Processing apparatus and processing method

Abstract

To provide a processing apparatus capable of reducing the probability that the center of the bottom surface of a recessed part formed on the rear surface of a wafer is deviated from the center of the upper surface of a chuck table.SOLUTION: The processing apparatus includes a chuck table having a main part capable of applying a suction force to a central area of a resin sheet such that the wafer is held on an upper surface of the chuck table through the central area of the resin sheet, and an applying part connected to the main part and capable of applying a suction force to an intermediate area of the resin sheet located between the central area and the outer peripheral area of the resin sheet and / or applying a suction force to the outer peripheral area of the resin sheet such that a ring frame is held on the upper surface of the chuck table through the outer peripheral area of the resin sheet.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to a processing device for processing a wafer in which a recess having a circular bottom surface is formed and the central region of a resin sheet whose outer peripheral region is fixed to a ring frame is fixed to the bottom surface of the recess, and to a processing method for processing such a wafer. [Background technology]

[0002] Chips for devices such as integrated circuits (ICs) are essential components in various electronic devices such as mobile phones and personal computers. These chips are manufactured, for example, by dividing a wafer having multiple devices formed on its surface along the boundaries between the devices. This wafer may be thinned prior to division in order to reduce the height of the resulting chips.

[0003] Wafer thinning is performed, for example, by a grinding device that includes a chuck table for holding the wafer on its upper surface and a spindle that is provided above the chuck table and has a grinding wheel attached to its lower end, the spindle having a plurality of grinding stones that are arranged discretely in an annular shape. When thinning a wafer with this grinding device, the wafer is first held on the upper surface of the chuck table so that its back surface is exposed.

[0004] Next, the chuck table is moved so that the center of the backside of the wafer is positioned directly under the trajectory of the grinding wheels when the grinding wheel is rotated together with the spindle. Next, while both the grinding wheel and the chuck table are rotating, the grinding wheel is lowered so that the grinding wheels come into contact with the backside of the wafer. Once the grinding wheels come into contact with the backside of the wafer, the backside of the wafer is ground, thereby thinning the wafer.

[0005] However, as the wafer becomes thinner, its rigidity decreases and it becomes more susceptible to cracking. Therefore, a method has been proposed in which a region where multiple devices are provided (device region) is thinned and a region surrounding the device region (peripheral excess region) is left as a ring-shaped reinforcing portion, thereby forming a recess with a circular bottom on the back surface of the wafer (see, for example, Patent Document 1). In this method, a recess is formed on the back surface of the wafer by grinding the back surface of the wafer as described above using a grinding wheel having an outer diameter smaller than the radius of the wafer.

[0006] Furthermore, the ring-shaped reinforcing portion can get in the way when dividing the wafer along the boundaries between multiple devices. In light of this, prior to this division, the wafer is sometimes processed so that the central region of a resin sheet, the outer periphery of which is fixed to a ring frame, is fixed to a recess formed on the back surface of the wafer, and then the ring-shaped reinforcing portion is removed (see, for example, Patent Document 2). [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-173487 [Patent Document 2] Japanese Patent Application Laid-Open No. 2011-61137 Summary of the Invention [Problem to be solved by the invention]

[0008] The above-described wafer processing is performed, for example, in a processing apparatus including a chuck table for holding the wafer via a central region of a resin sheet on its upper surface, and a processing unit for processing the wafer, which is provided above the chuck table. In this processing apparatus, the wafer is generally held via the central region on the upper surface of the chuck table by applying a suction force to the central region of the resin sheet.

[0009] However, if suction force is applied to the resin sheet when the center of the bottom surface of the recess formed on the back surface of the wafer is misaligned with the center of the top surface of the chuck table, a large force may be applied locally to the wafer (for example, near the boundary between the device region and the peripheral surplus region), potentially damaging the wafer. Therefore, it is preferable to hold the wafer on the top surface of the chuck table after aligning the center of the bottom surface of the recess formed on the back surface of the wafer with the center of the top surface of the chuck table in a plan view.

[0010] This alignment is performed, for example, in the following order: First, the center of the bottom surface of the recess is identified by referring to an image formed by an imaging unit capturing an image of the wafer placed on the upper surface of the chuck table. Then, the adjustment unit adjusts the position of the wafer so that this center coincides with the center of the upper surface of the chuck table in a plan view. Here, in processing machines, the imaging unit and the adjustment unit are often provided at a distance from each other.

[0011] Specifically, the imaging unit is often provided in a space (processing chamber) where wafers are processed by the processing unit to easily capture images of processed wafers, etc. On the other hand, the adjustment unit is often provided in a space (adjustment chamber) partitioned separately from the processing chamber to prevent the adhesion of processing debris. In this case, the chuck table on which the wafer is placed needs to be moved from the processing chamber to the adjustment chamber between imaging the wafer and adjusting its position.

[0012] Furthermore, when an orientation flat is formed on the wafer, that is, when the wafer includes a portion (orientation flat portion) that extends linearly around the periphery in a plan view, it may be necessary to determine the position of the orientation flat portion before adjusting the wafer position with the adjustment unit. In this case, imaging of the wafer and rotation of the chuck table on which the wafer is placed may be alternately and repeatedly performed.

[0013] However, if the chuck table, on which the wafer is simply placed without being held, is moved and / or rotated at high speed, the center of the bottom surface of the recess formed on the back surface of the wafer and the center of the top surface of the chuck table may become further misaligned. If the centers become further misaligned, it becomes difficult to adjust the position of the wafer using the adjustment unit so that the centers coincide with each other in a plan view.

[0014] Therefore, when adjusting the position of the wafer using the adjustment unit to accurately align the two centers, the chuck table must be moved and rotated at a slow speed prior to this adjustment, which causes another problem of increasing the time required for wafer processing.

[0015] In view of this, the object of the present invention is to provide a processing device and a processing method that can move and rotate a chuck table at high speed with the wafer simply placed on it via the central region of a resin sheet, without increasing the likelihood that the center of the bottom surface of the recess formed on the back surface of the wafer will be misaligned with the center of the top surface of the chuck table. [Means for solving the problem]

[0016] According to one aspect of the present invention, there is provided a processing apparatus for processing a wafer in which a device region in which a plurality of devices are provided is thinned and a recess having a circular bottom surface is formed so as to leave a peripheral excess region surrounding the device region as a ring-shaped reinforcing portion, and in which a central region of a resin sheet whose peripheral region is fixed to a ring frame is fixed in the recess, the processing apparatus comprising: a main body portion capable of applying a suction force to the central region of the resin sheet so as to hold the wafer via the central region on an upper surface thereof; and a top surface thereof connected to the main body portion and positioned outside and below the upper surface of the main body portion, the top surface thereof being configured to hold an intermediate region located between the central region and the peripheral region of the resin sheet. A processing apparatus is provided, which includes: a chuck table having an additional portion capable of applying suction force to an intermediate region and / or applying suction force to the outer circumferential region of the resin sheet so that the ring frame is held via the outer circumferential region of the resin sheet; an imaging unit for imaging the wafer in a state where it is placed on the upper surface of the main body of the chuck table via the central region of the resin sheet; an adjustment unit for adjusting the position of the wafer in a state where it is placed on the upper surface of the main body of the chuck table via the central region of the resin sheet; and a processing unit for processing the wafer in a state where it is held on the upper surface of the main body of the chuck table via the central region of the resin sheet.

[0017] It is preferable that the processing apparatus of the present invention further includes a moving mechanism for moving the chuck table between a processing chamber in which the imaging unit can image the wafer and the processing unit can process the wafer, and an adjustment chamber in which the adjustment unit can adjust the position of the wafer.

[0018] According to another aspect of the present invention, there is provided a method for processing a wafer in which a device region in which a plurality of devices are provided is thinned, a recess having a circular bottom surface is formed so that a peripheral excess region surrounding the device region remains as a ring-shaped reinforcing portion, and a resin sheet whose peripheral region is fixed to a ring frame has a central region fixed in the recess, the method comprising: placing the wafer on an upper surface of a main body of a chuck table via the central region of the resin sheet; and fixing an intermediate region located between the central region and the peripheral region of the resin sheet to the chuck table. a placing step of placing the resin sheet on an upper surface of the additional portion of the chuck table and / or placing the ring frame on the upper surface of the additional portion via the outer periphery; a temporary holding step of applying suction force to the intermediate region of the resin sheet so that the intermediate region is held on the upper surface of the additional portion of the chuck table and / or applying suction force to the outer periphery so that the ring frame is held via the outer periphery; and a temporary holding step of applying suction force to the intermediate region and / or the outer periphery of the resin sheet but not to the central region of the resin sheet after the temporary holding step. a specifying step of specifying the center of the bottom surface of the recessed portion by referring to an image formed by alternately repeating the imaging of the wafer and the rotation of the chuck table in a state where a suction force is applied to the intermediate region and / or the outer peripheral region of the resin sheet but not to the central region of the resin sheet; a positioning step of moving the chuck table after the specifying step in a state where a suction force is applied to the intermediate region and / or the outer peripheral region of the resin sheet but not to the central region of the resin sheet; and a positioning step of moving the chuck table after the positioning step so as to release the intermediate region and / or the ring frame of the resin sheet held in the temporary holding step. a releasing step of eliminating the suction force acting on the intermediate region and / or the outer peripheral region; an adjusting step of adjusting the position of the wafer after the releasing step so that the center of the bottom surface of the recess identified in the identifying step coincides with the center of the upper surface of the main body part of the chuck table in a plan view; a holding step of applying suction force to the central region of the resin sheet so that the wafer is held on the upper surface of the main body part of the chuck table via the central region; and a processing step of processing the wafer after the holding step.A processing method is provided, comprising:

[0019] Furthermore, if the wafer has a shape such that its outer periphery is divided into an arc portion extending in an arc shape and an orientation flat portion extending in a straight line when viewed in a plane, it is preferable that in the identification step, the center of a virtual circle whose outer periphery overlaps with the arc portion and the center of the orientation flat portion are identified based on the image including at least a portion of the arc portion and the orientation flat portion, and then a point spaced a predetermined distance from the center of the virtual circle in a direction from the center of the orientation flat portion toward the center of the virtual circle is identified as the center of the bottom surface of the recess. [Effects of the Invention]

[0020] In the present invention, a wafer is processed using a chuck table having an additional portion capable of applying a suction force to the intermediate region and / or the outer periphery region of a resin sheet, and therefore, in the present invention, it becomes possible to move and / or rotate the chuck table in a state in which a suction force is applied to the intermediate region and / or the outer periphery region of the resin sheet but not to the central region.

[0021] When the chuck table is moved and rotated in this state, the probability that the center of the bottom surface of the recess formed on the backside of the wafer will not be aligned with the center of the top surface of the main body of the chuck table is lower than when the chuck table is moved and rotated in a state where no suction force is acting on the resin sheet. Therefore, in the present invention, it is possible to move and rotate the chuck table at high speed in a state where the wafer is simply placed on the main body via the central region of the resin sheet, without increasing the probability that the center of the bottom surface of the recess will not be aligned with the center of the top surface of the chuck table. [Brief explanation of the drawings]

[0022] [Figure 1]FIG. 1(A) is a perspective view schematically showing an example of a frame unit constructed by integrating a wafer and a ring frame via a resin sheet, and FIG. 1(B) is a cross-sectional view schematically showing the frame unit shown in FIG. 1(A). [Figure 2] FIG. 2(A) is a top view schematically showing the frame unit shown in FIG. 1(A), and FIG. 2(B) is a bottom view schematically showing the frame unit shown in FIG. 1(A). [Figure 3] FIG. 3 is a perspective view that schematically shows an example of a cutting device (processing device) for cutting (processing) a wafer. [Figure 4] FIG. 4 is a top view schematically showing the main components of the cutting device that are exposed when the cover is removed from the base. [Figure 5] FIG. 5 is a diagram schematically illustrating an example of a transport unit integrated with an adjustment unit and some of the components connected to the transport unit. [Figure 6] FIG. 6 is a diagram schematically illustrating an example of a chuck table and some of the components connected to the chuck table. [Figure 7] FIG. 7 is a top view schematically showing how the position of the wafer placed on the main body of the chuck table is adjusted by the adjustment unit. [Figure 8] FIG. 8 is a flow chart that schematically shows an example of a wafer cutting method (processing method) for cutting (processing) a wafer in a cutting device. [Figure 9] FIG. 9 is a diagram schematically illustrating another example of the chuck table and some of the components connected to the chuck table. DETAILED DESCRIPTION OF THE INVENTION

[0023] An embodiment of the present invention will be described with reference to the accompanying drawings. Fig. 1(A) is a perspective view showing an example of a frame unit formed by integrating a wafer and a ring frame via a resin sheet. Fig. 1(B) is a cross-sectional view showing the frame unit, Fig. 2(A) is a top view showing the frame unit, and Fig. 2(B) is a bottom view showing the frame unit.

[0024] The frame unit 11 shown in Figures 1(A) and 1(B) and 2(A) and 2(B) has a wafer 13 made of a single crystal such as silicon (Si), silicon carbide (SiC), or gallium nitride (GaN), with an exposed surface 13a. An orientation flat 13b is formed on the wafer 13.

[0025] Therefore, the wafer 13 has a shape in which the outer periphery is divided into an arc-shaped portion (arc portion) and a linear portion (orientation flat portion) in a plan view. The wafer 13 also includes a device region 13c where a plurality of devices 15 are provided, and an outer periphery excess region 13d surrounding the device region 13c.

[0026] In the device region 13c, the boundaries of the multiple devices 15 are set in a grid pattern, and each of the multiple straight line portions included in the boundaries is also called a dividing line. Also, a recess 13f having a circular bottom is formed on the back surface 13e of the wafer 13 so as to thin the device region 13c and leave the peripheral excess region 13d as a ring-shaped reinforcing portion 17.

[0027] The recess 13f has a center R of its bottom surface. C and the center of the wafer 13 (specifically, the center of a virtual circle whose outer periphery overlaps with the arc portion included in the outer periphery of the wafer 13 in a plan view) W C Specifically, the center R of the bottom surface of the recess 13f is offset from the center R of the bottom surface of the recess 13f (see FIG. 2(B)). Cis the distance from the center Oc of the orientation flat portion included in the outer periphery of the wafer 13 to the center W of the wafer 13 in a plan view. C The center W of the wafer 13 in the direction C The electrode is spaced from the electrode by a predetermined distance d (for example, 1.8 mm to 2.2 mm).

[0028] Furthermore, a resin sheet 19 is fixed to the back surface 13e of the wafer 13. Specifically, the resin sheet 19 has a disk-like shape with a diameter larger than the above-mentioned imaginary circle, and the center of the resin sheet 19 is aligned with the center W of the wafer 13 in a plan view. C The resin sheet 19 is fixed to a recess 13f formed on the back surface 13e such that the central region of the resin sheet 19 coincides with the wafer 13. The resin sheet 19 has, for example, a flexible film-like base material and an adhesive layer (glue layer) provided on the wafer 13 side of the base material.

[0029] The substrate is made of polyolefin (PO), polyethylene terephthalate (PET), polyvinyl chloride (PVC), polystyrene (PS), or the like. The adhesive layer is made of ultraviolet-curing silicone rubber, an acrylic material, an epoxy material, or the like. Alternatively, the resin sheet 19 may be made of only this substrate. In this case, the wafer 13 and the resin sheet 19 are fixed together by, for example, thermocompression bonding them together.

[0030] Furthermore, a ring frame 21 is fixed to the outer peripheral region of the resin sheet 19. Specifically, a circular opening 21a having a diameter larger than the above-mentioned imaginary circle is formed in the ring frame 21, and the center of the opening 21a is aligned with the center W of the wafer 13 in a plan view. C A ring frame 21 is fixed to the outer peripheral region of the resin sheet 19 so as to coincide with the resin sheet 19. The ring frame 21 is made of an alloy such as an aluminum alloy. Alternatively, the ring frame 21 may be made of a ferromagnetic material such as ferritic or martensitic stainless steel.

[0031] Fig. 3 is a perspective view schematically showing an example of a cutting device (processing device) for cutting (processing) the wafer 13. Note that the direction indicated by the arrow X (X direction) and the direction indicated by the arrow Y (Y direction) shown in Fig. 3 are directions perpendicular to each other on a horizontal plane. Also, the direction indicated by the arrow Z (Z direction) is a direction (vertical direction) perpendicular to both the X direction and the Y direction.

[0032] The cutting device 12 shown in Fig. 3 includes a base 14 that supports each of the components. A cassette table 16 is installed at a corner of the base 14. A cassette 18 that can accommodate the frame unit 11 is placed on this cassette table 16. The cassette table 16 is connected to an elevating mechanism (not shown) for raising and lowering the cassette table 16. The elevating mechanism includes, for example, a ball screw and a motor.

[0033] Furthermore, a cover 20 is provided on the base 14 so as to surround the entire base 14 except for the corners where the cassette table 16 is provided. Fig. 4 is a top view schematically showing the main components of the cutting device 2 that are exposed when the cover 20 is removed from the base 14. In the Y direction as viewed from the cassette table 16, an adjustment chamber A and a cleaning chamber C are provided in this order. In addition, in the X direction as viewed from the adjustment chamber A, a processing chamber P is provided.

[0034] The adjustment chamber A is provided with a pair of guide rails 22 each extending along the Y direction. Each guide rail 22 includes a bottom wall 22a having an upper surface generally parallel to the horizontal plane, and a side wall 22b erected from the outer end of the bottom wall 22a. The pair of guide rails 22 are connected to a distance adjustment mechanism (not shown) including an actuator or the like for adjusting the distance between them in the X direction.

[0035] By operating this spacing adjustment mechanism, it is possible to widen the spacing between the pair of guide rails 22 so that the frame unit 11 (specifically, the ring frame 21) can pass between them, and to narrow the spacing between the pair of guide rails 22 so that both ends of the ring frame 21 in the X direction can be placed on the bottom walls 22a of the pair of guide rails 22, respectively.

[0036] The frame unit 11 housed in the cassette 18 is transported to the pair of guide rails 22 with the narrowed gap between them using a transport unit 24, etc. Figure 5 is a diagram showing a schematic diagram of the transport unit 24 integrated with an adjustment unit 56, which will be described later. Note that in Figure 5, some of the components connected to the transport unit 24 are shown in blocks.

[0037] The transport unit 24 has a support member 26 that has a disk-like shape with a recess formed on each end in the X direction in a plan view. The support member 26 is provided so that its center overlaps with the center in the X direction of the pair of guide rails 22. The support member 26 is also connected to an elevating mechanism 28 and a Y-direction movement mechanism 30, each of which includes a ball screw, a motor, etc.

[0038] A gripping portion 32 is provided on the end of the upper surface of the support member 26 that faces the cassette table 16. The gripping portion 32 includes a pillar portion 32a that stands upright from the upper surface of the support member 26, and a fixed claw 32b and a movable claw 32c that each extend in the direction opposite to the Y direction from the surface of the pillar portion 32a that faces the cassette table 16. The fixed claw 32b is fixed to the upper end of the pillar portion 32a.

[0039] Furthermore, the pillar 32a has a built-in lifting mechanism 32d including an actuator for raising and lowering the movable claw 32c. By operating this lifting mechanism 32d, the fixed claw 32b and the movable claw 32c can be brought closer together so that the ring frame 21 is gripped by them, or can be moved apart so that the gripped ring frame 21 is released.

[0040] As described above, when transporting the frame unit 11 housed in the cassette 18 to the pair of guide rails 22 whose gap is narrowed, first, the cassette table 16 is raised and lowered so that the ring frame 21 is positioned at a height corresponding to the pair of guide rails 22. Next, the transport unit 24 is raised and lowered and / or moved in the direction opposite to the Y direction so that one end of the ring frame 21 in the Y direction is positioned between the fixed claws 32b and movable claws 32c that are spaced apart.

[0041] Next, the movable claw 32c is raised so that one end of the ring frame 21 in the Y direction is gripped by the fixed claw 32b and the movable claw 32c. Next, the transport unit 24 is moved in the Y direction so as to carry out the ring frame 21, one end of which in the Y direction is gripped by the fixed claw 32b and the movable claw 32c, from the cassette 18. Then, once both ends of the ring frame 21 in the X direction are placed on the bottom walls 22a of the pair of ring frames 21, respectively, the movable claw 32c is lowered so that the ring frame 21 is released.

[0042] Next, the pair of guide rails 22 are brought close to each other so that the side walls 22b of the pair of guide rails 22 come into contact with both ends of the ring frame 21 in the X direction. This allows the center of the opening 21a formed in the ring frame 21 to be positioned at the same position in the X direction as the center of the support member 26. Then, this frame unit 11 is transported from the pair of guide rails 22 using the holding portion 34 of the transport unit 24, etc.

[0043] The holding portion 34 includes a pair of arms 34a each having a T-shape in plan view. The base end of each arm 34a is fixed to the support member 26 in a recess formed at each end of the support member 26 in the X direction in plan view. A communicating member 34b is inserted into each of the two tips of each arm 34a, and a suction pad 34c is provided at the lower end of the communicating member 34b.

[0044] Furthermore, each communicating member 34b can communicate with a suction source 38a via a valve 36a or the like, and can also communicate with an air supply source 38b via a valve 36b or the like. The suction source 38a includes, for example, an ejector. The air supply source 38b includes, for example, a tank for storing air, a filter for removing foreign matter mixed in the air supplied from the tank, and a regulator for adjusting the pressure of the air supplied from the tank.

[0045] When further transporting the frame unit 11 placed on the pair of guide rails 22 as described above, first, the transport unit 24 is raised and lowered and moved in the direction opposite to the Y direction so that all four suction pads 34c come into contact with the upper surface of the ring frame 21. Next, the valve 36a is opened and the suction source 38a is operated. As a result, a suction force is applied from each suction pad 34c to the ring frame 21, and the ring frame 21 is held on the lower surface of each suction pad 34c.

[0046] When the ring frame 21 is held on the lower surface of each suction pad 34c, the gap between the pair of guide rails 22 is widened so that the frame unit 11 (specifically, the ring frame 21) can pass between the pair of guide rails 22. This makes it possible to transport the frame unit 11 to the chuck table 40.

[0047] 6 is a diagram schematically illustrating the chuck table 40. In FIG. 6, some of the components connected to the chuck table 40 are shown as blocks. The chuck table 40 has a main body 42. The main body 42 has a circular upper surface that is generally parallel to the X and Y directions. The diameter of the upper surface of the main body 42 is slightly smaller than the diameter of the recess 13f formed in the back surface 13e of the wafer 13.

[0048] The main body 42 has a frame 42a including a disk-shaped bottom wall and side walls extending from the outer edge of the bottom wall. A disk-shaped porous plate 42b made of porous ceramics or the like is fixed to a recess defined by the bottom wall and the side walls of the frame 42a.

[0049] A flow path is formed in the bottom wall of frame 42a, and this flow path can be connected to suction source 46a via valve 44a and the like, and can be connected to air supply source 46b via valve 44b and the like. Suction source 46a has a structure similar to that of suction source 38a, for example. Air supply source 46b has a structure similar to that of air supply source 38b, for example.

[0050] Four additional portions 48 are provided around the periphery of the main body portion 42 at approximately equal angular intervals in a plan view. Each additional portion 48 is connected to the main body portion 42 via a connecting member 50 extending radially along the upper surface of the main body portion 42. Each additional portion 48 has an upper surface that is approximately parallel to the X and Y directions and is positioned a predetermined depth below the upper surface of the main body portion 42 (for example, the depth of a recess 13f formed in the back surface 13e of the wafer 13).

[0051] Each additional portion 48 may be provided in a manner that allows it to be raised and lowered relative to the main body portion 42. For example, a lifting mechanism (not shown) including an actuator for raising and lowering the connecting member 50 and the four additional portions 48 may be built into the side wall of the main body portion 42.

[0052] Further, each additional portion 48 is aligned with the center of the upper surface of the main body portion 42 of the chuck table 40 and the center W of the wafer 13. C The additional portions 48 are provided at positions that overlap with the ring frame 21 when the main body 42 of the chuck table 40 and the additional portions 48 are overlapped with each other. For example, each additional portion 48 is provided so that the distance between the center of the upper surface of the main body 42 of the chuck table 40 and each additional portion 48 in a plan view is approximately equal to the radius of the opening 21 a formed in the ring frame 21.

[0053] Each additional portion 48 has a frame 48a including a bottom wall shaped like a square plate and side walls extending from the outer edge of the bottom wall. A porous plate 48b made of porous ceramics or the like and shaped like a square plate is fixed to a recess defined by the bottom wall and side walls of the frame 48a.

[0054] Furthermore, a flow path is formed in each bottom wall of the frame body 48a of each additional portion 48, and this flow path can be connected to the suction source 46a via a valve 44c, etc., and can also be connected to the air supply source 46b via a valve 44d, etc.

[0055] Additionally, an X-direction movement mechanism 52 including, for example, a ball screw and a motor, and a rotation mechanism 54 including, for example, a pulley and a motor, are connected to the main body 42. When the X-direction movement mechanism 52 is operated, the chuck table 40 moves between the adjustment chamber A and the processing chamber P. When the rotation mechanism 54 is operated, the chuck table 40 rotates around a rotation axis that passes through the center of the upper surface of the main body 42 and is aligned in the Z direction.

[0056] When the frame unit 11, in which the ring frame 21 is held on the lower surface of each suction pad 34c, is transported to the chuck table 40, first, the chuck table 40 is positioned in the adjustment chamber A. Specifically, the center of the upper surface of the main body 42 of the chuck table 40 is positioned at the same position as the center of the support member 26 of the transport unit 24 in the X direction.

[0057] Next, the transfer unit 24 is raised and lowered and / or moved along the Y direction so that the recess 13f formed in the back surface 13e of the wafer 13 is fitted onto the upper surface side of the main body 42 of the chuck table 40 via the central region of the resin sheet 19. Next, the operation of the suction source 38a is stopped and the valve 36a is closed, and then the air supply source 38b is operated and the valve 36b is opened.

[0058] This eliminates the suction forces acting on the ring frame 21 from the four suction pads 34c. As a result, the wafer 13 is placed on the main body 42 of the chuck table 40 via the central region of the resin sheet 19, and the ring frame 21 is placed on each of the four additional portions 48 of the chuck table 40 via the outer circumferential region of the resin sheet 19.

[0059] The wafer 13 thus placed on the main body 42 of the chuck table 40 has its position adjusted by an adjustment unit 56 integrated with the transfer unit 24 before being held on the upper surface of the main body 42 (see FIGS. 4 and 5). The adjustment unit 56 has three contact pads 58.

[0060] The inside of each contact pad 58 (i.e., the side facing the center of the support member 26 in a plan view) is curved in an arc shape. Each contact pad 58 is made of an elastic material such as stainless steel or rubber. The lower end of a connecting member 60 is fixed to the upper surface of each contact pad 58. The connecting member 60 includes a cylindrical lower part and a rectangular parallelepiped upper part, and an actuator 62 is connected to the upper part.

[0061] The actuator 62 includes, for example, a housing 62a that extends along the normal to the outer periphery of the support member 26 in a plan view and is fixed to the upper surface of the support member 26. The housing 62a houses the base end of a rod 62b and a stepping motor that can move the rod 62b along the normal. The tip end of the rod 62b is fixed to a surface of the upper part of the connecting member 60 that faces the center of the support member 26 in a plan view.

[0062] The three actuators 62 provided on the upper surface of the support member 26 are arranged, in plan view, to have three-fold rotational symmetry with respect to the center of the support member 26. One of the three actuators 62 is positioned in the Y direction from the center of the support member 26, in plan view.

[0063] By operating each actuator 62, it is possible to make the distance between the center of the support member 26 and the contact pad 58 in a planar view larger than the radius of the wafer 13 (specifically, the radius of the above-mentioned virtual circle), and to make this distance smaller than the radius of the wafer 13.

[0064] 7 is a top view that schematically shows how the position of the wafer 13 placed on the main body 42 of the chuck table 40 is adjusted by the adjustment unit 56. During this adjustment, first, the adjustment unit 56 is moved along the Y direction together with the transport unit 24 so that the center of the support member 26 is positioned directly above a point that is located in the direction opposite to the Y direction by the above-mentioned predetermined distance d from the center of the upper surface of the main body 42 of the chuck table 40.

[0065] Next, each of the three contact pads 58 is moved until it is positioned at the outermost position. Then, the adjustment unit 56 is lowered together with the transport unit 24 so that the three contact pads 58 are positioned at a height corresponding to the upper surface of the main body 42 of the chuck table 40. Next, when all of the three contact pads 58 are in contact with the wafer 13, the center W of the wafer 13 in a plan view is positioned at a height corresponding to the upper surface of the main body 42 of the chuck table 40. C Each of the three contact pads 58 is moved inward so that it is positioned at a point displaced from the center of the support member 26 by a vector amount for fine adjustment (see FIG. 7).

[0066] Here, the vector amount for fine adjustment is the center R of the bottom surface of the recess 13f formed on the back surface 13e of the wafer 13. C The center W of the wafer 13 is located at a predetermined distance d from the point W in the direction opposite to the Y direction. C Therefore, this point corresponds to the center W of the wafer 13. C That is, when the center W of the wafer 13 coincides with the center W of the wafer 13, C is the center R of the bottom surface of the recess 13f C When the wafer 13 is spaced from the support member 26 by the predetermined distance d in the direction opposite to the Y direction, the center W of the wafer 13 is aligned with the center of the support member 26. CSpecifically, in this case, each of the three contact pads 58 is moved inward until the distance between each of the three contact pads 58 and the center of the support member 26 is equal to the radius of the wafer 13.

[0067] As a result, the center R of the bottom surface of the recess 13f formed on the back surface 13e of the wafer 13 in plan view C The center of the upper surface of the main body 42 of the chuck table 40 coincides with the center of the upper surface of the main body 42 of the chuck table 40. When the position of the wafer 13 is adjusted in this manner, the wafer 13 is held on the upper surface of the main body 42 of the chuck table 40 via the central region of the resin sheet 19. Specifically, the valve 44a communicating with the flow path formed in the frame 42a of the main body 42 is opened, and the suction source 46a is operated.

[0068] As a result, a suction force acts on the central region of the resin sheet 19, and the wafer 13 is held on the upper surface of the main body 42 via the central region of the resin sheet 19. Note that the wafer 13 is held at a position where the center R C is aligned with the center of the upper surface of the main body 42 of the chuck table 40 and then held on the upper surface of the main body 42.

[0069] In this case, there is a low possibility that a large force will act locally on the wafer 13 (for example, in a portion near the boundary between the device region 13c and the peripheral excess region 13d) during this holding, causing damage to the wafer 13. Furthermore, when the wafer 13 is held on the upper surface of the main body portion 42 of the chuck table 40, the ring frame 21 may be held on the upper surfaces of the four additional portions 48, respectively.

[0070] Specifically, the valves 44c communicating with the flow paths formed in the frame bodies 48a of the respective additional portions 48 are opened. As a result, suction force acts not only on the central region of the resin sheet 19 but also on the outer peripheral region thereof, and the ring frame 21 is held on the upper surfaces of the four additional portions 48 via the outer peripheral region of the resin sheet 19.

[0071] Once the wafer 13 is held on the upper surface of the main body 42 of the chuck table 40, the chuck table 40 is positioned in the processing chamber P, and the wafer 13 is cut (processed) by at least one of a pair of cutting units (processing units) 64 (see Figure 4).

[0072] Each cutting unit 64 has a spindle extending along the Y direction. A cutting blade 64a is attached to the tip of this spindle. The base end of the spindle is connected to a motor. When this motor is operated, the cutting blade 64a rotates together with the spindle, with a straight line along the Y direction as its rotation axis.

[0073] An imaging unit 66 is connected to each cutting unit 64. This imaging unit 66 is, for example, a camera that has an objective lens 66a located in the opposite direction to the X direction when viewed from the cutting blade 64a, and is capable of capturing an image of the area directly below this objective lens 66a.

[0074] Furthermore, each cutting unit 64 is connected to an X-direction movement mechanism (not shown) and a Z-direction movement mechanism (not shown) including, for example, a ball screw, a motor, etc. The X-direction movement mechanism moves the cutting unit 64 and the imaging unit 66 along the X direction inside the processing chamber P. The Z-direction movement mechanism moves the cutting unit 64 and the imaging unit 66 along the Z direction inside the processing chamber P.

[0075] In addition, a processing water supply unit (not shown) is provided near each cutting unit 64 for supplying processing water to at least one of the wafer 13 and the cutting blade 64a when cutting the wafer 13. This processing water supply unit has, for example, a nozzle (not shown) for supplying processing water to the contact interface between the wafer 13 and the cutting blade 64a.

[0076] In the processing chamber P, the wafer 13 is cut (processed) so as to separate the ring-shaped reinforcing portion 17 from the wafer 13. During this cutting, first, the chuck table 40 is moved along the X direction and / or the cutting unit 64 is moved along the Y direction so that a point included in the boundary between the device region 13c and the peripheral excess region 13d of the wafer 13 is positioned directly below the lower end of one cutting blade 64a of the pair of cutting units 64.

[0077] Next, the cutting blade 64a is rotated, and while supplying processing water to the surface 13a of the wafer 13, the cutting unit 64 is lowered until the lower end of the cutting blade 64a is positioned at a height corresponding to the resin sheet 19. Next, while supplying processing water to the contact interface between the rotating cutting blade 64a and the wafer 13, the chuck table 40 is rotated at least once. As a result, a groove is formed in the frame unit 11 that is located between the device region 13c and the outer peripheral excess region 13d of the wafer 13 and whose bottom surface is located on the resin sheet 19, and the ring-shaped reinforcing portion 17 is separated from the wafer 13.

[0078] Once processing of the wafer 13 in the processing chamber P is completed, the chuck table 40 is returned to the adjustment chamber A, and then the frame unit 11 is transported to the spinner table 68 installed in the cleaning chamber C using the holding portion 34 of the transport unit 24, and then the wafer 13 is cleaned.

[0079] The spinner table 68 has a circular upper surface that is generally parallel to the X and Y directions. The diameter of the upper surface of the spinner table 68 is slightly smaller than the diameter of the recess 13f formed in the back surface 13e of the wafer 13.

[0080] The spinner table 68 has a frame 68a including a disk-shaped bottom wall and side walls extending from the outer edge of the bottom wall. A disk-shaped porous plate 68b made of porous ceramics or the like is fixed to a recess defined by the bottom wall and side walls of the frame 68a.

[0081] A flow path is formed in the bottom wall of frame 68a, and this flow path can be connected to a suction source (not shown) via a valve (not shown) or the like, and can also be connected to an air supply source (not shown) via a valve (not shown) or the like. This suction source has a structure similar to that of suction source 38a, for example. This air supply source has a structure similar to that of air supply source 38b, for example.

[0082] Furthermore, four clamps 70 are provided around the periphery of the frame body 68a at approximately equal intervals along the circumferential direction of the frame body 68a. When holding the wafer 13 on the upper surface of the spinner table 68 via the central region of the resin sheet 19, each clamp 70 grips the ring frame 21 at a position lower than the upper surface of the spinner table 68.

[0083] In addition, a rotation mechanism (not shown) including, for example, a pulley and a motor is connected to the spinner table 68. When this rotation mechanism is operated, the spinner table 68 rotates around a rotation axis that passes through the center of the top surface of the spinner table 68 and is aligned in the Z direction.

[0084] A cleaning unit 72 is provided above the spinner table 68. This cleaning unit 72 has a pipe-shaped shaft that extends along the Z direction. A motor for rotating the shaft is connected to the lower end of this shaft. In addition, an arm is connected to the upper end of the shaft.

[0085] The arm is a pipe-shaped member that extends in a direction perpendicular to the Z direction with a length equivalent to the distance from the upper end of the shaft to the center of the upper surface of the spinner table 68. A cleaning nozzle is provided at the tip of the arm so as to spray cleaning water downward.

[0086] Furthermore, the shaft is connected to a cleaning water supply source. Therefore, for example, after the shaft is rotated so that the nozzle is positioned above the spinner table 68, cleaning water is supplied from the cleaning water supply source to the shaft and arm, and cleaning water is supplied from the cleaning nozzle to the upper surface of the spinner table 68.

[0087] When the frame unit 11 is transferred from the chuck table 40 returned to the adjustment chamber A to the spinner table 68, first, the operation of the suction source 46a is stopped and the valve 44a is closed, and then the air supply source 46b is operated and the valve 44b is opened. As a result, the suction force acting on the wafer 13 from the upper surface of the main body 42 through the central region of the resin sheet 19 disappears, and the wafer 13 is released.

[0088] Furthermore, when the wafer 13 is held on the upper surface of the main body 42 of the chuck table 40 and the ring frame 21 is held on the upper surfaces of the four additional portions 48, the valve 44c is closed and then the valve 44d is opened. As a result, the suction forces acting on the ring frame 21 from the upper surfaces of the four additional portions 48 via the resin sheet 19 disappear, and the ring frame 21 is released.

[0089] Next, the transport unit 24 is lowered and moved in the Y direction so that all four suction pads 34c of the holding portion 34 of the transport unit 24 come into contact with the upper surface of the ring frame 21. Next, the valve 36a is opened and the suction source 38a is operated. As a result, a suction force acts on the ring frame 21, and the ring frame 21 is held on the lower surfaces of the suction pads 34c.

[0090] Next, the cleaning nozzle is positioned so as not to overlap with the spinner table 68 in a plan view. Next, the transfer unit 24 is raised and moved in the Y direction so that the center of the support member 26 is positioned directly above the center of the upper surface of the spinner table 68. Next, the transfer unit 24 is lowered so that the recess 13f formed in the back surface 13e of the wafer 13 fits into the upper surface side of the spinner table 68 via the central region of the resin sheet 19.

[0091] Next, the operation of suction source 38a is stopped and valve 36a is closed, and then air supply source 38b is operated and valve 36b is opened. This causes the suction forces acting on ring frame 21 from each of four suction pads 34c to disappear. As a result, wafer 13 is placed on spinner table 68 via the central region of resin sheet 19, and ring frame 21 is placed on each of four clamps 70 via the outer circumferential region of resin sheet 19.

[0092] Next, the wafer 13 is held on the upper surface of the spinner table 68 via the central region of the resin sheet 19, and the ring frame 21 is gripped by each of the four clamps 70. Note that, if the wafer 13 has been cut as described above, that is, if the ring-shaped reinforcing portion 17 has been separated from the wafer 13, no large force acts locally on the wafer 13 when the wafer 13 is held on the upper surface of the spinner table 68. Therefore, in this case, it is not necessary to adjust the position of the wafer 13.

[0093] When cleaning the wafer 13 held on the upper surface of the spinner table 68 via the central region of the resin sheet 19, first, the cleaning nozzle is positioned at a position overlapping the wafer 13 in a plan view. Next, cleaning water is supplied from the cleaning nozzle to the wafer 13 while the spinner table 68 is being rotated. This cleans the wafer 13. During this cleaning, the cleaning nozzle may or may not be oscillated within the range overlapping the wafer 13 in a plan view.

[0094] 8 is a flowchart showing a schematic example of a wafer cutting method (processing method) for cutting (processing) the wafer 13 in the cutting device 12. In the following, explanations of the specific contents of each step included in this method that overlap with the contents described above will be omitted as appropriate, and only the main points of the operation of each step will be explained.

[0095] In this method, first, the wafer 13 and the ring frame 21 are placed on the chuck table 40 via the resin sheet 19 (placement step S1). Specifically, the chuck table 40 is positioned in the adjustment chamber A, and then the wafer 13 is placed on the main body 42 of the chuck table 40 via the central region of the resin sheet 19 using the holding portion 34 of the transport unit 24, and the ring frame 21 is placed on each of the four additional portions 48 of the chuck table 40 via the outer circumferential region of the resin sheet 19.

[0096] After the placing step S1, the ring frame 21 is held (temporarily holding step S2). Specifically, the valve 44c is opened and the suction source 46a is operated to apply a suction force to the outer peripheral region of the resin sheet 19. As a result, the ring frame 21 is held on the upper surfaces of the four additional portions 48 of the chuck table 40 via the outer peripheral region of the resin sheet 19.

[0097] After the temporary holding step S2, the center R of the bottom surface of the recess 13f is measured by referring to the image formed by capturing the image of the wafer 13. C The position of the wafer 13 is identified (identification step S3). Specifically, first, the chuck table 40 is moved from the adjustment chamber A to the processing chamber P. Next, the chuck table 40 is moved along the X direction and / or the imaging unit 66 is moved along the Y direction so that a point included in the outer periphery of the wafer 13 is positioned directly under the objective lens 66a of the imaging unit 66.

[0098] Next, an image including at least a part of the arc portion and the orientation flat portion on the outer periphery of the wafer 13 is formed by combining images formed by the imaging unit 66 multiple times. Specifically, imaging by the imaging unit 66 and rotation of the chuck table 40 are alternately repeated in a state in which the ring frame 21 is held via the outer periphery region of the resin sheet 19 on the upper surface of each of the four additional portions 48 of the chuck table 40, but the wafer 13 is not held via the central region of the resin sheet 19 on the upper surface of the main body portion 42.

[0099] Then, the center W of the wafer 13 is determined based on the formed image. C and the center of the orientation flat C Next, the center O of this orientation flat is determined. C From the center W of wafer 13 C The center W of the wafer 13 in the direction C The point separated by the predetermined distance d from the center R of the bottom surface of the recess 13f C In this way, the center R of the bottom surface of the recess 13f is specified as the position. C Once the position of the recess 13f is identified, the vector quantity for fine adjustment, i.e., the center R of the bottom surface of the recess 13f, C The center W of the wafer 13 is located at a predetermined distance d from the point W in the direction opposite to the Y direction. C The vector quantities leading up to can also be determined.

[0100] After the specifying step S3, the chuck table 40 is moved (repositioning step S4). Specifically, the chuck table 40 is moved from the processing chamber P to the adjustment chamber A in a state where the ring frame 21 is held on the upper surface of each of the four additional portions 48 of the chuck table 40 via the outer peripheral region of the resin sheet 19, but the wafer 13 is not held on the upper surface of the main body portion 42 via the central region of the resin sheet 19.

[0101] After the repositioning step S4, the ring frame 21 is released (releasing step S5). Specifically, the operation of the suction source 46a is stopped and the valve 44c is closed, and then the air supply source 46b is operated and the valve 44d is opened. As a result, the suction forces acting on the ring frame 21 from the upper surfaces of the four additional portions 48 of the chuck table 40 via the outer peripheral region of the resin sheet 19 disappear, and the ring frame 21 is released.

[0102] After the release step S5, the position of the wafer 13 is adjusted (adjustment step S6). Specifically, first, the adjustment unit 56 is moved along the Y direction together with the transport unit 24 so that the center of the support member 26 is positioned directly above a point located in the direction opposite to the Y direction by the above-mentioned predetermined distance d from the center of the upper surface of the main body 42 of the chuck table 40.

[0103] Next, each of the three contact pads 58 is moved until it is positioned at the outermost position. Then, the adjustment unit 56 is lowered together with the transport unit 24 so that the three contact pads 58 are positioned at a height corresponding to the upper surface of the main body 42 of the chuck table 40.

[0104] Next, when all three contact pads 58 are in contact with the wafer 13, the center W of the wafer 13 in a plan view is C The three contact pads 58 are moved inward so that the center R of the bottom surface of the recess 13f formed on the back surface 13e of the wafer 13 is positioned at a point moved from the center of the support member 26 by the vector amount for fine adjustment (see FIG. 7). C and the center of the upper surface of the main body 42 of the chuck table 40 coincide with each other.

[0105] After the adjusting step S6, the wafer 13 is held (holding step S7). Specifically, the valve 44a is opened and the suction source 46a is operated to apply a suction force to the central region of the resin sheet 19. As a result, the wafer 13 is held on the upper surface of the main body 42 of the chuck table 40 via the central region of the resin sheet 19.

[0106] In this holding step S7, the ring frame 21 may be held together with the wafer 13. That is, in this holding step S7, not only the valve 44a but also the valve 44c may be opened, so that suction force is applied not only to the central region of the resin sheet 19 but also to the outer peripheral region thereof.

[0107] After the holding step S7, the wafer 13 is processed (processing step S8). Specifically, the chuck table 40 is moved from the adjustment chamber A to the processing chamber P, and then the wafer 13 held on the upper surface of the main body 42 of the chuck table 40 via the resin sheet 19 is processed using the cutting unit 64 or the like.

[0108] 8, the wafer 13 is processed using a chuck table 40 having an additional portion 48 that can apply a suction force to the outer peripheral region of the resin sheet 19. Therefore, in this method, the chuck table 40 can be moved and rotated in a state where a suction force is applied to the outer peripheral region of the resin sheet 19 but not to the central region.

[0109] When the specifying step S3 and the position changing step S4 are performed in this state, the center R of the bottom surface of the recess 13f formed on the back surface 13e of the wafer 13 is smaller than when the chuck table 40 is moved and rotated without any suction force acting on the resin sheet 19. C Therefore, in this method, the center R of the bottom surface of the recess 13f is less likely to be misaligned with the center R of the top surface of the main body 42 of the chuck table 40. C It is possible to move and rotate the chuck table 40 at high speed with the wafer 13 simply placed on the main body 42 via the central region of the resin sheet 19, without increasing the likelihood of misalignment between the center of the upper surface of the main body 42 of the chuck table 40 and the wafer 13.

[0110] It should be noted that the above is one aspect of the present invention, and the present invention is not limited to the above. For example, the present invention may be a processing apparatus for processing a wafer having a structure different from wafer 13 (for example, a wafer having a notch formed therein, a wafer having two orientation flats formed therein, or a wafer having neither an orientation flat nor a notch formed therein), or a processing method for processing such a wafer.

[0111] The present invention may also be a processing device including a processing unit (for example, a laser processing unit) different from the cutting unit 64, or a processing method for performing processing (for example, laser processing) different from cutting.

[0112] The present invention may also be a processing apparatus including an adjustment unit that is provided separately and independently from the transport unit 24. The present invention may also be a processing apparatus in which not only the imaging unit 66 but also the adjustment unit is provided in the processing chamber P.

[0113] Furthermore, in the present invention, a chuck table having a structure different from that of chuck table 40 may be used. For example, in the present invention, a chuck table may be used that is provided with an additional portion that can apply a suction force to an intermediate region located between the central region and the outer peripheral region of resin sheet 19, instead of or in addition to the outer peripheral region.

[0114] The processing device of the present invention may also include a chuck table provided with one additional portion including an upper surface shaped like a ring in a plan view so as to surround the main body portion 42. Alternatively, the processing device of the present invention may include a chuck table provided with n (n is a natural number equal to or greater than 2 and excluding 4) additional portions having the same structure as the additional portion 48.

[0115] The processing apparatus of the present invention may also include a chuck table provided with an additional part that does not include a porous plate. This additional part is made of, for example, stainless steel, and has a groove formed on its upper surface that can communicate with suction source 46a via valve 44c and with air supply source 46b via valve 44d.

[0116] Furthermore, when the ring frame 21 included in the frame unit 11 is made of a ferromagnetic material, an electromagnet may be provided inside each of one or more additional parts instead of a flow path that can communicate with the suction source 46a, etc. In this case, a flow path that can communicate with the suction source 46a, etc. may be formed in some of the multiple additional parts, and an electromagnet may be provided inside the remaining parts.

[0117] Furthermore, in the processing apparatus of the present invention, a suction source and an air supply source may be provided separately for the main body portion 42 of the chuck table 40 and for the four additional portions 48. Fig. 9 is a diagram schematically showing the chuck table 40 provided in such a processing apparatus. Note that in Fig. 9, some of the components connected to the chuck table 40 are shown as blocks.

[0118] The chuck table 40 shown in FIG. 9 is connected to the same components as the chuck table 40 shown in FIG. 6, except that the flow path formed in the frame 42a of the main body 42 can be connected to suction source 46c rather than suction source 46a via valve 44a, and can be connected to air supply source 46d rather than air supply source 46b via valve 44b.

[0119] Furthermore, the wafer processing method of the present invention is not limited to the wafer processing method shown in Fig. 8. For example, in the wafer processing method of the present invention, a specific step S3 may be performed after the placing step S1 and before the temporary holding step S2.

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

[0121] 11: Frame unit 12: Cutting equipment 13: Wafer (13a: front surface, 13b: orientation flat) (13c: Device area, 13d: Surplus outer area) (13e: back surface, 13f: recess) 14: Base 15: Device 16: Cassette table 17: Ring-shaped reinforcement part 18: Cassette 19: Resin sheet 20: Cover 21: Ring frame (21a: opening) 22: Guide rail (22a: bottom wall, 22b: side wall) 24: Transport unit 26: Support member 28: Lifting mechanism 30:Y direction movement mechanism 32: Gripping part (32a: Pillar part, 32b: Fixed claw, 32c: Movable claw, 32d: Lifting mechanism) 34: Holding portion (34a: connecting arm, 34b: communicating member, 34c: suction pad) 36a, 36b: Valve 38a: Suction source 38b: Air supply source 40: Chuck table 42: Main body (42a: frame, 42b: porous plate) 44a, 44b, 44c, 44d: Valves 46a: Suction source 46b: Air supply source 46c: Suction source 46d: Air supply source 48: Additional portion (48a: frame, 48b: porous plate) 50: Connecting member 52:X direction movement mechanism 54: Rotation mechanism 56: Adjustment unit 58: Contact pad 60: Connecting member 62: Actuator (air cylinder) (62a: rod, 62b: housing) 64: Cutting unit (processing unit) (64a: cutting blade) 66: Imaging unit (66a: objective lens) 68: Spinner table (68a: frame, 68b: porous plate) 70: Clamp 72: Cleaning unit

Claims

1. A processing apparatus for processing a wafer in which a device region in which a plurality of devices are provided is thinned, a recess having a circular bottom surface is formed so that a peripheral excess region surrounding the device region remains as a ring-shaped reinforcing portion, and a resin sheet whose peripheral region is fixed to a ring frame has a central region fixed in the recess, a chuck table having a main body portion on an upper surface capable of applying a suction force to the central region of the resin sheet so that the wafer is held via the central region, and an additional portion connected to the main body portion and located on the outer side and below the upper surface of the main body portion, capable of applying a suction force to an intermediate region located between the central region and the outer peripheral region of the resin sheet so that the intermediate region is held, and / or applying a suction force to the outer peripheral region of the resin sheet so that the ring frame is held via the outer peripheral region; an imaging unit for imaging the wafer placed on the top surface of the main body of the chuck table via the central region of the resin sheet; an adjustment unit for adjusting the position of the wafer placed on the upper surface of the main body of the chuck table via the central region of the resin sheet; a processing unit for processing the wafer held on the upper surface of the main body of the chuck table via the central region of the resin sheet; A processing device comprising:

2. 2. The processing apparatus according to claim 1, further comprising a moving mechanism for moving the chuck table between a processing chamber in which the imaging unit can image the wafer and the processing unit can process the wafer, and an adjustment chamber in which the adjustment unit can adjust the position of the wafer.

3. A processing method for processing a wafer in which a device region in which a plurality of devices are provided is thinned, a recess having a circular bottom surface is formed so that a peripheral excess region surrounding the device region remains as a ring-shaped reinforcing portion, and a resin sheet whose peripheral region is fixed to a ring frame has a central region fixed in the recess, a placing step of placing the wafer on the upper surface of a main body portion of a chuck table via the central region of the resin sheet, and placing an intermediate region located between the central region and the outer peripheral region of the resin sheet on the upper surface of an additional portion of the chuck table, and / or placing the ring frame on the upper surface of the additional portion via the outer peripheral region; a temporary holding step of applying a suction force to the intermediate region of the resin sheet so that the intermediate region is held on the upper surface of the additional portion of the chuck table after the placing step, and / or applying a suction force to the outer circumferential region so that the ring frame is held via the outer circumferential region; a specifying step of specifying the position of the center of the bottom surface of the recessed portion by referring to an image formed by alternately repeating imaging of the wafer and rotation of the chuck table in a state in which, after the temporary holding step, a suction force is applied to the intermediate region and / or the outer peripheral region of the resin sheet but no suction force is applied to the central region of the resin sheet; a position changing step of moving the chuck table after the specifying step in a state where a suction force is applied to the intermediate region and / or the outer peripheral region of the resin sheet but no suction force is applied to the central region of the resin sheet; a releasing step of eliminating the suction force acting on the intermediate region and / or the outer peripheral region of the resin sheet so as to release the intermediate region and / or the ring frame of the resin sheet held in the temporary holding step after the position changing step; an adjusting step of adjusting a position of the wafer after the releasing step so that the center of the bottom surface of the recess identified in the identifying step coincides with the center of the upper surface of the main body portion of the chuck table in a plan view; a holding step of applying a suction force to the central region of the resin sheet so that the wafer is held on the upper surface of the main body of the chuck table via the central region after the adjusting step; a processing step of processing the wafer after the holding step; A processing method comprising:

4. the wafer has an outer periphery that is divided into an arc portion extending in an arc shape and an orientation flat portion extending linearly in a plan view; 4. The processing method of claim 3, wherein in the identifying step, the center of a virtual circle whose outer periphery overlaps with the arc portion and the center of the orientation flat portion are identified based on the image including at least a portion of the arc portion and the orientation flat portion, and then a point spaced a predetermined distance from the center of the virtual circle in a direction from the center of the orientation flat portion toward the center of the virtual circle is identified as the center of the bottom surface of the recess.

Images