JP2023114076A - Method for processing workpiece - Google Patents

Abstract

To provide a method for processing a workpiece that can provide high flatness of a surface to be polished while efficiently processing a workpiece.SOLUTION: A method for processing a workpiece which is applied when processing a plate-like workpiece having a first surface and a second surface located on an opposite side to the first surface includes: a grinding step of grinding a workpiece from a second surface side with a grinding wheel; a washing step of washing a surface to be ground of the workpiece after the grinding step; and a polishing step for polishing the workpiece from the side of the surface to be ground with a polishing pad after the washing step.SELECTED DRAWING: Figure 4

Description

TECHNICAL FIELD The present invention relates to a method for processing a plate-like workpiece such as a wafer.

2. Description of the Related Art In order to realize small and lightweight device chips, there are increasing opportunities to thin wafers having devices such as integrated circuits provided on the front side thereof. For example, the front side of the wafer is held by a chuck table, and a grinding wheel to which a grinding wheel containing abrasive grains is fixed is rotated with the chuck table to supply a liquid such as pure water to the rear side of the wafer. This wafer is ground and thinned by pressing a grinding wheel against it.

On the other hand, when a wafer is ground with a grinding wheel (grinding wheel) as described above, a damaged area including scratches and distortion is formed on the surface to be ground, and the mechanical strength (bending strength, etc.) of the wafer is insufficient. easy to do Therefore, after the wafer is ground, for example, the ground surface of the wafer is polished with a polishing pad in order to remove this damaged area. In recent years, in order to efficiently perform such processing, a composite processing apparatus having a structure capable of continuously performing grinding and polishing has been proposed (see, for example, Patent Document 1).

JP-A-2005-153090

In the above-described composite processing apparatus, the chuck table moves from the grinding area where the grinding wheel is arranged to the polishing area where the polishing pad is arranged, thereby continuously grinding and polishing the wafer. will be implemented. However, a small amount of scraps generated during grinding may remain on the wafer and chuck table after grinding. The flatness of the surface is deteriorated.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a method of processing a workpiece that can achieve high flatness of the surface to be polished while efficiently processing the workpiece.

According to one aspect of the present invention, there is provided a method for machining a plate-shaped workpiece having a first surface and a second surface opposite to the first surface. a grinding step of grinding the workpiece from the second surface side with a grinding wheel; after the grinding step, a cleaning step of cleaning the ground surface of the workpiece; and a polishing step of polishing the workpiece with a polishing pad from the side of the surface to be ground.

According to another aspect of the present invention, there is provided a method for machining a plate-shaped workpiece having a first surface and a second surface opposite to the first surface. a holding step of holding the first surface side of the workpiece with a chuck table; and after the holding step, holding the workpiece held by the chuck table from the second surface side. a grinding step of grinding with a grinding wheel; after the grinding step, a cleaning step of cleaning the ground surface of the workpiece held by the chuck table together with the chuck table; and a polishing step of polishing the workpiece held by a chuck table with a polishing pad from the side of the surface to be ground.

Preferably, in the cleaning step, the cleaning nozzle is moved together with the polishing pad while supplying cleaning fluid from the cleaning nozzle.

In the method for processing a workpiece according to one aspect of the present invention, after grinding the workpiece with the grinding wheel, the surface to be ground of the workpiece is washed, and then the workpiece is polished with the polishing pad. When the workpiece is polished with the polishing pad, the debris generated during grinding is sufficiently removed from the surface to be ground.

Therefore, even in a situation in which grinding and polishing are continuously performed, high flatness of the surface to be polished is achieved. That is, according to the method for processing a workpiece according to one aspect of the present invention, it is possible to realize high flatness of the surface to be polished while efficiently processing the workpiece.

Similarly, in a method for processing a workpiece according to another aspect of the present invention, after grinding the workpiece with a grinding wheel, the surface to be ground of the workpiece is washed together with the chuck table, and then the workpiece is ground. is polished with a polishing pad, when the workpiece is polished with the polishing pad, dust generated during grinding is sufficiently removed from the surface to be ground and the chuck table.

Therefore, even in a situation where grinding and polishing are continuously performed, it is possible to prevent debris from being caught between the polishing pad and the workpiece, thereby realizing high flatness of the surface to be polished. That is, according to the method for processing a workpiece according to another aspect of the present invention, it is possible to realize high flatness of the surface to be polished while efficiently processing the workpiece.

FIG. 1 is a perspective view schematically showing how a protective member is attached to a disk-shaped workpiece. FIG. 2 is a cross-sectional view schematically showing how the workpiece is held on the chuck table via the protective member. FIG. 3 is a cross-sectional view schematically showing how the workpiece held on the chuck table is ground by the grinding wheel. FIG. 4 is a cross-sectional view schematically showing how the surface to be ground of the workpiece and the chuck table are cleaned. FIG. 5 is a cross-sectional view schematically showing how the workpiece held on the chuck table is polished by the polishing pad. FIG. 6 is a front view schematically showing a polishing unit moving mechanism that is also used as a nozzle swinging mechanism.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the method for processing a workpiece according to the present embodiment, first, a protective member is attached to a disk-shaped workpiece to be processed (attaching step). FIG. 1 is a perspective view schematically showing how a protective member 21 is attached to a disk-shaped work piece 11. As shown in FIG.

The workpiece 11 is, for example, a disk-shaped wafer made of a semiconductor such as silicon (Si). That is, the workpiece 11 has a circular front surface (first surface) 11a and a circular rear surface (second surface) 11b opposite to the front surface 11a. The surface 11a side of the workpiece 11 is partitioned into a plurality of small regions by a plurality of streets (planned division lines) 13 that intersect each other, and each small region contains a device such as an integrated circuit (IC). 15 are formed.

In the method for processing a workpiece according to the present embodiment, the workpiece 11 is processed from the back surface 11b side so that the workpiece 11 as a whole becomes thin. More specifically, in the method for processing a workpiece according to the present embodiment, the workpiece 11 is ground with a grinding wheel from the back surface 11b side and then ground with a polishing pad.

In this embodiment, a disk-shaped wafer made of a semiconductor such as silicon is used as the workpiece 11, but the material, shape, structure, size, etc. of the workpiece 11 are not limited to this aspect. is not limited to For example, a substrate or the like made of other materials such as semiconductors, ceramics, resins, and metals can be used as the workpiece 11 . Similarly, the type, quantity, shape, structure, size, arrangement, etc. of the device 15 are not limited to the above-described modes. The device 15 may not be formed on the workpiece 11 .

The protective member 21 attached to the workpiece 11 is typically a circular resin tape (resin film) having a diameter approximately equal to that of the workpiece 11, a resin substrate, or a material similar or different to that of the workpiece 11. wafers, etc. For example, on the surface 21 a side of the protective member 21 , an adhesive layer is provided that exhibits adhesive strength to the workpiece 11 . Therefore, as shown in FIG. 1 , the protective member 21 is attached to the surface 11 a of the workpiece 11 by bringing the surface 21 a of the protective member 21 into close contact with the surface 11 a of the workpiece 11 .

As a result, the protection member 21 mitigates the impact applied when the workpiece 11 is processed from the back surface 11b side, and the device 15 and the like on the front surface 11a side are protected. If the protective member 21 can be adhered and fixed to the workpiece 11 without the adhesive layer, the protective member 21 may not have the adhesive layer. In addition, the protective member 21 does not necessarily have to be attached to the workpiece 11 when the impact on the surface 11a side applied when the workpiece 11 is processed does not pose a problem.

After the protective member 21 is attached to the surface 11a of the workpiece 11, the surface 11a side of the workpiece 11 is held by the chuck table through the protective member 21 (holding step). FIG. 2 is a cross-sectional view schematically showing how the workpiece 11 is held on the chuck table 4 of the processing apparatus 2 via the protective member 21. As shown in FIG. In addition, in each of the following steps, the composite processing apparatus 2 shown in FIG. 2 and the like is used.

The processing device 2 includes a chuck table 4 configured to hold a workpiece 11 . The chuck table 4 includes, for example, a disk-shaped frame 6 made of ceramics or the like. A concave portion 6a having a circular opening at the upper end is formed on the upper surface side of the frame 6, and a holding plate 8 made of ceramics or the like and configured in a porous disc shape is fixed to the concave portion 6a. there is

The upper surface 8a of the holding plate 8 is configured, for example, in a shape corresponding to the side surface of a cone, and functions as a holding surface for holding the workpiece 11 and the like. The height difference (height difference) between the center 8b of the upper surface 8a of the holding plate 8 corresponding to the apex of the cone and the outer peripheral edge of the upper surface 8a of the holding plate 8 is about 10 μm to 30 μm. In this embodiment, the back surface 21 b of the protective member 21 contacts the upper surface (holding surface) 8 a of the holding plate 8 .

The lower surface side of the holding plate 8 is connected to a suction source (not shown) such as an ejector via a flow path 6b provided inside the frame 6, a valve (not shown) arranged outside the frame 6, or the like. It is connected to the. Therefore, when the back surface 21 b of the protective member 21 is brought into contact with the upper surface 8 a of the holding plate 8 , the valve is opened to apply the negative pressure of the suction source, and the back surface 21 b of the protective member 21 is sucked by the chuck table 4 . be. That is, the workpiece 11 is held on the chuck table 4 via the protective member 21 so that the back surface 11b thereof is exposed upward.

A rotary drive source (not shown) such as a motor is connected to the lower portion of the frame 6 . The chuck table 4 rotates about an axis extending in the vertical direction or an axis slightly inclined with respect to the vertical direction so that the center 8b of the upper surface 8a becomes the center of rotation by the force generated by this rotational drive source. . The frame 6 is supported by a chuck table moving mechanism (not shown) typified by a turntable that can be rotated by a rotary drive source such as a motor. , to move horizontally.

After the workpiece 11 is held by the chuck table 4 via the protective member 21, the workpiece 11 held by the chuck table 4 is ground from the rear surface 11b side (grinding step). FIG. 3 is a cross-sectional view schematically showing how the workpiece 11 held on the chuck table 4 is ground. In addition, in FIG. 3, the side surface of some elements is shown for convenience of explanation.

As shown in FIG. 3, a grinding unit 10 is arranged above the chuck table 4 of the processing device 2 . Grinding unit 10 includes, for example, a cylindrical spindle housing (not shown). A space inside the spindle housing accommodates a columnar spindle 12 . A disk-shaped mount 14 , for example, is provided at the lower end of the spindle 12 . An annular grinding wheel 16 having approximately the same diameter as the mount 14 is fixed to the lower surface of the mount 14 with bolts (not shown) or the like.

Grinding wheel 16 includes an annular wheel base 18 constructed of metal such as stainless steel or aluminum. A plurality of grinding wheels 20 are fixed to the annular lower surface of the wheel base 18 along the circumferential direction of the wheel base 18 . That is, the plurality of grinding wheels 20 are arranged in a ring. Each grinding wheel 20 has, for example, a structure in which abrasive grains made of diamond or the like are dispersed in a binder made of resin or the like.

A rotary drive source (not shown) such as a motor is connected to the upper end side of the spindle 12 . Grinding wheel 16 rotates about an axis along the vertical direction or an axis slightly inclined with respect to the vertical direction by the force generated by this rotary drive source. The spindle housing is supported by, for example, a ball screw type grinding unit moving mechanism (not shown), and the grinding unit 10 is vertically moved by the force generated by this grinding unit moving mechanism.

A grinding fluid supply nozzle 22 is arranged beside the grinding wheel 16 to supply a grinding fluid (grinding fluid) 31 such as water to a portion where the workpiece 11 and the grinding wheel 20 are in contact with each other. Instead of or together with the grinding liquid supply nozzle 22, a grinding liquid supply port used to supply the liquid 31 may be provided in the grinding wheel 16 or the like.

When grinding the workpiece 11 with the grinding unit 10 (grinding wheel 16 ), first, the chuck table 4 moves directly below the grinding unit 10 . More specifically, the chuck table moving mechanism adjusts the horizontal position of the chuck table 4 so that the plurality of grinding wheels 20 pass through the space directly above the center 8 b of the chuck table 4 when the grinding wheel 16 is rotated. to adjust.

After that, the chuck table 4 and the grinding wheel 16 rotate, and the grinding unit 10 (grinding wheel 16) descends. That is, the grinding wheel 16 and the workpiece 11 move relative to each other in the vertical direction intersecting the back surface 11b of the workpiece 11 while rotating with each other. At this time, the grinding liquid 31 is supplied from the grinding liquid supply nozzle 22 to the workpiece 11, the grinding wheel 20, and the like. As a result, as shown in FIG. 3, the grinding wheel 20 comes into contact with the workpiece 11 from the back surface 11b side, and grinding of the workpiece 11 is started.

In addition, there is no big restriction|limiting to the specific conditions of grinding. For example, when the grinding wheel 20 is composed of relatively large abrasive grains and the workpiece 11 is roughly ground by the grinding wheel 20, the rotation speed of the chuck table 4 is 100 rpm to 600 rpm, typically , 300 rpm, the number of revolutions of the grinding wheel 16 is set to 1000 rpm to 7000 rpm, typically 4500 rpm, and the lowering speed (grinding feed rate) of the grinding unit 10 is set to 1.0 μm/s to 10 μm/s. .0 μm/s, typically set to 6.0 μm/s.

Further, when the grinding wheel 20 is composed of relatively small abrasive grains and the workpiece 11 is ground with high precision by the grinding wheel 20, the rotation speed of the chuck table 4 is typically 100 rpm to 600 rpm. is set to 300 rpm, the rotation speed of the grinding wheel 16 is set to 1000 rpm to 7000 rpm, typically 4000 rpm, and the lowering speed of the grinding unit 10 is set to 0.1 μm/s to 1.5 μm/s. s, typically set at 0.5 μm/s.

Of course, the workpiece 11 may be ground with both a grinding wheel containing relatively large abrasive grains and a grinding wheel containing relatively small abrasive grains. That is, after the workpiece 11 is roughly ground using a grinding wheel containing relatively large abrasive grains, the workpiece 11 is ground with high precision using a grinding wheel containing relatively small abrasive grains. good too. When the workpiece 11 is thinned to the preset finishing thickness, the grinding unit 10 is lifted and the grinding of the workpiece 11 is finished.

By the way, when the workpiece 11 is ground, the liquid 31 is supplied from the grinding fluid supply nozzle 22, and most of the scrap generated during grinding is removed from the workpiece 11 and the chuck table 4 by this liquid 31. removed from On the other hand, the grinding liquid supply nozzle 22 is configured mainly for supplying the liquid 31 to the portion where the grinding wheel 20 and the workpiece 11 are in contact with each other, and does not necessarily clean the workpiece 11 and the chuck table 4 . is not optimized for Therefore, a small amount of scrap may remain on the workpiece 11 and the chuck table 4 .

In the composite processing apparatus 2 having a structure in which grinding and polishing are continuously performed, the workpiece 11 after being ground moves while being held by the chuck table 4, and is polished as it is. However, if the work piece 11 is polished while dust remains on the work piece 11 and the chuck table 4, the work piece 11 is scratched by the dust and the flatness of the polished surface is reduced. There was a time when I was lost.

Therefore, in this embodiment, after the workpiece 11 is ground, the ground surface of the workpiece 11 held by the chuck table 4 and the chuck table 4 are cleaned (cleaning step). FIG. 4 is a cross-sectional view schematically showing how the surface 11c to be ground of the workpiece 11 and the chuck table 4 are cleaned. In addition, in FIG. 4, the side surface of some elements is shown for convenience of explanation.

As shown in FIG. 4, a cleaning nozzle 24 used for cleaning the ground surface 11c of the workpiece 11 and the chuck table 4 is arranged at a position above the chuck table 4 of the processing apparatus 2. there is The cleaning nozzle 24 is supported by, for example, a ball-screw type nozzle swinging mechanism (not shown), and is horizontally moved by the force generated by the nozzle swinging mechanism to move the cleaning fluid (cleaning fluid). 33 can be jetted downward. As the cleaning fluid 33, for example, a mixed fluid (two fluids) in which water and air are mixed is used.

When cleaning the grinding surface 11 c of the workpiece 11 and the chuck table 4 with the cleaning nozzle 24 , first, the chuck table 4 moves directly below the cleaning nozzle 24 . More specifically, a chuck table moving mechanism is provided so that the nozzle swing mechanism can swing the cleaning nozzle 24 between above the center 8b of the chuck table 4 and above the outer peripheral edge of the chuck table 4. adjusts the horizontal position of the chuck table 4 .

Thereafter, for example, while the chuck table 4 is rotating at a rotational speed of approximately 10 rpm to 500 rpm, the cleaning nozzle 24 is swung while injecting the fluid 33 at a high pressure of approximately 0.05 MPa to 0.15 MPa. As a result, the fluid 33 is sprayed onto the entire surface to be ground 11c of the workpiece 11 and the exposed portion of the chuck table 4, and scraps are sufficiently removed from the surface to be ground 11c and the chuck table 4. FIG.

In this embodiment, a so-called two-fluid nozzle capable of injecting a mixed fluid in which water and air are mixed is used as the cleaning nozzle 24. However, as the cleaning nozzle 24, a cleaning liquid (typically Specifically, a so-called water curtain nozzle that can form a water curtain by spraying water in a curtain shape may be used.

In this case, for example, the water curtain nozzle is fixed at a predetermined position and does not swing. By moving the chuck table 4 so as to pass through the water curtain formed by the water curtain nozzle, the entire ground surface 11c of the workpiece 11 and the exposed portion of the chuck table 4 are sprayed with the liquid, The scraps are sufficiently removed from the ground surface 11c and the chuck table 4. As shown in FIG.

The water curtain nozzle may be arranged near the boundary between the grinding area and the polishing area in the processing apparatus 2 . In this case, by forming a water curtain with the water curtain nozzle during grinding of the workpiece 11, scattering of debris from the grinding area to the polishing area is suppressed.

After the ground surface 11c of the workpiece 11 and the chuck table 4 are washed, the workpiece 11 held by the chuck table 4 is subjected to chemical mechanical polishing (CMP) from the ground surface 11c side. Polishing) or the like (polishing step). FIG. 5 is a cross-sectional view schematically showing how the workpiece 11 held on the chuck table 4 is polished. In addition, in FIG. 5, the side surface of some elements is shown for convenience of explanation.

As shown in FIG. 5, a polishing unit 26 is arranged above the chuck table 4 of the processing device 2 . The polishing unit 26 includes, for example, a tubular spindle housing (not shown). A columnar spindle 28 is accommodated in the space inside the spindle housing. A disk-shaped mount 30 , for example, is provided at the lower end of the spindle 28 . A disk-shaped polishing pad 32 is fixed to the lower surface of the mount 30 with bolts (not shown) or the like.

The polishing pad 32 is made of, for example, a non-woven fabric or polymer foam containing no abrasive grains and is formed in a disk shape. is provided with a polishing liquid supply port (not shown) used for The polishing liquid supply port is connected to a polishing liquid supply source via, for example, a channel provided in the mount 30 or the spindle 28 . Note that the polishing pad 32 may contain abrasive grains. In that case, a chemical solution containing no abrasive grains is used as the polishing liquid.

A rotational drive source (not shown) such as a motor is connected to the upper end side of the spindle 28 . The polishing pad 32 rotates about an axis along the vertical direction or an axis slightly inclined with respect to the vertical direction by the force generated by this rotational drive source. The spindle housing is supported by, for example, a ball screw type polishing unit moving mechanism (not shown), and the polishing unit 26 is vertically moved by the force generated by this polishing unit moving mechanism.

When polishing the surface 11 c of the workpiece 11 to be ground by the polishing unit 26 (polishing pad 32 ), first, the chuck table 4 moves directly below the polishing unit 26 . More specifically, the chuck table moving mechanism moves the chuck table 4 horizontally so that the entire ground surface 11c of the workpiece 11 held on the chuck table 4 overlaps the polishing pad 32 when viewed from above. to adjust.

After that, the chuck table 4 and the polishing pad 32 rotate, and the polishing unit 26 (polishing pad 32) descends. In other words, the polishing pad 32 and the workpiece 11 move relative to each other in the vertical direction intersecting the ground surface 11c of the workpiece 11 while rotating with each other. At this time, the polishing liquid is supplied from the polishing liquid supply port to the workpiece 11, the polishing pad 32, and the like.

As a result, as shown in FIG. 5, the polishing pad 32 comes into contact with the workpiece 11 from the ground surface 11c side, and polishing of the workpiece 11 is started. In FIG. 5, for convenience of explanation, the polishing pad 32 is shown in contact with a part of the surface 11c to be ground. The height difference between the outer peripheral edge and the edge is small. Therefore, the polishing pad 32 actually contacts the entire surface 11c to be ground.

In addition, there is no big restriction|limiting in the specific conditions of polishing. For example, the rotation speed of the chuck table 4 is set to 10 rpm to 600 rpm, typically 500 rpm, and the rotation speed of the polishing pad 32 is set to 200 rpm to 600 rpm, typically 500 rpm. A load applied to the workpiece 11 is set to 10 kPa to 35 kPa, typically 25 kPa. After a preset time elapses, the polishing pad 32 is lifted and the polishing of the workpiece 11 is completed.

In this embodiment, after the workpiece 11 is ground and before it is polished, the ground surface 11c of the workpiece 11 and the chuck table 4 are washed, and the debris generated during grinding is removed from the ground surface 11c. and the chuck table 4 are sufficiently removed. Therefore, the workpiece 11 is not damaged by the scraps remaining on the ground surface 11c. In addition, scraps remaining on the chuck table 4 are not caught between the polishing pad 32 and the workpiece 11, and the workpiece 11 is not damaged.

As described above, in the method for processing a workpiece according to the present embodiment, after the workpiece 11 is ground by the grinding wheel 16, the ground surface 11c of the workpiece 11 is washed together with the chuck table 4, Since the workpiece 11 is polished by the polishing pad 32, when the workpiece 11 is polished by the polishing pad 32, scraps generated during grinding are sufficiently removed from the ground surface 11c and the chuck table 4. ing.

Therefore, even when grinding and polishing are continuously performed, debris is prevented from being caught between the polishing pad 32 and the workpiece 11, and high flatness of the polished surface is realized. That is, according to the method for processing a workpiece according to the present embodiment, it is possible to realize high flatness of the surface to be polished while efficiently processing the workpiece 11 .

It should be noted that the present invention is not limited to the description of the above-described embodiment and can be implemented with various modifications. For example, in the above-described embodiment, the cleaning nozzle 24 is horizontally swung by a nozzle swinging mechanism independent of the polishing unit moving mechanism or the like. good.

FIG. 6 is a side view schematically showing the polishing unit moving mechanism 34 which is also used as a nozzle swinging mechanism. As shown in FIG. 6, the polishing unit moving mechanism 34 has a pair of guide rails 36 substantially parallel to the horizontal direction. The guide rail 36 is fixed, for example, to the front side of a columnar support structure (not shown). A horizontally moving plate 38 is attached to the guide rail 36 in a slidable manner.

A nut portion (not shown) constituting a ball screw is provided on the back side of the horizontal movement plate 38, and a screw shaft 40 substantially parallel to the guide rail 36 is rotatable in this nut portion. Concatenated. A rotary drive source 42 such as a motor is connected to one end of the screw shaft 40 . By rotating the screw shaft 40 with the rotation drive source 42 , the horizontal movement plate 38 moves along the guide rail 36 .

A pair of guide rails 44 that are substantially parallel to the vertical direction are fixed to the front side of the horizontal movement plate 38 . A vertical movement plate 46 is slidably attached to the guide rail 44 .

A nut portion (not shown) forming a ball screw is provided on the rear side of the vertical movement plate 46, and a screw shaft 48 substantially parallel to the guide rail 44 is rotatable in this nut portion. Concatenated. A rotary drive source 50 such as a motor is connected to one end of the screw shaft 48 . By rotating the screw shaft 48 with the rotation drive source 50 , the vertical movement plate 46 moves along the guide rail 44 .

A support 52 is provided on the front side of the vertical movement plate 46 . The support 52 supports a spindle housing 54 that constitutes the polishing unit 26 of the above-described embodiment. Further, the base end side of the cleaning nozzle 24 of the embodiment described above is supported by the support 52 . Therefore, the polishing unit moving mechanism 34 can horizontally swing the cleaning nozzle 24 together with the polishing unit 26 .

When the polishing unit moving mechanism 34 according to this modified example is used, for example, the polishing unit moving mechanism 34 swings the polishing unit 26 in the horizontal direction during polishing of the workpiece 11 (polishing step). . Thereby, the entire workpiece 11 can be uniformly polished by the polishing pad 32, and the flatness of the polished surface can be further improved.

Further, when the workpiece 11 and the chuck table 4 are cleaned (cleaning step), the polishing unit moving mechanism 34 swings the cleaning nozzle 24 in the horizontal direction. That is, the cleaning nozzle 24 moves together with the polishing pad 32 while supplying the cleaning fluid.

In addition, the structures, methods, and the like according to the above-described embodiments and modifications can be modified as appropriate without departing from the scope of the present invention.

11: workpiece 11a: surface (first surface)
11b: back surface (second surface)
11c: surface to be ground 13: street (divided line)
Reference Signs List 15: Device 21: Protective member 21a: Front surface 21b: Back surface 31: Liquid (grinding liquid)
33: fluid (cleaning fluid)
2: processing device 4: chuck table 6: frame 6a: concave portion 6b: flow path 8: holding plate 8a: upper surface (holding surface)
8b: Center 10: Grinding Unit 12: Spindle 14: Mount 16: Grinding Wheel 18: Wheel Base 20: Grinding Wheel 22: Grinding Fluid Supply Nozzle 24: Cleaning Nozzle 26: Polishing Unit 28: Spindle 30: Mount 32: Polishing Pad 34 : Polishing unit movement mechanism 36 : Guide rail 38 : Horizontal movement plate 40 : Screw shaft 42 : Rotation drive source 44 : Guide rail 46 : Vertical movement plate 48 : Screw shaft 50 : Rotation drive source 52 : Support 54 : Spindle housing

Claims (3)

A method for machining a plate-shaped workpiece having a first surface and a second surface opposite to the first surface, the method comprising:
a grinding step of grinding the workpiece from the second surface side with a grinding wheel;
After the grinding step, a cleaning step of cleaning the ground surface of the workpiece;
and a polishing step of polishing the workpiece from the side of the surface to be ground with a polishing pad after the cleaning step. A method for machining a plate-shaped workpiece having a first surface and a second surface opposite to the first surface, the method comprising:
a holding step of holding the first surface side of the workpiece with a chuck table;
After the holding step, a grinding step of grinding the workpiece held by the chuck table from the second surface side with a grinding wheel;
After the grinding step, a cleaning step of cleaning the ground surface of the workpiece held by the chuck table together with the chuck table;
a polishing step of polishing the workpiece held by the chuck table with a polishing pad from the side of the surface to be ground after the cleaning step. 3. The method for processing a workpiece according to claim 1, wherein in the cleaning step, the cleaning nozzle is moved together with the polishing pad while supplying a cleaning fluid from the cleaning nozzle.

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