JP7431052B2 - Wafer processing method - Google Patents

Description

The present invention relates to a wafer processing method.

As disclosed in Patent Document 1, the TAIKO wafer is formed by grinding the central portion of a disc-shaped wafer, and has a concave portion in the central portion and an annular convex portion around the concave portion. . In the technique described in this document, the opposite surface of the TAIKO wafer to the recess is held by an electrostatic chuck in a vacuum chamber, and a metal layer is formed on the bottom surface of the recess in the vacuum chamber.

JP2007-019461A

In TAIKO wafers, the recesses are thinned to have a thickness of 150 μm or less by grinding the approximately 700 μm wafer. Therefore, the thickness changes rapidly at the boundary between the concave portion and the annular convex portion. If such a TAIKO wafer is held by an electrostatic chuck and a metal layer is formed on the bottom surface of the recess, the TAIKO wafer may crack at the boundary between the recess and the annular projection.
Possible causes of this cracking include, for example, the following facts (1) to (4).

(1) When TAIKO wafers are ground to form recesses, the boundary between the bottom surface of the recess, which has been ground and has become thinner, and the annular protrusion may lose its flatness slightly. Since the electrostatic chuck uses a flat suction surface to suction the opposite surface (lower surface) of the bottom of the TAIKO wafer's concave part with a strong suction force, the boundary between the concave part and the annular convex part of the TAIKO wafer, which is not flat, may crack due to suction. .

(2) With the fine film-forming debris on the inner wall of the vacuum chamber falling on the top surface of the electrostatic chuck and being sandwiched between the top surface of the electrostatic chuck and the bottom surface of the TAIKO wafer, the TAIKO wafer is attracted to the suction surface with a strong suction force. The TAIKO wafer is cracked.

(3) After forming the metal layer, etc., the TAIKO wafer is pushed up with a push-up pin in order to separate it from the adsorption surface of the electrostatic chuck. The TAIKO wafer cracks due to the impact caused by this pushing up.

(4) Peel off the protective tape attached to the TAIKO wafer to form the recesses before forming the metal layer. The protective tape is attached with strong adhesion to prevent grinding water from entering during the grinding process. A strong force is applied to the TAIKO wafer in order to peel off the protective tape, which has strong adhesion, and the TAIKO wafer cracks.
Further, since there is a boundary between a thinned part and a non-thinned part of the TAIKO wafer, an impact is applied when the tape is peeled off, causing the TAIKO wafer to crack.

Therefore, an object of the present invention is to suppress cracking of TAIKO wafers during formation of metal layers.

A wafer processing method according to the present invention (this processing method) is a wafer processing method in which a plurality of devices are formed in an area demarcated by streets on one surface of the wafer. A protective member forming step in which a protective member is formed by coating the entire surface with a heat-resistant resin, and a recess and an annular protrusion along the outer periphery of the recess are formed by grinding the center of the other surface of the wafer. a grinding step in which the wafer is held by an electrostatic chuck through the protective member in a vacuum chamber, and a metal layer forming step in which a metal layer is formed on the bottom surface of the recess; a holding step of protecting the surface of the metal layer of the wafer with a dicing tape, and holding the wafer on a dicing table via the dicing tape so that the protective member side of the wafer faces upward; and holding the wafer on the dicing table through the dicing tape. An annular processing process in which the protection member and the wafer are subjected to an annular dividing process from the protection member side along the outer periphery of the bottom surface of the wafer, and after the annular processing process, the dicing table is an annular protrusion removing step of removing the annular protrusion and a portion covering the annular protrusion of the protective member divided in the annular processing step from the held wafer ; After the protrusion removal process, a protection member removal process of removing the protection member from the wafer from which the annular protrusion has been removed and which is held on the dicing table; a cutting step of cutting the wafer held on the dicing table into small pieces by cutting the wafer held on the dicing table; It is also used in the steps up to the annular processing step.

In this processing method, an ultraviolet curable resin may be used as the resin.

In this processing method, the protective member forming step includes spreading a liquid resin over the entire surface of the one surface of the wafer, and applying an external stimulus to the liquid resin to harden the liquid resin. May include.

Alternatively, in this processing method, the protective member forming step includes placing a sheet-shaped resin on one surface of the wafer, and applying heat to the sheet-shaped resin to bring it into close contact with the wafer. May include. The method for processing a wafer according to claim 1.

In addition, in this processing method, the protective member removing step is performed by injecting air from outside the outer periphery of the protective member toward the outer periphery of the protective member, thereby removing the protective member from one surface of the wafer. The protective member may be removed from the wafer by intervening air during the process to blow out the protective member.

In this processing method, the protective member formed on the wafer in the protective member forming step is also used in the steps from the grinding step to the annular processing step. Thereby, the steps from the grinding step to the annular processing step can be performed while the wafer is reinforced and protected by the protection member. Therefore, it is possible to prevent the wafer from cracking during formation of the metal layer.

FIG. 2 is a perspective view showing the configuration of a wafer. It is an explanatory view showing a protection member formation process. It is an explanatory view showing a protection member formation process. It is an explanatory view showing a grinding process. It is an explanatory view showing a grinding process. It is an explanatory view showing a metal layer formation process. It is an explanatory view showing a metal layer formation process. FIG. 3 is a perspective view showing the configuration of a work set. It is an explanatory view showing a holding process. It is an explanatory view showing an annular processing process. It is an explanatory view showing an annular processing process. It is an explanatory view showing an annular convex part removal process. It is an explanatory view showing an annular convex part removal process. It is an explanatory view showing a protection member removal process. It is an explanatory view showing a protection member removal process. It is an explanatory view showing a cutting process. It is an explanatory view showing a protection member formation process of other aspects. It is an explanatory view showing a protection member formation process of other aspects.

As shown in FIG. 1, a wafer 100, which is an object to be processed in the wafer processing method according to the present embodiment, is a disk-shaped semiconductor wafer. A grid-like street 102 is formed on a front surface 101 that is one side of the wafer 100 . A plurality of devices 103 are formed in the area defined by the streets 102. The other side of wafer 100, back side 104, does not have devices 103.

In this embodiment, this wafer 100 is divided to form a plurality of chips each including one device 103.
To this end, in this embodiment, the wafer 100 is subjected to a protective member forming process, a grinding process, a metal layer forming process, a holding process, an annular processing process, an annular convex part removal process, a protective member removing process, and a cutting process. do.

(1) Protective member forming process In the protective member forming process, a protective member is formed on the front surface 101 of the wafer 100 by covering the entire surface with a heat-resistant resin.

In this step, as shown in FIG. 2, the wafer 100 is set in the protective film forming apparatus 10. The protective film forming apparatus 10 includes a holding table 11 that holds the wafer 100 using a holding surface 14 . The holding table 11 is formed into a disk shape smaller than the wafer 100. The holding surface 14 is made of a porous material, and is able to suction and hold the wafer 100 by communicating with a suction source (not shown). The wafer 100 is held by the holding surface 14 of the holding table 11 with the front surface 101 facing upward.

The protective film forming apparatus 10 also includes a liquid resin supply nozzle 12 that supplies liquid resin 200 to the wafer 100 held on the holding table 11, and a rotating shaft of the holding table 11, which is rotated in a direction perpendicular to the holding surface 14. and an extending spindle 13. In this embodiment, the liquid resin 200 is a thermosetting resin.

The spindle 13 is disposed below the holding table 11, and is driven to rotate, for example, in the direction of an arrow 301 by a motor (not shown). As a result, the holding table 11 is rotated together with the spindle 13.

The liquid resin supply nozzle 12 is connected to a liquid resin supply source (not shown), and supplies liquid resin 200 from above to the surface 101 of the wafer 100 held on the holding surface 14 and rotating together with the holding table 11. As a result, the liquid resin 200 is spread over the entire surface 101 of the wafer 100.

Thereafter, the liquid resin 200 is hardened by applying an external stimulus to the liquid resin 200. In this embodiment, the liquid resin 200 is cured by heating the liquid resin 200 using a heating device (not shown). As a result, as shown in FIG. 3, a protective member 105 made of liquid resin 200 is formed on the surface 101 of the wafer 100 so as to cover the entire surface.

Note that the liquid resin 200 may be an ultraviolet curable resin. In this case, the liquid resin 200 includes, for example, a polyester resin as a main material and an acrylic resin as a diluent, and has a heat resistance temperature of about 200 degrees.

When using an ultraviolet curable resin as the liquid resin 200, the protective member 105 is formed on the surface 101 by spreading the liquid resin 200 over the entire surface 101 of the wafer 100 and then irradiating the liquid resin 200 with ultraviolet rays.

(2) Grinding process In the grinding process (TAIKO grinding process), the center of the back surface 104 of the wafer 100 is ground to form a recess and an annular protrusion along the outer periphery of the recess on the back surface 104.

In this step, as shown in FIG. 4, the wafer 100 on which the protective member 105 is formed is set in the grinding device 20. The grinding device 20 includes a chuck table 21 that holds the wafer 100 with a holding surface 22 . The holding surface 22 is made of a porous material, and is able to suction and hold the wafer 100 by communicating with a suction source (not shown). The wafer 100 is held by the holding surface 22 of the chuck table 21 via the protection member 105 so that the back surface 104 faces upward.

Further, the grinding device 20 has a grinding means 23 above the chuck table 21 for grinding the back surface 104 of the wafer 100. The grinding means 23 includes a spindle 24 extending in a direction perpendicular to the holding surface 22, a mount 25 attached to the tip of the spindle 24, and a plurality of grinding wheels 26 arranged annularly on the lower surface of the mount 25.

In the grinding process, with the grinding means 23 disposed above the wafer 100, the outer edge of the grinding wheel 26 is disposed inside the outer periphery of the wafer 100 by a predetermined distance 401. In this state, the spindle 24 is rotationally driven by a motor (not shown), for example, as shown by an arrow 303, thereby rotating the mount 25 and the grinding wheel 26 attached to the lower end of the spindle 24.

Thereafter, the grinding means 23 is ground and sent downward toward the wafer 100 held on the holding surface 22. Further, the chuck table 21 is rotated by a drive source (not shown). As a result, the rotating grinding wheel 26 comes into contact with the back surface 104 of the wafer 100 held on the holding surface 22 of the rotating chuck table 21, and grinds this back surface 104.

In this grinding, the outer edge of the grinding wheel 26 is placed inside the outer periphery of the wafer 100 by a predetermined distance 401 . Therefore, the center of the back surface 104 of the wafer 100 is ground by the grinding wheel 26 . As a result, as shown in FIG. 5, a recess (circular recess) 110 having a bottom surface 111 is formed on the back surface 104 of the wafer 100. Further, an annular protrusion 112 is formed along the outer periphery of the recess 110.

In this way, by forming the recess 110 and the annular protrusion 112 on the back surface 104 of the wafer 100, the wafer 100 can be made into a TAIKO wafer. That is, the wafer 100, which is thinned at the center, is reinforced by the annular convex portion 112 on the outer periphery. Therefore, for example, when the wafer 100 is transferred to an apparatus that forms a metal layer on the bottom surface 111 of the recess 110, damage to the wafer 100 can be suppressed.

(3) Metal layer forming step In the metal layer forming step, a metal layer is formed on the bottom surface 111 of the recess 110 formed on the back surface 104 of the wafer 100.
In this step, as shown in FIG. 6, the wafer 100 on which the concave portion 110 and the annular convex portion 112 are formed is set in the reduced pressure film forming apparatus 30.

This reduced pressure film forming apparatus 30 includes an electrostatic chuck 32 inside a chamber 31 that is a vacuum chamber. This electrostatic chuck 32 electrostatically holds the wafer 100 via the protective member 105. A sputtering source 34 made of metal is disposed above the electrostatic chuck 32 at a position facing the electrostatic chuck 32 while being supported by an excitation member 33 . A high frequency power source 35 is connected to this sputtering source 34 .

Furthermore, a sputtering gas inlet 36 is provided on one side of the chamber 31 . A sputtering gas such as argon gas is introduced into the chamber 31 through the sputtering gas inlet 36, as indicated by an arrow 305. The other side of the chamber 31 is provided with a decompression port 37 that communicates with a decompression source (not shown).

In the reduced pressure film forming apparatus 30 , the wafer 100 is electrostatically held by the electrostatic chuck 32 via the protection member 105 , so that the bottom surface 111 of the recess 110 of the wafer 100 faces the sputtering source 34 . Further, the annular convex portion 112 of the wafer 100 is subjected to masking (not shown).

Then, high frequency power of, for example, about 13.56 MHz is applied from the high frequency power supply 35 to the sputtering source 34 magnetized by the excitation member 33, and the inside of the chamber 31 is heated to 10 ⁻² Pa to 10 through the pressure reducing port 37. The pressure is reduced to about ^-4 Pa, and sputtering gas is introduced from the sputtering gas inlet 36.

As a result, plasma is generated, ions in the plasma collide with the sputter source 34, metal particles are thrown out, and the thrown out metal particles are deposited on the bottom surface 111 of the recess 110 of the wafer 100. In this way, a metal layer 113 is formed on the bottom surface 111 of the recess 110, as shown in FIG. This metal layer 113 has a thickness of, for example, about 30 to 60 nm.
Note that in this metal layer forming step, the metal layer 113 may be formed on the bottom surface 111 of the recess 110 of the wafer 100 by using vapor deposition, CVD, or the like.

Thereafter, the protection member 105 formed on the wafer 100 is pushed up from below by a lift pin (not shown) provided on the electrostatic chuck 32. As a result, the protection member 105 and the wafer 100 are removed from the electrostatic chuck 32.

(4) Holding process The holding process is performed after the metal layer forming process. In the holding step, first, as shown in FIG. 8, a dicing tape 122 is attached to the back surface 104 side of the wafer 100, which is the surface on which the metal layer 113 is formed. Further, a ring frame 121 is attached to the outer periphery of the dicing tape 122.

Thereby, the wafer 100 is integrated with the ring frame 121 via the dicing tape 122 with the protection member 105 exposed. As a result, a work set 120 including the wafer 100, dicing tape 122, and ring frame 121 is formed. Furthermore, the surface of the metal layer 113 formed on the bottom surface 111 of the recess 110 of the wafer 100 is protected by the dicing tape 122.

Thereafter, the work set 120 including the wafer 100 is set in the cutting device 40, as shown in FIG. The cutting device 40 includes a dicing table 41 that holds the wafer 100 by a holding surface 42 with a dicing tape 122 interposed therebetween. The holding surface 42 is made of a porous material, and is able to suction and hold the wafer 100 by communicating with a suction source (not shown).

Additionally, a clamp 43 for holding the ring frame 121 of the work set 120 is provided around the dicing table 41. Work set 120 is held on dicing table 41 by holding surface 42 and clamp 43 .

(5) Annular processing step In the annular processing step (annular groove forming step), along the outer periphery of the bottom surface 111 of the recess 110 of the wafer 100 held on the dicing table 41, that is, along the boundary between the recess 110 and the annular protrusion 112, , An annular dividing process (circle cut) is performed on the protective member 105 and the wafer 100 from the protective member 105 side.

As shown in FIG. 9, a dicing table spindle 44 is provided on the lower surface of the dicing table 41 and extends in a direction perpendicular to the holding surface 42. The dicing table spindle 44 rotates the dicing table 41 by being driven by a motor (not shown).

Further, a cutting mechanism 45 is arranged above the dicing table 41. The cutting mechanism 45 includes a blade spindle 46 extending horizontally parallel to the holding surface 42 and a cutting blade 47 provided at the tip of the blade spindle 46 and extending parallel to a plane perpendicular to the holding surface 42.

In the annular processing step, the cutting blade 47 is placed on the boundary between the recess 110 and the annular protrusion 112 in the wafer 100 held on the dicing table 41 . Then, as shown in FIG. 10, the dicing table spindle 44 rotates the dicing table 41, for example, as shown by an arrow 307. Furthermore, the cutting mechanism 45 is lowered toward the wafer 100 held on the holding surface 42 while rotating the cutting blade 47 by the blade spindle 46, for example, as shown by arrow 309.

Thereby, an annular dividing process is performed on the protection member 105 and the wafer 100 from the protection member 105 side along the boundary between the recess 110 and the annular projection 112. By such dividing processing, a dividing groove 125 is formed along the boundary between the recess 110 and the annular protrusion 112, and the annular protrusion 112 is cut from the wafer 100, as shown in FIG.

(6) Annular protrusion removal process The annular protrusion removal process is performed after the annular processing process. In the annular protrusion removal step, the annular protrusion 112 is removed from the wafer 100.

In this step, as shown in FIG. 12, the transport means 48 is placed above the dicing table 41 holding the wafer 100 in which the dividing grooves 125 are formed. The conveyance means 48 includes a base body 49 extending in the horizontal direction, and a pair of lower support parts 50 provided at both ends of the base body 49 and extending in the vertical direction. Further, the conveying means 48 includes a vertical moving means 51 that moves the base body 49 and the lower support part 50 in the vertical direction, and a horizontal moving means 52 that moves the base body 49, the lower support part 50, and the vertical moving means 51 in the horizontal direction. We are prepared.

In the conveyance means 48, the base body 49, the lower support part 50, and the vertical movement means 51 are moved in the horizontal direction by the vertical movement means 51 so that the pair of lower support parts 50 are arranged above the annular convex part 112 on the wafer 100. move it to Thereafter, the base body 49 and the lower support part 50 are lowered by the vertical movement means 51, and the hook-shaped tip of the lower support part 50 supports the lower surface of the annular convex part 112 from the outside. In this state, the base body 49 and the lower support part 50 are moved upward by the vertical moving means 51. Thereby, as shown in FIG. 13, the annular convex portion 112 is removed from the wafer 100.

(7) Protective member removal process The protective member removal process is performed after the annular protrusion removal process. In the protective member removal step, the protective member 105 is removed from the wafer 100.

In this step, as shown in FIG. 14, an air injection device 55 is placed on the outer side of the wafer 100 and the protection member 105 that are held on the holding surface 42 of the dicing table 41 with the annular convex portion 112 removed. be done. The air injection device 55 includes an air injection nozzle 56 and an air supply source 57 that communicates with the air injection nozzle 56.

The air injection device 55 injects air from outside the outer periphery of the protection member 105 toward the outer periphery of the protection member 105 using the air injection nozzle 56 . As a result, the air injection device 55 inserts air between the protective member 105 and the back surface 104 of the wafer 100 to blow away the protective member 105 and remove the protective member 105 from the wafer 100, as shown in FIG. do.

(8) Cutting process The cutting process is performed after the protective member removal process. In the cutting process, the wafer 100 is cut into small pieces by cutting the wafer 100 along the streets 102 (see FIG. 1).

In this step, as shown in FIG. 16, a cutting mechanism 45 is placed above the wafer 100 held on the holding surface 42 of the dicing table 41 with the protective member 105 removed.

In the cutting mechanism 45, the cutting blade 47 is arranged along the streets 102 on the wafer 100. The cutting blade 47 is then rotated by the blade spindle 46, for example, as shown by arrow 311. In this state, the cutting blade 47 is lowered until the lower end of the cutting blade 47 touches the dicing tape 122 of the work set 120, and then the cutting blade 47 is moved horizontally along the street 102 as shown by the arrow 313. move it. Thereby, the wafer 100 can be cut along the streets 102.

By cutting the wafer 100 along all the streets 102 in this manner, the wafer 100 can be divided into small pieces. By peeling the wafer 100 into small pieces from the dicing tape 122, a plurality of chips including one device 103 (see FIG. 1) can be obtained.

As described above, in this embodiment, the protective member 105 formed on the wafer 100 in the protective member forming process is also used in the processes from the grinding process to the annular processing process. Thereby, the steps from the grinding step to the annular processing step can be performed while the wafer 100 is reinforced and protected by the protection member 105. Therefore, it is possible to prevent the wafer 100 from cracking when forming the metal layer 113.

That is, in this embodiment, the wafer 100 is attracted and held by the electrostatic chuck 32 (see FIG. 6) via the protective member 105 in the metal layer forming step. Therefore, even if the wafer 100 is attracted to the electrostatic chuck 32 with a strong attraction force in a state where the wafer 100 has slightly lost its flatness or a state where there are film-forming debris on the electrostatic chuck 32, the wafer 100 can be protected. Since the wafer 100 is reinforced and protected by the member 105, cracking of the wafer 100 can be suppressed.

Further, when removing the wafer 100 from the electrostatic chuck 32, the protection member 105 formed on the wafer 100 is pushed up by the lift pin. Therefore, it is possible to prevent the impact from the lift pins from being directly transmitted to the wafer 100, thereby suppressing the wafer 100 from being broken.

Furthermore, the formation of the protective member 105 makes it difficult for the wafer 100 to bend. Therefore, even when the center of the wafer 100 is pushed up with one lift pin, cracking of the wafer 100 due to bending can be suppressed.

Furthermore, in this embodiment, the protection member 105 can be removed from the wafer 100 by air injection from the air injection device 55, as shown in FIGS. 14 and 15.
That is, the adhesive force of the protective member 105 is smaller than that of a general protective tape. Therefore, the protective member 105 can be easily removed (peeled off) from the wafer 100 by jetting air. Therefore, when removing the protective member 105 from the wafer 100, it is possible to avoid applying strong force to the wafer 100 that would cause the wafer 100 to crack. Further, since the protective member 105 can be removed in a short time, work efficiency can be improved.

Further, in this embodiment, after forming the metal layer 113 on the wafer 100, the wafer 100 with the protective member 105 formed thereon is subjected to an annular processing step to form the recesses 110 and annular protrusions 112. A dividing groove 125 is formed along the boundary. That is, in this embodiment, the annular convex portion 112 is cut from the wafer 100 along with the protection member 105 for suppressing cracking of the wafer 100. Therefore, chipping that may occur on the cut surface that is the outer circumference of the wafer 100 when cutting the annular convex portion 112 can be reduced. As a result, in the cutting process of cutting the wafer 100 into pieces, it is possible to suppress the wafer 100 from being broken starting from the chippings formed on the outer periphery.

In this embodiment, in the protective member forming step, the protective member 105 is formed on the wafer 100 using liquid resin 200, as shown in FIG.
Instead, as shown in FIG. 17, the protective member forming step includes placing a sheet-like resin 130 made of a thermosetting resin on the surface 101 of the wafer 100, and applying heat to the sheet-like resin 130. The structure may include bringing the wafer 100 into close contact with the wafer 100. This also allows a protective member 131 made of sheet-like resin 130 to be formed on the surface 101 of the wafer 100, as shown in FIG. Alternatively, grains or pellets made of thermosetting resin may be arranged over the surface 101 of the wafer 100, and heat may be applied to the grains or pellets to bring them into close contact with the wafer to form the protective member 105. Good too.
The thermosetting resin forming the protective members 105 and 131 is made of polyolefin resin, urethane resin, chloride resin (vinyl chloride, vinylidene chloride, etc.), acrylic resin, etc. It has heat resistance and adhesive strength (releasability) that allows it to be peeled off by air injection.
Note that the removal of the protective member is not limited to air injection. A liquid mixture of air and water may be injected from an air injection device. Alternatively, mixed air in which powder is mixed with air may be injected.

10: Protective film forming device, 12: Liquid resin supply nozzle, 200: Liquid resin,
11: Holding table, 13: Spindle, 14: Holding surface,
20: Grinding device, 21: Chuck table, 22: Holding surface,
23: Grinding means, 24: Spindle, 25: Mount, 26: Grinding wheel,
30: reduced pressure film forming apparatus, 31: chamber, 32: electrostatic chuck,
33: Excitation member, 34: Sputter source, 35: High frequency power supply,
36: sputtering gas introduction port, 37: pressure reduction port,
40: cutting device, 41: dicing table, 42: holding surface, 43: clamp,
44: dicing table spindle,
45: cutting mechanism, 46: blade spindle, 47: cutting blade,
48: conveyance means, 49: base body, 50: lower support part,
51: Vertical movement means, 52: Horizontal movement means,
55: Air injection device, 56: Air injection nozzle, 57: Air supply source,
100: wafer, 101: front surface, 104: back surface,
102: Street, 103: Device, 105: Protective member,
110: recess, 111: bottom surface, 112: annular protrusion, 113: metal layer,
120: Work set, 121: Ring frame, 122: Dicing tape,
130: Sheet-like resin, 131: Protective member

Claims (5)

A method for processing a wafer in which a plurality of devices are formed in an area demarcated by streets on one surface, the method comprising:
a protective member forming step of forming a protective member on one side of the wafer by coating the entire surface with a heat-resistant resin;
a grinding step of forming a recess and an annular protrusion along the outer periphery of the recess by grinding the center of the other surface of the wafer;
a metal layer forming step of holding the wafer with an electrostatic chuck through the protection member in a vacuum chamber and forming a metal layer on the bottom surface of the recess;
After the metal layer forming step, the surface of the metal layer of the wafer is protected with a dicing tape , and the wafer is held on a dicing table via the dicing tape so that the protective member side of the wafer faces upward. a holding process;
an annular processing step of performing an annular dividing process on the protection member and the wafer from the protection member side along the outer periphery of the bottom surface of the wafer held on the dicing table;
After the annular processing step , the annular protrusion and the portion covering the annular protrusion of the protective member divided in the annular processing step are removed from the wafer held on the dicing table . a step of removing an annular convex portion;
After the annular protrusion removing step, a protective member removing step of removing the protective member from the wafer held on the dicing table from which the annular protrusion has been removed ;
After the protective member removing step, a cutting step of cutting the wafer held on the dicing table along the streets to cut the wafer into small pieces,
The protective member formed on the wafer in the protective member forming step is also used in the steps from the grinding step to the annular processing step.
Wafer processing method. Using an ultraviolet curable resin as the resin,
The method for processing a wafer according to claim 1. The protective member forming step includes:
spreading a liquid resin over the entire surface of the one side of the wafer; and
curing the liquid resin by applying an external stimulus to the liquid resin;
The method for processing a wafer according to claim 1. The protective member forming step includes arranging a sheet-like resin on one surface of the wafer, and
applying heat to the sheet-like resin to bring it into close contact with the wafer;
The method for processing a wafer according to claim 1. The protective member removal step includes:
By injecting air toward the outer periphery of the protective member from outside the outer periphery of the protective member, air is inserted between the protective member and one surface of the wafer, and the protective member is blown away. and removing the wafer from the wafer.
The method for processing a wafer according to claim 1.

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