a spinner table 111 constituting the cleaning apparatus 11 of this embodiment. The spinner table 111 includes a holding surface 111a and a frame 111b surrounding the holding surface 111a. As shown in the figure, the holding surface 111a has a suction area for sucking the wafer W, which is divided into an outer peripheral area 113a and a central area 113b surrounded by the outer peripheral area 113a. The spinner table 111 is supported by a rotating shaft 115 and includes a drive motor 116 provided as a drive source for rotating the rotating shaft 115 in the direction indicated by arrow R9 to rotate the spinner table 111, and a rotary joint 117 provided at the lower end of the rotating shaft 115.

[0029] As shown in the figure, the outer diameter D1 of the spinner table 111 is configured to be smaller than the outer diameter D2 of the wafer W described above, and multiple fans 114 are installed below the holding surface 111a of the spinner table 111 to generate an ascending air current by rotating in conjunction with the rotation of the spinner table 111 (rotation in the direction indicated by the arrow R9 described above).

[0030] Referring to FIG. 5, an overview of the fluid path that generates negative pressure on holding surface 111a of spinner table 111 or ejects fluid will be described. In FIG. 5, only spinner table 111 is shown in cross section. Inside frame 111b of spinner table 111, path 111c is formed, which is connected to outer circumferential region 113a that constitutes holding surface 111a of spinner table 111, and path 111d is formed, which is connected to central region 113b that constitutes holding surface 111a. Rotary joint 117 includes first connecting portion 117a and second connecting portion 117b. First connecting portion 117a is connected to path 111c of frame 111b via a passage (not shown) in rotation shaft 115, and second connecting portion 117b is connected to path 111d of frame 111b via another passage (not shown) in rotation shaft 115.

[0031] A path P1 is connected to the first connecting portion 117a, through which air H1 is sucked by a suction source S1 to generate a negative pressure in the outer peripheral region 113a, and a path P2 is connected to the second connecting portion 117b for supplying a fluid (either water H2 or air H3, or both) to the central region 113b. A path P3 is also provided, which is connected to the suction source S1 and connects to the path P2. A path P4 branches off from the path P2 and is connected to a water source S2 that supplies water H2, and a path P5 branches off from the path P2 and is connected to an air source S3 that supplies air H3. An on-off valve V1 is provided on the path P1, an on-off valve V2 on the path P3, an on-off valve V3 on the path P4, and an on-off valve V4 on the path P5. The on-off valves V1 to V4 are controlled by the control means 100.

[0032] The grinding apparatus 1 including the cleaning apparatus 11 of this embodiment has a configuration generally as described above, and the grinding process performed by the grinding apparatus 1, as well as the functions and effects of the cleaning apparatus 11 will be described below.

[0033] When performing grinding using the grinding apparatus 1, first, the first cassette 7 containing a plurality of wafers W as described above is set in the grinding apparatus 1 shown in FIG. 1 , and an empty second cassette 8 is also set. Next, the turntable 5 is operated to position the chuck table 6, which does not hold a wafer W, in the workpiece carry-in / out area A. Next, the workpiece carry-in / out means 13 is operated to carry out the unprocessed wafer W from the first cassette 7 and place it on the temporary storage means 9, where it is centered. The centered wafer W is then sucked and transported by the suction part 142 of the carry-in means 14, and placed on the chuck table 6 positioned in the workpiece carry-in / out area A with the protective tape T facing downward.

[0034] Once the wafer W is placed on the chuck table 6, a suction source (not shown) is activated to generate negative pressure on the holding surface of the chuck table 6, thereby supporting the wafer W. Next, the turntable 5 is rotated 120 degrees in the direction indicated by the arrow R3 in FIG. 1, and the chuck table 6 supporting the unprocessed wafer W is moved toward the rough grinding area B.

[0035] Once the chuck table 6 supporting the wafer W is positioned in the rough grinding area B, rough grinding is performed. More specifically, the chuck table 6 is rotated in the direction indicated by the arrow R4 in FIG. 1 at, for example, 300 rpm. Simultaneously, the rough grinding unit 3 is operated to rotate the rough grinding wheel 34 in the direction indicated by the arrow R1 in FIG. 1 at, for example, 6000 rpm. Then, the grinding feed mechanism 39 is operated to lower the rough grinding unit 3, bringing the grinding wheel 35 into contact with the back surface Wb of the wafer W from above, and grinding is performed at a grinding feed rate of, for example, 1.0 μm / sec. At this time, the grinding water supply means (not shown) is operated to introduce grinding water L from the upper end 32a of the rotating shaft 32 and supply the grinding water L from the underside of the rough grinding wheel 34 toward the grinding wheel 35 and the back surface Wb of the wafer W. At the same time, grinding can be carried out while measuring the thickness of the wafer W using a contact or non-contact measuring gauge (not shown), and the back surface Wb of the wafer W is roughly ground to bring the wafer W to the desired thickness for rough grinding, thereby completing the rough grinding process.

[0036] As described above, once the rough grinding is completed, the turntable 5 is rotated another 120 degrees in the direction indicated by the arrow R3 in FIG. 1 to move the chuck table 6, which has undergone the rough grinding, to the finish grinding area C, i.e., directly below the finish grinding unit 4. Once the chuck table 6 has been moved directly below the finish grinding unit 4, the finish grinding wheel 44 of the finish grinding unit 4 is rotated at, for example, 6000 rpm, while the chuck table 6 is rotated at, for example, 300 rpm. Then, the grinding feed mechanism 49 is operated to lower the finish grinding unit 4, bringing the grinding wheel 45 into contact with the back surface Wb of the wafer W from above and grinding the wafer W downward at a grinding feed rate of, for example, 0.1 μm / sec. At this time, as in the rough grinding, grinding water L is introduced from the upper end 42a of the rotating shaft 42 and supplied from the underside of the finish grinding wheel 44 to the grinding surface of the wafer W, i.e., the back surface Wb. At the same time, grinding can be carried out while measuring the thickness of the wafer W using a contact or non-contact measuring gauge (not shown), and the back surface Wb of the wafer W is ground to the desired thickness for finish grinding, completing the finish grinding process, and the grinding process consisting of the above-mentioned rough grinding process and the above-mentioned finish grinding process is completed.

[0037] In addition, when the above-mentioned rough grinding process is performed, if a wafer W that has been subjected to the rough grinding process is positioned in the adjacent finish grinding process area C, the above-mentioned finish grinding process can be performed simultaneously with the above-mentioned rough grinding process.

[0038] Once the above-described finish grinding is completed, the turntable 5 is rotated another 120 degrees in the direction indicated by R3, and the chuck table 6 supporting the wafer W for which finish grinding has been completed is positioned in the workpiece loading / unloading area A. Next, cleaning water L is sprayed from the cleaning water supply nozzle 16 onto the back surface Wb, which is the grinding surface of the wafer W, to clean the back surface Wb to some extent. Note that cleaning by the cleaning water supply nozzle 16 does not sufficiently clean the back surface Wb of the wafer W.

[0039] Here, the above-mentioned unloading means 15 is operated to position the lower surface of the suction part 152 of the unloading means 15 on the grinding surface (upper surface) of the wafer W positioned in the workpiece loading / unloading area A, and is lowered to approach the wafer W. Next, a negative pressure is generated on the lower surface where the suction holes are formed in the suction part 152 of the unloading means 15, and the negative pressure generated on the holding surface of the chuck table 6 is released. As a result, the grinding surface of the wafer W supported on the chuck table 6 is sucked and held by the suction part 152 of the unloading means 15. Once the grinding surface of the wafer W has been sucked by the suction part 152, the unloading means 15 is raised to unload the wafer W from the chuck table 6.

[0040] The wafer W unloaded from the chuck table 6 is positioned above the suction surface cleaning means 12 by rotating the arm member 151 of the unloading means 15 in the direction indicated by arrow R6 in Fig. 1. Next, the drive source 121 of the suction surface cleaning means 12 is operated to rotate the sponge holding part 123 in the direction indicated by arrow R8 at a predetermined speed (e.g., 10 rpm) and to spray a predetermined amount of cleaning water L (e.g., 1 L / min) from the spray holes 125a of the cleaning water supply part 125, as shown in Fig. 6. Next, as shown in Fig. 6, the sponge unloading means 15 of the suction surface cleaning means 12 is lowered to bring the suction surface of the wafer W, to which the protective tape T has been attached and which has been sucked and supported by the chuck table 6, into contact with the sponge part 124 of the suction surface cleaning means 12, and the arm member 151 of the unloading means 15 is swung in the direction indicated by arrow R6 at a predetermined speed (e.g., 5° / sec) to clean the entire suction surface of the wafer W. The adsorption surface is cleaned in this manner for a predetermined time (for example, 15 seconds).

[0041] As a result of the above, the suction surface of the wafer W supported by the chuck table 6 is cleaned, and contaminants including contaminants adhering to the suction surface of the wafer W to which the protective tape T is attached are removed.

[0042] After the suction surface cleaning means 12 has cleaned the suction surface of the wafer W supported on the chuck table 6, i.e., the protective tape T side, the wafer W is transported by the unloading means 15 to the cleaning apparatus 11 described with reference to FIGS. 1, 4, and 5, and the protective tape T side of the wafer W is placed on the spinner table 111. At this time, the wafer W is placed so that the center of the wafer W coincides with the center of the holding surface 111a of the spinner table 111. Then, the on-off valves V1 and V2 are opened, and the other on-off valves V3 and V4 are closed, and air H1 is sucked in by the suction source S1. As a result, a negative pressure is generated in the outer peripheral region 113a and the central region 113b that constitute the holding surface 111a of the spinner table 111, and the wafer W is suction-held. As described above, the outer diameter D1 of the spinner table 111 is configured to be smaller than the outer diameter D2 of the wafer W, and when the wafer W is held by suction using the spinner table 111, the outer periphery of the protective tape T attached to the surface Wa of the wafer W is exposed to the outside of the spinner table 111.

[0043] 7, while the spinner table 111 is rotated at high speed in the direction indicated by arrow R9, the cleaning nozzle 112 is oscillated horizontally above the back surface Wb (upper surface), which is the grinding surface of the wafer W, and cleaning water L is sprayed from the tip of the cleaning nozzle 112 toward the grinding surface of the wafer W. Note that, for convenience of explanation, some of the multiple fans 114 are omitted in FIG. 7 and FIG. 8, which will be described below.

[0044] In this way, cleaning with the cleaning water L sprayed from the cleaning nozzle 112 is carried out for a predetermined time, thereby cleaning the entire ground surface of the wafer W. Furthermore, after the ground surface of the wafer W has been cleaned with the cleaning water L, the cleaning water supply source is switched to an air supply source (neither is shown), and air is sprayed from the cleaning nozzle 112 toward the upper surface of the wafer W to dry the ground surface of the wafer W, and cleaning of the wafer W by the ground surface cleaning means 11 is completed.

[0045] As described above, a plurality of fans 114 for generating an ascending air current are formed below the spinner table 111 in the cleaning apparatus 11 of this embodiment, and as the spinner table 111 rotates, an ascending air current is generated in the direction indicated by arrow R10 in FIG. 7 , i.e., upward along the outer edge of the spinner table 111. When the ground surface of the wafer W is cleaned in the cleaning apparatus 11, this ascending air current prevents the grinding water L containing contaminants, etc., supplied from the cleaning nozzle 112 and removed from the ground surface from flowing around the outer edge of the wafer W and being sucked into the holding surface 111a of the spinner table 111. This prevents the suction surface of the wafer W, cleaned by the suction surface cleaning means 12, particularly the outer peripheral region on the protective tape T side, from being recontaminated. As a result, the suction surface (lower surface) and the ground surface (upper surface) of the wafer W are cleaned, and the entire wafer W is brought into a clean state.

[0046] 5, the cleaning apparatus 11 of this embodiment has a water source S2 and an air source S3 connected to the central region 113b of the holding surface 111a of the spinner table 111. After the cleaning of the grinding surface by the cleaning apparatus 11 is completed as described above, the grinding surface (back surface Wb) of the wafer W is sucked by the suction portion 13a of the workpiece carrying-in / out means 13 and transported to the second cassette 8, as shown in FIG. 8. At the same time, the on-off valves V1 and V2 are closed to release the negative pressure generated on the holding surface 111a. Next, the on-off valves V3 and V4 described with reference to FIG. 5 are opened to supply water H2 from the water source S2 and supply air H3 from the air source S3. As a result, a fluid mixture of water H2 and air H3 is ejected from the central region 113b of the holding surface 111a via the above-mentioned path P2 and the second connecting portion 117b of the rotary joint 117, and by further raising the workpiece carrying-in / out means 13, the wafer W is slightly lifted in the direction indicated by the arrow R11 in FIG. 8.

[0047] As described above, when floating the wafer W from the holding surface 111a of the spinner table 111, by ejecting a fluid mixture of water H2 and air H2 only from the central region 113b, even if a small amount of contaminants or the like is sucked into the outer peripheral region 113a of the holding surface 111a, the contaminants or the like are prevented from adhering again to the suction surface of the wafer W. After floating the wafer W, the on-off valve V3 may be closed and the on-off valve V4 may be opened so that only air H3 is ejected from the central region 113. In this way, the suction surface of the wafer W and the holding surface 111a of the spinner table 111 can be dried, and contaminants or the like can be prevented from remaining on both. In the above embodiment, when the wafer W is floated from the holding surface 111a, a fluid mixture of water H2 and air H3 is ejected from the central region 113b. However, it is also possible to open only the on-off valve V3 and eject only the water H2. [Explanation of symbols]

[0048] 1: Grinding device 2: Device housing 20: Drain pan 21:Supporting wall 22, 23: Guide rails 3: Rough grinding unit 31: Unit housing 32: Rotation axis 32a:Top end 33: Wheel mount 34: Rough grinding wheel 35: Grinding wheel 36: Electric motor 37: Support member 38: Mobile base 39: Grinding feed mechanism 4: Finish grinding unit 41: Unit housing 42: Rotation axis 42a:Top end 43: Wheel mount 44: Finishing grinding wheel 45: Grinding wheel 46: Electric motor 47: Support member 48: Mobile base 49: Grinding feed mechanism 5: Turntable 6: Chuck table 7: First Cassette 8: Second cassette 9: Temporary table 11: Cleaning equipment 111: Spinner table 111a: Holding surface 111b: Frame 112: Cleaning nozzle 113a: Outer area 113b: Central area 114: Fan 115: Rotation axis 116: Drive motor 117: Rotary joint 117a: First connection part 117b:Second connection part 12: Support surface cleaning means 121: Power source 122: Rotation axis 123: Sponge holder 124: Sponge part 125: Cleaning water supply unit 125a:Blowout hole 13: Workpiece loading / unloading means 14: Means of transport 141: Arm member 142: Adsorption part 15: Export means 151: Arm member 152: Adsorption part 16: Cleaning water supply nozzle 100: Control means P1~P5: Route V1 to V4: On-off valves

Claims

1. A cleaning apparatus for cleaning a wafer, a spinner table having a holding surface for suction-holding a wafer, a drive source for rotating the spinner table, and a nozzle for supplying cleaning water to the wafer held on the spinner table; The outer diameter of the spinner table is configured to be smaller than the outer diameter of the wafer, and a fan that rotates in conjunction with the rotation of the spinner table to generate an ascending air current is installed below the holding surface of the spinner table, A cleaning device that prevents cleaning water supplied when cleaning a wafer from flowing around the wafer and being sucked from the holding surface.

2. a suction area for sucking the wafer on the holding surface of the spinner table is divided into an outer periphery area and a central area; 2. The cleaning apparatus according to claim 1, wherein a fluid is ejected from the central region when the wafer is transferred from the chuck table after cleaning.

Images