JP2012033671A - Protective tape peeling method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a protective tape peeling tape capable of restraining cracks of wafer.SOLUTION: A method for peeling a protective tape 11 adhered on a surface of a wafer 10 from the wafer 10 includes a step for fixing the wafer 10 to a stage so that a face opposite to a face, to which the protective tape 11 is adhered, is in contact with the stage. Also, the method includes a step for adhering a peeling tape 40 having elasticity and a constant width to the surface of the protective tape 11. Also, the method includes a step for peeling the protective tape 11 from the wafer 10 by pulling the peeling tape 40 against the wafer 10. Then, in the step for peeling the protective tape 11, a direction for pulling the peeling tape 40 is within a range of ±15° from a direction vertical to a cleavage surface orthogonal to the surface of the wafer 10.

Description

  The present application relates to a method for peeling off a protective tape attached to a surface of a semiconductor wafer.

  One of the processes for manufacturing a semiconductor device includes a process for polishing and thinning the back surface of a semiconductor wafer having an element structure formed on the surface, and a process for forming a back diffusion layer. In order to protect the device structure during these steps, a protective tape is attached to the surface of the wafer. The protective tape adhered to the wafer surface needs to be peeled off from the wafer surface after the completion of these steps. In order to peel off the protective tape from the wafer, a protective tape removing device is used. For example, in the removing apparatus disclosed in Patent Document 1, a semiconductor wafer is sucked and fixed to a table. Then, the release tape is attached to the upper surface of the protective tape attached to the surface of the wafer, and the protective tape is peeled off from the wafer together with the release tape by pulling the release tape.

JP 2003-124146 A

  When peeling off the protective tape from the semiconductor wafer, if the force acting on the semiconductor wafer from the protective tape becomes larger than the force to fix the semiconductor wafer to the table, the semiconductor wafer floats upward from the table and the semiconductor wafer is folded in two. Work. Then, the semiconductor wafer may be broken.

  The technology of the present application has been developed to solve the above problems. That is, this application provides the technique which makes it difficult to break a semiconductor wafer when peeling off the protective tape stuck on the surface of the semiconductor wafer.

  In the method for peeling off the protective tape disclosed in the present application, in the method of peeling off the protective tape attached to the surface of the semiconductor wafer from the semiconductor wafer, the surface opposite to the surface on which the protective tape is attached is the stage. Protecting the semiconductor wafer by securing the semiconductor wafer to the stage so that it contacts the surface, attaching the release tape having elasticity and a certain width to the surface of the protective tape, and pulling the release tape against the semiconductor wafer And a step of peeling the tape from the semiconductor wafer. The direction in which the peeling tape is pulled in the step of peeling off the protective tape is within a range of ± 15 ° from the direction perpendicular to the cleavage plane perpendicular to the surface of the semiconductor wafer when the semiconductor wafer is viewed in plan. It is characterized by that.

  Various single crystals, which are materials for semiconductor wafers, have the property of cleaving. For example, silicon single crystals are known to cleave at {110} and {111} planes where the atomic force is weak. Therefore, in a semiconductor wafer, cracks are likely to progress on a cleavage plane perpendicular to the surface of the semiconductor wafer.

  When the release tape is pulled with respect to the semiconductor wafer, a force for pulling the release tape acts on the protective tape via the release tape. When the force acting on the protective tape is transmitted to the semiconductor wafer, the protective tape is peeled off from the surface of the semiconductor wafer. When the force transmitted to the semiconductor wafer becomes larger than the force for fixing the semiconductor wafer to the stage, the semiconductor wafer floats upward from the stage and acts to fold the semiconductor wafer in half around the folding line. The bending line is generated in a direction perpendicular to the in-plane direction of the force transmitted to the semiconductor wafer. When the direction of the fold line coincides with the direction in which the cleavage of the cleavage plane progresses, the semiconductor wafer is easily cracked. From the above, when the direction in the wafer surface of the force transmitted to the semiconductor wafer is perpendicular to the cleavage plane perpendicular to the surface of the semiconductor wafer, the direction of the fold line and the direction in which cracking at the cleavage interface progresses are the same. It turns out that the semiconductor wafer is easily broken.

  In the present application, since the release tape has elasticity, the release tape extends when pulled. When the release tape is extended, an action of reducing the width of the release tape occurs. Due to this influence, the direction of the force acting on the protective tape via the release tape is shifted in the direction toward the center line of the release tape with respect to the direction of pulling the release tape. Then, the wafer in-plane direction of the force transmitted from the protective tape to the semiconductor wafer is also shifted in the direction toward the center line of the peeling tape with respect to the direction in which the peeling tape is pulled. In the present application, the direction in which the peeling tape is pulled is within a range of ± 15 ° from the direction perpendicular to the cleavage plane perpendicular to the surface of the semiconductor wafer when the semiconductor wafer is viewed in plan. Therefore, the probability that the direction in the wafer surface of the force transmitted to the semiconductor wafer deviates from the orthogonal direction with respect to the cleavage plane perpendicular to the surface of the semiconductor wafer. That is, there is a high probability that the direction of the fold line generated by the force transmitted to the semiconductor wafer deviates from the direction in which the crack at the cleavage interface progresses. As described above, since the in-plane direction of the force transmitted to the semiconductor wafer can be made difficult to be orthogonal to the cleavage plane perpendicular to the surface of the semiconductor wafer, the semiconductor wafer can be made difficult to break.

  In the method for peeling off the protective tape disclosed in the present application, the semiconductor wafer is a silicon single crystal and the plane orientation is the {100} plane. In the step of peeling off the protective tape, the crystal orientation of the semiconductor wafer is < It is preferable to pull the release tape in the 011> direction. In a silicon wafer having a {100} plane, the cleavage of the cleavage plane perpendicular to the surface of the semiconductor wafer progresses in the <011> direction of the crystal orientation. Since the <011> direction is a generic name for equivalent directions, it includes two directions on the wafer surface. Therefore, there are two directions of crack propagation on the cleavage plane perpendicular to the surface of the semiconductor wafer. In addition, the propagation directions of the cracks on the two cleaved surfaces are orthogonal to each other. Therefore, by pulling the release tape in the <011> direction, the release tape is pulled in the direction of crack propagation on one cleavage surface, and at the same time, the release tape is pulled in a direction perpendicular to the direction of crack propagation on the other cleavage surface. become. Thereby, the direction which pulls a peeling tape can be made into the direction perpendicular | vertical with respect to the cleavage plane perpendicular | vertical to the surface of a semiconductor wafer.

  Further, in the method for peeling off the protective tape disclosed in the present application, in the step of attaching the peeling tape to the surface of the protective tape, the peeling tape crosses the semiconductor wafer and the longitudinal direction of the peeling tape is perpendicular to the surface of the semiconductor wafer. In the step of attaching the protective tape so as to be perpendicular to the surface and peeling off the protective tape, it is preferable to pull in the longitudinal direction of the peeling tape. Thereby, the direction which pulls a peeling tape can be determined with the direction which affixes a peeling tape. Therefore, the direction in which the peeling tape is pulled can be determined with high accuracy.

  In the method for peeling off the protective tape disclosed in the present application, in the step of peeling off the protective tape, the notch position of the semiconductor wafer is detected, and the cleavage plane perpendicular to the surface of the semiconductor wafer is determined based on the detected notch position. It is preferable. The notch position is formed so as to be located in a predetermined specific crystal orientation with respect to the plane orientation of the surface of the semiconductor wafer. Therefore, if the crystal orientation of the notch is known, it becomes possible to specify the cleavage plane on the semiconductor wafer with reference to the notch position.

  According to the protective tape peeling method disclosed in the present application, it is possible to suppress cracking of the wafer.

It is a top view of a wafer. It is a schematic block diagram of a protective tape peeling apparatus. It is a conceptual diagram which shows the crystal orientation of a wafer. It is a figure (the 1) which shows a cleavage plane. It is a figure (the 2) which shows a cleavage plane. It is a figure which shows the state by which the peeling tape was stuck on the protective tape. It is a figure which shows the state of the peeling start of a protective tape. It is VIII-VIII sectional drawing of FIG. It is a figure (the 1) which shows the relationship between the crack propagation direction and cleavage line of a cleavage plane. It is a figure (the 2) which shows the relationship between the crack propagation direction and cleavage line of a cleavage plane. It is a conceptual diagram which shows the crystal orientation of SiC. It is a conceptual diagram which shows the crystal orientation of a wafer.

The main features of the embodiments described below are listed.
(Characteristic 1) The semiconductor wafer is a silicon single crystal and has a {100} plane orientation, and in the step of peeling the protective tape, the peeling tape is pulled in the <011> direction of the crystal orientation of the semiconductor wafer.
(Feature 2) The semiconductor wafer is 4H polytype SiC and the plane orientation is {0001} plane, and in the step of peeling the protective tape, <110> or <1-10 of the crystal orientation of the semiconductor wafer Pull the release tape in the> direction.

  Embodiment 1 will be described below with reference to FIGS. FIG. 1 is a plan view of a wafer 10 to which the protective tape peeling method according to the present application is applied. A circuit pattern is formed on the surface of the wafer 10 and a protective tape 11 is attached. Moreover, the wafer 10 is thinned by polishing the back surface of the wafer 10. The wafer 10 has a notch 12 representing a predetermined crystal orientation.

  In FIG. 2, the schematic block diagram of the protective tape peeling apparatus 30 is shown. The protective tape peeling device 30 is a device for peeling the protective tape 11 adhered to the wafer 10. The protective tape peeling device 30 includes a base 31, a stage 32, a peeling tape supply unit 33, a guide roller 34, a guide unit 35, a peeling tape winding unit 36, and a cylindrical shaft 37.

  A number of vacuum holes (not shown) are formed on the surface of the stage 32. The wafer 10 is fixed on the stage 32 by adsorbing the back side of the wafer 10 placed on the stage 32 through the vacuum hole. The stage 32 is attached to the base 31 via a cylindrical shaft 37. A motor (not shown) is attached to the cylindrical shaft 37. The stage 32 is rotationally driven by a motor around a rotation axis that passes through the center of the wafer 10 and is perpendicular to the surface of the wafer 10.

  An optical sensor 38 is disposed above the stage 32. The optical sensor 38 includes a camera (not shown) that images the wafer 10 placed on the stage 32. The optical sensor 38 detects the position of the notch 12 of the mounted wafer 10. By detecting the position of the notch 12 by the optical sensor 38, the stage 32 can be rotated so that the notch 12 has a predetermined orientation.

  The guide roller 34 guides the peeling tape 40. The guide roller 34 is configured to be able to roll on the wafer 10 in the range from the position P1 to the position P2.

  The release tape supply unit 33 holds the release tape 40 in a wound state. The release tape 40 has elasticity and has a property of extending when pulled. Moreover, the peeling tape 40 has a certain width. The release tape 40 is taken up by the release tape winding unit 36 via the guide roller 34 and the guide unit 35. The peeling tape 40 has an adhesive surface on the side facing the stage 32 (S1 side in FIG. 2). The adhesive strength of the peeling tape 40 to the protective tape 11 is higher than the adhesive strength of the protective tape 11 to the wafer 10.

  The cleavage plane of the wafer 10 will be described with reference to FIGS. As an example, a case where the wafer 10 is a silicon single crystal and the plane orientation is the (100) plane will be described. A case where the notch orientation is [0-11] will be described. FIG. 3 is a conceptual diagram showing the crystal orientation of the wafer 10 whose plane orientation is the (100) plane. When the notch orientation of the wafer 10 is [0-11], the position of the notch 12 is the position shown in FIG.

  In the wafer 10, wafer cracking is likely to progress along the cleavage plane. In addition, it is known that a silicon single crystal wafer is cleaved at {110} plane and {111} plane where atomic force is weak. Here, parentheses {} indicate equivalent directions together. Therefore, the {110} plane is (110), (101), (011), (-110), (-101), (0-11), (1-10), (10-1), (01- 1), (-1-10), (-10-1), and (0-1-1) equivalent planes.

  Here, attention is focused on a cleavage plane perpendicular to the surface of the wafer 10. In the wafer 10, since the plane orientation is the (100) plane, the cleavage plane perpendicular to the wafer 10 surface is the first cleavage plane CP1 ((011) plane) in the basic unit cell shown in FIG. Two examples are the second cleavage plane CP2 ((0-11) plane) in the basic unit cell. Then, as shown in FIG. 3, on the surface of the wafer 10, the first cleavage plane CP <b> 1 progresses in the first progress direction C <b> 1 ([0-11] direction of crystal orientation). The second cleavage plane CP2 extends in the second progress direction C2 (the [011] direction of the crystal orientation). The first cleavage surface CP1 and the second cleavage surface CP2 are orthogonal to each other. Note that the [0-11] direction and the [011] direction of the crystal orientation can also be collectively referred to as the <011> direction.

  Next, the operation of the protective tape peeling device 30 will be described. First, the process of fixing the wafer 10 to the stage 32 will be described. The wafer 10 to which the protective tape 11 is attached is placed on the stage 32 manually or by an automatic transfer device. The surface opposite to the surface on which the protective tape 11 is adhered is placed so as to contact the stage 32. Next, the wafer 10 is fixed to the stage 32 by suction. The motor 32 is driven to rotate the stage 32, and the optical sensor 38 detects the notch 12. When the notch 12 is detected, the rotation angle of the wafer 10 is determined by rotating the stage 32 with reference to the position of the notch 12. Details of the method for determining the rotation angle will be described later.

  Next, the process of sticking the peeling tape 40 on the surface of the protective tape 11 will be described. The peeling tape 40 is pulled out from the peeling tape supply unit 33 by the guide roller 34. And the peeling tape 40 is stuck on the surface of the protective tape 11 because the guide roller 34 moves from the position P1 to the position P2. FIG. 6 shows a diagram in which the state where the peeling tape 40 is adhered to the protective tape 11 is observed in the direction of the arrow Y2 in FIG. As shown in FIG. 6, the release tape 40 is stuck across the wafer 10.

  Here, how to determine the rotation angle of the wafer 10 when the release tape 40 is attached to the protective tape 11 will be described. Since the release tape 40 is wound up by the release tape winding portion 36, the pulling direction D1 coincides with the longitudinal direction D2. Therefore, the pulling direction D1 of the peeling tape 40 can be determined by the longitudinal direction D2 when the peeling tape 40 is applied.

  In this embodiment, a case will be described in which the longitudinal direction D2 is determined so that the pulling direction D1 is within a range of ± 15 ° from the direction perpendicular to the second cleavage plane CP2. Here, if the position of the notch 12 is determined, the second cleavage plane CP2 is determined using the crystal orientation relationship of FIG. Therefore, as shown in FIG. 6, by rotating the wafer 10 so that the notch direction [0-11] and the longitudinal direction D2 coincide with each other, the tensile direction D1 can be made perpendicular to the second cleavage plane CP2. it can.

  The rotation angle of the wafer 10 is not limited to the angle shown in FIG. Even in the case of 180 ° rotation from the state of FIG. 6, the pulling direction D1 can be made perpendicular to the second cleavage plane CP2. Further, when rotated 90 ° or 270 ° from the state of FIG. 6, the pulling direction D1 can be made perpendicular to the first cleavage plane CP1.

  Next, a process of peeling the protective tape 11 from the wafer 10 will be described. The release tape 40 is wound up by the release tape winding unit 36. At the same time, the guide roller 34 moves from the position P2 toward the position P1 according to the winding amount of the peeling tape 40. Thereby, the peeling tape 40 can be pulled in the pulling direction D1 shown in FIG. Therefore, the protective tape 11 can be peeled from the wafer 10.

  The effect | action which a crack generate | occur | produces in the wafer 10 at the time of peeling of the protective tape 11 is demonstrated. First, the direction of the force transmitted to the wafer 10 will be described. FIG. 7 shows a partially enlarged view of the state in which the protective tape 11 starts to peel in the direction of the arrow Y1 in FIG. FIG. 8 shows a sectional view taken along line VIII-VIII in FIG. In FIG. 7, the peeling line L1 is indicated by a bold line. The peeling line L1 is a boundary line between a portion where the protective tape 11 is adhered to the surface of the wafer 10 and a portion where the protective tape 11 is not adhered. In the peeling line L1, the point P11a that is the intersection of the end portion 40a of the peeling tape 40 and the peeling line L1, and the point P11b that is the intersection of the end portion 40b of the peeling tape 40 and the peeling line L1 are the center portion 40c of the peeling line L1. Rather than the center side of the wafer 10. And the peeling line L1 will be in the state which drew the arc so that it might swell to the outer peripheral side of the wafer 10. FIG. This is because, since the peeling tape 40 has elasticity, the protective tape 11 is pulled mainly by the end portions 40a and 40b of the peeling tape 40 due to the influence of the peeling tape 40 when it is pulled. Therefore, the protective tape 11 at the points P11a and P11b is peeled off before the central portion 40c. And the protection tape 11 of the center part 40c is peeled off so that it may be pulled by the point P11a and the point P11b by the elasticity of the peeling tape 40.

  Here, paying attention to the force transmitted from the protective tape 11 to the wafer 10, the transmission force F1a acting on the point P11a and the transmission force F1b acting on the point P11b are the main transmission forces. Further, the in-plane direction of the wafer 10 of the transmission force F1a is a direction perpendicular to the tangent to the peeling line L1 at the point P11a. Similarly, the in-plane direction of the wafer 10 of the transmission force F1b is a direction perpendicular to the tangent to the peeling line L1 at the point P11b. Therefore, as shown in FIG. 7, the in-plane direction of the wafer 10 of the transmission forces F1a and F1b is shifted toward the center line 40L of the peeling tape 40 with respect to the pulling direction D1 of the peeling tape 40. Further, as shown in FIG. 8, the direction of the transmission force F <b> 1 b in the VIII-VIII cross section is directed upward of the wafer 10.

  Further, when the release tape 40 is extended, an action of reducing the width W1 of the release tape 40 occurs. Due to this influence, the in-plane direction of the wafer 10 of the transmission forces F1a and F1b in FIG. 7 is further shifted in the direction toward the center line 40L of the peeling tape 40 with respect to the pulling direction D1 of the peeling tape 40.

  From the above, the in-plane direction of the wafer 10 of the transmission forces F1a and F1b is greatly inclined toward the center line 40L of the peeling tape 40 with respect to the pulling direction D1. In this embodiment, the directions of the transmission forces F1a and F1b are inclined by about 45 ° in the direction of the center line 40L of the peeling tape 40 with respect to the pulling direction D1.

  Next, the effect | action which a crack generate | occur | produces in the wafer 10 is demonstrated. When the transmission forces F1a and F1b transmitted to the wafer 10 are larger than the force for attracting the wafer 10 to the stage 32, the wafer 10 floats upward from the stage 32 as shown in a region R1 in FIG. Then, a fold line is formed at the boundary between the floated place and the adsorbed place, and the action of bending the wafer 10 in two folds works with this fold line as an axis. Further, the bending line is generated in a direction perpendicular to the transmission forces F1a and F1b in FIG.

  As a comparative example, the relationship between the crack propagation direction of the cleaved surface and the fold line in the wafer 10a with the notch orientation [001] will be described with reference to FIG. In the peeling method shown in FIG. 9, the pulling direction D1 of the peeling tape 40 is shifted by 45 ° from the vertical direction of the cleavage plane CP2, and is also shifted by 45 ° from the vertical direction of the cleavage plane CP1. Further, as described above, the transmission forces F1a and F1b are shifted in the direction toward the center line of the peeling tape 40 with respect to the pulling direction D1. A fold line BLa is formed in the direction perpendicular to the transmission force F1a, and a fold line BLb is formed in the direction perpendicular to the transmission force F1b. Then, the fold line BLa and the first progress direction C1 of the cleavage plane are close to being parallel. Further, the bend line BLb and the second progress direction C2 of the cleavage plane are close to parallel. Therefore, the wafer 10a is easily broken.

  The effect which can prevent a crack of a wafer with the peeling method of the protective tape 11 of this application is demonstrated. In the peeling method of the present application, the relationship between the crack propagation direction of the cleavage plane and the fold line when the wafer 10 having the notch orientation [0-11] is used will be described with reference to FIG. In the peeling method of the present application, the pulling direction D1 of the peeling tape 40 is a direction perpendicular to the cleavage plane CP2. Further, as described above, the transmission forces F1a and F1b are shifted in the direction toward the center line of the peeling tape 40 with respect to the pulling direction D1. Then, neither the first progress direction C1 nor the second progress direction C2 of the cleavage plane is close to the fold line BLa. In addition, both of the first progress direction C1 and the second progress direction C2 of the cleavage plane are not in parallel with the bending line BLb. Thereby, it is possible to make the wafer 10 difficult to break.

  In addition, when the wafer 10 is thinned by a mechanical method such as backside polishing, minute cracks called a crushed layer are formed on the ground surface or the outer peripheral edge of the wafer. If the crushed layer exists, the wafer 10 is easily broken starting from the crushed layer. Therefore, the process which removes a crushing layer from a grinding surface is performed by performing the etching by hydrofluoric acid or the etching by the gas plasma containing a fluorine. However, the crushing layer may remain at the outer peripheral end of the wafer 10 without removing the crushing layer. Further, the vacuum hole provided in the stage 32 is not arranged at a position near the outer peripheral end portion of the wafer 10 so that air leakage does not occur at the time of suction. As a result, the suction force at the outer peripheral edge of the wafer 10 is weakened, so that the wafer end is likely to float when the protective tape 11 at the outer peripheral edge of the wafer 10 is peeled off. As described above, the wafer 10 is likely to be cracked at the beginning of the peeling of the protective tape 11, which is a case where the protective tape 11 is peeled off from the outer peripheral edge of the wafer 10. Therefore, in order to prevent the generation | occurrence | production of the crack in the wafer 10 outer peripheral edge part, the peeling method of the protective tape 11 of this application exhibits an effect.

  An experimental example using the peeling method of the protective tape 11 of the present application will be described. The back surface of the silicon wafer having the semiconductor device formed on the front surface side was polished to 185 (μm). Thereafter, the crushed layer was removed by etching with hydrofluoric acid for 20 (μm), and the wafer thickness was reduced to 165 (μm). Then, under condition A and condition B, 960 wafers were peeled off from the protective tape, respectively.

  Condition A is a condition in which the pulling direction D1 is the same as the notch orientation in the wafer 10 whose notch orientation is [0-11] as shown in FIG. As shown in FIG. 10, under the condition A, the pulling direction D1 is perpendicular to the second cleavage plane CP2. That is, the condition A is a condition that makes it difficult to break the wafer because the crack propagation direction of the cleavage plane and the folding line can be made difficult to be parallel.

  On the other hand, as shown in FIG. 9, the condition B is a condition in which the pulling direction D1 is the same as the notch orientation in the wafer 10a having the notch orientation [001]. As shown in FIG. 9, under the condition B, the pulling direction D1 of the peeling tape 40 is shifted by 45 ° from the vertical direction of the cleavage planes CP1 and CP2. That is, the condition B is a condition in which the wafer is easily cracked because the crack propagation direction of the cleavage plane and the fold line approach parallel.

  As a result of the experiment, under condition A, the wafer 10 was not cracked (defective rate 0 (%)). On the other hand, under condition B, six cracks occurred on the wafer 10 (defective rate 0.6 (%)). All the broken wafers 10 were cracked at the cleavage plane. From the above, it can be seen that cracking of the wafer 10 can be effectively prevented by making the pulling direction D1 perpendicular to the cleavage plane.

  A second embodiment will be described with reference to FIGS. 11 and 12. Example 2 is a protective tape peeling method in the case of using a SiC (silicon carbide) wafer. SiC has a larger band gap, higher electron mobility, and higher breakdown voltage than Si. Therefore, it is used as a material for high-power, high-speed, high-temperature power devices. In addition, SiC has 3C, 4H, and 6H polytypes (crystal polymorphism: many crystal structures having different one-dimensional stacked structures). A 4H polytype is used for the power semiconductor.

  The cleavage plane of SiC wafer 10b will be described with reference to FIGS. As an example, a case where it is 4H polytype SiC and the plane orientation is the (0001) plane will be described. FIG. 11 is a conceptual diagram showing the crystal orientation of 4H polytype SiC. As shown in FIG. 11, 4H polytype SiC has a hexagonal lattice. A first cleavage plane CP1b ((11-20) plane) and a second cleavage plane CP2b ((1-100) plane) exist.

  FIG. 12 is a conceptual diagram showing the crystal orientation of the wafer 10b having a (0001) plane. The wafer 10b has a surface perpendicular to the c-axis. Also, as shown in FIG. 12, on the surface of the wafer 10b, the first cleavage plane CP1b advances in the first extension direction C1b ([1-10] direction of crystal orientation). The second cleavage plane CP2b extends in the second progress direction C2b (the [110] direction of the crystal orientation). The first cleavage plane CP1b and the second cleavage plane CP2b are orthogonal to each other.

  In order to prevent the wafer 10b from being cracked by the peeling method of the protective tape 11 of the present application, the pulling direction D1 of the peeling tape 40 may be set to a direction perpendicular to the cleavage plane CP1b or CP2b. . That is, in FIG. 12, the pulling direction D1 may be the [110] direction or the [1-10] direction. Thereby, as described above, the first progress direction C1b or the second progress direction C2b and the fold line can be made difficult to be parallel, and thus the wafer 10b can be made difficult to break.

  Specific examples of the present invention have been described in detail above, but these are merely examples and do not limit the scope of the claims. The technical elements described in this specification or the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technology illustrated in the present specification or the drawings can achieve a plurality of purposes at the same time, and has technical utility by achieving one of the purposes.

  Although the silicon wafer having the (100) plane orientation has been described in the first embodiment, the present invention is not limited to this mode. For example, the protective tape peeling method of the present application can be applied to a silicon wafer having a (111) plane or a (110) plane. In addition, the silicon wafer with the (100) plane orientation has the lowest SiO2-Si interface charge density of the device and the most stable compared to the silicon wafer with the (111) plane and (110) plane orientation. An interface state is obtained. Therefore, a silicon wafer having a (100) plane orientation is generally used in many cases.

  10: Wafer, 11: Protective tape, 30: Protective tape peeling device, 32: Stage, 40: Release tape, CP1 and CP2: Cleaved surface, D1: Pull direction

Claims (4)

In the method of peeling the protective tape attached to the surface of the semiconductor wafer from the semiconductor wafer,
Fixing the semiconductor wafer to the stage so that the surface opposite to the surface on which the protective tape is adhered contacts the stage;
A step of attaching an elastic release tape having a certain width to the surface of the protective tape;
And a step of peeling the protective tape from the semiconductor wafer by pulling the peeling tape on the semiconductor wafer,
The direction in which the peeling tape is pulled in the process of peeling off the protective tape is within ± 15 ° from the direction perpendicular to the cleavage plane perpendicular to the surface of the semiconductor wafer when the semiconductor wafer is viewed in plan. A method for peeling off a protective tape. The semiconductor wafer is a single crystal of silicon and has a {100} plane orientation.
The method for peeling a protective tape according to claim 1, wherein in the step of peeling the protective tape, the peeling tape is pulled in a <011> direction of the crystal orientation of the semiconductor wafer. In the step of attaching the release tape to the surface of the protective tape, the release tape crosses the semiconductor wafer and is attached so that the longitudinal direction of the release tape is perpendicular to the cleavage plane perpendicular to the surface of the semiconductor wafer.
The method for peeling off the protective tape according to claim 1 or 2, wherein in the step of peeling off the protective tape, the protective tape is pulled in a longitudinal direction.   4. The step of peeling off the protective tape detects a notch position of the semiconductor wafer, and determines a cleavage plane perpendicular to the surface of the semiconductor wafer based on the detected notch position. The method for peeling off the protective tape according to Item.

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