Processing apparatus and method for processing a wafer

Abstract

To provide a processing device capable od performing both edge trimming and notch trimming on a wafer.SOLUTION: A processing device includes: a holding table having a holding surface to hold a wafer; a first processing unit having a first spindle extending in a Y-axis direction parallel to the holding surface, the first processing unit processing the wafer held on the holding table with a cutting blade mounted on the first spindle; and a second processing unit having a second spindle extending in a Z-axis direction perpendicular to the holding surface, the second processing unit processing the wafer held on the holding table with a cylindrical processing tool mounted on the second spindle.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a processing apparatus for processing a wafer and a method for processing a wafer.

Background Art

[0002] Chips of devices such as IC (Integrated Circuit) and LSI (Large Scale Integration) are essential components in various electronic devices such as mobile phones and personal computers. Such chips are manufactured, for example, by forming a large number of devices on the surface of a wafer made of a semiconductor material and then dividing the wafer into regions each containing an individual device.

[0003] Wafers used in chip manufacturing are prone to cracking starting from cracks occurring in the outer peripheral region. Therefore, in the chip manufacturing process, it is common for the outer peripheral region to be chamfered prior to various processes. Further, in the chip manufacturing process, for the purpose of miniaturizing the manufactured chips, etc., the back surface side of the wafer is often ground prior to dividing the wafer to thin the wafer.

[0004] However, when the back surface side of a wafer with a chamfered outer peripheral region is ground to thin the wafer, the back surface side of the outer peripheral region becomes a shape like a knife edge. Stress concentrates in this portion and cracks are likely to occur. Therefore, in the chip manufacturing process, after edge trimming to remove a part of the surface side of the outer peripheral region, the back surface side of the wafer may be ground to remove the remaining portion of the outer peripheral region (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] In a part of the outer peripheral region (notch region) of a wafer used for manufacturing a chip, generally, a notch indicating the crystal orientation of the wafer is formed. This notch is used, for example, for positioning the wafer in the chip manufacturing process. However, if such a wafer is subjected to edge trimming with a wide processing width and backside grinding, the notch may disappear, making it difficult to position the wafer in subsequent processes.

[0007] On the other hand, by performing edge trimming with a narrow processing width on the wafer so that an end portion (inner end portion) of the notch closer to the center of the wafer remains after grinding the backside of the wafer, it is possible to facilitate wafer positioning and the like in subsequent processes. However, in this case, due to the remaining portion (inner portion) closer to the center of the wafer in the chamfered notch region, there is a risk of cracking the wafer when grinding the backside of the wafer.

[0008] Also, notch trimming may be performed to remove a part of the surface side of the inner portion of the notch region after performing edge trimming with a narrow processing width. In this case, since the inner end portion of the notch remains, wafer positioning and the like in subsequent processes become easier. Furthermore, since a part of the surface side of the inner portion of the chamfered notch region is removed, the occurrence of cracks when grinding the backside of the wafer is suppressed.

[0009] However, edge trimming and notch trimming are performed in separate apparatuses. Therefore, when performing both, a process of transporting the wafer and the like becomes further necessary. As a result, in this case, there is a risk of increasing the manufacturing time and manufacturing cost of the chips manufactured by dividing the wafer.

[0010] In view of these points, an object of the present invention is to provide a processing apparatus capable of performing both edge trimming and notch trimming on a wafer, and a method for processing a wafer using this processing apparatus.

Means for Solving the Problem

[0012] According to one aspect of the present invention, there is provided a holding table having a holding surface for holding a wafer, a first spindle extending in the Y-axis direction parallel to the holding surface, and a cutting blade attached to the first spindle for processing the wafer held by the holding table; a second spindle extending in the Z-axis direction perpendicular to the holding surface, and a second processing unit for processing the wafer held by the holding table with a columnar processing tool attached to the second spindle; an XY coordinate plane moving mechanism for relatively moving the holding table, the first processing unit, and the second processing unit on an XY coordinate plane parallel to the holding surface; a first Z-axis moving mechanism for relatively moving the holding table and the first processing unit along the Z-axis direction; and a second Z-axis moving mechanism for relatively moving the holding table and the second processing unit along the Z-axis direction. A groove extending from the center to the outer edge is formed on the tip surface of the machining tool. A processing apparatus is provided. 。

[0013] According to another aspect of the present invention, there is provided a holding table having a holding surface for holding a wafer, a first spindle extending in the Y-axis direction parallel to the holding surface, a cutting blade mounted on the first spindle for machining the wafer held on the holding table, a second spindle extending in the Z-axis direction perpendicular to the holding surface, a second machining unit for machining the wafer held on the holding table with a columnar machining tool mounted on the second spindle, an XY coordinate plane moving mechanism for relatively moving the holding table, the first machining unit, and the second machining unit on an XY coordinate plane parallel to the holding surface, a first Z-axis moving mechanism for relatively moving the holding table and the first machining unit along the Z-axis direction, and a second Z-axis moving mechanism for relatively moving the holding table and the second machining unit along the Z-axis direction. A groove extending from the center to the outer edge is formed on the tip surface of the processing tool. A wafer processing method for processing a wafer having an outer peripheral region including a notch region in which a notch is formed and an arc region extending in an arc shape, and the notch region and the arc region are chamfered, using the processing apparatus described above, the method comprising: a holding step of holding the wafer on the holding table; an edge trimming step of cutting the cutting blade into the arc region of the wafer using the first machining unit after the holding step to remove at least a part of the arc region; and a notch trimming step of cutting the machining tool into the notch region of the wafer using the second machining unit after the holding step to remove at least a part of the inner part of the notch region.

Advantages of the Invention

[0014] In the present invention, both edge trimming and notch trimming can be performed without transferring the wafer between different apparatuses. Thereby, it is possible to suppress an increase in the manufacturing time and the manufacturing cost of chips manufactured by dividing the wafer.

Brief Description of the Drawings

[0015]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Embodiments for Carrying Out the Invention

[0016] Embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1(A) is a top view schematically showing an example of a wafer on which edge trimming and notch trimming are performed, and FIG. 1(B) is a cross-sectional view schematically showing a cross-section of the wafer along line A0B0 shown in FIG. 1(A).

[0017] The wafer 11 shown in FIGS. 1(A) and 1(B) is made of a semiconductor material such as silicon (Si), and a notch 11a for indicating the crystal orientation is formed in a part of its outer peripheral region (notch region). Further, the outer peripheral region (arc region) other than the notch region of the wafer 11 extends in an arc shape. That is, the wafer 11 has an outer peripheral region including a notch region where the notch 11a is formed and an arc region extending in an arc shape.

[0018] Also, this outer peripheral region (notch region and arc region) is chamfered. That is, the side surface 11b of the wafer 11 is curved so as to be convex outward. Further, the surface 11c side of the wafer 11 is partitioned into a plurality of regions by a plurality of planned division lines intersecting each other, and a device 13 such as an IC or LSI is formed in each region.

[0019] Note that there are no restrictions on the material, shape, structure, size, etc. of the wafer 11. The wafer 11 may be made of a semiconductor material other than silicon (for example, silicon carbide (SiC) or gallium nitride (GaN), etc.). Similarly, there are no restrictions on the type, quantity, shape, structure, size, arrangement, etc. of the device 13.

[0020] Also, the wafer 11 may be integrated with a ring frame via an adhesive tape in order to facilitate its handling. For example, the back surface 11d of the wafer 11 may be adhered to the central region of a disk-shaped adhesive tape having a diameter longer than that of the wafer 11, and a ring frame having an inner diameter longer than the diameter of the wafer 11 may be adhered to the outer peripheral region of the adhesive tape.

[0021] FIG. 2 is a perspective view schematically showing an example of a processing apparatus that performs both edge trimming and notch trimming on the wafer 11. Note that the X-axis direction (front-rear direction) and the Y-axis direction (left-right direction) shown in FIG. 2 are directions perpendicular to each other on a horizontal plane, and the Z-axis direction (up-down direction) is a direction perpendicular to the X-axis direction and the Y-axis direction (vertical direction).

[0022] The processing apparatus 2 shown in Fig. 2 has a base 4 that supports each component. On the base 4, an X-axis movement mechanism (a part of the XY coordinate plane movement mechanism) 6 is provided. The X-axis movement mechanism 6 is fixed to the upper surface of the base 4 and has a pair of guide rails 8 extending along the X-axis direction. On the upper surface (front surface) side of this pair of guide rails 8, a moving plate 10 is connected in a slidable manner along the pair of guide rails 8.

[0023] Also, between the pair of guide rails 8, a screw shaft 12 extending along the X-axis direction is arranged. At one end of this screw shaft 12, a motor 14 for rotating the screw shaft 12 is connected. And on the surface of the screw shaft 12 where a spiral groove is formed, a nut portion (not shown) for accommodating balls that roll on the surface of the rotating screw shaft 12 is provided, and a ball screw is configured.

[0024] That is, when the screw shaft 12 rotates, the balls circulate within the nut portion, and the nut portion moves along the X-axis direction. Also, this nut portion is fixed to the lower surface (back surface) side of the moving plate 10. Therefore, if the motor 14 rotates the screw shaft 12, the moving plate 10 moves along the X-axis direction together with the nut portion.

[0025] Around the X-axis movement mechanism 6, a water case 16 is provided for temporarily storing liquid or the like supplied to the wafer 11 when processing the wafer 11. The liquid stored in the water case 16 is discharged to the outside of the processing apparatus 2 through a drain (not shown) or the like. On the upper surface (front surface) side of the moving plate 10, a cylindrical θ table 18 is provided.

[0026] At the upper end of the θ table 18, the lower part of a disk-shaped holding table 20 is fixed. This holding table 20 has, for example, a disk-shaped frame body 22 made of a metal material such as stainless steel. The frame body 22 has a disk-shaped bottom wall and an annular side wall extending upward from the outer peripheral portion of this bottom wall. And a recess is defined on the upper surface side of the frame body 22 by the bottom wall and the side wall, and a disk-shaped porous plate 24 made of ceramics or the like is fixed in this recess.

[0027] Furthermore, the porous plate 24 has an upper surface parallel to the X-axis direction and the Y-axis direction, and on the lower surface side thereof, it is connected to a suction source (not shown) such as an ejector via a suction path (not shown) and a valve formed inside the holding table 20 and the θ table 18. When the valve is opened with this suction source operating, a negative pressure is generated in the space near the upper surface. Therefore, the upper surface of the porous plate 24 functions as the holding surface of the holding table 20 that holds the wafer 11.

[0028] That is, when a negative pressure is generated in the space near the upper surface of the porous plate 24 with the wafer 11 placed on the upper surface of the porous plate 24, the wafer 11 is sucked and held by the holding table 20. Furthermore, the holding table 20 is connected to a rotational drive source (not shown) such as a motor that rotates the holding table 20 about a straight line passing through the center of the holding surface and parallel to the Z-axis direction as the rotation axis via the θ table 18.

[0029] Also, a table cover 26 is provided around the θ table 18. Furthermore, bellows-shaped dust and drip-proof covers (not shown) that can expand and contract along the X-axis direction are provided in front of and behind the table cover 26. When the X-axis movement mechanism 6 moves the moving plate 10, the table cover 26 moves along the X-axis direction together with the θ table 18 and the holding table 20, and the dust and drip-proof cover expands and contracts in accordance with the moving table cover 26.

[0030] A support structure 30 is provided on the base 4 so as to straddle the X-axis movement mechanism 6. Specifically, the support structure 30 has a pair of flat plate-shaped standing portions 30a and 30b provided on the base 4 so as to sandwich the X-axis movement mechanism 6, and a flat plate-shaped bridging portion 30c provided on the pair of standing portions 30a and 30b so as to span the space above the X-axis movement mechanism 6.

[0031] On the front (surface) side of this bridging section 30c, a first Y-axis movement mechanism (a part of the XY coordinate plane movement mechanism) 32a and a second Y-axis movement mechanism (another part of the XY coordinate plane movement mechanism) 32b are provided. The first Y-axis movement mechanism 32a and the second Y-axis movement mechanism 32b are fixed to the front surface of the bridging section 30c and share a pair of guide rails 34 extending along the Y-axis direction. On the front (surface) side of this pair of guide rails 34, a moving plate 36a and a moving plate 36b are provided.

[0032] The moving plate 36a is closer to the standing section 30a than the moving plate 36b, and the moving plate 36b is closer to the standing section 30b than the moving plate 36a. And the moving plate 36a and the moving plate 36b are connected to the front (surface) side of the guide rails 34 in a slidable manner along the pair of guide rails 34 within a range where they do not contact each other.

[0033] Also, between the pair of guide rails 34, a screw shaft 38a and a screw shaft 38b extending along the Y-axis direction are arranged. At the end of the screw shaft 38a on the side of the standing section 30b, a motor 40a for rotating the screw shaft 38a is connected. Similarly, at the end of the screw shaft 38b on the side of the standing section 30a, a motor (not shown) for rotating the screw shaft 38b is connected.

[0034] And on the surface of the screw shaft 38a where the spiral groove is formed, a nut portion (not shown) for accommodating balls that roll on the surface of the rotating screw shaft 38a is provided, and a ball screw is configured. That is, when the screw shaft 38a rotates, the balls circulate through the nut member, and the nut portion moves along the Y-axis direction. Also, this nut portion is fixed to the rear (back) side of the moving plate 36a. Therefore, if the screw shaft 38a is rotated by the motor 40a, the moving plate 36a moves along the Y-axis direction together with the nut portion.

[0035] Similarly, on the surface of the screw shaft 38b where the spiral groove is formed, a nut portion (not shown) for accommodating balls that roll on the surface of the rotating screw shaft 38b is provided, and a ball screw is configured. That is, when the screw shaft 38b rotates, the balls circulate through the nut member, and the nut portion moves along the Y-axis direction. Further, this nut portion is fixed to the rear surface (back surface) side of the moving plate 36b. Therefore, if the screw shaft 38b is rotated by a motor connected to the end portion on the standing portion 30a side of the screw shaft 38b, the moving plate 36b moves along the Y-axis direction together with the nut portion.

[0036] Note that the first Y-axis movement mechanism 32a includes a ball screw (such as the screw shaft 38a) and a motor 40a for moving the moving plate 36a along the Y-axis direction. Further, the second Y-axis movement mechanism 32b includes a ball screw (such as the screw shaft 38b) for moving the moving plate 36b along the Y-axis direction and a motor connected to the end portion on the standing portion 30a side of the screw shaft 38b.

[0037] On the front surface (surface) of the moving plate 36a, a first Z-axis movement mechanism 42 is provided. The first Z-axis movement mechanism 42 is fixed to the front surface (surface) of the moving plate 36a and has a pair of guide rails 44 extending along the Z-axis direction. On the front surface (surface) side of the pair of guide rails 44, a moving plate 46 is connected in a slidable manner along the pair of guide rails 44.

[0038] Also, between the pair of guide rails 44, a screw shaft 48 extending along the Z-axis direction is arranged. At the upper end portion of this screw shaft 48, a motor 50 for rotating the screw shaft 48 is connected. And on the surface of the screw shaft 48 where the spiral groove is formed, a nut portion (not shown) for accommodating balls that roll on the surface of the rotating screw shaft 48 is provided, and a ball screw is configured.

[0039] That is, when the screw shaft 48 rotates, the balls circulate within the nut portion, and the nut portion moves along the Z-axis direction. Further, this nut portion is fixed to the rear surface (back surface) side of the moving plate 46. Therefore, if the screw shaft 48 is rotated by the motor 50, the moving plate 46 moves along the Z-axis direction together with the nut portion.

[0040] A first processing unit 52 is fixed to the lower part of the moving plate 46. The first processing unit 52 has a cylindrical spindle housing 54 extending along the Y-axis direction. A spindle (first spindle) extending in the Y-axis direction is accommodated in the spindle housing 54. This spindle is supported by the spindle housing 54 in a rotatable state.

[0041] Also, the end portion (tip portion) on the standing portion 30b side of this spindle is exposed outside the spindle housing 54, and a cutting blade 56 having an annular cutting edge is attached to this tip portion. The cutting blade 56 is, for example, a hub type cutting blade. The hub type cutting blade is composed of an annular base made of metal or the like and an annular cutting edge formed along the outer peripheral edge of the base.

[0042] The cutting edge of this cutting blade is composed of, for example, an electroformed grinding wheel in which abrasive grains made of diamond or cubic boron nitride (cBN) or the like are fixed by a binder such as nickel. Alternatively, the cutting blade 56 may be a washer type cutting blade. The washer type cutting blade is composed of an annular cutting edge in which abrasive grains are fixed by a binder made of metal, ceramics, resin, or the like.

[0043] Furthermore, the spindle housing 54 houses a rotational drive source (not shown) such as a motor connected to the base end portion of the spindle. Therefore, if the spindle is rotated by this rotational drive source, the cutting blade 56 rotates with a straight line along the Y-axis direction as the rotation axis. Also, an imaging unit 58 is fixed to the side surface of the spindle housing 54.

[0044] The imaging unit 58 includes, for example, a light source such as an LED (Light Emitting Diode), an objective lens, and an imaging device such as a CCD (Charge Coupled Device) image sensor or a CMOS (Complementary Metal Oxide Semiconductor) image sensor.

[0045] Also, a second Z-axis movement mechanism 60 is provided on the front surface (the surface) of the moving plate 36b. The second Z-axis movement mechanism 60 is fixed to the front surface (the surface) of the moving plate 36b and has a pair of guide rails 62 extending along the Z-axis direction. A moving plate 64 is connected to the front surface (the surface) side of the pair of guide rails 62 in a slidable manner along the pair of guide rails 62.

[0046] Also, a screw shaft 66 extending along the Z-axis direction is disposed between the pair of guide rails 62. A motor 68 for rotating the screw shaft 66 is connected to the upper end portion of the screw shaft 66. A nut portion (not shown) for accommodating balls that roll on the surface of the rotating screw shaft 66 is provided on the surface of the screw shaft 66 where a spiral groove is formed, and a ball screw is configured.

[0047] That is, when the screw shaft 66 rotates, the balls circulate within the nut portion, and the nut portion moves along the Z-axis direction. Also, this nut portion is fixed to the rear surface (the back surface) side of the moving plate 64. Therefore, if the screw shaft 66 is rotated by the motor 68, the moving plate 64 moves along the Z-axis direction together with the nut portion.

[0048] A second processing unit 70 is fixed to the side portion of the standing portion 30a side of the moving plate 64. The second processing unit 70 has a cylindrical spindle housing 72 extending along the Z-axis direction. A spindle (second spindle) 74 extending in the Z-axis direction is accommodated in the spindle housing 72. The spindle 74 is supported by the spindle housing 72 in a rotatable state.

[0049] Further, the lower end portion of the spindle 74 is exposed outside the spindle housing 72, and a columnar cutting tool 76 is mounted on this lower end portion. FIG. 3 is a perspective view showing the cutting tool 76 and the like. As shown in FIG. 3, a cross-shaped groove 76b is formed in the tip (lower end) surface 76a of the cutting tool 76.

[0050] By forming this groove 76b in the tip surface 76a, the temperature rise (burning) of the central region of the tip surface 76a during notch trimming is suppressed. Thereby, the occurrence of processing defects during notch trimming can be suppressed. Note that there is no limitation on the shape of the groove formed in the tip surface 76a of the cutting tool 76.

[0051] This groove may be, for example, a groove that extends from the center to the outer edge of the tip surface 76a. Specifically, this groove may have a shape (radial shape) in which each of three or five or more points on the outer edge arranged at equal intervals along the circumferential direction of the tip surface 76a and the center of the tip surface 76a are linearly connected.

[0052] Also, the length of the cutting tool 76 along the Z-axis direction is designed to be longer than, for example, the thickness of the wafer 11, and the diameter of its lower surface is designed to be longer than, for example, the width of the notch 11a formed in the wafer 11 (the length along the radial direction of the wafer 11).

[0053] This cutting tool 76 includes, for example, a bond material such as a vitrified bond or a resin bond having pores therein, and abrasive grains such as diamond or cubic boron nitride dispersed in this bond material. Further, it is preferable that the cutting tool 76 is configured so that contamination of metal elements from the cutting tool 76 to the wafer 11 is minimized.

[0054] For example, it is preferable that the bonding material of the cutting tool 76 does not intentionally contain a filler used to improve the characteristics (such as wear resistance, etc.) of the cutting tool 76. That is, it is preferable that the bonding material of the cutting tool 76 does not contain metal elements other than metal elements (inevitable impurities) inevitably mixed in during its manufacturing process or the like.

[0055] Furthermore, the spindle housing 72 houses a rotational drive source (not shown) such as a motor connected to the upper end of the spindle 74. Therefore, if the spindle 74 is rotated by this rotational drive source, the cutting tool 76 rotates with a straight line along the Z-axis direction as the rotation axis.

[0056] FIG. 4 is a flowchart schematically showing an example of a wafer processing method for processing the wafer 11 using the processing apparatus 2. In this method, first, the wafer 11 is held by the holding table 20 (holding step: S1). Specifically, first, the holding table 20 is moved to a position where the wafer 11 can be carried in. For example, the X-axis moving mechanism 6 moves the holding table 20 forward along the X-axis direction.

[0057] Next, in a plane parallel to the X-axis direction and the Y-axis direction (XY coordinate plane), with the surface 11c facing up, the wafer 11 is carried into the holding table 20 so that the center of the wafer 11 coincides with the center of the holding surface of the holding table 20. Next, the suction source connected to the holding table 20 is operated to generate a negative pressure in the space near the holding surface of the holding table 20.

[0058] If the holding step (S1) is carried out, edge trimming of the wafer 11 is performed using the first processing unit 52 (edge trimming step: S2). Specifically, first, in the XY coordinate plane, the first Y-axis moving mechanism 32a moves the first processing unit 52 along the Y-axis direction so that the outer peripheral region of the wafer 11 located in the Y-axis direction as viewed from the center of the wafer 11 is arranged in the X-axis direction as viewed from the cutting blade 56.

[0059] At this time, the position of the first processing unit 52 is adjusted so that the width of the outer peripheral region of the wafer 11 arranged in the X-axis direction as viewed from the cutting blade 56 (the length along the radial direction of the wafer 11) is shorter than the width of the notch 11a formed in the wafer 11. Next, the first Z-axis moving mechanism 42 lowers the first processing unit 52 so that the lowermost end of the cutting blade 56 is positioned at the height between the height obtained by subtracting the finish thickness of the wafer 11 from the height of the front surface 11c of the wafer 11 and the height of the back surface 11d.

[0060] Next, the rotation drive source housed in the spindle housing 54 rotates the spindle (first spindle) so as to rotate the cutting blade 56. Then, while rotating the cutting blade 56, the X-axis moving mechanism 6 moves the holding table 20 backward along the X-axis direction so as to cut the cutting blade 56 into the wafer 11.

[0061] When the lowermost end of the cutting blade 56 reaches the outer peripheral region of the wafer 11 located in the Y-axis direction as viewed from the center of the wafer 11, the movement of the holding table 20 by the X-axis moving mechanism 6 is stopped. Then, while rotating the cutting blade 56, the rotation drive source connected to the holding table 20 rotates the holding table 20 at least once. Thereby, the edge trimming for the wafer 11 is completed.

[0062] FIG. 5(A) is a top view schematically showing the wafer 11 edge-trimmed in this way, and FIG. 5(B) is a cross-sectional view schematically showing a cross-section of the wafer 11 along the line A1B1 shown in FIG. 5(A). As shown in FIGS. 5(A) and 5(B), in the wafer 11 edge-trimmed in this way, the surface side of the portion (inner portion) close to the center of the wafer 11 in the chamfered notch region (the region where the notch 11a is formed) remains without being removed.

[0063] If the edge trimming step (S2) is performed, notch trimming of the wafer 11 is carried out using the second processing unit 70 (notch trimming step: S3). Specifically, first, in the XY coordinate plane, the X-axis moving mechanism 6 moves the holding table 20 along the X-axis direction and the second Y-axis moving mechanism 32b moves the second processing unit 70 along the Y-axis direction so that the notch region of the wafer 11 and the processing tool 76 overlap.

[0064] At this time, the positions of the holding table 20 and the second processing unit 70 are adjusted so that the processing tool 76 overlaps the inner part of the chamfered notch region remaining on the wafer 11 in the XY coordinate plane. Next, the rotation drive source housed in the spindle housing 72 rotates the spindle (second spindle) 74 so as to rotate the processing tool 76.

[0065] Next, while the processing tool 76 is rotating, the second Z-axis moving mechanism 60 lowers the second processing unit 70 so as to cut the processing tool 76 into the wafer 11. Then, when the tip (lower end) surface 76a of the processing tool 76 reaches a height between the height obtained by subtracting the finish thickness of the wafer 11 from the height of the front surface 11c of the wafer 11 and the height of the back surface 11d, the lowering of the second processing unit 70 by the second Z-axis moving mechanism 60 is stopped. Thereby, the notch trimming of the wafer 11 is completed.

[0066] FIG. 6(A) is a top view schematically showing the wafer 11 notch-trimmed in this way, and FIG. 6(B) is a cross-sectional view schematically showing the cross-section of the wafer 11 along the line A2B2 shown in FIG. 6(A). As shown in FIGS. 6(A) and 6(B), in the wafer 11 notch-trimmed in this way, the surface side of the inner part of the wafer 11 in the notch region is removed.

[0067] In the method for processing the wafer 11 shown in FIG. 4, by using the processing apparatus 2, both edge trimming and notch trimming can be performed without transporting the wafer 11 between different apparatuses. Thereby, an increase in the manufacturing time and the manufacturing cost of the chips manufactured by dividing the wafer 11 can be suppressed.

[0068] Note that the above-described processing apparatus and processing method are one aspect of the present invention, and the present invention is not limited to the above-described processing apparatus or processing method. For example, in the processing apparatus 2, the first processing unit 52 and the second processing unit 70 are arranged at positions facing each other via the holding table 20, but in the processing apparatus of the present invention, these positional relationships are not limited.

[0069] That is, in the processing apparatus of the present invention, the arrangement of the first processing unit 52, the second processing unit 70, and the holding table 20 may be changed according to the layout of the clean room in which it is installed. For example, as viewed from the holding table 20, one of the first processing unit 52 and the second processing unit 70 may be arranged in the X-axis direction and the other may be arranged in the Y-axis direction.

[0070] Also, in the processing apparatus 2, the holding table 20 is movable in the X-axis direction, and the first processing unit 52 and the second processing unit 70 are movable in the Y-axis direction and the Z-axis direction, but in the processing apparatus of the present invention, these moving directions are not limited.

[0071] That is, in the processing apparatus of the present invention, any structure may be used as long as relative movement on the XY coordinate plane among the holding table 20, the first processing unit 52, and the second processing unit 70, relative movement along the Z-axis direction between the holding table 20 and the first processing unit 52, and relative movement along the Z-axis direction between the holding table 20 and the second processing unit 70 are possible.

[0072] Specifically, in the processing apparatus of the present invention, the moving mechanism (XY coordinate plane moving mechanism) that relatively moves the holding table 20, the first processing unit 52, and the second processing unit 70 on the XY coordinate plane is not limited to the X-axis moving mechanism 6, the first Y-axis moving mechanism 32a, and the second Y-axis moving mechanism 32b. For example, this XY coordinate plane moving mechanism may be composed of a Y-axis moving mechanism that moves the holding table 20 along the Y-axis direction, a first X-axis moving mechanism that moves the first processing unit 52 along the X-axis direction, and a second X-axis moving mechanism that moves the second processing unit 70 along the X-axis direction.

[0073] Also, in the processing apparatus of the present invention, the moving mechanism that relatively moves the holding table 20 and the first processing unit 52 along the Z-axis direction is not limited to the first Z-axis moving mechanism 42 that moves the first processing unit 52 along the Z-axis direction. For example, this moving mechanism may be a moving mechanism that moves the holding table 20 along the Z-axis direction.

[0074] Similarly, in the processing apparatus of the present invention, the moving mechanism that relatively moves the holding table 20 and the second processing unit 70 along the Z-axis direction is not limited to the second Z-axis moving mechanism 60 that moves the second processing unit 70 along the Z-axis direction. For example, this moving mechanism may be a moving mechanism that moves the holding table 20 along the Z-axis direction.

[0075] Also, in the processing method shown in FIG. 4, the notch trimming step (S3) was performed after the edge trimming step (S2), but in the processing method of the present invention, the notch trimming step (S3) may be performed after the holding step (S1) and before the edge trimming step (S2).

[0076] Also, in the edge trimming step (S2) and notch trimming step (S3) of the processing method shown in FIG. 4, edge trimming and notch trimming are performed so as to leave a part of the back surface 11d side of the outer peripheral region of the wafer 11. However, in the edge trimming step (S2) and notch trimming step (S3) of the processing method of the present invention, all of the outer peripheral region of the wafer 11 may be removed.

[0077] That is, in the processing step of the method of the present invention, edge trimming and notch trimming may be performed so that side surfaces orthogonal to the front surface 11c and the back surface 11d of the wafer 11 are formed without forming a step in the outer peripheral portion of the wafer 11.

[0078] Such edge trimming is performed, for example, by positioning the height of the lowermost end of the cutting blade 56 below the back surface 11d of the wafer 11 and processing the wafer 11 while maintaining this height before cutting the cutting blade 56 into the wafer 11. Further, such notch trimming is performed, for example, by lowering the second processing unit 70 by the second Z-axis moving mechanism 60 until the machining tool 76 cut into the wafer 11 reaches the back surface 11d of the wafer 11.

[0079] In addition, when such edge trimming and notch trimming are performed, it is preferable that an adhesive tape is attached to the back surface 11d side of the wafer 11. That is, it is preferable that edge trimming and notch trimming of the wafer 11 are performed while the wafer 11 is held on the holding table 20 via this adhesive tape.

[0080] In addition, the structures and methods according to the above-described embodiments can be appropriately changed and implemented without departing from the scope of the object of the present invention.

Explanation of Reference Numerals

[0081] 11: Wafer (11a: Notch, 11b: Side surface, 11c: Front surface, 11d: Back surface) 13: Device 2: Cutting device 4: Base 6: X-axis moving mechanism 8: Guide rail 10: Moving plate 12: Screw shaft 14: Motor 16: Water case 18: θ table 20: Holding table 22: Frame body 24: Porous plate 26: Cover 30: Support structure (30a, 30b: Standing part, 30c: Crossing part) 32a: First Y-axis moving mechanism 32b: Second Y-axis moving mechanism 34: Guide rail 36a, 36b: Moving plate 38a, 38b: Screw shaft 40a: Motor 42: First Z-axis moving mechanism 44: Guide rail 46: Moving plate 48: Screw shaft 50: Motor 52: First processing unit 54: Spindle housing 56: Cutting blade 58: Imaging unit 60: First Z-axis moving mechanism 62: Guide rail 64: Moving plate 66: Screw shaft 68: Motor 70: Second processing unit 72: Spindle housing 74: Spindle 76: Tool (76a: Tip (lower end) surface, 76b: Groove)

Claims

1. A holding table having a holding surface for holding a wafer, a first processing unit having a first spindle extending in the Y-axis direction parallel to the holding surface, and processing the wafer held on the holding table with a cutting blade attached to the first spindle, a second processing unit having a second spindle extending in the Z-axis direction perpendicular to the holding surface, and processing the wafer held on the holding table with a columnar processing tool attached to the second spindle, an XY coordinate plane moving mechanism for relatively moving the holding table, the first processing unit, and the second processing unit on an XY coordinate plane parallel to the holding surface, a first Z-axis moving mechanism for relatively moving the holding table and the first processing unit along the Z-axis direction, a second Z-axis moving mechanism for relatively moving the holding table and the second processing unit along the Z-axis direction, and a processing apparatus in which a groove extending from the center to the outer edge is formed on the tip surface of the processing tool.

2. A holding table having a holding surface for holding a wafer, a first processing unit having a first spindle extending in the Y-axis direction parallel to the holding surface, and processing the wafer held on the holding table with a cutting blade attached to the first spindle, a second processing unit having a second spindle extending in the Z-axis direction perpendicular to the holding surface, and processing the wafer held on the holding table with a columnar processing tool attached to the second spindle, an XY coordinate plane moving mechanism for relatively moving the holding table, the first processing unit, and the second processing unit on an XY coordinate plane parallel to the holding surface, a first Z-axis moving mechanism for relatively moving the holding table and the first processing unit along the Z-axis direction, a second Z-axis moving mechanism for relatively moving the holding table and the second processing unit along the Z-axis direction, and using the processing apparatus in which a groove extending from the center to the outer edge is formed on the tip surface of the processing tool, a wafer processing method for processing a wafer having an outer peripheral region including a notch region where a notch is formed and an arc region extending in an arc shape, and the notch region and the arc region are chamfered, comprising: a holding step of holding the wafer on the holding table, After performing the holding step, an edge trimming step of cutting the cutting blade into the arc region of the wafer using the first processing unit to remove at least a part of the arc region; After performing the holding step, a notch trimming step of cutting the machining tool into the notch region of the wafer using the second processing unit to remove at least a part of the inner portion of the notch region close to the center of the wafer that is not removed in the edge trimming step, the method for processing a wafer being characterized by comprising these steps.

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