JP2014204044A - Method of processing wafer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of processing a wafer enabling the wafer to be easily peeled from a support member.SOLUTION: The method of processing a wafer comprises: a wafer pasting step in which, a resin R that cures due to external stimulation is applied on an upper surface S1 of a support member S, a wafer W is pressurized against and placed on the upper surface S1 and external stimulation is applied to the resin, so that the resin is cured; a thickness reducing step in which a rear surface of the wafer is ground, so that its thickness is reduced to be a prescribed thickness; a protective tape pasting step in which a protective tape is pasted on a rear surface W2 of the wafer; a scraper member inserting step in which two or more scraper members 6 each having a thick wall part 61 and an insert part 62 are inserted in an interface between the support member and the resin while the insert parts oriented toward a wafer center with a diameter of the wafer interposed between the insert parts; and a support member peeling step in which when a protective tape side is placed on a suction holding table 71 and the wafer is suction-held through the protective tape, a lower part of the thick wall part of the scraper member abuts on a suction-holding surface 71a through the protective tape, and at the same time, an upper part of the thick wall part push up the support member, so that the support member is peeled from the resin.

Description

  The present invention relates to a wafer processing method.

  Usually, when grinding a wafer, a protective tape as disclosed in Japanese Patent Laid-Open No. 05-198542 is applied to protect the surface of the wafer. However, when the wafer is ground to reduce the thickness (for example, 90 μm or less), the warpage of the wafer cannot be suppressed during processing, and the wafer may be damaged by the warping force of the wafer itself. Furthermore, there is a possibility that cracks or cracks may occur due to the knife edge during processing. Therefore, for example, a method of grinding a wafer after sticking the wafer on a support member made of a rigid body as disclosed in Japanese Patent Application Laid-Open No. 2004-207606 is employed. Usually, a wafer is stuck on a support member with wax, photo-curing resin or the like.

JP 05-198542 A JP 2004-207606 A

  Since the warping of the wafer can be suppressed by making the supporting member a rigid body, thinning can be performed, but it is difficult to peel the processed wafer from the supporting member. For example, it is preferable that the wafer can be easily peeled from the support member, such as damage to the support member and the wafer when the wafer is peeled from the support member can be suppressed.

  The objective of this invention is providing the processing method of the wafer which can peel a wafer easily from a supporting member.

  The wafer processing method of the present invention is a wafer processing method for thinning a wafer, wherein a resin that is cured by an external stimulus is applied to the upper surface of a support member, the wafer surface is faced, and the wafer is buried in the resin. The wafer is pressed and placed until the resin rises to the back surface of the wafer over the entire outer periphery of the wafer, and the resin is cured by applying an external stimulus to the resin, and the wafer is bonded and fixed on the support member. After performing the sticking step, the wafer sticking step, holding the support member side with a holding table, grinding the back surface of the wafer and thinning it to a predetermined thickness, and carrying out the thinning step Then, a protective tape attaching step for attaching a protective tape having an outer diameter larger than the outer diameter of the support member to the back surface, and the support member is a rigid member having a thickness that can be bent by an external force. Formed Insertion inserted into the interface between the thick part having a thickness greater than the thickness from the back surface of the wafer to the top surface of the support member and the resin and the top surface of the support member after performing the protective tape attaching step A scraper member insertion step of inserting two or more scraper members into the interface between the support member and the resin in a direction in which each insertion portion faces the wafer center across the diameter of the wafer, and the scraper member insertion step. Later, when the protective tape side is placed on a suction holding table having a suction holding surface having an outer diameter equivalent to the outer diameter of at least the support member, and the wafer is sucked and held on the suction holding table via the protective tape, The lower part of the thick part of the scraper member abuts against the suction holding surface via the protective tape, and the upper part of the thick part pushes the support member upward, thereby supporting the support from the resin. Characterized in that it comprises a support member peeling step of peeling off the member.

  In the wafer processing method, the support member is preferably composed of a metal substrate formed to a thickness that can be bent by an external force, or a chemically strengthened glass plate that can be bent by an external force.

  The wafer processing method according to the present invention includes a scraper member insertion step of inserting two or more scraper members into the interface between the support member and the resin in a direction in which each insertion portion faces the center of the wafer across the diameter of the wafer, and a suction When the protective tape side is placed on the holding table and the wafer is sucked and held on the suction holding table via the protective tape, the lower part of the thick part of the scraper member comes into contact with the suction holding surface via the protective tape and the thick part And a support member peeling step of peeling the support member from the resin by pushing up the support member upward. According to the wafer processing method of the present invention, there is an effect that the wafer can be easily peeled from the support member.

Drawing 1 is a figure showing signs that resin is applied to a support member in a wafer sticking process concerning an embodiment. FIG. 2 is a diagram illustrating a state in which the wafer is placed on the support member in the wafer adhering process according to the embodiment. FIG. 3 is a diagram illustrating a state in which the wafer is pressed in the wafer bonding process according to the embodiment. FIG. 4 is a diagram illustrating a state in which the resin is cured in the wafer attaching process according to the embodiment. FIG. 5 is a diagram illustrating a thinning process according to the embodiment. FIG. 6 is a diagram illustrating a modified layer forming step according to the embodiment. FIG. 7 is a diagram illustrating a protective tape attaching process according to the embodiment. FIG. 8 is a cross-sectional view illustrating a scraper member insertion step according to the embodiment. FIG. 9 is a plan view showing a scraper member insertion step according to the embodiment. FIG. 10 is an enlarged view showing the inserted scraper member. FIG. 11 is a view illustrating a state before the start of the support member peeling step according to the embodiment. FIG. 12 is a diagram illustrating a state where the support member is peeled in the support member peeling step according to the embodiment. FIG. 13 is a diagram illustrating a resin peeling process according to the embodiment. FIG. 14 is a plan view showing a scraper member according to a first modification of the embodiment.

  Hereinafter, a wafer processing method according to an embodiment of the present invention will be described in detail with reference to the drawings. In addition, this invention is not limited by this embodiment. In addition, constituent elements in the following embodiments include those that can be easily assumed by those skilled in the art or those that are substantially the same.

[Embodiment]
The embodiment will be described with reference to FIGS. 1 to 13. This embodiment relates to a wafer processing method. FIG. 1 is a diagram illustrating a state in which a resin is applied to a support member in a wafer bonding process according to an embodiment of the present invention, and FIG. 2 is a diagram in which a wafer is placed on the support member in a wafer bonding process according to the embodiment. FIG. 3 is a diagram illustrating how the wafer is pressed in the wafer bonding process according to the embodiment, and FIG. 4 is a diagram illustrating how resin is cured in the wafer bonding process according to the embodiment. FIG. 5 is a view showing a thinning process according to the embodiment, FIG. 6 is a view showing a modified layer forming process according to the embodiment, and FIG. 7 is a view showing a protective tape attaching process according to the embodiment. 8 is a cross-sectional view showing the scraper member insertion step according to the embodiment, FIG. 9 is a plan view showing the scraper member insertion step according to the embodiment, and FIG. 10 is an enlarged view showing the inserted scraper member, FIG. In the embodiment FIG. 12 is a diagram illustrating a state before the start of the supporting member peeling step, FIG. 12 is a diagram illustrating a state in which the supporting member is peeled in the supporting member peeling step according to the embodiment, and FIG. 13 is a resin peeling step according to the embodiment. FIG.

  The wafer processing method according to the present embodiment is a wafer processing method for thinning a wafer, and includes a wafer sticking step, a thinning step, a protective tape sticking step, a scraper member inserting step, and a support member. And a peeling step.

(Wafer pasting process)
In the wafer sticking step, a resin R that is cured by an external stimulus is applied to the upper surface S1 of the support member S, the front surface W1 of the wafer W is faced, the wafer W is buried in the resin R, and the entire outer periphery of the wafer W is covered. This is a step of pressing and placing the wafer W until the resin R rises to the back surface W2 of the wafer W, applying an external stimulus to the resin R, and curing the resin W on the support member S.

  In the wafer sticking step, first, a liquid resin R is applied to the upper surface S1 of the support member S by the resin application device 1 shown in FIG. The resin coating apparatus 1 includes a nozzle 11 that can discharge a liquid material downward. The resin coating device 1 discharges the resin R from the nozzle 11. The resin coating device 1 applies the resin R to the center portion of the upper surface S1 with respect to the disk-shaped support member S.

  Next, as shown in FIG. 2, the wafer W is placed on the resin R applied to the upper surface S <b> 1 of the support member S. The wafer W is placed so that the surface W1 faces the upper surface S1 of the support member S and the resin R is sandwiched between the wafer W and the support member S. The wafer W of this embodiment is an optical device wafer in which a gallium nitride compound semiconductor layer is laminated on a surface W1 of a sapphire substrate having a substantially disk shape. On the surface W <b> 1 of the wafer W, grid-like division lines (not shown) are provided. On the surface W1 of the wafer W, an optical device is formed in each region partitioned by the planned division lines.

  The support member S is formed of a rigid member having a thickness that can be bent by an external force. The support member S can be bent by elastic deformation by an external force. The support member S is a substrate having a substantially disk shape. The support member S may be a metal substrate made of a metal material such as aluminum, stainless steel, or copper, or may be a glass substrate made of chemically strengthened glass. When the support member S is a metal substrate, the thickness of the support member S can be set to 100 μm to 1 mm, for example. Chemically tempered glass is glass in which a compressed layer is formed on the surface by immersing the glass in a molten salt and performing ion exchange. As the chemically strengthened glass, for example, “Dragonrail” (registered trademark) manufactured by Asahi Glass Co., Ltd. can be used. When making the supporting member S into the glass substrate of chemically strengthened glass, the thickness of the supporting member S can be 100 micrometers-2 mm, for example. The upper surface S1 of the support member S is a surface to which the resin R is applied. In the subsequent processes, the process may be performed with the upper surface S1 of the support member S facing downward.

  The resin R has photocurability that is cured by being irradiated with ultraviolet light. The resin R is preferably solventless. As the resin R, for example, “TEMPLOC” (registered trademark) manufactured by Denki Kagaku Kogyo Co., Ltd. can be used.

  After the wafer W is placed on the support member S, the wafer W is pressed by the press device 2 as shown in FIG. The press device 2 includes a holding table 21 and a pressing portion 22. The holding table 21 has a holding surface 21a, and holds the support member S on the holding surface 21a. The holding surface 21a is made of, for example, a porous ceramic that communicates with a suction source (not shown), and sucks and holds the support member S. The support member S on which the resin R is applied and the wafer W is placed is placed on the holding table 21 so that the lower surface S2 faces the holding surface 21a.

  The pressing portion 22 is disposed to face the holding surface 21a of the holding table 21, and is movable in a direction orthogonal to the holding surface 21a. The front end surface of the pressing part 22 is circular, and its outer diameter is slightly smaller than the outer diameter of the wafer W. The pressing device 2 moves the pressing portion 22 toward the holding surface 21 a in a state where the supporting member S is sucked and held on the holding surface 21 a, and presses the wafer W toward the supporting member S. When the back surface W2 of the wafer W is pressed by the front end surface 22a of the pressing portion 22, the distance between the wafer W and the support member S is narrowed, and the resin R spreads radially. The radially spreading resin R spreads outside the outer periphery of the wafer W and buryes the wafer W. The press device 2 immerses the wafer W in the resin R and presses the wafer W until the resin R rises to the back surface W2 of the wafer W over the entire outer periphery of the wafer W. In the wafer sticking step of the present embodiment, the press device 2 embeds the wafer W in the resin R until the resin R and the back surface W2 of the wafer W are flush with each other. As shown in FIG. 3, the wafer W of the embodiment has an outer peripheral corner Wc having an arc shape. For this reason, the resin R goes around to the back surface W2 side of the wafer W and firmly fixes the wafer W.

  When the pressing device 2 presses and places the wafer W on the support member S, the resin R is irradiated with ultraviolet light UV as shown in FIG. The ultraviolet light irradiation device 3 shown in FIG. 4 includes a holding table 31 and an ultraviolet light irradiation unit 32. The holding table 31 has a holding surface 31a, and holds the support member S on the holding surface 31a. The holding surface 31a is made of, for example, a porous ceramic that communicates with a suction source (not shown), and sucks and holds the support member S. The support member S on which the wafer W is pressed and placed is placed on the holding table 31 so that the lower surface S2 faces the holding surface 31a.

  The ultraviolet light irradiation unit 32 includes a light source 33 that emits ultraviolet light. The ultraviolet light irradiation unit 32 irradiates the support member S, the resin R, and the wafer W held on the holding table 31 with ultraviolet light UV from the back surface W2 side of the wafer W. The wafer W is made of sapphire resin that transmits ultraviolet light UV. For this reason, the irradiated ultraviolet light UV passes through the wafer W and reaches the resin R. The resin R is cured by a chemical reaction with ultraviolet light UV, and fixes the wafer W to the support member S. That is, the ultraviolet light irradiation device 3 applies the ultraviolet light UV, which is an external stimulus, to the resin R and cures the resin R, thereby fixing the wafer W to the support member S.

(Thinning process)
The thinning process is a process of holding the supporting member S side with a holding table and grinding the back surface W2 of the wafer W to a predetermined thickness after performing the wafer sticking process. The thinning process is executed by the grinding apparatus 4 shown in FIG. The grinding device 4 includes a holding table 41 and a grinding means 42.

  The holding table 41 has a holding surface 41a, and holds the support member S on the holding surface 41a. The holding surface 41a is made of, for example, a porous ceramic that communicates with a suction source (not shown), and sucks and holds the support member S. The support member S to which the wafer W is adhered and fixed is placed on the holding table 41 so that the lower surface S2 faces the holding surface 41a. The holding table 41 is held rotatably about the center axis C1 as a rotation center. The holding table 41 is rotationally driven by a rotation mechanism such as a motor (not shown).

  The grinding means 42 includes a grinding wheel 43 and a grinding wheel 44. The center axis C2 of the grinding wheel 43 is offset in the radial direction of the holding table 41 with respect to the center axis C1 of the holding table 41. The grinding wheel 43 can rotate around the central axis C2. The grinding wheel 43 is rotationally driven by a rotation mechanism such as a motor (not shown). A grinding wheel 44 is disposed on the tip surface of the grinding wheel 43.

  The grinding device 4 grinds the back surface W2 of the wafer W by rotating the holding table 41 and the grinding wheel 43 while the grinding wheel 44 is in contact with the back surface W2 of the wafer W. The grinding device 4 grinds the resin R raised on the outer peripheral portion of the wafer W together with the back surface W2 of the wafer W.

  The grinding device 4 thins the wafer W to a predetermined thickness. The grinding device 4 has a height gauge (not shown) and can measure the thickness of the wafer W. Based on the detection result of the height gauge, the grinding device 4 grinds the back surface W2 of the wafer W so that the thickness of the wafer W is a predetermined thickness inputted in advance. When the thinning of the wafer W to a predetermined thickness is completed, the thinning process is finished.

(Modified layer formation process)
The modified layer forming step is a step of forming the modified layer K in the wafer W by irradiating the wafer W with the laser beam L after performing the thinning step. The modified layer forming step is executed by the laser processing apparatus 5 shown in FIG. The laser processing device 5 includes a holding table 51 and laser beam irradiation means 52.

  The holding table 51 has a holding surface 51a, and holds the support member S on the holding surface 51a. The holding surface 51a is made of, for example, a porous ceramic that communicates with a suction source (not shown), and sucks and holds the support member S. The support member S is placed on the holding table 51 so that the lower surface S2 faces the holding surface 51a. The wafer W thinned by grinding the back surface W2 is held on the holding table 51 via the support member S.

  The laser beam irradiation means 52 irradiates the wafer W held on the holding table 51 with a laser beam L having a wavelength having transparency. The laser beam irradiation means 52 irradiates the laser beam L with the condensing point positioned inside the wafer W. The laser processing apparatus 5 includes a moving unit (not shown) that moves the laser beam irradiation unit 52 and the holding table 51 relative to each other. The moving means relatively moves the laser beam irradiation means 52 and the holding table 51 in a direction orthogonal to the optical axis of the laser beam L. The laser processing apparatus 5 relatively moves the laser beam irradiation unit 52 and the holding table 51 while irradiating the laser beam L with the laser beam irradiation unit 52, and forms the modified layer K along the planned division line of the wafer W.

(Protective tape application process)
A protective tape sticking process is a process of sticking the protective tape T which has an outer diameter larger than the outer diameter of the supporting member S on the back surface W2, after implementing a thinning process. In this embodiment, a protective tape sticking process is performed after implementing a modified layer formation process. As shown in FIG. 7, the protective tape T has an outer diameter larger than the outer diameter of the support member S, and has an adhesive layer T1 on one surface. An adhesive layer T1 of the protective tape T is adhered to the back surface W2 of the wafer W. That is, the protective tape T is attached to the back surface W2 of the wafer W so that the wafer W and the resin R are sandwiched between the support member S and the wafer W.

(Scraper member insertion process)
In the scraper member insertion step, after performing the protective tape attaching step, the thick portion having a thickness larger than the thickness from the back surface W2 of the wafer W to the upper surface S1 of the support member S, the resin R, and the upper surface S1 of the support member S Support member S and resin R in a direction (see arrow Y1 in FIG. 8) in which each insertion part faces wafer center C3 across the diameter of wafer W. This is a step of inserting two or more into the interface.

  As shown in FIGS. 8 and 9, the scraper member 6 includes a thick part 61 and an insertion part 62. FIG. 9 shows a plan view of the wafer W viewed from the back surface W2 side. In FIG. 9, the protective tape T is omitted. As shown in FIG. 8, the scraper member 6 according to the present embodiment is a rod-shaped member having a right triangle. Further, as shown in FIG. 9, the length L1 of the scraper member 6 of the present embodiment is smaller than the diameter R1 of the wafer W and larger than the radius r of the wafer W. As shown in FIG. 10, the scraper member 6 has a first corner portion 63 and a second corner portion 64. The first corner portion 63 and the second corner portion 64 are corner portions in which the internal angles θ1 and θ2 in the cross-sectional shape are acute angles. In the scraper member 6 of the present embodiment, the inner angle θ1 of the first corner portion 63 is smaller than the inner angle θ2 of the second corner portion 64.

  The second corner 64 is the tip of the insertion part 62 that is inserted into the interface B between the resin R and the upper surface S1 of the support member S. The insertion part 62 is preferably wedge-shaped. The contact surface 65 forms the opposite side of the first corner 63 in the cross-sectional shape. The contact surface 65 contacts the upper surface S1 of the support member S and supports the support member S. The thick part 61 includes a side surface 66. The side surface 66 forms the opposite side of the second corner 64 in the cross-sectional shape. The thickness t of the thick portion 61 is the width of the side surface 66, that is, the length of the opposite side of the second corner portion 64 in the cross-sectional shape. The thickness t of the thick portion 61 is larger than the thickness t1 from the back surface W2 of the wafer W to the upper surface S1 of the support member S.

  As shown in FIGS. 8 and 9, the scraper member 6 is inserted into the interface B between the support member S and the resin R in a direction in which each insertion portion 62 faces the wafer center C3 across the diameter R1 of the wafer W. . In the present embodiment, two scraper members 6 are inserted into the interface B. The pair of scraper members 6 are inserted into the interface B between the support member S and the resin R so as to face each other with the center C3 of the wafer W therebetween and to be parallel to each other. The scraper member insertion step may be performed by an operator, for example. By inserting the insertion portion 62 of the scraper member 6 into the interface B, the edge portion of the resin R is peeled off from the support member S. Further, since the insertion portion 62 is inserted between the resin R and the support member S and exerts a force that pushes the gap between the resin R and the support member S, peeling easily proceeds from this portion.

(Support member peeling process)
With reference to FIG. 11, a support member peeling process is demonstrated. The support member peeling step is executed after the scraper member inserting step. In the supporting member peeling step, the protective tape T side is placed on the suction holding table 71 having a suction holding surface 71a having an outer diameter equal to at least the outer diameter of the supporting member S, and the wafer W is sucked and held via the protective tape T. When sucked and held on the table 71, the lower part of the thick part 61 of the scraper member 6 comes into contact with the sucking and holding surface 71a via the protective tape T, and the upper part of the thick part 61 pushes the support member S upward, thereby In this step, the support member S is peeled off from R.

  The supporting member peeling step may be executed by, for example, the dividing apparatus 7 that divides the wafer W on which the modified layer K is formed into individual devices. The dividing device 7 includes a suction holding table 71, a suction source 72, and a switching valve 73.

  The suction holding table 71 has a suction holding surface 71a. The outer diameter of the suction holding surface 71a is at least equal to the outer diameter of the support member S. The outer diameter of the suction holding surface 71a is larger than the outer diameter of the wafer W and larger than the outer diameter of the resin R. The suction holding surface 71a is made of, for example, porous ceramic and holds the support member S by suction. The suction holding surface 71 a is connected to the suction source 72. The suction source 72 generates negative pressure and can supply negative pressure to the suction holding surface 71a. The switching valve 73 is a switching valve that communicates or blocks the suction holding surface 71a and the suction source 72.

  FIG. 11 shows a state where the switching valve 73 is closed and the suction holding surface 71a and the suction source 72 are shut off. The wafer W is placed on the suction holding table 71 with the back surface W2 side to which the protective tape T is attached facing the suction holding surface 71a. Since the thickness t of the scraper member 6 is larger than the thickness t1 from the back surface W2 of the wafer W to the upper surface S1 of the support member S, the support member S is supported by the suction holding table 71 via the scraper member 6. It becomes. As a result, a space 8 is formed between the suction holding surface 71a and the protective tape T. That is, the portion of the protective tape T that is adhered to the back surface W2 of the wafer W is in a state of being lifted from the suction holding surface 71a.

  As shown in FIG. 12, when the switching valve 73 is opened and the suction holding surface 71a communicates with the suction source 72, the air in the space portion 8 (see FIG. 11) is sucked and the space portion 8 becomes negative pressure. Become. Thereby, the protective tape T, the wafer W, the resin R, and the support member S are sucked toward the suction holding surface 71a. The protective tape T, the wafer W, and the resin R are moved toward the suction holding surface 71a by the suction force, and the protective tape T is sucked and held by the suction holding surface 71a as shown in FIG. That is, the suction holding table 71 sucks and holds the wafer W via the protective tape T. At this time, the support member S is supported by the scraper member 6 and is restricted from moving toward the suction holding surface 71a. In the scraper member 6, the first corner 63 abuts on the suction holding table 71 via the protective tape T, and the abutment surface 65 abuts on the support member S to push the support member S upward. The support member S bends toward the suction holding surface 71a by the suction force toward the suction holding surface 71a.

  Here, in the scraper member insertion step, the insertion portion 62 of the scraper member 6 is inserted at the boundary between the support member S and the resin R, and the resin R and the support member S are partially separated. Further, the insertion portion 62 is inserted between the resin R and the support member S, and pushes the resin R and the support member S away from each other. Accordingly, the support member S and the resin R are sequentially peeled (propagated) from the outer edge portion into which the insertion portion 62 is inserted toward the center portion (radially inner side), and the support member S is peeled from the resin R.

  In the support member peeling step, the support member S may be completely peeled from the resin R by the suction force of the suction holding table 71, and the support member S may be peeled from the resin R leaving a partial region. It may be. When the support member S is completely separated from the resin R by the suction force, it is preferable to provide a means for suppressing the support member S so that the support member S does not jump up by the reaction at the moment of complete separation.

  When the support member S is peeled off from the resin R without leaving a part of the region, the resin R and a part of the support member S are stuck and fixed. Can be left. The step of completely peeling the support member S from the resin R may be performed by an operator, for example.

  Whether or not the support member S is completely peeled from the resin R by the suction force of the suction holding table 71 depends on, for example, the suction force (negative pressure) of the suction holding table 71 or the thick portion 61 of the scraper member 6. Can be adjusted by the thickness t, the number of scraper members 6, the rigidity of the support member S, and the like.

(Resin peeling process)
The resin peeling process will be described with reference to FIG. The resin peeling step is performed after the support member peeling step. The resin peeling step is a step of peeling the resin R from the wafer W. In the resin peeling step, the resin R is peeled from the wafer W by pulling a part of the outer periphery of the resin R in a direction away from the protective tape T. A resin peeling process is performed in the state which stuck the outer peripheral part of the masking tape T to the cyclic | annular flame | frame F, for example.

  As described above, according to the wafer processing method of the present embodiment, the support member S can be easily peeled by peeling the support member S from the resin R by the suction force of the suction holding table 71. . After the processing of the wafer W is completed, the scraper member 6 is interposed at the interface B between the resin R and the support member S, and the scraper member 6 is raised with respect to the wafer back surface to peel off the support member. Can be peeled from the resin R.

  According to the wafer processing method according to the present embodiment, since the wafer W is bonded and fixed to the support member S, cracks and cracks due to warping of the wafer W during processing or the like can be suppressed. Further, by peeling the wafer W from the support member S by suction force, it is possible to suppress breakage of the wafer W at the time of peeling and to divide the wafer W well.

  In this embodiment, the wafer W is an optical device wafer made of sapphire. However, the present invention is not limited to this. For example, a semiconductor wafer made of silicon, a compound semiconductor wafer, an SiC or GaN wafer, etc. Good.

  The resin R may be cured by an external stimulus other than light. For example, the resin R may be a thermosetting resin that is cured by heat.

  The wafer processing method according to the present embodiment is also applicable to other wafer processing methods having a thinning process.

[First Modification of Embodiment]
A first modification of the embodiment will be described. FIG. 14 is a plan view showing a scraper member according to a first modification of the embodiment. The scraper member 9 according to the first modification is different from the scraper member 6 of the above embodiment in that it is curved. The scraper member 9 includes a thick part 91 and an insertion part 92. The thick portion 91 and the insertion portion 92 of the scraper member 9 are each curved in an arc shape in plan view. The curved shape of the scraper member 9 is convex outward in the radial direction when the insertion portions 92 are inserted into the interface between the support member S and the resin R in the direction toward the wafer center C3 across the diameter R1 of the wafer W. This is the shape.

  The radius of the arc formed by the inner periphery 92a of the insertion portion 92 of the scraper member 9 may be, for example, equal to the radius r of the wafer W or may be larger than the radius r of the wafer W. Since the scraper member 9 is curved, the scraper member 9 can be inserted between the resin R and the support member S in a wide range in the circumferential direction to peel the support member S from the resin R. Further, since the scraper member 9 is curved, stability when supporting the support member S against the suction force of the suction holding table 71 is improved.

[Second Modification of Embodiment]
A second modification of the embodiment will be described. In the above embodiment, the number of the scraper members 6 inserted into the interface between the support member S and the resin R is two. However, the present invention is not limited to this, and even when three or more scraper members 6 are inserted. Good. For example, the number of inserted scraper members 6 is appropriately changed according to the thickness of the wafer W (thickness after execution of the thinning process), the thickness of the resin R, the diameter R1 of the wafer W, and the like. For example, when the thickness of the wafer W or the resin R is large, the number of the scraper members 6 is increased as compared with the case where the thickness is small. Further, when the diameter R1 of the wafer W is large, the number of the scraper members 6 may be increased as compared with the case where the diameter R1 is small.

  The thickness t of the thick portion 61 of the scraper member 6 may be appropriately changed according to the thickness of the wafer W (thickness after execution of the thinning process), the thickness of the resin R, the diameter R1 of the wafer W, and the like. For example, when the thickness of the wafer W or the resin R is large, the thickness t of the thick portion 61 may be made larger than when the thickness is small. Further, when the diameter R1 of the wafer W is large, the thickness t of the thick portion 61 may be made larger than when the diameter R1 is small.

  The contents disclosed in the above embodiments and modifications can be executed in appropriate combination.

6 Scraper member 61 Thick part 62 Insertion part 71 Suction holding table 71a Suction holding surface 72 Suction source 73 Switching valve L Laser beam L1 Length of scraper member R Resin S Support member S1 Upper surface S2 Lower surface T Protective tape W Wafer W1 Front surface W2 Back surface

Claims (2)

A wafer processing method for thinning a wafer,
Apply a resin that cures by external stimulus on the upper surface of the support member, face the wafer surface, bury the wafer in the resin, and press the wafer until the resin rises to the back surface of the wafer over the entire circumference of the wafer A wafer adhering step in which the resin is cured by applying an external stimulus to the resin, and the wafer is adhered and fixed on the support member;
After carrying out the wafer sticking step, the supporting member side is held by a holding table, the back surface of the wafer is ground and thinned to a predetermined thickness, and
After carrying out the thinning step, a protective tape attaching step of attaching a protective tape having an outer diameter larger than the outer diameter of the support member to the back surface;
The support member is formed of a rigid member having a thickness that can be bent by an external force. After performing the protective tape attaching step, the support member is thicker than the thickness from the back surface of the wafer to the upper surface of the support member. A scraper member having an insertion portion to be inserted at the interface between the thick portion having a thickness and the resin and the upper surface of the support member is supported in a direction in which each insertion portion faces the center of the wafer across the diameter of the wafer. A scraper member insertion step of inserting two or more at the interface between the member and the resin;
After the scraper member insertion step, the protective tape side is placed on a suction holding table having a suction holding surface having an outer diameter at least equal to the outer diameter of the support member, and the wafer is sucked and held via the protective tape. When sucked and held on the table, the lower part of the thick part of the scraper member comes into contact with the sucking and holding surface via the protective tape, and the upper part of the thick part pushes the support member upward, whereby the resin A support member peeling step for peeling the support member from
A wafer processing method comprising:   The wafer processing method according to claim 1, wherein the support member is formed of a metal substrate formed to have a thickness that can be bent by an external force, or a chemically strengthened glass plate that can be bent by an external force.

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