JP2014067982A - Wafer processing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wafer processing method capable of preventing wafer breakage when peeling a support member from a thinly ground wafer having high working efficiency.SOLUTION: A wafer processing method comprises the steps of: a first sticking step of sticking one adhesive layer (A1) of a double-sided adhesive tape (DT) to a rigid support member (S); a wafer mounting step of bringing a part of an outer periphery on a surface (W1) side of a wafer (W) to the other adhesive layer (A2) of the double-sided adhesive tape and mounting the wafer on the double-sided adhesive tape so as to bring down the wafer; a second sticking step of sticking the wafer to the rigid support member by pressing a rear surface (W2) side of the mounted wafer; a grinding step of thinning the wafer to a prescribed finishing thickness (t) by grinding the rear surface side of the wafer; an adhesive layer curing step of reducing an adhesive force by curing the adhesive layer of the double-sided adhesive tape by irradiating the adhesive layer with ultraviolet light (UV) through the rigid support member or the wafer; and a removal step of removing the rigid support member and the double-sided adhesive tape from the wafer.

Description

  The present invention relates to a wafer processing method, and more particularly to a wafer processing method in which a wafer attached to a support member is ground and thinned to a predetermined thickness.

  In recent years, in order to realize a small and light device, it is required to thin the wafer. The wafer is thinned by grinding the back surface after forming a device in each region defined by the division lines on the front surface. In this thinning, in order to protect the device, a protective tape is generally attached to the surface of the wafer (see, for example, Patent Document 1).

  By the way, the rigidity of a wafer falls remarkably as it is thinned. For this reason, the wafer is greatly warped as the grinding process proceeds, and there is a high possibility that a crack or a crack will occur. Further, when the outer peripheral portion of the wafer is thinned by being knife-edged, there is a possibility that cracks, cracks, chips, etc. may be generated in the outer peripheral portion.

  In order to solve the above-mentioned problems associated with grinding, a method of attaching and grinding a wafer as a workpiece on a rigid support member has been proposed (for example, see Patent Document 2). In this method, since the wafer is reinforced by supporting the wafer with a support member made of a rigid body, the warpage of the wafer during grinding can be suppressed and damage can be prevented.

JP-A-5-198542 JP 2006-346836 A

  In the method described in Patent Document 2, a wafer as a workpiece is fixed to the surface of a support member with wax. However, in this method, it is necessary to heat and melt the wax when the wafer is adhered to the support member. In order to peel the support member from the wafer, it is necessary to oxidize the wax by heating it to 400 ° C. or higher. For this reason, there is a problem that it takes a long time to attach the wafer and peel off the support member, resulting in a reduction in work efficiency.

  Further, the above-mentioned adhesive strength of wax is not completely lost by heating. For this reason, when the support member is peeled from the wafer, local stress is generated on the wafer due to the adhesive force of the wax. Since the rigidity of the wafer after thinning is extremely low, the wafer may be damaged if such local stress occurs.

  The present invention has been made in view of such points, and has an object to provide a wafer processing method that has high work efficiency and can prevent damage to the wafer when the support member is peeled off from a thinly ground wafer. To do.

  The wafer processing method of the present invention is a wafer processing method in which the back surface of the wafer is ground and thinned, and a double-sided adhesive tape in which an adhesive layer made of an ultraviolet curable adhesive is formed on both surfaces of a base sheet. After carrying out the first sticking step of sticking one adhesive layer to the rigid support member and the first sticking step, the other adhesive layer of the double-sided tape is exposed on the upper surface to hold the rigid support member The wafer is held on the table, the wafer surface is opposed to the other adhesive layer, and one end of the wafer in the outer diameter direction is brought into contact with one end of the double-sided adhesive tape in the outer diameter direction of the double-sided adhesive tape. From the state in which the edge is directed upward, the entire outer surface of the wafer is applied to the adhesive layer by tilting the other end in the outer diameter direction of the wafer toward the other end in the outer diameter direction of the other adhesive layer of the double-sided adhesive tape. Wafer placement process and wafer placement After carrying out the process, the second sticking step of pressing the wafer from the wafer side and sticking the wafer to the other adhesive layer of the double-sided tape attached to the rigid support member and the second sticking step were carried out. Later, the rigid support member is held on a holding table, and the back surface of the wafer is ground to reduce the thickness to a predetermined thickness, and the wafer or the rigid support member and the base sheet of the double-sided adhesive tape are exposed to ultraviolet rays. An adhesive layer curing step for irradiating the adhesive layer of the double-sided tape with ultraviolet rays to cure the adhesive layer and lowering the adhesive strength, and the adhesive layer curing step. And a removal step of peeling the rigid support member and the double-sided pressure-sensitive adhesive tape from the wafer after being carried out.

  According to this configuration, since the wafer is attached to the rigid support member using the double-sided pressure-sensitive adhesive tape, it is possible to increase the work efficiency related to the attachment of the wafer. Further, since the adhesive force is reduced by irradiating the pressure-sensitive adhesive layer made of an ultraviolet curable pressure-sensitive adhesive, the double-sided pressure-sensitive adhesive tape and the double-sided pressure-sensitive adhesive tape and The rigid support member can be peeled off.

  In the wafer processing method of the present invention, when the orientation flat indicating the crystal orientation is formed on the wafer, the orientation flat is disposed at one end side in the outer diameter direction of the adhesive layer of the double-sided adhesive tape during the wafer mounting step. The other end on the opposite side of the orientation flat of the wafer from the state where the other end on the opposite side to the orientation flat of the wafer is directed upward. You may defeat it. According to this configuration, since the direction in which the wafer falls is determined based on the orientation flat, the wafer and the double-sided adhesive tape can be easily aligned.

  According to the present invention, it is possible to provide a wafer processing method with high work efficiency and capable of preventing the wafer from being damaged when the support member is peeled from the thinly ground wafer.

It is a figure which shows a mode that a double-sided adhesive tape is affixed on a rigid support member in the 1st adhesion process of this Embodiment. It is a figure which shows a mode that a wafer is mounted on a double-sided adhesive tape in the wafer mounting process of this Embodiment. It is a figure which shows a mode that a wafer is pressed in the 2nd sticking process of this Embodiment. It is a figure which shows a mode that a wafer is ground in the grinding process of this Embodiment. It is a figure which shows a mode that the adhesion layer is hardened | cured in the adhesion layer hardening process of this Embodiment. It is a figure which shows a mode that a rigid support member and a double-sided adhesive tape are removed from a wafer in the removal process of this Embodiment. It is a figure shown about a wafer mounting process in case the orientation flat is formed in the wafer.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. In the following, a wafer processing method using a silicon wafer as a processing target will be described. However, the wafer to be processed according to the present invention is not limited to a silicon wafer.

  The processing method of the wafer of this Embodiment contains a 1st sticking process, a wafer mounting process, a 2nd sticking process, a grinding process, an adhesion layer hardening process, and a removal process. In the first attaching step, one adhesive layer A1 of the double-sided adhesive tape DT including the adhesive layers A1 and A2 is brought into contact with the surface S1 of the rigid support member S, and the double-sided adhesive tape DT is attached to the rigid support member S. (See FIG. 1). In the wafer mounting process, the part of the outer periphery on the surface W1 side of the wafer W is brought into contact with the other adhesive layer A2 of the double-sided adhesive tape DT, and the wafer W is placed on the double-sided adhesive tape DT so as to be tilted toward the adhesive layer A2. (See FIG. 2).

  In the second attaching step, the back surface W2 side of the wafer W placed on the rigid support member S via the double-sided adhesive tape DT is pressed to attach the wafer W to the rigid support member S (see FIG. 3). . In the grinding process, the back surface W2 side of the wafer W is ground to thin the wafer W to a predetermined finish thickness t (see FIG. 4). In the adhesive layer curing step, the adhesive layers A1 and A2 of the double-sided adhesive tape DT are irradiated with ultraviolet rays UV through the rigid support member S (or wafer W) to cure the adhesive layers A1 and A2 and reduce the adhesive force (FIG. 5). reference). In the removal step, the rigid support member S and the double-sided adhesive tape DT are removed from the wafer W (see FIG. 6).

  In this Embodiment, since the wafer W is stuck to the rigid support member S using the double-sided adhesive tape DT, the work efficiency concerning the sticking of the wafer W can be improved. Further, since the adhesive force is reduced by irradiating the adhesive layer A2 of the double-sided adhesive tape DT with ultraviolet rays UV, the work efficiency related to the peeling of the double-sided adhesive tape DT and the rigid support member S is improved, and the wafer W is not damaged. The support member S and the double-sided adhesive tape DT can be peeled off. Details of the wafer processing method according to the present embodiment will be described below.

  In the wafer W to be processed by the processing method of the present embodiment, various functional films are formed on a disk-shaped silicon wafer (see FIG. 2). On the surface W1 of the wafer W, grid-like division planned lines (not shown) are provided, and devices (not shown) are formed in each region partitioned by the division lines.

  In the wafer processing method according to the present embodiment, first, a first sticking step of sticking the double-sided adhesive tape DT to the surface S1 side of the rigid support member S is performed. FIG. 1 is a diagram illustrating a state in which the double-sided pressure-sensitive adhesive tape DT is adhered to the rigid support member S in the first adhesion step. As shown in FIG. 1, the double-sided adhesive tape DT includes adhesive layers A1 and A2 on both main surfaces of a base sheet B made of PET (polyethylene terephthalate), and is the same as the wafer W (FIG. 2). It is formed in a disk shape having a certain diameter. The adhesive layers A1 and A2 are formed of an ultraviolet curable adhesive that is cured with ultraviolet UV (FIG. 5). For this reason, if the double-sided pressure-sensitive adhesive tape DT is irradiated with ultraviolet rays UV, the adhesive strength of the double-sided pressure-sensitive adhesive tape DT can be greatly reduced.

  The rigid support member S is a disk-shaped glass substrate and has a diameter larger than that of the wafer W so that the entire wafer W can be supported. Further, the surface S1 of the rigid support member S is rougher than the surface W1 of the wafer W. In a 1st sticking process, the back surface S2 side of the rigid support member S is first hold | maintained at the holding table 11 of the sticking apparatus 1 so that the surface S1 of this rigid support member S may face up. Then, on a part of the outer periphery of the rigid support member S, the surface S1 of the rigid support member S and the adhesive layer A1 of the double-sided adhesive tape DT are brought into contact with each other, and the vicinity of this contact portion is adhered to the adhesive layer by the roller 12 of the sticking device 1. Press from the A2 side.

  By moving the roller 12 in the opposite direction (the direction indicated by the arrow a1 in FIG. 1) sandwiching the center of the rigid support member S while keeping the pressing force by the roller 12 constant, the double-sided adhesive tape DT Affixed to the surface S1. In the first attaching step, the release paper RP is attached to the adhesive layer A2 of the double-sided adhesive tape DT, and the adhesive layer A2 and the roller 12 are not in contact with each other. The release paper RP is peeled off from the adhesive layer A2 when the first sticking step is completed.

  After the first sticking step, a wafer placing step is performed. FIG. 2 is a diagram illustrating a state in which the wafer W is placed on the double-sided adhesive tape DT in the wafer placing process. In the wafer placing process, the back surface S2 side of the rigid support member S is held on the holding table 21 as in the first attaching process. That is, the rigid support member S is disposed such that the adhesive layer A2 of the double-sided adhesive tape DT that is attached faces upward.

  Next, the wafer W is positioned above the rigid support member S so that the adhesive layer A2 of the double-sided adhesive tape DT and the surface W1 of the wafer W face each other. Then, a part of the outer periphery (end W3) of the wafer W is held by a holding unit (not shown) located above the holding table 21. Further, another part (end part W4) of the wafer W located on the opposite side of the end part W3 across the center is brought into contact with a part of the outer periphery (end part DT1) of the double-sided adhesive tape DT from above. That is, the surface W1 of the wafer W and the adhesive layer A2 of the double-sided adhesive tape DT are in contact with each other at a part of the outer periphery.

  Thereafter, when the holding of the end portion W3 is released, the wafer W is rotated by gravity with the end portion W4 as a fulcrum (arrow a2 in FIG. 2), and is placed on the double-sided adhesive tape DT. That is, the end W3 of the wafer W is tilted toward another part (end DT2) of the double-sided adhesive tape DT located on the opposite side of the end DT1 across the center. In this way, by placing the wafer W so that the end W3 side is directed upward from the state facing the adhesive layer A2, air bubbles and the like are not mixed between the wafer W and the adhesive layer A2. The adhesion between the wafer W and the double-sided pressure-sensitive adhesive tape DT can be improved.

  A 2nd sticking process is implemented after a wafer mounting process. FIG. 3 is a diagram illustrating a state in which the wafer is pressed in the second sticking step. In a 2nd sticking process, as shown in FIG. 3, the wafer W is pressed from the back surface W2 side using the press apparatus 3. As shown in FIG. The press device 3 includes a holding table 31 having a suction surface made of a porous ceramic material. The wafer W is held on the holding table 31 via the rigid support member S by adsorbing the rear surface S2 of the rigid support member S to the holding table 31. Above the holding table 31, a pressing portion 32 that presses the back surface W2 of the wafer W is provided so as to be movable up and down.

  When the pressing portion 32 is lowered and a downward force is applied to the wafer W, the surface W1 of the wafer W is pressed against the adhesive layer A2, and the wafer W is adhered to the double-sided adhesive tape DT. The pressing force by the pressing unit 32 is adjusted so that an adhesive force necessary to support the wafer W can be obtained. Thus, by sticking the wafer W to the rigid support member S using the double-sided pressure-sensitive adhesive tape DT, it is not necessary to heat the wafer W when sticking, and work efficiency can be improved. Further, as described above, the wafer W is placed on the double-sided pressure-sensitive adhesive tape DT so as to be tilted toward the pressure-sensitive adhesive layer A2, and then pressed to prevent entry of bubbles and the like, thereby preventing the wafer W and the double-sided pressure-sensitive adhesive tape. Adhesiveness with DT can be improved and adhesive force can be improved. In the present embodiment, the entire back surface W2 of the wafer W is pressed by the pressing unit 32 of the pressing device 3, but the second attaching step is not limited to this. You may press with a roller like a 1st sticking process.

  As described above, since the surface S1 of the rigid support member S is rougher than the surface W1 of the wafer W, the contact area between the rigid support member S and the adhesive layer A1 is larger than the contact area between the wafer W and the adhesive layer A2. Become wider. Thereby, the double-sided pressure-sensitive adhesive tape DT is firmly bonded to the rigid support member S side, and the rigid support member S and the double-sided pressure-sensitive adhesive tape DT can be easily peeled in the subsequent removal step. The surface roughness of the rigid support member S can be adjusted by, for example, sand blasting or rough grinding.

  A grinding process is implemented after a 2nd sticking process. FIG. 4 is a diagram illustrating how the wafer W is ground in the grinding process. In the grinding process, as shown in FIG. 4, the back surface W <b> 2 side of the wafer W is ground by the grinding device 4. The grinding device 4 includes a holding table 41 having a suction surface made of a porous ceramic material. A rotation mechanism (not shown) is provided below the holding table 41, and the holding table 41 is rotated around the rotation axis C1. The wafer W is held on the holding table 41 via the rigid support member S.

  A grinding wheel 42 is provided above the holding table 41 so as to be movable up and down. The grinding wheel 42 is connected to a rotation mechanism (not shown) and is rotated around the rotation axis C2. A grinding wheel 43 is disposed below the grinding wheel 42. By rotating the holding table 41 and the grinding wheel 42 in a state where the grinding wheel 43 is in contact with the back surface W2 of the wafer W, the back surface W2 side of the wafer W is ground. The grinding wheel 42 is rotated at a higher speed than the holding table 41.

  A height gauge (not shown) is provided in the vicinity of the holding table 41 so that the thickness of the wafer W can be measured. By grinding while measuring the thickness of the wafer W with this height gauge, the wafer W is thinned to the finished thickness t. In the processing method of the present embodiment, the wafer W is supported by the rigid support member S via the double-sided adhesive tape DT. The rigid support member S has high rigidity capable of appropriately holding the wafer W. The double-sided pressure-sensitive adhesive tape DT uses a base material sheet B made of PET that is not easily deformed compared to a liquid resin or the like. For this reason, by supporting the wafer W on the rigid support member S via the double-sided adhesive tape DT, the fixing force of the wafer W is increased, and warpage of the wafer W and chipping of the outer peripheral portion in the grinding process can be suppressed.

  After the grinding process, an adhesive layer curing process is performed. FIG. 5 is a diagram illustrating how the adhesive layers A1 and A2 are cured in the adhesive layer curing step. In the adhesive layer curing step, as shown in FIG. 5, the ultraviolet ray irradiation device 5 irradiates the adhesive layers A 1 and A 2 of the double-sided adhesive tape DT with ultraviolet (ultraviolet light) UV. The ultraviolet irradiation device 5 includes a holding table 51 that holds the rigid support member S and an ultraviolet light source 52 below the holding table 51. The holding table 51 is made of a material such as glass that transmits ultraviolet rays UV from the ultraviolet ray source 52. For this reason, the ultraviolet light UV from the ultraviolet light source 52 passes through the holding table 51 and is irradiated to the back surface S 2 side of the rigid support member S held by the holding table 51.

  The rigid support member S is made of a glass substrate that transmits ultraviolet light UV having a predetermined wavelength. Moreover, the base material sheet B of the double-sided pressure-sensitive adhesive tape DT is made of PET that transmits ultraviolet rays UV having a predetermined wavelength. For this reason, the ultraviolet ray UV irradiated to the back surface S2 side of the rigid support member S passes through the rigid support member S and the base sheet B and reaches the adhesive layers A1 and A2. The adhesive layers A1 and A2 irradiated with ultraviolet rays UV are cured by a chemical reaction, and the adhesive force is reduced. In addition, before or after the adhesive layer curing step, the protective tape T stretched on the annular frame F is attached to the back surface W2 of the wafer W (see FIG. 6).

  A removal process is implemented after the adhesion layer hardening process. FIG. 6 is a diagram showing how the rigid support member S and the double-sided adhesive tape DT are removed from the wafer W in the removing step. In the removal step, the back surface W2 side of the wafer W is held by the holding table 61 and the rigid support member S is pulled upward. Since the adhesive strength of the adhesive layer A2 is reduced by the adhesive layer curing step, the rigid support member S and the double-sided adhesive tape DT are both peeled from the wafer W. Although the adhesive strength of the adhesive layer A1 is also reduced by the adhesive layer curing step, the rigid support member S and the double-sided adhesive tape DT are peeled together because the double-sided adhesive tape DT is firmly bonded to the rigid support member S side. Is done. In addition, since there is no need for heating in the removing step, the removing step can be performed in a state where the protective tape T is adhered to the back surface W2 of the wafer W.

  Thus, by reducing the adhesive strength of the double-sided pressure-sensitive adhesive tape DT with ultraviolet UV, there is no need for heating when the double-sided pressure-sensitive adhesive tape DT and the rigid support member S are peeled off. The work efficiency concerning peeling can be improved. Moreover, since the adhesive force of the double-sided pressure-sensitive adhesive tape DT is reduced by ultraviolet UV, the double-sided pressure-sensitive adhesive tape DT and the support member S can be peeled without damaging the wafer W. The removal process is performed by, for example, a peeling device (not shown), but may be performed manually by an operator. Moreover, if the rigid support member S after peeling is reused, the cost for processing the wafer W can be suppressed.

  As described above, according to the wafer processing method according to the present embodiment, since the wafer W is adhered to the rigid support member S using the double-sided adhesive tape DT, the work efficiency relating to the adhesion of the wafer W is increased. be able to. Further, since the adhesive force is reduced by irradiating the adhesive layer A2 of the double-sided pressure-sensitive adhesive tape DT with ultraviolet rays UV, the working efficiency relating to the peeling of the double-sided pressure-sensitive adhesive tape DT and the rigid support member S is improved, and both sides of the wafer W are not damaged. The adhesive tape DT and the rigid support member S can be peeled off.

  In addition, this invention is not limited to description of the said embodiment, A various change can be implemented. For example, when an orientation flat (orientation flat) indicating a crystal orientation is formed on the wafer W, the wafer placement process can be performed with reference to the orientation flat. FIG. 7 is a diagram showing a wafer placing process when the orientation flat OF is formed on the wafer W.

  Also in this case, the rigid support member S is arranged on the holding table 11 so that the adhesive layer A2 of the double-sided adhesive tape DT faces upward (see FIG. 2). Further, the adhesive layer A2 and the surface W1 of the wafer W are aligned so as to face each other, and a part of the outer periphery of the wafer W is held above the holding table 11. Here, as shown in FIG. 7, a part (end W3a) of the wafer W located on the opposite side of the orientation flat OF across the center is held upward. Then, the orientation flat OF is brought into contact with a part of the outer periphery (end portion DT1a) of the double-sided adhesive tape DT from above.

  Thereafter, when the holding of the end W3a is released, the wafer W is rotated by gravity with the orientation flat OF as a fulcrum (arrow a3 in FIG. 7) and placed on the double-sided adhesive tape DT. That is, the end portion W3a of the wafer W is tilted toward another part (end portion DT2a) of the double-sided adhesive tape DT located on the opposite side of the end portion DT1a across the center. In this way, by placing the wafer W so that the end W3a side is directed upward toward the adhesive layer A2, air bubbles and the like are not mixed between the wafer W and the adhesive layer A2. The adhesion between the wafer W and the double-sided pressure-sensitive adhesive tape DT can be improved. Moreover, since the direction in which the wafer W falls is determined based on the shape of the orientation flat OF, the wafer W and the double-sided adhesive tape DT can be easily aligned.

  In addition, although the case where a silicon wafer is used as a processing target is shown in the above embodiment, the processing target is not limited to this. For example, various semiconductor substrates such as a gallium arsenide (GaAs) substrate, silicon carbide (SiC) substrate, and gallium nitride (GaN) substrate, various insulator substrates such as a ceramic substrate, a glass substrate, and a sapphire substrate may be used as a processing target. good.

  Moreover, in the said embodiment, although the case where a glass substrate is used as a rigid support member is shown, a rigid support member is not restricted to this. A rigid support member of any material may be used as long as it has high supportability in the grinding process. For example, a rigid support member made of aluminum, stainless steel, copper, sapphire, silicon, or the like may be used. Further, the shape of the rigid support member is not limited to the disc shape, and may be an arbitrary shape.

  In the adhesive layer curing step, the adhesive layer is irradiated with ultraviolet rays, so that at least one of the rigid support member and the wafer needs to transmit ultraviolet rays. For example, when the wafer to be processed does not transmit ultraviolet light, the rigid support member needs to transmit ultraviolet light. In this case, ultraviolet rays are irradiated from the rigid support member side. When the rigid support member does not transmit ultraviolet light, the wafer to be processed needs to transmit ultraviolet light. In this case, ultraviolet rays are irradiated from the wafer side.

  Moreover, in the said embodiment, although holding | maintenance of a wafer is cancelled | released in a wafer mounting process and it is made to tilt a wafer toward an adhesion layer, a wafer mounting process is not restricted to this. In the wafer mounting process, at least a part of the outer periphery of the wafer may be brought into contact with the double-sided adhesive tape, and then a part on the opposite side with the center interposed therebetween may be brought into contact with the double-sided adhesive tape. For example, the wafer may be placed so as to gradually lower the end W3 side shown in FIG.

  Moreover, in the said embodiment, although PET is used as a base material sheet of a double-sided adhesive tape, a base material sheet may be comprised with another material. Any material can be used for the base sheet as long as it can transmit ultraviolet rays in the adhesive layer curing step and is not easily deformed compared to a liquid resin or the like.

  Moreover, in the said embodiment, although the surface of the rigid support member is made rougher than the surface of a wafer, the surface of a rigid support member may be smooth. If the double-sided pressure-sensitive adhesive tape cannot be removed by the above-described removal step, a step of removing the double-sided pressure-sensitive adhesive tape after the rigid support substrate is removed may be added.

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

  The present invention is useful when a wafer or the like is ground and processed to a predetermined thickness.

DESCRIPTION OF SYMBOLS 1 Adhesion apparatus 3 Press apparatus 4 Grinding apparatus 5 Ultraviolet irradiation apparatus 11 Holding table 12 Roller 21 Holding table 31 Holding table 32 Press part 41 Holding table 42 Grinding wheel 43 Grinding wheel 51 Holding table 52 Ultraviolet source 61 Holding table A1, A2 Adhesive Layer B Base sheet DT Double-sided adhesive tape DT1, DT2, DT1a, DT2a, W3, W4, W3a Edge F Frame OF Orientation flat (Orientation flat)
S support member S1, W1 surface S2, W2 back surface T protective tape UV UV W wafer a1, a2, a3 arrow t finish thickness

Claims (2)

A wafer processing method for grinding and thinning the back surface of a wafer,
A first adhering step of adhering one adhesive layer of a double-sided adhesive tape in which an adhesive layer made of an ultraviolet curable adhesive is formed on both surfaces of a base sheet to a rigid support member;
After carrying out the first sticking step, the other adhesive layer of the double-sided tape is exposed on the upper surface, the rigid support member is held on a holding table, and the wafer surface is opposed to the other adhesive layer. One end of the outer diameter direction of the wafer is brought into contact with one end side of the adhesive layer of the double-sided pressure-sensitive adhesive tape and the other end in the outer diameter direction of the wafer faces upward. A wafer placing step of placing the entire surface of the wafer on the adhesive layer by tilting toward the other end side in the outer diameter direction of the other adhesive layer of the double-sided adhesive tape;
A second adhering step of pressing the wafer from the wafer side and adhering the wafer to the other adhesive layer of the double-sided tape affixed to the rigid support member;
After carrying out the second sticking step, holding the rigid support member on a holding table, grinding the back surface of the wafer and thinning it to a predetermined thickness;
The wafer or the rigid support member and the base sheet of the double-sided adhesive tape are formed of a material that transmits ultraviolet rays, and after the grinding step, the adhesive layer of the double-sided tape is irradiated with ultraviolet rays. An adhesive layer curing step that cures and lowers the adhesive strength;
After performing the adhesive layer curing step, a removal step of peeling the rigid support member and the double-sided adhesive tape from the wafer;
A wafer processing method comprising:   When the orientation flat indicating the crystal orientation is formed on the wafer, the orientation flat is brought into contact with one end side in the outer diameter direction of the adhesive layer of the double-sided adhesive tape and the orientation flat of the wafer From the state in which the other end of the opposite side faces upward, the other end of the wafer opposite to the orientation flat is tilted toward the other end side in the outer diameter direction of the other adhesive layer of the double-sided adhesive tape, The wafer processing method according to claim 1.

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