Wafer processing method

A method of processing a wafer includes coating the front side of the wafer with a water-soluble liquid resin to form a thin film; fixing the wafer to a protective plate for protecting the front side of the wafer, with a bond material interposed between the protective plate and the thin film; holding by a chuck table the protective plate with the wafer fixed thereto and grinding the back side of the wafer to make the wafer have a predetermined thickness; releasing step of releasing the bond material together with the protective plate to which the wafer has been fixed; and supplying water to the bond material remaining on the front side of the wafer to remove the thin film together with the bond material.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to a method of processing a wafer which is formed on a front side thereof with a plurality of division lines in a crossing pattern and in which a plurality of devices are formed in a plurality of regions partitioned by the division lines.

Description of the Related Art

In the semiconductor device manufacturing process, for example, devices such as integrated circuits (ICs) and large-scale integrations (LSIs) are formed in a plurality of regions partitioned by division lines formed in a crossing pattern on a front side of a substantially disk-shaped wafer, and the regions formed with the devices are divided along the division lines, to produce individual device chips. Meanwhile, the wafer is generally subjected to grinding of the back side by a grinding apparatus to have a predetermined thickness before the division into the individual device chips.

The grinding apparatus includes grinding means and grinding feeding means. The grinding means includes a chuck table having a holding surface for holding the wafer thereon, and a grinding wheel for grinding an upper side of the wafer held on the chuck table. The grinding feeding means moves the grinding means in a direction perpendicular to the holding surface of the workpiece holding means. A protective member is adhered to the front side of the wafer by a bond material such as a wax in order to protect the devices, the protective member together with the wafer fixed thereon is placed on the holding surface of the chuck table, and the back side of the wafer is ground by the grinding means to make the wafer have a predetermined thickness (see, for example, Japanese Patent Laid-Open Nos. 1998-50642, 2010-219461, and 2012-160515).

SUMMARY OF THE INVENTION

When a protective plate is adhered to the front side of the wafer by a bond material such as a wax, however, there is a problem that part of the bond material is slightly left on the front side of the wafer upon removal of the bond material together with the protective plate from the front side of the wafer after grinding of the back side of the wafer, resulting in a lowering of device quality. The phenomenon in which the bond material is left on the front side of the wafer is frequently generated in the case where electrodes provided for the devices are formed as bumps projecting by 50 to 200 μm.

Accordingly, it is an object of the present invention to provide a wafer processing method by which a bond material for mounting a protective plate to the front side of a wafer in order to protect devices at the time of grinding the back side of the wafer can be reliably removed from the front side of the wafer after the grinding.

In accordance with an aspect of the present invention, there is provided a method of processing a wafer which is formed on a front side thereof with a plurality of division lines in a crossing pattern and in which a plurality of devices are formed in a plurality of regions partitioned by the division lines, the method including: a water-soluble resin coating step of coating the front side of the wafer with a water-soluble liquid resin to form a thin film; a protective plate fixing step of fixing the wafer to a protective plate for protecting the front side of the wafer, with a bond material interposed between the protective plate and the thin film; a back side grinding step of holding by a chuck table the protective plate with the wafer fixed thereto and grinding a back side of the wafer to make the wafer have a predetermined thickness; a protective plate releasing step of releasing the bond material together with the protective plate to which the wafer has been fixed, after the back side grinding step is conducted; and a bond material removing step of supplying water to the bond material remaining on the face side of the wafer having been subjected to the protective plate releasing step, to remove the thin film together with the bond material.

Preferably, the wafer processing method further includes a cut groove forming step of forming cut grooves corresponding to a finished thickness of the devices along the division lines from the side of the face side of the wafer before the water-soluble resin coating step is conducted, and, in the back side grinding step, the cut grooves are exposed to the back side of the wafer to thereby divide the wafer into the individual devices.

Preferably, the wafer processing method further includes a modified layer forming step of applying a laser beam having such a wavelength as to be transmitted through the wafer along the division lines, with a focal point of the laser beam being positioned inside the wafer, to form a modified layer serving as a division start point along each of the division lines inside the wafer, and, in the back side grinding step, the wafer is divided along the division lines along which the modified layers serving as the division start points have been formed, into the individual devices.

According to the present invention, the wafer processing method includes the bond material removing step of supplying water to the bond material remaining on the front side of the wafer having been subjected to the protective plate releasing step, to thereby remove the thin film together with the bond material. Therefore, even if the bond material is left on the front side of the wafer upon the protective plate releasing step, the removal of the thin film formed of a water-soluble resin and coating the front side of the wafer by water in the bond material removing step causes the bond material to be also removed, so that the quality of the device chips is prevented from being lowered due to such bond material.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Some preferred embodiments of the wafer processing method according to the present invention will be described in detail below, referring to the attached drawings.FIG. 1depicts a perspective view of a semiconductor wafer to be processed according to the present invention. The semiconductor wafer2depicted inFIG. 1is a silicon wafer having a thickness of, for example, 600 μm, and is formed on its front side2awith a plurality of division lines21in a crossing pattern, and devices22such as ICs and LSIs are formed in a plurality of regions partitioned by the division lines21. In the following, a wafer processing method in which the back side2bof the semiconductor wafer2is ground to make the semiconductor wafer2have a predetermined thickness will be described. The workpiece to be processed is not limited to the semiconductor wafer but includes other wafers such as an optical device wafer.

First, a water-soluble resin coating step of coating the front side2aof the above-mentioned semiconductor wafer2with a water-soluble liquid resin to form a thin film is conducted. The water-soluble resin coating step is carried out by use of a resin film forming apparatus3depicted inFIGS. 2A and 2B. The resin film forming apparatus3depicted inFIGS. 2A and 2Bincludes a spinner table31for holding the workpiece, and a liquid resin supply nozzle32disposed on the upper side of a center of rotation of the spinner table31. On the spinner table31of the resin film forming apparatus3configured in this way, the semiconductor wafer2is placed with its back side2bon the lower side. Then, suction means (not depicted) is operated to suction hold the semiconductor wafer2on the spinner table31. Therefore, the semiconductor wafer2held on the spinner table31has its front side2aon the upper side. After the semiconductor wafer2is held on the spinner table31in this manner, the spinner table31is rotated at a predetermined rotational speed (for example, 500 to 3,000 rpm) in the direction indicated by arrow31aas depicted inFIG. 2A, and, while continuing the rotation, a predetermined amount of a liquid resin30is dropped to a central region of the front side2aof the semiconductor wafer2from the liquid resin supply nozzle32disposed on the upper side of the spinner table31. Then, with the spinner table31rotated for approximately 60 seconds, a thin film300is formed on the front side2aof the semiconductor wafer2as depicted inFIGS. 2B and 2C. The thickness of the thin film300formed on the front side2aof the semiconductor wafer2by the coating is determined by the amount of the liquid resin30dropped, and may be approximately 1 to 3 μm. Note that the water-soluble liquid resin is desirably a liquid resin that is cured when irradiated with ultraviolet (UV) rays. Examples of resins usable as the liquid resin that is cured by irradiation with UV rays include polyvinyl alcohol (PVA), polyethylene glycol (PEPG) and polyethylene oxide (PEO).

After the aforementioned water-soluble resin coating step is performed, a thin film curing step is carried out in which the thin film300formed on the front side2aof the semiconductor wafer2is cured by irradiation with UV rays. Specifically, as depicted inFIG. 3, the thin film300formed on the front side2aof the semiconductor wafer2is irradiated with UV rays by a UV irradiation device4. As a result, the thin film300formed of the liquid resin30curable by irradiation with UV rays is cured.

Next, a protective plate fixing step is conducted in which the semiconductor wafer2having been subjected to the water-soluble resin coating step is fixed to a protective plate for protecting the front side2aof the semiconductor wafer2, with a bond material interposed between the protective plate and the thin film300. Specifically, as depicted inFIGS. 4A and 4B, a predetermined amount of a bond material5is supplied onto the thin film300formed on the front side2aof the semiconductor wafer2, and the bond material5is pressed by a protective plate6uniformly over the whole area, whereby the semiconductor wafer2is fixed to the protective plate6through a bond layer50having a uniform thickness, as depicted inFIG. 4B. Note that the thickness of the bond layer50interposedly formed between the protective plate6and the thin film300formed on the front side2aof the semiconductor wafer2may be approximately 10 to 200 μm. In addition, the bond material5is desirably a resin that is curable by irradiation with UV rays. Examples of resins usable as the UV-curable resin include polyester (meth)acrylate, polyurethane (meth)acrylate, and epoxy (meth)acrylate. Besides, the protective plate6is desirably a resin sheet transparent to UV rays; for example, a polyethylene terephthalate (PET) resin sheet, polyolefin resin sheets and the like having a thickness of approximately 500 μm to 1 mm, for example, can be used.

After the aforementioned protective plate fixing step is conducted, a bond layer curing step is carried out in which the bond layer50is cured by irradiation with UV rays through the protective plate6to which the semiconductor wafer2is fixed. Specifically, as depicted inFIG. 5, UV rays are applied by a UV irradiation device4from the side of the protective plate6to which the semiconductor wafer2is fixed. In the embodiment illustrated, since the protective plate6includes a resin sheet transparent to UV rays, the bond layer50is irradiated with UV rays through the protective plate6, whereby the bond layer50is cured.

Subsequently, a back side grinding step is performed in which the protective plate6with the semiconductor wafer2fixed thereto is held on a chuck table, and the back side2bof the semiconductor wafer2is ground to make the semiconductor wafer2have a predetermined thickness. The back side grinding step is carried out using a grinding apparatus7depicted inFIG. 6A. The grinding apparatus7depicted inFIG. 6Aincludes a chuck table71as holding means for holding the workpiece thereon, and grinding means72for grinding the workpiece held on the chuck table71. The chuck table71is configured such as to suction hold the workpiece on its upper surface, and is rotated in the direction indicated by arrow71ainFIG. 6Aby a rotational driving mechanism (not depicted). The grinding means72includes a spindle housing721, a rotating spindle722rotatably supported on the spindle housing721and rotated by a rotational driving mechanism (not depicted), a mounter723attached to a lower end of the rotating spindle722, and a grinding wheel724mounted to a lower surface of the mounter723. The grinding wheel724includes a circular annular base725, and abrasive grindstones726mounted to a lower surface of the base725in an annular pattern. The base725is mounted to the lower surface of the mounter723by fastening bolts727.

In carrying out the back side grinding step by use of the aforementioned grinding apparatus7, the protective plate6with the semiconductor wafer2fixed thereto is placed on an upper surface (holding surface) of the chuck table71as depicted inFIG. 6A. Then, suction means (not depicted) is operated to suction hold the semiconductor wafer2on the chuck table71through the protective plate6therebetween (wafer holding step). Therefore, the semiconductor wafer2held on the chuck table71has its back side2bon the upper side. After the semiconductor wafer2thus suction held on the chuck table71through the protective plate6, the chuck table71is rotated at, for example, 300 rpm in the direction indicated by arrow71ainFIG. 6A. While keeping the rotation, the grinding wheel724of the grinding means72is rotated at, for example, 6,000 rpm in the direction indicated by arrow724ainFIG. 6A, the abrasive grindstones726are brought into contact with the back side2bof the semiconductor wafer2serving as a work surface as depicted inFIG. 6B, and the grinding wheel724is put to grinding feed by a predetermined amount downward (in the direction perpendicular to the holding surface of the chuck table71) at a grinding feed rate of, for example, 1 μm/second as indicated by arrow724b. As a result, the back side2bof the semiconductor wafer2is ground to make the semiconductor wafer2have a predetermined thickness (for example, 100 μm).

Next, a protective plate releasing step is carried out to release the bond layer50formed of the bond material5together with the protective plate6to which the semiconductor wafer2having been subjected to the back side grinding step is fixed. Specifically, as illustrated inFIGS. 7A and 7B, the back side2bof the semiconductor wafer2is adhered to a front side of a dicing tape T which includes a synthetic resin sheet of polyolefin or the like and an outer peripheral portion of which is disposed such as to cover an inside opening portion of an annular frame F, and the bond layer50is released from the semiconductor wafer2together with the protective plate6to which the semiconductor wafer2has been fixed. Note that in releasing the bond layer50from the semiconductor wafer2together with the protective plate6, the releasing operation can be easily performed by carrying out the operation while supplying steam to the bond layer50interposed between the semiconductor wafer2and the protective plate6. Even when the bond layer50is released from the semiconductor wafer2together with the protective plate6in this way, part of the bond material5may be left on the front side2aof the semiconductor wafer2.

After the aforementioned protective plate releasing step is conducted, a bond material removing step is carried out in which water is supplied to the bond material5remaining on the front side2aof the semiconductor wafer2, to remove the thin film300together with the bond material5. Specifically, as depicted inFIG. 8A, the semiconductor wafer2which has been subjected to the protective plate releasing step and which is supported on the annular frame F through the dicing tape T is placed on a holding table81of a cleaning device8through the dicing tape T, and suction means (not depicted) is operated to suction hold the semiconductor wafer2on the holding table81through the dicing tape T. Then, cleaning water is supplied to the bond material5remaining on the front side2aof the semiconductor wafer2and the thin film300from a cleaning water supply nozzle82disposed on the upper side of the holding table81. As a result, the thin film300is easily removed by the cleaning water as depicted inFIG. 8Bbecause it is formed of the water-soluble resin, and the bond material5remaining on the front side2aof the semiconductor wafer2is also removed. Therefore, a situation where part of the bond material5is left on surfaces of devices is obviated, and, accordingly, device quality can be prevented from being lowered due to such bond material5.

The semiconductor wafer2thus having been subjected to the bond material removing step is carried to the subsequent step, namely, a wafer dividing step in the state of being supported on the annular frame F through the dicing tape T, and is divided along division lines21into individual devices22.

Now, a second embodiment of the wafer processing method of the present invention will be described below. In the second embodiment, before the aforementioned water-soluble resin coating step is conducted, a cut groove forming step of forming cut grooves corresponding to a finished thickness of the devices22along the division lines21from the side of the front side2aof the semiconductor wafer2is carried out, and, in the back side grinding step, the cut grooves are exposed to the back side2bof the semiconductor wafer2to thereby divide the semiconductor wafer2into the individual devices22.

Here, the cut groove forming step will be described referring toFIGS. 9A and 9B.

The cut groove forming step is carried out using a cutting apparatus9depicted inFIG. 9A. The cutting apparatus9depicted inFIG. 9Aincludes a chuck table91for holding a workpiece thereon, cutting means92for cutting the workpiece held on the chuck table91, and imaging means93for imaging the workpiece held on the chuck table91. The chuck table91is configured to suction hold the workpiece, is moved in a cutting feed direction indicated by arrow X inFIG. 9Aby a cutting feeding mechanism (not depicted), and is moved in an indexing feed direction indicated by arrow Y by an indexing feeding mechanism (not depicted).

The cutting means92includes a spindle housing921disposed substantially horizontally, a rotating spindle922rotatably supported on the spindle housing921, and a cutting blade923attached to a tip portion of the rotating spindle922, and the rotating spindle922is rotated in the direction indicated by arrow922aby a servo motor (not depicted) disposed inside the spindle housing921. Note that the thickness of the cutting blade923is set to 30 μm in this embodiment. The imaging means93is mounted to a tip portion of the spindle housing921, and includes illumination means for illuminating the workpiece, an optical system for capturing a region illuminated by the illumination means, an imaging element (charge-coupled device: CCD) for picking up an image captured by the optical system, and the like, and an image signal thus obtained is sent to control means (not depicted).

In carrying out the cut groove forming step by use of the aforementioned cutting apparatus9, the semiconductor wafer2is placed on the chuck table91with its back side2bon the lower side, as depicted inFIG. 9A, and suction means (not depicted) is operated to suction hold the semiconductor wafer2on the chuck table91. Therefore, the semiconductor wafer2held on the chuck table91has its front side2aon the upper side. The chuck table91with the semiconductor wafer2suction held thereon in this way is positioned directly under the imaging means93by a cutting feeding mechanism (not depicted).

After the chuck table91is positioned directly under the imaging means93, an alignment work is carried out in which a cutting region where to form a cut groove along the division line21of the semiconductor wafer2is detected by the imaging means93and control means (not depicted). Specifically, the imaging means93and the control means (not depicted) perform image processing such as pattern matching for matching the position of the division line21formed in a predetermined direction of the semiconductor wafer2and the position of the cutting blade923to each other, to thereby achieve alignment of the cutting region (alignment step). In addition, alignment of the cutting region is conducted also for the division lines21formed on the semiconductor wafer2to extend in a direction orthogonal to the predetermined direction.

After the alignment for detecting the cutting region of the semiconductor wafer2held on the chuck table91is thus conducted, the chuck table91with the semiconductor wafer2held thereon is moved to a cutting start position of the cutting region. Then, the cutting blade923being rotated in a direction indicated by arrow922ainFIG. 9Ais moved downward to perform cutting-in feed. The cutting-in feed position is set in such a manner that an outer peripheral edge of the cutting blade923reaches a depth position (for example, 100 μm) corresponding to the finished thickness of the devices from the front side2aof the semiconductor wafer2. After the cutting-in feed of the cutting blade923is performed in this manner, while rotating the cutting blade923the chuck table91is subjected to cutting feed in the direction indicated by arrow X inFIG. 9A, whereby a cut groove210having a width of 30 μm and a depth (for example, 100 μm) corresponding to the finished thickness of the devices is formed along the division line21as depicted inFIG. 9B(cut groove forming step).

After the aforementioned cut groove forming step is conducted, the water-soluble resin coating step and the protective plate fixing step are performed, after which the back side grinding step is carried out. In the back side grinding step, when the back side2bof the semiconductor wafer2is ground and the thickness of the semiconductor wafer2reaches, for example, 100 μm, the cut grooves210are exposed to the back side2band the semiconductor wafer2is divided into individual devices, as illustrated inFIGS. 10A and 10B. Note that in this embodiment, the water-soluble resin coating step is conducted after the cut groove forming step is performed, and, therefore, the water-soluble resin fills the cut grooves210. Accordingly, when the cut grooves210are exposed to the back side2bof the semiconductor wafer2, the water-soluble resin filling the cut grooves210is exposed.

Now, a third embodiment of the wafer processing method of the present invention will be described below. In the third embodiment, before the water-soluble resin coating step is conducted, a modified layer forming step is carried out in which a laser beam of such a wavelength as to be transmitted through the semiconductor wafer2is applied to the semiconductor wafer2along the division lines21, with the focal point of the laser beam positioned inside the semiconductor wafer2, whereby a modified layer serving as a division start point is formed inside the semiconductor wafer2along each of the division lines21. Then, in the back side grinding step, the semiconductor wafer2is divided along the division lines21along which the modified layers serving as the division start points have been formed, into the individual devices.

Here, the modified layer forming step will be described referring toFIGS. 11A to 11C. The modified layer forming step is carried out using a laser processing apparatus10depicted inFIG. 11A. The laser processing apparatus10depicted inFIG. 11Aincludes a chuck table11for holding a workpiece thereon, laser beam application means12for applying a laser beam to the workpiece held on the chuck table11, and imaging means13for imaging the workpiece held on the chuck table11. The chuck table11, configured to suction hold the workpiece, is moved in a processing feed direction indicated by arrow X inFIG. 11Aby processing feeding means (not depicted), and is moved in an indexing feed direction indicated by arrow Y inFIG. 11Aby indexing feeding means (not depicted).

The laser beam application means12includes a hollow cylindrical casing121disposed substantially horizontally. Inside the casing121is disposed pulsed laser beam oscillating means (not depicted) that includes a pulsed laser beam oscillator and repetition frequency setting means. To a tip portion of the casing121is mounted a focusing device122for focusing the pulsed laser beam oscillated from the pulsed laser beam oscillating means. Note that the laser beam application means12includes focal point adjusting means (not depicted) for adjusting a focal point position of the pulsed laser beam focused by the focusing device122.

The imaging means13mounted to a tip portion of the casing121constituting the laser beam application means12includes illumination means for illuminating the workpiece, an optical system for capturing a region illuminated by the illumination means, and an imaging element (CCD) for picking up an image captured by the optical system, and the like, and an image signal thus obtained is sent to control means (not depicted).

In conducting the modified layer forming step by use of the aforementioned laser processing apparatus10, first, the semiconductor wafer2is placed on the chuck table11with its back side2bon the lower side, as depicted inFIG. 11A. Then, the semiconductor wafer2is suction held onto the chuck table11by suction means (not depicted). Therefore, the semiconductor wafer2held on the chuck table11has its front side2aon the upper side. The chuck table11with the semiconductor wafer2suction held thereon is positioned directly under the imaging means13by processing feeding means (not depicted).

After the chuck table11is positioned directly under the imaging means13, an alignment work for detecting a processing region to be laser processed of the semiconductor wafer2, by the imaging means13and the control means (not depicted), is carried out. Specifically, the imaging means13and the control means (not depicted) perform image processing such as pattern matching for matching the position of the division line21formed in a predetermined direction of the semiconductor wafer2and the position of the focusing device122of the laser beam application means12for applying the laser beam along the division line21to each other, to thereby carry out alignment of the laser beam applying position. In addition, the alignment of the laser beam applying position is conducted also for the division lines21formed on the semiconductor wafer2to extend in a direction orthogonal to the predetermined direction.

After the division lines21formed on the semiconductor wafer2held on the chuck table11are detected and the alignment of the laser beam applying position is conducted in this way, the chuck table11is moved into a laser beam application region where the focusing device122of the laser beam application means12for applying the laser beam is located as depicted inFIG. 11B, and one end (the left end inFIG. 11B) of a predetermined division line21is positioned directly under the focusing device122of the laser beam application means12. Next, the focal point P of the pulsed laser beam applied from the focusing device122is positioned at an intermediate portion in the thickness direction of the semiconductor wafer2. Subsequently, while a pulsed laser beam having such a wavelength (for example, 1,064 nm) as to be transmitted through the silicon wafer is being applied from the focusing device122, the chuck table11is moved at a predetermined feed rate in a direction indicated by arrow X1inFIG. 11B. Then, when the applying position of the focusing device122of the laser beam application means12has reached the position of the other end of the division line21as depicted inFIG. 11C, the application of the pulsed laser beam is stopped and the movement of the chuck table11is stopped. As a result, a modified layer220is formed inside the semiconductor wafer2along the division line21as depicted inFIG. 11C(modified layer forming step). This modified layer forming step is carried out along all the division lines21formed on the semiconductor wafer2.

After the aforementioned modified layer forming step is conducted, the water-soluble resin coating step and the protective plate fixing step are performed, after which the back side grinding step is carried out. In the back side grinding step, as depicted inFIGS. 12A and 12B, the back side2bof the semiconductor wafer2is ground to make the semiconductor wafer2have a predetermined thickness (for example, 100 μm), and cracks221are generated along the division lines21, where strength has been lowered due to the formation of the modified layers220, whereby the semiconductor wafer2is divided into individual devices. Note that in the aforementioned modified layer forming step, an example has been depicted in which the laser beam is applied from the front side2aof the semiconductor wafer2along the division lines21with the focal point of the laser beam being positioned inside the semiconductor wafer2. In this connection, in the case where the laser beam is applied from the back side2bof the semiconductor wafer2along the division lines21with the focal point of the laser beam being positioned inside the semiconductor wafer2, the modified layer forming step may be carried out after the water-soluble resin coating step and the protective plate fixing step are conducted.

After the back side grinding step in the second and third embodiments is conducted in this manner, a protective plate releasing step is carried out wherein the bond layer50formed of the bond material5is released from the semiconductor wafer2together with the protective plate6to which the semiconductor wafer2has been fixed, like in the protective plate releasing step illustrated inFIGS. 7A and 7Babove. Specifically, as depicted inFIGS. 13A and 13B, the back side2bof the semiconductor wafer2divided into the individual devices22is adhered to a surface of a dicing tape T including a synthetic resin sheet of a polyolefin or the like of which an outer peripheral portion is so mounted as to cover an inside opening portion of an annular frame F, and the bond layer50is released from the semiconductor wafer2together with the protective plate6to which the semiconductor wafer2has been fixed. Note that in this embodiment, upon the back side grinding step, the semiconductor wafer2has been divided into the individual devices22due to the exposure of the cut grooves210to the back side2bof the semiconductor wafer2or the generation of the cracks221. Even after the bond layer50is released from the semiconductor wafer2together with the protective plate6, part of the bond material5may remain on the front side2aof the semiconductor wafer2divided into the individual devices22.

After the aforementioned protective plate releasing step is conducted, a bond material removing step of supplying water to the bond material5remaining on the front side2aof the semiconductor wafer2to thereby remove the thin film300together with the bond material5is carried out, like in the bond material removing step illustrated inFIGS. 8A and 8Babove. Specifically, as depicted inFIG. 14A, the semiconductor wafer2divided into the individual devices22and supported on the annular frame F through the dicing tape T after the protective plate releasing step is conducted is suction held on a holding table81of a cleaning device8through the dicing tape T therebetween, and cleaning water is supplied from a cleaning water supply nozzle82to the bond material5remaining on the front side2aof the semiconductor wafer2and to the thin film300. As a result, as depicted inFIGS. 14B and 14C, the thin film300is easily removed by the cleaning water because of being formed of a water-soluble resin, and the bond material5remaining on the front side2aof the semiconductor wafer2is also removed. Therefore, a situation in which part of the bond material5is left on the front side of the devices22is obviated, and, accordingly, the quality of the devices22can be prevented from being lowered due to such bond material5.