Wafer machining method

Abstract

To efficiently trim the edge of a wafer by maintaining the wafer highly clean and shortening time for cleaning the wafer.SOLUTION: This wafer machining method having a chamfered part on the outer periphery comprises: a holding step of placing a wafer on the holding surface of a chuck table having the holding surface on the upper surface and rotatable about a table rotary shaft crossing the holding surface, exposing the surface of the wafer above, and holding the wafer on the chuck table; and a cutting step of cutting the chamfered part of the outer periphery of the wafer while rotating the chuck table about the table rotary shaft. In the cutting step, machining water containing one or both of a surfactant and a dispersant is supplied to the surface of the wafer. Preferably, the machining water contains one or more of an anionic surfactant, a cationic surfactant, an amphoteric surfactant, and a nonionic surfactant.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a wafer processing method for performing edge trimming by cutting the outer periphery of a wafer having a chamfered portion on the outer periphery. [Background technology]

[0002] In the manufacturing process of device chips used in electronic devices such as mobile phones and personal computers, first, multiple intersecting division lines (streets) are set on the surface of a wafer made of a material such as a semiconductor. Then, devices such as ICs (Integrated Circuits) and LSIs (Large-scale Integrations) are formed in each area defined by the division lines. After that, the wafer is divided along the division lines to form individual device chips. If the wafer is thinned before being divided, thin chips can be obtained in the end.

[0003] A chamfered portion (also called a bevel portion) is formed on the outer periphery of a wafer to prevent chipping of the edge. On the outer periphery of a wafer where a chamfered portion is formed, the cross-sectional shape of the wafer is an arc extending from the front surface to the back surface. Therefore, when a wafer with a chamfered portion formed on the outer periphery is ground from the back surface side to be thinned, a knife-edge shape (also called a sharp edge) consisting of the arc surface constituting the chamfer and the flat ground surface is formed on the outer periphery of the wafer, and chipping is likely to occur on the outer periphery of the wafer.

[0004] Therefore, before grinding the wafer, an edge trimming process is performed in which an annular cutting blade is cut into the outer periphery of the wafer to remove at least a part of the chamfered portion (see Patent Documents 1 to 4). When a wafer that has been edge trimmed is ground to thin it, a knife edge shape is not formed on the outer periphery of the wafer. However, since edge trimming generates processing waste from the wafer, the wafer is washed immediately after processing. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2000-173961 A [Patent Document 2] JP 2004-207459 A [Patent Document 3] JP 2015-182166 A [Patent Document 4] JP 2016-127098 A Summary of the Invention [Problem to be solved by the invention]

[0006] In recent years, with the diversification of materials used for wafers, it has become necessary to edge trim wafers made of materials with low processability. In this case, processing must be performed at a slow processing speed, which increases the processing time. In addition, the diameter of wafers has increased, increasing the amount of processing, and the time required for edge trimming has become longer. Furthermore, there are cases where special edge trimming processing is performed in stages from the outer periphery of the wafer to the inside, which also increases the time required for edge trimming.

[0007] Incidentally, there are cases where a wafer before grinding is integrated by bonding another device wafer or a support substrate. In this case, the integration is performed after edge trimming is performed on the wafer. However, if edge trimming is performed for a long period of time, the amount of processing waste generated increases more than in the past. If processing waste adheres to the surface of the wafer, it becomes difficult to properly bond the device wafer or the support substrate to the wafer, which is problematic. Even if a support substrate or the like is not bonded to the wafer, the processing waste adheres to the wafer, which is problematic because it reduces the quality of the chips that are ultimately manufactured.

[0008] Due to these circumstances, as the time required for edge trimming increases, it becomes necessary to more strongly suppress the adhesion of processing debris to the wafer, and it becomes necessary to perform the cleaning process of the wafer after edge trimming more strongly and for a longer time. Therefore, it takes a long time to remove the wafer from the cutting device that performs edge trimming, and as a result, the time required to manufacture chips from the wafer becomes longer, which is a problem.

[0009] The present invention has been made in consideration of the above problems, and an object of the present invention is to provide a wafer processing method capable of maintaining a high degree of cleanliness of the wafer, shortening the time required for cleaning the wafer, and efficiently performing edge trimming processing on the wafer. [Means for solving the problem]

[0010] According to one aspect of the present invention, there is provided a method for processing a wafer having a chamfered portion formed on its outer periphery, comprising: a holding step of placing a wafer on a holding surface of a chuck table which has a holding surface on an upper surface and can rotate around a table rotation axis which intersects with the holding surface to expose the surface of the wafer upward, and holding the wafer on the chuck table; and a cutting step of cutting the chamfered portion on the outer periphery of the wafer with a cutting blade while rotating the chuck table around the table rotation axis, wherein in the cutting step, processing water containing one or both of a surfactant and a dispersant is supplied to the surface of the wafer.

[0011] Preferably, the processing water contains one or more of an anionic surfactant, a cationic surfactant, an amphoteric surfactant, and a nonionic surfactant.

[0012] More preferably, the method further includes a transfer step of transferring the wafer from the chuck table after the cutting step, and in the transfer step, supply water containing one or both of a surfactant and a dispersant is supplied to the surface of the wafer.

[0013] More preferably, the feed water contains one or more of an anionic surfactant, a cationic surfactant, an amphoteric surfactant, and a nonionic surfactant. Effect of the Invention

[0014] In a wafer processing method according to one aspect of the present invention, when cutting a chamfered portion on the outer periphery of the wafer, processing water containing one or both of a surfactant and a dispersant is supplied to the surface of the wafer.

[0015] When processing water containing a surfactant or the like is supplied to the surface of a wafer, the processing debris is surrounded by the surfactant or the like and dispersed in the processing water, and the wafer surface is made hydrophilic, etc., so that the processing debris is prevented from adhering to the wafer surface. Therefore, the wafer surface is kept relatively clean. In other words, even when a large amount of processing debris is generated in the edge trimming process, the amount of processing debris adhering to the wafer is reduced.

[0016] If there is less processing debris adhering to the wafer, it is not necessary to perform a long wafer cleaning process, and the overall time required for the chip manufacturing process can be shortened. In addition, the cleanliness of the wafer surface can be maintained at a high level. This improves the quality of the chips manufactured by dividing the wafer, and shortens the time required for chip manufacturing, thereby increasing the efficiency of chip manufacturing.

[0017] Therefore, according to one aspect of the present invention, there is provided a wafer processing method capable of maintaining high cleanliness of the wafer, shortening the time required for cleaning the wafer, and efficiently processing the wafer by edge trimming. [Brief description of the drawings]

[0018] [Figure 1] FIG. 2 is a perspective view showing a cutting device. [Diagram 2] FIG. 13 is a perspective view showing a typical holding step. [Diagram 3] FIG. 2 is a perspective view showing a schematic diagram of a first stage of a cutting step. [Figure 4] FIG. 11 is a perspective view showing a second stage of the cutting step. [Diagram 5] FIG. 11 is a cross-sectional view showing a schematic second stage of the cutting step. [Figure 6] FIG. 2 is a perspective view showing a schematic diagram of a transport unit. [Figure 7] 4 is a perspective view showing a schematic rear surface side of a holding portion of the transport unit. FIG. [Figure 8] FIG. 11 is a cross-sectional view illustrating a transport step. [Figure 9] 3 is a flowchart showing the flow of each step of a wafer processing method. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] An embodiment according to one aspect of the present invention will be described with reference to the accompanying drawings. First, a workpiece to be processed by the wafer processing method according to this embodiment will be described. Fig. 2 includes a perspective view showing a wafer 1. The wafer 1 is a disk-shaped wafer made of, for example, Si (silicon), SiC (silicon carbide), GaN (gallium nitride), GaAs (gallium arsenide), or other semiconductor material.

[0020] The front surface 1a of the wafer 1 is partitioned by a plurality of planned dividing lines 3 that intersect with each other. Devices 5 such as ICs and LSIs are formed in each region partitioned by the planned dividing lines 3 on the front surface 1a of the wafer 1. The region on the front surface 1a of the wafer 1 in which the plurality of devices 5 are formed is a device formation region 7, and the region surrounding this is a peripheral surplus region 9. The wafer 1 is ground from the back surface 1b side to thin it, and then divided along the planned dividing lines 3 to form individual device chips.

[0021] Before thinning the wafer 1, a support substrate may be attached to the wafer 1. When the support substrate is attached to the wafer 1, the wafer 1 is reinforced by the support substrate when the wafer 1 is thinned, making the wafer 1 easier to handle.

[0022] Furthermore, in order to increase the integration density of the device chips, other device chips may be stacked on the device chips. For example, another wafer is stacked on the wafer 1 on which the devices 5 are formed, and the stack is divided along the planned division lines 3. In this way, stacked device chips are manufactured.

[0023] In order to prevent chipping or cracking at the edge of the wafer 1, a chamfered portion (see FIG. 5, etc.) is formed by cutting off the corners at the outer periphery 1c of the wafer 1. The cross-sectional shape of the chamfered portion is, for example, an arc shape extending from the front surface 1a to the back surface 1b. In addition, a cutout called a notch 11 that indicates the crystal orientation of the material that constitutes the wafer 1 is formed at the outer periphery 1c of the wafer 1.

[0024] When the wafer 1 with the chamfered portion formed on the outer periphery 1c is ground from the back surface 1b side to thin it, a knife-edge shape formed by the chamfered portion and the ground surface is generated on the cross section of the wafer 1 at the outer periphery 1c. Therefore, chipping is likely to occur on the outer periphery 1c of the wafer 1 that has been ground and thinned. Therefore, before grinding the wafer 1, a process called edge trimming is performed on the wafer 1, in which the outer periphery 1c of the wafer 1 is cut to remove the chamfered portion. FIG. 1 is a perspective view showing a cutting device 2.

[0025] The wafer 1 to be edge-trimmed by the cutting device 2 may be carried into the cutting device 2 in a state where it is integrated with, for example, an annular frame (not shown) having an opening with a diameter larger than that of the wafer 1, and a tape (not shown) attached to the annular frame so as to cover the opening of the annular frame. When the wafer 1, the tape, and the annular frame are integrated to form a frame unit, the wafer 1 can be easily handled. Note that the annular frame and the tape are omitted from each drawing.

[0026] In recent years, the diameter of the wafer 1 has become larger, and the time required for edge trimming has become longer. In addition, as the materials used for the wafer 1 have become more diverse, it has become necessary to edge trim the wafer 1 made of a material with low workability, and in this case, long processing time is unavoidable at a low processing speed. Furthermore, as a special edge trimming process, there is a case where the edge trimming process is carried out in stages from the outer periphery 1c of the wafer 1 toward the inside, which also causes an increase in the time required for edge trimming.

[0027] When edge trimming is performed for a long time, the amount of processing waste generated increases more than in the past. For example, when another device wafer or a support substrate is attached to the wafer 1 before grinding to integrate it, the integration is performed after the edge trimming process is performed on the wafer 1. However, if processing waste generated by the edge trimming process adheres to the front surface 1a of the wafer 1, the device wafer or the support substrate cannot be properly attached to the wafer 1, which is a problem. Even when a support substrate or the like is not attached to the wafer 1, the adhesion of processing waste to the wafer 1 causes a problem because it reduces the quality of the chips that are finally manufactured.

[0028] Due to these circumstances, as the time required for edge trimming increases, it becomes necessary to more strongly suppress adhesion of processing debris to the wafer 1, and it becomes necessary to perform the cleaning process of the wafer 1 after the edge trimming with greater intensity and for a longer time. Therefore, it takes a long time to transport the wafer 1 from the cutting device 2 that performs the edge trimming, and as a result, the time required for manufacturing chips from the wafer 1 becomes longer, which is a problem. Therefore, in the wafer processing method according to this embodiment, the cleanliness of the edge-trimmed wafer 1 is kept high, and the time required for cleaning the wafer 1 is shortened.

[0029] Next, the cutting device 2 used for edge trimming will be described. The cutting device 2 includes a base 4 that supports each component. A cassette table 6 on which a cassette 13 is placed is provided at a corner of the base 4. The cassette table 6 can be raised and lowered in the vertical direction (Z-axis direction) by a lifting mechanism (not shown). In FIG. 1, the outline of the cassette 13 placed on the cassette table 6 is indicated by a two-dot chain line.

[0030] A temporary placement table 10 including a pair of guide rails 8 which move toward and away from each other while maintaining a parallel state in the Y-axis direction (left-right direction, indexing feed direction) is provided on the upper surface of the base 4 at a position adjacent to the cassette table 6. Also, a carry-out unit 12 which carries out the wafers 1 contained in the cassette 13 placed on the cassette table 6 from the cassette 13 is provided on the upper surface of the base 4 at a position adjacent to the temporary placement table 10. The carry-out unit 12 has a gripping portion on its front surface which can grip the wafers 1.

[0031] When unloading the wafer 1 contained in the cassette 13, the unloading unit 12 is moved toward the cassette 13 and the wafer 1 is gripped by the gripping portion, and then the unloading unit 12 is moved in a direction away from the cassette 13. Then, the wafer 1 is pulled out from the cassette 13 onto the temporary placement table 10. At this time, the pair of guide rails 8 are moved in an interlocking manner in a direction approaching each other in the X-axis direction, and the wafer 1 is sandwiched between the pair of guide rails 8, whereby the wafer 1 is positioned at a predetermined position.

[0032] An opening 4a that is long in the X-axis direction (front-rear direction, processing feed direction) is formed at a position adjacent to the cassette table 6 on the upper surface of the base 4. A ball screw type X-axis movement mechanism (processing feed unit) (not shown) and a bellows-shaped dust-proof and drip-proof cover 26 that covers the upper part of the X-axis movement mechanism are disposed in the opening 4a.

[0033] The X-axis movement mechanism is connected to the lower part of the X-axis movement table 16, and has a function of moving the X-axis movement table 16 in the X-axis direction. For example, the X-axis movement table 16 moves between a carry-in / out area adjacent to the cassette table 6 and a processing area below the cutting unit 32 described below.

[0034] A chuck table 18 is provided on the X-axis moving table 16. Fig. 2 includes a perspective view that shows a schematic view of the chuck table 18. The chuck table 18 includes a porous plate 22 having the same diameter as the wafer 1, and a frame 20 that houses the porous plate 22 while exposing it upward.

[0035] One end of a suction path (not shown) formed in the chuck table 18 is connected to the porous plate 22. The other end of the suction path is connected to a suction source (not shown). When the suction source is operated, negative pressure is generated on the surface of the porous plate 22. As a result, the surface of the porous plate 22 functions as a holding surface 24 that holds the wafer 1 by suction.

[0036] A rotation drive mechanism (not shown) that rotates the chuck table 18 about a predetermined rotation axis is provided below the chuck table 18. The chuck table 18 moves in the X-axis direction by the above-mentioned X-axis movement mechanism.

[0037] The wafer 1 is transported from the temporary placement table 10 to the chuck table 18 by a first transport unit 14 provided at a position adjacent to the temporary placement table 10 and the opening 4a on the upper surface of the base 4. The first transport unit 14 has a shaft portion that protrudes upward from the upper surface of the base 4 and is movable up and down and rotatable, an arm portion that extends horizontally from the upper end of the shaft portion, and a holder provided below the tip of the arm portion.

[0038] When the first transport unit 14 transports the wafer 1 from the temporary placement table 10 to the chuck table 18, the X-axis moving table 16 is moved to position the chuck table 18 in the carry-in / out area. Then, the wafer 1 temporarily placed on the temporary placement table 10 is held by the holding portion, the wafer 1 is lifted, and the shaft portion is rotated to move the wafer 1 above the chuck table 18. Thereafter, the wafer 1 is lowered and placed on the holding surface 24 of the chuck table 18. Then, the wafer 1 is suction-held by the chuck table 18.

[0039] The cutting device 2 includes a support structure 28 disposed above the movement path of the X-axis moving table 16 from the carry-in / out area to the processing area, so as to cross the opening 4a. The support structure 28 is provided with an imaging unit 30 facing downward. The imaging unit 30 is, for example, a camera equipped with a CMOS sensor or a CCD sensor. The imaging unit 30 captures an image of the wafer 1 held by suction on the chuck table 18 from above, and detects the position of the wafer 1 to be cut.

[0040] In the processing area where cutting of the wafer 1 is performed, a cutting unit 32 that cuts the wafer 1 held on the chuck table 18 is provided. Figures 3 and 4 include perspective views that typically show the cutting unit 32, and Figure 5 includes a side view that typically shows a portion of the cutting unit 32.

[0041] The cutting unit 32 includes a cutting blade 36 having an annular cutting edge on its outer periphery, and a spindle 44 along the Y-axis direction, to the tip of which the cutting blade 36 is attached and which serves as the axis of rotation of the cutting blade 36.

[0042] A rotary drive source (not shown) such as a motor is connected to the base end of the spindle 44, and the cutting blade 36 attached to one end of the spindle 44 rotates by the force generated by this rotary drive source. The base end of the spindle 44 and the rotary drive source are housed in the spindle housing 34 shown in FIG. 3 etc.

[0043] A flange mechanism 46 for fixing the cutting blade 36 is attached to the tip of the spindle 44. The flange mechanism 46 includes a support surface that supports the cutting blade 36 and a cylindrical boss portion provided in the center of the support surface. The cutting blade 36 has a through hole that passes through the center in the thickness direction, and the cutting blade 36 can be fixed to the tip of the spindle 44 by passing the through hole of the cutting blade 36 through the boss portion of the flange mechanism 46 and tightening a nut portion 48 to the tip of the boss portion.

[0044] The cutting blade 36 includes an annular base 36a made of aluminum or the like, and an annular cutting blade 36b fixed to the outer periphery of the base 36a. A through hole is formed in the center of the base 36a, through which the boss of the flange mechanism 46 passes. The cutting blade 36b includes a countless number of abrasive grains and a bonding material (bond) that disperses and fixes the abrasive grains. For example, the abrasive grains are made of a material such as diamond or cubic boron nitride (cBN), and the bonding material is a nickel plating layer, a resin bond, a vitrified bond, a metal bond, or the like.

[0045] The thickness of the cutting blade 36 (thickness of the cutting edge 36b) is determined, for example, according to the width of the chamfered portion formed on the outer circumferential portion 1c of the wafer 1. The thickness of the cutting blade 36 is preferably, for example, 2 mm or more. However, the thickness is not limited to this.

[0046] A blade cover 38 is attached to the tip of the spindle housing 34, surrounding the cutting blade 36 fixed to the tip of the spindle 44. A connection part 40 is provided on the upper surface of the blade cover 38, to which a pipe that serves as a path for supplying machining water to the blade cover 38 is connected. A machining water supply source 58 (see FIG. 4) is connected to the connection part 40 through a pipe. The machining water supplied by the supply source 58 will be described in detail later.

[0047] The blade cover 38 is provided with a pair of jet nozzles 42 extending along both sides of the cutting blade 36. Pipes (not shown) are provided inside the blade cover 38, and the jet nozzles 42 are connected to the connection part 40 through the pipes. The jet nozzle 42 is provided with a plurality of jet ports (not shown) facing the cutting edge 36b of the cutting blade 36. When processing water is supplied from the supply source 58 to the connection part 40, the processing water is supplied from the jet ports of the jet nozzles 42 to the cutting blade 36 and the wafer 1.

[0048] The blade cover 38 may have a nozzle (not shown) other than the injection nozzle 42, and processing water may be supplied from the nozzle to the cutting blade 36. When processing water is supplied to the cutting blade 36, the supplied processing water falls onto the wafer 1, so supplying processing water to the cutting blade 36 includes supplying processing water to the wafer 1.

[0049] The cutting device 2 also includes an indexing feed unit inside the support structure 28 that moves the cutting unit 32 along a plane parallel to the holding surface 24 of the chuck table 18. When the processing feed unit and the indexing feed unit are operated, the chuck table 18 that holds the wafer 1 by suction and the cutting unit 32 can be moved relatively.

[0050] 4 and 5, the cutting device 2 may include a processing water jet nozzle 50 above the chuck table 18 positioned in the processing area. The processing water jet nozzle 50 is, for example, a pipe-shaped member connected to a supply source 56 of processing water 52, and includes a large number of jet holes (not shown) facing downward. When processing water 52 is supplied from the supply source 56 to the processing water jet nozzle 50, the processing water 52 is jetted from each jet hole, and the processing water 52 is supplied to the wafer 1 held on the chuck table 18 and processed by the cutting unit 32. The configuration of the processing water 52 will be described in detail later.

[0051] The spindle 44 is rotated to rotate the cutting blade 36 around the blade rotation axis 44a (see FIG. 5), causing the cutting edge 36b to cut into the outer periphery 1c of the wafer 1. In this state, the wafer 1 is rotated one or more times around the table rotation axis 18a (see FIG. 5) perpendicular to the holding surface 24 of the chuck table 18. Then, the wafer 1 is cut along the outer periphery 1c of the wafer 1, and edge trimming is performed.

[0052] Thereafter, the chuck table 18 is moved to the carry-in / out area by the X-axis moving mechanism. An opening 4b is formed on the upper surface of the base 4 at a position adjacent to the temporary placement table 10 and the opening 4a, and a cleaning unit 60 for cleaning the wafer 1 after processing is housed in the opening 4b.

[0053] Cleaning unit 60 includes a spinner table that holds wafer 1, and a cleaning nozzle that sprays cleaning liquid onto wafer 1 held on the spinner table. Cleaning unit 60 holds wafer 1 on the spinner table, and while rotating the spinner table, supplies cleaning liquid from the cleaning nozzle onto the upper surface of wafer 1 held on the spinner table, thereby cleaning wafer 1 after processing.

[0054] The cutting device 2 includes a display 62 capable of displaying various information, etc. A touch panel may be attached to the display 62, and an operation screen of the cutting device 2 may be displayed on the display 62. In other words, the display 62 may function as an input interface.

[0055] The cutting device 2 includes a second transport unit 64 that transports the wafer 1 from the chuck table 18 positioned in the loading / unloading area to the cleaning unit 60. Fig. 6 is a perspective view showing the second transport unit 64. The second transport unit 64 has an arm 76 that is movable along the Y-axis direction, and a holder 85 provided below the tip of the arm 76. Next, the second transport unit 64 will be described in more detail.

[0056] The second transport unit 64 includes a moving unit 66 that moves the arm 76 along the Y-axis direction. The moving unit 66 includes a pair of guide rails 68 disposed along the Y-axis direction, and a moving body 70 slidably connected to the pair of guide rails 68. The moving unit 66 further includes a ball screw 72 parallel to the pair of guide rails 68, and a motor 74 connected to one end of the ball screw 72.

[0057] An arm 76 is fixed to the moving body 70. A ball screw 72 is screwed into a nut (not shown) on the back side of the moving body 70. When the motor 74 is operated to rotate the ball screw 72, the moving body 70 moves along the guide rail 68. In other words, when the motor 74 is operated, a holder 85 fixed to the tip of the arm 76 can be moved.

[0058] A lifting unit 78 that lifts and lowers the holding unit 85 is fixed to the tip of the arm 76. The lifting unit 78 is configured, for example, by a cylinder body, and can move the piston rod 82 in the up and down direction (Z-axis direction). The upper end of the piston rod 82 is housed in the cylinder body, and the holding unit 85 is fixed to the lower end of the piston rod 82 via the lifting body 80. The second transport unit 64 can lift and lower the holding unit 85 by operating the lifting unit 78 to lift and lower the piston rod 82.

[0059] The lifting body 80 is fixed to an upper surface 86a of a disk-shaped support 86 of the holding part 85. The diameter of the support 86 corresponds to the diameter of the wafer 1. The holding part 85 has a function of holding the wafer 1. When the arm part 76 is moved by the moving unit 66 while the wafer 1 is held by the holding part 85, the wafer 1 can be transported.

[0060] The following describes the structure of the holding portion 85 that contributes to holding the wafer 1. Fig. 7 is a perspective view that typically shows the lower surface 86b side of the holding portion 85, and Fig. 8 is a cross-sectional view that typically shows the wafer 1 held by the holding portion 85.

[0061] A plurality of long holes 96 are formed in the support 86 of the holding part 85, penetrating the support 86 from top to bottom. Each long hole 96 is provided in the support 86 along the radial direction, with one end reaching the vicinity of the outer periphery of the support 86. A support pillar 90 passes through each long hole 96, and a moving body 92 is fixed to the upper end of the support pillar 90. The moving body 92 has a size and shape that prevents it from passing through the long hole 96, and it can move along the long hole 96 by a movement mechanism (not shown).

[0062] A disk-shaped claw 94 is fixed to the lower end of the support column 90. When the movable body 92 is moved along the long hole 96, the support column 90 and the claw 94 move inward and outward along the radial direction of the support body 86.

[0063] The procedure for holding the wafer 1 placed on the chuck table 18 by the holding part 85 of the second transport unit 64 will be described. First, the holding part 85 is moved above the wafer 1. Also, the movable body 92 is moved radially outward of the support body 86 along the long holes 96. The shapes and sizes of the support pillars 90, the claw bodies 94, and the long holes 96 are determined so that the wafer 1 can pass between the claw bodies 94 at this time.

[0064] Thereafter, the holding unit 85 is lowered to pass the wafer 1 between the claws 94. Then, each movable body 92 is moved radially inward along the long holes 96. As a result, the claws 94 enter the gap between the wafer 1 and the chuck table 18, and the wafer 1 is supported by the claws 94. When the holding unit 85 is raised in this state, the wafer 1 can be transported. FIG. 8 includes a cross-sectional view that typically shows the wafer 1 being transported by the second transport unit 64.

[0065] The second transport unit 64 will now be described. The second transport unit 64 has a structure for supplying the supply water to the wafer 1 while transporting the wafer 1. The lifting body 80 fixed to the upper surface 86a of the support 86 is provided with a connection part 84 to which a supply pipe (not shown) for the supply water is connected. In addition, an injection body 98 having a countless number of injection holes 100 is fixed to the lower surface 86b of the support 86.

[0066] A supply source 102 is connected to a supply pipe connected to the connection part 84. Supply water 104 is supplied from the supply source 102 through the supply pipe to the connection part 84. A flow path is formed inside the lifting body 80 and the support body 86, leading from the connection part 84 to the jet body 98. In FIG. 8, the piping and the flow path are shown diagrammatically by dashed lines. The jet body 98 has an internal space connected to this flow path. Supply water 104 is supplied to the jet body 98 through this flow path.

[0067] The upper ends of the injection holes 100 communicate with this space, and the supply water 104 supplied to the injection body 98 is injected downward through the injection holes 100. The supply water 104 injected from the injection holes 100 is supplied to the front surface 1a of the wafer 1 held by the holding part 85, and prevents the wafer 1 from drying out.

[0068] The wafer 1 transported from the chuck table 18 by the second transport unit 64 is wet with the processing water 52, 54. The processing water 52, 54 adhering to the wafer 1 contains processing debris and the like generated during edge trimming of the wafer 1. Therefore, if the processing water 52, 54 evaporates or disappears during transport of the wafer 1, the processing debris and the like adheres to the wafer 1. The processing debris and the like adhered to the wafer 1 cannot be sufficiently removed even if the wafer 1 is later washed by the cleaning unit 60.

[0069] Therefore, while the wafer 1 is being transported by the second transport unit 64, supply water 104 is supplied to the wafer 1 from each injection hole 100. Supplying the supply water 104 to the wafer 1 prevents the wafer 1 from drying out and prevents processing debris and the like from adhering to the wafer 1.

[0070] When the second transfer unit 64 transfers the wafer 1 from the chuck table 18 to the cleaning unit 60, first, the wafer 1 is held by the holder 85. Then, the arm 76 is moved along the Y-axis direction to place the wafer 1 on the spinner table of the cleaning unit 60. Thereafter, the wafer 1 is held by the spinner table and cleaned.

[0071] The wafer 1 cleaned in the cleaning unit 60 is stored in the cassette 13 placed on the cassette table 6. When storing the wafer 1 in the cassette 13, the first transport unit 14 is used to transport the wafer 1 from the cleaning unit 60 to the temporary placement table 10. Then, the carry-out unit 12 is moved toward the cassette 13 to push the wafer 1 into the cassette 13.

[0072] In this manner, in the cutting device 2, the wafer 1 is carried out of the cassette 13, the wafer 1 is suction-held on the chuck table 18, and the wafer 1 is cut by the cutting unit 32. Thereafter, the wafer 1 is cleaned in the cleaning unit 60 and stored again in the cassette 13. In the cutting device 2, the wafers 1 are carried out one after another from the cassette 13, and the wafers 1 are cut one after another by the cutting unit 32 on the chuck table 18.

[0073] Next, a wafer processing method according to this embodiment, which is carried out by the cutting device 2, will be described. That is, a procedure for edge trimming using the cutting device 2 will be described. The wafer processing method according to this embodiment is mainly carried out by the cutting device 2. FIG. 9 is a flowchart showing the flow of each step of the wafer processing method according to this embodiment.

[0074] In the wafer processing method according to this embodiment, first, a holding step S10 is performed in which the wafer 1 is held by the chuck table 18. In the holding step S10, the wafer 1 is placed on the holding surface 24 of the chuck table 18, which has a holding surface 24 on its upper surface and can rotate around a table rotation axis 18a intersecting the holding surface 24, to expose the front surface 1a of the wafer 1 upward. Then, the wafer 1 is held by the chuck table 18.

[0075] The holding step S10 will be described in detail. First, the cassette 13 containing the wafer 1 to be edge-trimmed is carried into the cassette table 6 of the cutting device 2. Then, the wafer 1 to be processed is pulled out from the cassette 13 to the temporary placement table 10 using the carry-out unit 12. After that, the pair of guide rails 8 are moved in directions approaching each other to clamp the wafer 1, thereby adjusting the position of the wafer 1.

[0076] Next, the wafer 1 is transported to the chuck table 18 by the first transport unit 14. At this time, the chuck table 18 is moved in advance to a loading / unloading area. Then, the wafer 1 is placed on the holding surface 24 of the chuck table 18 with the surface 1a facing upward. FIG. 2 is a perspective view showing a schematic view of the wafer 1 placed on the chuck table 18 by the first transport unit 14. Note that the first transport unit 14 is omitted in FIG. 2.

[0077] At this time, the center of the wafer 1 whose position has been adjusted coincides with the center of the holding surface 24. Here, the table rotation shaft 18a (see FIG. 5), which serves as the rotation center of the chuck table 18, passes through the center of the holding surface 24. Therefore, when the wafer 1 is placed on the holding surface 24 of the chuck table 18, the center of the wafer 1 is also passed through by the table rotation shaft 18a.

[0078] Thereafter, a suction source connected to the chuck table 18 is operated to suction-hold the wafer 1 on the chuck table 18. Figure 3 includes a perspective view that shows a schematic diagram of the wafer 1 being suction-held on the chuck table 18.

[0079] Next, in the wafer processing method according to this embodiment, a cutting step S20 is performed to perform edge trimming of the wafer 1. In the cutting step S20, the chamfered portion of the outer circumferential portion 1c of the wafer 1 is cut by the cutting blade 36 while the chuck table 18 is rotated around the table rotation axis 18a.

[0080] The cutting step S20 will be described in detail. First, in the first stage, the position of the cutting unit 32 is adjusted to position the cutting edge 36b of the cutting blade 36 near one end of the holding surface 24 of the chuck table 18. Fig. 3 includes a perspective view showing the cutting unit 32 whose position has been adjusted. In addition, the spindle 44 starts to rotate, and the cutting blade 36 is rotated around the blade rotation axis 44a (see Fig. 5) at a rotation speed of about 30,000 revolutions per minute.

[0081] Next, in the second stage, the cutting blade 36 is lowered to a predetermined height position. Here, the predetermined height position is the height position of the cutting blade 36 when the lowest point of the cutting edge 36b of the cutting blade 36 is lower than the surface 1a of the wafer 1 held by suction on the chuck table 18. More specifically, it is the height position of the cutting blade 36 when the lowest point of the cutting edge 36b is lower than the surface 1a of the wafer 1 at a depth greater than the final finishing thickness of the wafer 1 after grinding.

[0082] For example, the cutting blade 36 is lowered from above the notch position on the outer circumferential portion 1c of the wafer 1 toward the outer circumferential portion 1c of the wafer 1 and positioned at a predetermined height. At this time, when the cutting edge 36b of the rotating cutting blade 36 comes into contact with the wafer 1, the wafer 1 is cut.

[0083] Alternatively, the cutting blade 36 is lowered to a predetermined height position outside the outer periphery 1c of the wafer 1. Thereafter, the chuck table 18 is moved in a direction parallel to the holding surface 24, and the cutting blade 36b is moved to a cutting position in the outer periphery 1c of the wafer 1. At this time, when the cutting blade 36b of the rotating cutting blade 36 comes into contact with the wafer 1, the wafer 1 is cut.

[0084] Fig. 4 is a perspective view showing a state in which the cutting blade 36 has cut into the wafer 1 (the second stage of the cutting step S20). Fig. 5 is a side view showing a state in which the cutting blade 36 has cut into the wafer 1 (the second stage of the cutting step S20).

[0085] Next, in the third step, the chuck table 18 is rotated around the table rotation axis 18a by one or more revolutions while the cutting blade 36b is cutting into the cutting position of the outer periphery 1c of the wafer 1. Then, the wafer 1 is cut along the outer periphery 1c, and a part of the chamfered portion is removed. This completes the edge trimming process for the wafer 1.

[0086] In the cutting step S20, the cutting blade 36b may be gradually moved radially inwardly of the wafer 1 while rotating the chuck table 18 five or more revolutions while cutting into the outer circumferential portion 1c of the wafer 1. That is, the wafer 1 may be cut radially inwardly from the outer circumferential portion 1c while the chuck table 18 rotates about the table rotation axis 18a. When edge trimming is performed on a wafer 1 with low machinability, it is necessary to perform the edge trimming at a slow proceeding speed in this manner.

[0087] In the wafer processing method according to this embodiment, when the wafer 1 is cut by the cutting blade 36 in the cutting step S20, processing water 54 composed of pure water or the like is sprayed onto the wafer 1 and the cutting blade 36, and the processing water 54 removes processing debris and frictional heat generated by cutting.

[0088] Processing water 54 is supplied from a supply source 58 to the blade cover 38, and is sprayed from a spray nozzle 42 provided on the blade cover 38 onto the cutting blade 36 and the wafer 1. Processing water 52 is supplied from a supply source 56 to a processing water spray nozzle 50, and is sprayed from the processing water spray nozzle 50 toward the front surface 1a of the wafer 1.

[0089] Here, in the cutting step S20 of the wafer processing method according to this embodiment, processing water 52, 54 containing one or both of a surfactant and a dispersant is supplied to the surface 1a of the wafer 1. When the processing water 52, 54 contains a surfactant, the surfactant is any one of an anionic surfactant, a cationic surfactant, an amphoteric surfactant, and a nonionic surfactant. In other words, the processing water 52, 54 contains, for example, one or more of an anionic surfactant, a cationic surfactant, an amphoteric surfactant, and a nonionic surfactant.

[0090] Examples of the anionic surfactant to be mixed into the processing water 52, 54 include polyoxyethylene alkyl ether sulfate, alkyl benzene sulfonate, alkyl ether sulfate, alkenyl succinate, alkyl naphthalene sulfonate, alkyl sulfate, alkyl phosphate, polycarboxylate ether, polycarboxylate, sulfate, etc. However, the anionic surfactant to be mixed into the processing water 52, 54 is not limited to these.

[0091] Examples of the nonionic surfactant to be mixed into the processing water 52, 54 include polyoxyalkylene alkyl ether, polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene alkyl allyl ether, polyoxyalkylene alkyl amine, sorbitan fatty acid ester, etc. However, the nonionic surfactant to be mixed into the processing water 52, 54 is not limited to these.

[0092] Furthermore, examples of the cationic surfactant mixed into the processing water 52, 54 include alkyl trimethyl ammonium sulfate, alkyl dimethyl benzyl ammonium sulfate, etc. However, the cationic surfactant mixed into the processing water 52, 54 is not limited to these. Examples of the amphoteric surfactant mixed into the processing water 52, 54 include alkyl betaine, amido betaine, etc. However, the amphoteric surfactant mixed into the processing water 52, 54 is not limited to these.

[0093] The dispersant mixed into the processing water 52, 54 is a chemical substance used when dispersing powder particles in a liquid, and is an additive having the function of dispersing particles in a liquid. Examples of the dispersant mixed into the processing water 52, 54 include polyacrylic acid and its salts, polyacrylic acid maleate copolymers, olefin maleate copolymers, polyalkylene glycols, cellulose, hydroxyalkyl cellulose, carboxyalkyl cellulose, hexametaphosphate, lignin sulfonate, alkylphenyl ether sulfate, polyvinyl alcohol, polyvinylpyrrolidone, polyvinyl acetate, polyoxyethylene polyoxypropylene glycol ether, etc. The molecular weight of the compound used as the dispersant is preferably 12000 or less. However, the dispersant mixed into the processing water 52, 54 is not limited to this.

[0094] When the processing water 52, 54 contains a surfactant or a dispersant, the processing debris generated during the edge trimming process of the wafer 1 is surrounded by the surfactant or the like and dispersed in the processing water 52, 54, or the surface 1a of the wafer 1 is made hydrophilic, etc. Therefore, the adhesion of the processing debris to the surface 1a of the wafer 1 is inhibited, and the surface 1a of the wafer 1 is kept relatively clean.

[0095] For example, consider the case where the rotation speed of the chuck table 18 is slower than usual to perform edge trimming on a wafer 1 with low machinability, or the case where the wafer 1 is gradually cut from the outer periphery 1c side toward the inside in the radial direction while rotating the chuck table 18 two or more times. In these cases, the edge trimming is performed for a longer time than usual, and a large amount of processing waste is generated accordingly.

[0096] However, in the wafer processing method according to this embodiment, the processing water 52, 54 contains a surfactant or the like, which reduces the amount of processing debris adhering to the wafer 1, and therefore the surface 1a of the wafer 1 is kept relatively clean.

[0097] If the amount of processing debris adhering to the wafer 1 is reduced, it becomes unnecessary to carry out a long cleaning process for the wafer 1, and therefore the time required for the chip manufacturing process as a whole can be shortened. Furthermore, if the cleanliness of the front surface 1a of the wafer 1 is maintained at a high level, the quality of the chips manufactured by dividing the wafer 1 is improved and the time required for chip manufacturing is shortened, thereby increasing the efficiency of chip manufacturing.

[0098] The wafer processing method according to the present embodiment may further include a transfer step S30 of transferring the wafer 1 from the chuck table 18 after the cutting step S20. That is, the transfer step S30 may be performed after the cutting step S20. In the transfer step S30, for example, the wafer 1 is transferred from the chuck table 18 to the cleaning unit 60.

[0099] The transport step S30 will be described in detail. Fig. 8 is a cross-sectional view showing the wafer 1 in the transport step S30. Fig. 8 includes a side view showing the second transport unit 64 that transports the wafer 1 and the chuck table 18 that holds the wafer 1 by suction.

[0100] In the transport step S30, first, the chuck table 18 is moved from the processing area to the loading / unloading area, and the holding part 85 of the second transport unit 64 is moved above the wafer 1. In addition, the movable body 92 is moved radially outward of the support body 86 along the long hole 96. Thereafter, the holding part 85 is lowered to pass the wafer 1 between the claw bodies 94. Then, each movable body 92 is moved radially inward along the long hole 96. Then, the claw bodies 94 enter the gap between the wafer 1 and the chuck table 18, and the wafer 1 is supported by the claw bodies 94.

[0101] Next, the suction hold of the wafer 1 by the chuck table 18 is released, and the holder 85 is raised. Then, the wafer 1 is lifted by the claws 94, and the wafer 1 is released from the chuck table 18, and transportation of the wafer 1 begins. Then, the holder 85 is moved to above the cleaning unit 60, and the holder 85 is lowered to place the wafer 1 on the spinner table of the cleaning unit 60.

[0102] In addition, in the transport step S30, in order to prevent the processing water adhering to the wafer 1 from evaporating, etc., and causing the wafer 1 to dry out, a liquid (supply water) whose main component is water may be supplied to the surface 1a of the wafer 1 while the wafer 1 is being transported.

[0103] 8 is a schematic diagram showing how the supply water 104 is supplied from the holder 85 of the second transport unit 64 to the front surface 1a of the wafer 1. When the wafer 1, which has been cut and has the processing waters 52, 54 adhering thereto, dries during transport, the processing debris and the like that have been taken in the processing waters 52, 54 adhere to the front surface 1a of the wafer 1. The processing debris and the like that have adhered to the wafer 1 cannot be easily removed even by the cleaning unit 60. In contrast, if the supply water 104 is supplied to the front surface 1a of the wafer 1 during transport, the wafer 1 does not dry, and therefore the processing debris and the like are prevented from adhering to the wafer 1.

[0104] In the wafer processing method according to this embodiment, the supply water 104 contains one or both of a surfactant and a dispersant. That is, in the wafer processing method according to this embodiment, preferably, in the transfer step S30, the supply water 104 containing one or both of a surfactant and a dispersant is supplied to the front surface 1a of the wafer 1. The supply water 104 supplied to the wafer 1 preferably contains one or more of an anionic surfactant, a cationic surfactant, an amphoteric surfactant, and a nonionic surfactant.

[0105] If the supply water supplied to the wafer 1 in the transport step S30 does not contain a surfactant or the like, the concentration of the surfactant or the like in the processing water 52, 54 adhering to the wafer 1 while absorbing processing debris or the like will decrease. Therefore, it is considered that the processing debris will adhere to the wafer 1. On the other hand, if the supply water 104 mixed with a surfactant or the like is supplied to the wafer 1, the processing debris is less likely to adhere to the wafer 1.

[0106] Furthermore, the supply water 104 mixed with a surfactant or the like washes away processing debris remaining in the vicinity of the wafer 1. That is, the supply water 104 cleans the wafer 1 before the wafer 1 arrives at the cleaning unit 60, so the cleaning strength required for cleaning the wafer 1 in the cleaning unit 60 is reduced. Therefore, for example, the cleaning time performed in the cleaning unit 60 can be shortened and the wafer 1 can be carried out from the cutting device 2 earlier, so that the efficiency of the edge trimming process of the wafer 1 is improved.

[0107] The surfactants, etc. mixed into the supply water 104 are similar to those mixed into the above-mentioned processing waters 52, 54, and the above description can be referred to as appropriate. However, the surfactants, etc. mixed into the processing waters 52, 54 and the surfactants, etc. mixed into the supply water 104 do not need to be of the same type, and the same amount of surfactants, etc. do not need to be mixed into both.

[0108] For example, if the surfactant, etc. mixed into the supply water 104 and the surfactant, etc. mixed into the processing waters 52, 54 are of the same type, it is preferable that the concentration of the surfactant, etc. is higher in the supply water 104 than in the processing waters 52, 54.

[0109] In particular, it is preferable that the concentration of the surfactant or dispersant in the supply water 104 is at least three times higher than the concentration of the surfactant or dispersant in the processing waters 52, 54. For example, when preparing an undiluted solution of a surfactant or the like and diluting the undiluted solution with water to produce the processing waters 52, 54 and the supply water 104, it is preferable to produce the processing waters 52, 54 from the undiluted solution at a dilution rate three times the dilution rate used to produce the supply water 104 from the undiluted solution.

[0110] The higher the concentration of surfactants, etc. mixed into the processing waters 52, 54, the more efficiently the processing waters 52, 54 can remove processing debris generated during edge trimming from the wafer 1. Here, in order to ensure that the processing waters 52, 54 reach the processing point in the cutting step S20, the processing waters 52, 54 are sprayed at a relatively high pressure onto the wafer 1 and the cutting blade 36. When the processing waters 52, 54 mixed with a high concentration of surfactants, etc. are sprayed onto the wafer 1, etc., a non-negligible amount of foaming occurs in the processing waters 52, 54.

[0111] In contrast, in the transport step S30, the supply water 104 does not need to be supplied to the wafer 1 with a strong force, and is supplied to the wafer 1 with a relatively weak force compared to the processing waters 52 and 54. That is, the amount of foaming caused by the supply of the supply water 104 is relatively small. Therefore, a surfactant or the like can be mixed into the supply water 104 at a relatively high concentration. When the concentration of the surfactant or the like is higher in the supply water 104 than in the processing waters 52 and 54, processing debris or the like can be efficiently removed from the wafer 1.

[0112] After carrying out the transport step S30, the wafer 1 is cleaned in the cleaning unit 60. In the wafer processing method according to the present embodiment, the edge trimming process is carried out while the processing water 52, 54 containing a surfactant or the like is supplied to the wafer 1. Therefore, processing debris remaining on the wafer 1 carried to the cleaning unit 60 is relatively small, and the cleaning strength required in the cleaning process carried out in the cleaning unit 60 is small.

[0113] That is, in the wafer processing method according to this embodiment, the cleaning process of the wafer 1 can be performed in a short time, and therefore the wafer 1 can be quickly removed from the cutting device 2. Therefore, according to the wafer processing method according to this embodiment, the edge trimming process of the wafer 1 can be completed early, and therefore the efficiency of the edge trimming process can be improved.

[0114] The present invention is not limited to the above embodiment, and can be modified in various ways. For example, in the above embodiment, the supply water 104 is supplied to the wafer 1 in the transfer step S30 in which the wafer 1 that has been edge-trimmed in the cutting step S20 is transferred from the chuck table 18 to the cleaning unit 60. However, one aspect of the present invention is not limited to this.

[0115] For example, in the holding step S10 of a wafer processing method according to one embodiment of the present invention, water containing one or both of a surfactant and a dispersant may be supplied to the surface 1a of the wafer 1 before the wafer 1 is placed on the holding surface 24 of the chuck table 18.

[0116] In the cutting device 2, before cutting a workpiece such as a wafer 1 with the cutting blade 36, a dressing step is performed in which the cutting blade 36 cuts into a dressing board. During this step, processing debris is generated from the dressing board and the cutting edge 36b of the cutting blade 36, and the processing debris scatters into the processing chamber of the cutting device 2. If the wafer 1 is carried into the processing chamber in a state where the processing debris is accumulated in the processing chamber, the processing debris may adhere to the wafer 1 before processing, causing a problem.

[0117] In contrast, in the holding step S10, if water mixed with a surfactant or the like is supplied to the front surface 1a of the wafer 1 before the wafer 1 is placed on the holding surface 24 of the chuck table 18, the water will suppress adhesion of processing debris to the wafer 1. More specifically, when the processing debris that has reached the wafer 1 is taken up in the water supplied to the front surface 1a of the wafer 1, the action of the surfactant or the like makes it difficult for the processing debris to adhere to the front surface 1a of the wafer 1. In addition, the water will wash away the processing debris from the wafer 1.

[0118] For example, in the cutting device 2, the first transport unit 14 may have a water supply mechanism similar to the mechanism that supplies the supply water 104 to the wafer 1 being transported by the second transport unit 64. In this case, in the holding step S10, while the first transport unit 14 is transporting the wafer 1 onto the chuck table 18, the first transport unit 14 may supply water mixed with a surfactant or the like to the wafer 1.

[0119] Suppressing the adhesion of processing debris to the wafer 1 before it is processed by the cutting unit 32 not only reduces the required strength of the cleaning process performed later on the wafer 1, but also makes it easier for the processing by the cutting unit 32 to proceed appropriately. Therefore, the yield rate of the cutting process performed by the cutting unit 32 increases, and the efficiency of the cutting process performed by the cutting device 2 can be improved.

[0120] In addition, the structures, methods, etc. according to the above-described embodiments can be modified as appropriate without departing from the scope of the object of the present invention. [Explanation of symbols]

[0121] 1 wafer 1a surface 1b back side 1c outer periphery 3. Planned division line 5 Devices 7 Device formation area 9 Surplus outer area 11 Notches 13 Cassette 2 Cutting equipment 4 Foundation 4a,4b opening 6 Cassette Table 8 Guide rail 10 Temporary table 12 Unloading unit 14 First transport unit 16 X-axis moving table 18 Chuck table 18a Table rotation axis 20 Frame 22 Porous Plate 24 Holding surface 26 Dust-proof / water-proof cover 28 Support structure 30 Imaging unit 32 Cutting unit 34 Spindle housing 36 Cutting Blade 36a base 36b: cutting blade 38 Blade Cover 40 Connection 42 Injection nozzle 44 Spindle 44a Blade rotation shaft 46 Flange mechanism 48 Nut 50 Processing water injection nozzle 52,54 Processed water 56,58 Source 60 Cleaning Unit 62 Display 64 Second transport unit 66 Mobile Units 68 Guide Rail 70 Mobile 72 Ball screw 74 Motor 76 Arm 78 Lifting section 80 Lifting body 82 Piston rod 84 Connection 85 Holding part 86 Support 86a Top side 86b Bottom surface 90 Support column 92 Mobile 94 Claw Body 96 long hole 98 Projectile 100 injection holes 102 Source 104 Supply water

Claims

1. A method for processing a wafer having a chamfered portion formed on an outer periphery thereof, comprising the steps of: a holding step of placing a wafer on a holding surface of a chuck table that has a holding surface on an upper surface thereof and is rotatable around a table rotation axis that intersects with the holding surface, exposing a surface of the wafer upward, and holding the wafer on the chuck table; a cutting step of cutting the chamfered portion of the outer periphery of the wafer with a cutting blade while rotating the chuck table around the table rotation axis, A wafer processing method, characterized in that in the cutting step, processing water containing one or both of a surfactant and a dispersant is supplied to the surface of the wafer.

2. 2. The method for processing a wafer according to claim 1, wherein the processing water contains at least one of an anionic surfactant, a cationic surfactant, an amphoteric surfactant, and a nonionic surfactant.

3. a transfer step of transferring the wafer from the chuck table after the cutting step; 3. The wafer processing method according to claim 1, wherein in the transporting step, supply water containing one or both of a surfactant and a dispersant is supplied to the surface of the wafer.

4. 4. The method of claim 3, wherein the supply water contains at least one of an anionic surfactant, a cationic surfactant, an amphoteric surfactant, and a nonionic surfactant.

Images