Method for manufacturing semiconductor device

Abstract

This method for manufacturing a semiconductor device is provided with: a step for preparing a semiconductor wafer having a crystal axis inclined with respect to a perpendicular line to a first surface; a step for forming a first crack in the semiconductor wafer, the first crack extending in the thickness direction of the semiconductor wafer along a first direction by pressing a pressing member against the first surface with a first load in the first direction along the inclination direction of the crystal axis; a step for forming a second crack in the semiconductor wafer, the second crack extending in the thickness direction of the semiconductor wafer along a second direction by pressing the pressing member against the first surface at a second load smaller than the first load in the second direction orthogonal to the first direction in the first surface; and a step for dividing the semiconductor wafer along the first crack and the second crack by pressing the dividing member against the semiconductor wafer along the first crack and the second crack from a second surface side located on the back side of the first surface. As a result, residual stress caused by the formation of cracks in the semiconductor wafer can be reduced.

Description

Technical Field

[0001] The technology disclosed in this specification relates to a method for manufacturing a semiconductor device. Background Art

[0002] In Patent Document 1, a technology for dividing a substrate by a scribe and break method is disclosed. In Patent Document 1, after forming a crack extending in the first direction on the substrate by pushing a pushing member against the surface of the substrate along the first direction, a crack extending in the second direction is formed on the substrate by pushing the pushing member against the surface of the substrate along the second direction intersecting the first direction. Then, the substrate is divided along the formed crack by pushing a dividing member.

[0003] In Patent Document 1, the load for pushing the pushing member against the surface of the substrate when forming the crack in the first direction is greater than the load for pushing the pushing member against the surface of the substrate when forming the crack in the second direction. Thereby, it is possible to suppress a defective condition (such as chipping) of the substrate near the intersection of the crack in the first direction and the crack in the second direction.

[0004] Prior Art Documents

[0005] Patent Documents

[0006] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2009 - 6715 Summary of the Invention

[0007] In recent years, there has been a case where a scribe and break method is used to divide a semiconductor wafer. There is a case where the crystal axis of the semiconductor wafer is inclined with respect to the perpendicular line to the surface. Cracks are likely to be formed inside the semiconductor wafer along the crystal axis in the thickness direction of the semiconductor wafer. When a crack is formed in a direction intersecting the inclination direction of the crystal axis, the formation direction of the crack in the thickness direction of the semiconductor wafer (the direction inclined with respect to the perpendicular line) is inclined with respect to the pushing direction of the pushing member against the surface of the semiconductor wafer (the direction along the perpendicular line), so stress is generated inside the semiconductor wafer. That is, depending on the direction in which the crack is formed, the magnitude of the stress generated inside the semiconductor wafer is different. As a result, after the semiconductor wafer is divided, this stress also exists as residual stress, and the characteristics of the manufactured semiconductor device deteriorate. In this specification, a technology for reducing the residual stress caused by the formation of cracks in the semiconductor wafer is proposed.

[0008] According to the first aspect of the manufacturing method of the semiconductor device disclosed in this specification, it includes: a process of preparing a semiconductor wafer with a crystal axis inclined with respect to the perpendicular line of the first surface; a process of forming a first crack extending in the thickness direction of the semiconductor wafer along the first direction by pressing a pressing member against the first surface with a first load along the first direction in the first surface, where the first direction is along the inclination direction of the crystal axis; a process of forming a second crack extending in the thickness direction of the semiconductor wafer along the second direction by pressing the pressing member against the first surface with a second load smaller than the first load along a second direction orthogonal to the first direction in the first surface; and a process of dividing the semiconductor wafer along the first crack and the second crack by pressing a dividing member against the semiconductor wafer from the second surface side located on the back side of the first surface. Additionally, either the first crack forming process or the second crack forming process can be implemented first.

[0009] In this manufacturing method, since the first direction is along the inclination direction of the crystal axis, if the first crack is formed along the first direction, the formation direction of the first crack in the thickness direction of the semiconductor wafer is substantially the same as the pressing direction of the pressing member. Therefore, the stress generated inside the semiconductor wafer due to the formation of the first crack is small. On the other hand, since the second direction is the direction orthogonal to the inclination direction of the crystal axis, if the second crack is formed along the second direction, the formation direction of the second crack in the thickness direction of the semiconductor wafer is inclined with respect to the pressing direction of the pressing member. Therefore, the stress generated inside the semiconductor wafer due to the formation of the second crack becomes large. However, in this manufacturing method, the second load of the pressing member when forming the second crack is smaller than the first load of the pressing member when forming the first crack. Therefore, when forming the second crack, the stress due to the difference between the formation direction of the second crack and the pressing direction of the pressing member decreases. As a result, the residual stress of the entire semiconductor device after dividing the semiconductor wafer decreases, and a semiconductor device with high reliability can be manufactured. Description of the Drawings

[0010] Figure 1 It is a top view of the semiconductor wafer.

[0011] Figure 2 It is a diagram for explaining the crystal structure of SiC.

[0012] Figure 3 It is a diagram for explaining the element structure forming process.

[0013] Figure 4 It is a diagram for explaining the support plate pasting process.

[0014] Figure 5 It is a diagram for explaining the crack formation process.

[0015] Figure 6 It is a scanning electron microscope image of a cross-section of a semiconductor wafer having cracks formed therein.

[0016] Figure 7 It is a diagram for explaining the metal film formation process.

[0017] Figure 8 It is a diagram for explaining the dicing tape pasting process.

[0018] Figure 9 It is a diagram for explaining the support plate peeling process.

[0019] Figure 10 It is a diagram for explaining the protective component covering process.

[0020] Figure 11 It is a diagram for explaining the dicing process.

[0021] Figure 12 It is a diagram for explaining the pickup process.

[0022] Figure 13 It is a drawing in which the residual stress of the semiconductor devices of the examples and comparative examples was measured from the first surface toward the second surface. Detailed Description

[0023] In the manufacturing method of an example disclosed in this specification, it may also be that, before the above-described process of forming the above-described first crack and the above-described process of forming the above-described second crack, there is a process of forming a plurality of the above-described element structures in a matrix arrangement on the above-described second surface of the above-described semiconductor wafer, and it may also be that, in the above-described process of forming the above-described first crack and the above-described process of forming the above-described second crack, the above-described first crack and the above-described second crack are formed along the boundaries of the above-described element structures.

[0024] When forming a crack, stress is likely to be generated near the surface against which the pressing member is pressed. According to the above structure, the pressing member is pressed from the first surface side located on the back side thereof instead of from the second surface side where the element structure is provided. Therefore, even if there is residual stress near the first surface, the influence on the element structure for realizing the functions of the semiconductor device can be reduced.

[0025] In the manufacturing method of an example disclosed in this specification, it may also be that, after the above-described process of forming the above-described first crack and the above-described process of forming the above-described second crack and before the above-described process of dicing the above-described semiconductor wafer, there is a process of forming a metal film on the above-described first surface.

[0026] Under such a structure, the metal film formed on the first surface can function as an electrode of the semiconductor device.

[0027] In the manufacturing method of an example disclosed in this specification, the above semiconductor wafer may be made of SiC. In addition, the above crystal axis may be the c-axis.

[0028] (Example)

[0029] The manufacturing method of the example will be described with reference to the accompanying drawings. Figure 1 Fig. shows a plan view of a semiconductor wafer 2 used in the manufacture of a semiconductor device. The semiconductor wafer 2 has a disc shape. On the outer peripheral surface of the semiconductor wafer 2, an orientation flat 2f is provided. In the semiconductor wafer 2, a plurality of element regions 3 are arranged in a matrix. In Figure 1 each, the respective element regions 3 are schematically shown by solid lines. The element region 3 is a region where element structures such as transistors and diodes are formed. For the sake of convenience of explanation, the line that is the boundary between adjacent element regions 3 and will be the line for dividing the semiconductor wafer 2 into individual element regions 3 later is called the division predetermined line 4. The division predetermined line 4 is not an actual line marked on the semiconductor wafer 2 but an imaginary line. The division predetermined line 4 may also be a line or groove that can be visually actually drawn on the semiconductor wafer 2. The semiconductor wafer is made of SiC. In addition, the semiconductor wafer 2 may also be made of other semiconductor materials such as Si and GaN. As Figure 3 shown, the semiconductor wafer 2 has a first surface 2a and a second surface 2b located on the back side of the first surface 2a.

[0030] The semiconductor wafer 2 has Figure 2 the crystal structure of a hexagonal crystal as shown. As Figure 2 shown, the semiconductor wafer 2 has a plurality of crystal planes. Although not shown, the plane parallel to the Figure 2 paper surface of is the (0001) plane. In this embodiment, as Figure 1 shown, the crystal axis A (i.e., the c-axis) of SiC is inclined by about 4° in the x direction with respect to the Figure 1 z direction (i.e., the perpendicular line V erected on the second surface 2b of the semiconductor wafer 2) as shown. The crystal axis A is not inclined in the y direction with respect to the perpendicular line V. That is, the crystal axis A is inclined in the xz plane with respect to the perpendicular line V. In other words, in this embodiment, the (0001) plane (i.e., the c-plane) is inclined by about 4° in the x direction with respect to the second surface 2b of the semiconductor wafer 2, the (1 - 100) plane is a plane parallel to the orientation flat 2f, and the (11 - 20) plane is inclined by about 4° in the x direction with respect to the plane perpendicular to the orientation flat 2f.

[0031] The manufacturing method of the embodiment includes an element structure forming step, a support plate pasting step, a first crack forming step, a second crack forming step, a metal film forming step, a cutting tape pasting step, a support plate peeling step, a protective component covering step, and a dicing step.

[0032] (Element structure forming step)

[0033] In the element structure forming step, as Figure 3 shown, a plurality of element structures 6 are formed on the second surface 2b of the semiconductor wafer 2. The element structure 6 has at least one of an electrode, an insulating film, an n-type region, and a p-type region provided on the second surface 2b side. The element structure 6 includes, for example, structures such as trenches and gate electrodes for realizing the functions of a semiconductor device. In this step, for each element region 3, an element structure 6 is formed respectively. Thus, each element structure 6 is formed to be arranged in a matrix on the second surface 2b of the semiconductor wafer 2. In addition, in this step, the element structure 6 is formed, and structures (not shown) having the functions of transistors and diodes are formed inside the semiconductor wafer 2 in each element region 3. For example, when forming the structure of a MOSFET inside the semiconductor wafer 2, in the region exposed to the second surface 2b, a source region and a body region are formed separately for each element structure 6. On the other hand, in the region exposed to the first surface 2a, a drain region is formed over substantially the entire region of the first surface 2a. That is, the drain region is formed at a position exposed to the first surface 2a so as to straddle a plurality of element regions 3.

[0034] (Support plate pasting step)

[0035] In the support plate pasting step, as Figure 4 shown, a support plate 12 is pasted on the second surface 2b of the semiconductor wafer 2. The support plate 12 is pasted on the second surface 2b via an adhesive 11. The support plate 12 is made of, for example, glass. The adhesive 11 is, for example, a silicone-based adhesive and has, in addition to the function of bonding the semiconductor wafer 2 to the support plate 12, a function of protecting the element structure 6 formed on the second surface 2b of the semiconductor wafer 2. Thus, here, the adhesive 11 is coated so that the thickness of the adhesive 11 is thicker than the thickness of the element structure 6. Then, if necessary, the first surface 2a of the semiconductor wafer 2 is ground with a grinding stone to thin the semiconductor wafer 2. It should be noted that in Figure 4 and Figure 5 , the semiconductor wafer 2 is depicted with the first surface 2a facing upward.

[0036] (First crack forming step)

[0037] After thinning the semiconductor wafer 2, Figure 5The first crack formation process shown. In the first crack formation process, the scribing wheel 32 is pressed against the first surface 2a of the semiconductor wafer 2 adhered to the support plate 12, thereby forming a scribe line accompanied by a crack 5 inside the semiconductor wafer 2. The scribing wheel 32 is a disc-shaped (ring-shaped) member and is supported by a support device (not shown) on its axis. In this process, while pressing the scribing wheel 32 against the first surface 2a of the semiconductor wafer 2, it is moved (scanned) along each dicing predetermination line 4 extending in the Figure 1 x direction. When the scribing wheel 32 moves along the dicing predetermination line 4, it rotates without slipping on the first surface 2a of the semiconductor wafer 2 like a tire rotating on a road surface. Although the peripheral portion of the scribing wheel 32 is sharp, it does not cut the semiconductor wafer 2, but is only pressed against the first surface 2a. In the first crack formation process, the scribing wheel 32 is pressed against the first surface 2a with a load of about 2.0 N. When the first surface 2a is pressed by the scribing wheel 32, compressive stress is generated in the surface layer region of the first surface 2a inside the semiconductor wafer 2. A scribe line (i.e., a groove) is formed at the pressing portion of the scribing wheel 32. On the other hand, directly below the region where the compressive stress is generated, tensile stress is generated inside the semiconductor wafer 2. The tensile stress is generated in the direction away from the dicing predetermination line 4 along the first surface 2a of the semiconductor wafer 2 directly below the region where the compressive stress is generated. Through this tensile stress, a crack 5 extending in the x direction and in the thickness direction of the semiconductor wafer 2 is formed inside the semiconductor wafer 2. Here, by pressing the scribing wheel 32 against the first surface 2a and moving it along the dicing predetermination line 4 in the x direction, the crack 5 is formed along the boundary of the adjacent element regions 3 in the y direction and in the thickness direction of the semiconductor wafer 2. The crack 5 is formed near the surface layer of the first surface 2a of the semiconductor wafer 2. The scribing wheel 32 is an example of a "pressing member".

[0038] (Second crack formation process)

[0039] Next, the second crack formation process is implemented. In the second crack formation process, while pressing the scribing wheel 32 against the first surface 2a of the semiconductor wafer 2, it is moved (scanned) along each dicing predetermination line 4 extending in the Figure 1 y direction. This process is the same as the first crack formation process except that the direction in which the scribing wheel 32 is scanned and the load pressing the scribing wheel 32 against the first surface 2a are about 1.5 N.

[0040] Figure 6 is a scanning electron microscope image of the cross section of the semiconductor wafer 2 after the crack 5 is formed by the scribing wheel 32. Figure 6 (a) is a cross-sectional view of the y - z plane near the first surface 2a of the semiconductor wafer 2, Figure 6Figure (b) is a cross-sectional view of the x-z plane near the first surface 2a of the semiconductor wafer 2. As Figure 6 shown, it can be seen that by pressing the scribing wheel 32 against the dicing line 4, cracks 5a and 5b are formed along the boundary of the element region 3 inside the semiconductor wafer 2. In addition, the first surface 2a of the semiconductor wafer 2 is observed to be slightly indented due to the plastic deformation of the semiconductor wafer 2 caused by the scribing wheel 32. In addition, as Figure 6 shown in Figure (a), in the y-z cross-section, since the crystal axis A of SiC is not inclined with respect to the perpendicular V to the first surface 2a, the first crack 5a is formed to extend in a direction substantially consistent with the pressing direction of the scribing wheel 32 in the thickness direction of the semiconductor wafer 2. On the other hand, as Figure 6 shown in Figure (b), in the x-z cross-section, since the crystal axis A of SiC is inclined with respect to the perpendicular V to the first surface 2a, the second crack 5b is formed to extend in a direction inclined with respect to the pressing direction of the scribing wheel 32 in the thickness direction of the semiconductor wafer 2.

[0041] (Metal film forming process)

[0042] Next, the Figure 7 shown metal film forming process is carried out. In the metal film forming process, a metal film 8 is formed on the first surface 2a of the semiconductor wafer 2. The material constituting the metal film 8 is not particularly limited. For example, it is a multilayer film in which aluminum, nickel, and gold are laminated. The metal film 8 is formed so as to cover substantially the entire area of the first surface 2a. That is, the metal film 8 is formed on the first surface 2a so as to straddle a plurality of element regions 3. The metal film 8 functions as an electrode of the completed semiconductor device.

[0043] (Cutting tape pasting process)

[0044] Next, the Figure 8 shown cutting tape pasting process is carried out. In the cutting tape pasting process, a cutting tape 13 is pasted on the surface of the metal film 8. The cutting tape 13 is pasted so as to cover substantially the entire area of the metal film 8. The cutting tape 13 is fixed to a cutting frame (not shown). In addition, it should be noted that after Figure 8 , the semiconductor wafer 2 is depicted again with the second surface 2b facing up.

[0045] (Support plate peeling process)

[0046] Next, the Figure 9 shown support plate peeling process is carried out. In the support plate peeling process, the support plate 12 and the adhesive 11 are peeled from the second surface 2b of the semiconductor wafer 2. Here, for example, by dissolving the adhesive 11 with a solvent, the support plate 12 and the adhesive 11 are peeled together from the second surface 2b. Thus, the semiconductor wafer 2 is in a state supported by the cutting tape 13.

[0047] (Protective component covering process)

[0048] Next, implement Figure 10 In the protective component covering step, a protective component 15 is attached across the surface of each element structure 6 of each element region 3 of the semiconductor wafer 2, so that the second surface 2b of the semiconductor wafer 2 is covered with the protective component 15. The material of the protective component 15 is not particularly limited, and for example, a resin or the like can be used. By covering with the protective component 15, the second surface 2b of the semiconductor wafer 2 is protected in the subsequent dividing step or the like.

[0049] (Separation process)

[0050] Next, implement Figure 11 The dividing process shown. In the dividing process, the cutting blade 33 is pushed along the predetermined dividing line 4, and the semiconductor wafer 2 is divided along the predetermined dividing line 4 (along the boundary of the element area 3). Here, first, the semiconductor wafer 2 is placed on two support tables 34. The two support tables 34 are arranged with a gap. When the semiconductor wafer 2 is placed on the support tables 34, the semiconductor wafer 2 is placed in such a way that the gap is located below the position to be divided (the position to which the cutting blade 33 is pushed). Then, the cutting blade 33 is pushed from the second surface 2b side of the semiconductor wafer 2 through the protective component 15. The cutting blade 33 is a plate-shaped component, and the lower end (the edge pushed against the second surface 2b) part is ridge-shaped (sharp blade-shaped), but the semiconductor wafer 2 is not cut, but is only pushed.

[0051] Since there is no support table 34 below the cutting blade 33 (there is an interval between the two support tables 34), if the cutting blade 33 is pushed against the second surface 2b, the semiconductor wafer 2 flexes and enters the interval between the two support tables 34. Here, a crack 5 is formed on the first surface 2a side of the semiconductor wafer 2. Therefore, if the cutting blade 33 is pushed against the semiconductor wafer 2 from the second surface 2b side, the semiconductor wafer 2 flexes about the pushed portion (line) as an axis, and on the first surface 2a side, a force acts on the crack 5 in a direction to pull apart the two element regions 3 adjacent to the dividing position. In addition, as described above, a tensile stress is applied around the crack 5. Therefore, if the cutting blade 33 is pushed against the second surface 2b, the crack 5 extends in the thickness direction of the semiconductor wafer 2, and starting from the crack 5, the semiconductor wafer 2 cleaves along the crystal plane. Thus, the semiconductor wafer 2 is divided. In addition, since the metal film 8 is formed on the first surface 2a of the semiconductor wafer 2, a force also acts on the metal film 8 in a direction to pull apart the two element regions 3 adjacent to the dividing position, and the metal film 8 is pulled apart and deformed and thus divided. Alternatively, instead of the two support tables 34, the entire first surface 2a of the semiconductor wafer 2 can be supported by one elastic support plate (or supported by one or more support tables with one elastic support plate interposed therebetween). In this case, although the elastic support plate exists below the cutting blade 33, if the semiconductor wafer 2 flexes, the elastic support plate deforms corresponding to the flexure of the semiconductor wafer 2. Therefore, if the cutting blade 33 is pushed against the second surface 2b, the same as the case supported by the two support tables 34 (the case where there is no support table 34 below the cutting blade 33), a force acts on the crack 5 in a direction to pull apart the two element regions 3 adjacent to the dividing position. The cutting blade 33 is an example of a "dividing member".

[0052] In the dividing process, the process of pushing the above-mentioned cutting blade 33 against the second surface 2b is repeatedly performed along each dividing predetermined line 4. Thereby, the semiconductor wafer 2 and the metal film 8 can be divided along the boundaries of the respective element regions 3. Then, as Figure 12 shown, the singulated element regions 3 and the metal film 8 are peeled off from the cutting tape 13. Thereby, a plurality of semiconductor devices 10 having a metal film 8 (electrode) formed on the surface are completed.

[0053] As described above, according to the manufacturing method of the present embodiment, since the x direction is along the inclination direction of the crystal axis, if the first crack 5a is formed along the x direction, the formation direction of the first crack 5a in the thickness direction of the semiconductor wafer 2 (i.e., Figure 6 the direction in which the crystal axis A of (a) extends) and the pushing direction of the scribing wheel 32 (i.e., Figure 6is substantially the same as the direction in which the perpendicular line V of (a) extends. Therefore, the stress generated inside the semiconductor wafer 2 due to the formation of the first crack 5a is small. On the other hand, since the y-direction is the direction orthogonal to the inclination direction of the crystal axis, if the second crack 5b is formed along the y-direction, the formation direction of the second crack 5b in the thickness direction of the semiconductor wafer 2 (i.e., Figure 6 the direction in which the crystal axis A of (b) extends) is inclined with respect to the pressing direction of the scribe wheel 32 (i.e., Figure 6 the direction in which the perpendicular line V of (b) extends). Therefore, the stress generated inside the semiconductor wafer 2 due to the formation of the second crack 5b becomes large. These stresses also exist as residual stresses after the semiconductor wafer 2 is divided. If there are residual stresses, when the manufactured semiconductor device operates repeatedly, loads are likely to act near the region where the residual stresses exist, and the reliability of the semiconductor device decreases.

[0054] However, according to the manufacturing method of the present embodiment, the load of the scribe wheel 32 when forming the second crack 5b (about 1.5 N) is smaller than the load of the scribe wheel 32 when forming the first crack 5a (about 2.0 N). Therefore, when forming the second crack 5b, the stress due to the difference between the formation direction of the second crack 5b and the pressing direction of the scribe wheel 32 is reduced. Figure 6 Regions Ra and Rb represent the compressive stress generated inside the semiconductor wafer 2 by the pressing of the scribe wheel 32. As Figure 6 shown, by making the load of the scribe wheel 32 during the formation of the second crack 5b smaller than the load of the scribe wheel 32 during the formation of the first crack 5a, the range of region Rb (i.e., the magnitude of the compressive stress) can be made substantially equal to the range of region Ra. Thereby, the residual stress of the entire manufactured semiconductor device 10 can be reduced.

[0055] In addition, Figure 13 represents a graph showing the residual stresses of the semiconductor devices of the comparative example ( Figure 13 (a)) and the embodiment ( Figure 13 (b)). In Figure 13 , the horizontal axis represents the value of the residual stress, and the vertical axis represents the distance from the dividing surface (i.e., the surface pressed by the scribe wheel). The residual stress represents tensile stress as a positive value and compressive stress as a negative value. In the comparative example, the loads of the scribe wheel 32 when forming the first crack 5a and the second crack 5b are substantially equal. As described above, in the x-z cross section, since the crystal axis A is inclined with respect to the pressing direction of the scribe wheel 32, as Figure 13As shown in (a) of FIG. [0], it can be seen that in the semiconductor device of the comparative example, a relatively large residual stress (about 84 MPa) exists near the dividing surface (i.e., near the crack). On the other hand, in the semiconductor device 10 of the embodiment, by making the load of the scribing wheel 32 during the formation of the second crack 5b smaller than the load of the scribing wheel 32 during the formation of the first crack 5a, as Figure 13 shown in (b) of FIG. [1], the residual stress in the x - z cross - section can be reduced to a value equivalent to the residual stress (about 55 MPa) in the y - z cross - section. Thus, according to the manufacturing method of the present embodiment, the residual stress of the entire semiconductor device 10 is reduced, and a highly reliable semiconductor device 10 can be obtained.

[0056] In addition, in the present embodiment, the element structure 6 is formed not on the first surface 2a side where the scribing wheel 32 presses but on the second surface 2b located on the back side of the first surface 2a. Therefore, even if there is residual stress on the first surface 2a side, the influence on the element structure 6 for realizing the functions of the manufactured semiconductor device 10 can be reduced.

[0057] Furthermore, in the above - mentioned embodiment, the support plate pasting process, the cutting tape pasting process, and the protection component covering process may not be performed. In addition, the metal film forming process may be performed before the first crack forming process and the second crack forming process, or may not be performed. That is, in the technology disclosed in this specification, it is sufficient to perform at least the first crack forming process, the second crack forming process, and the dividing process on a semiconductor wafer whose crystal axis is inclined with respect to the perpendicular line of the surface of the semiconductor wafer.

[0058] As described above, the embodiments have been described in detail, but they are merely examples and do not limit the scope of the claims. In the technology described in the claims, variously deformed and modified forms of the specific examples illustrated above are included. The technical elements described in this specification or the drawings exhibit technical usefulness alone or through various combinations, and are not limited to the combinations described in the claims at the time of application. In addition, the technologies illustrated in this specification or the drawings achieve multiple purposes simultaneously, and achieving one of these purposes itself has technical usefulness.

Claims

1. A manufacturing method, which is a method for manufacturing a semiconductor device, characterized in that: have: A step of preparing a semiconductor wafer having a crystal axis inclined relative to a perpendicular line of the first surface; A step of pressing a pressing member against the first surface with a first load along a first direction in the first surface to form a first crack in the semiconductor wafer along the first direction and extending in a thickness direction of the semiconductor wafer, wherein the first direction is along an inclination direction of the crystal axis; A step of pushing the pressing member against the first surface along a second direction perpendicular to the first direction at a second load smaller than the first load, thereby forming a second crack in the semiconductor wafer extending along the second direction and in a thickness direction of the semiconductor wafer; as well as A step of pressing a dividing member against the semiconductor wafer along the first crack and the second crack from a second surface side located on the back side of the first surface, thereby dividing the semiconductor wafer along the first crack and the second crack.

2. The manufacturing method according to claim 1, characterized in that Before the step of forming the first crack and the step of forming the second crack, there is further provided a step of forming a plurality of the element structures in a matrix arrangement on the second surface of the semiconductor wafer; In the step of forming the first crack and the step of forming the second crack, the first crack and the second crack are formed along a boundary of the element structure.

3. The manufacturing method according to claim 1, characterized in that: After the step of forming the first crack and the step of forming the second crack and before the step of dividing the semiconductor wafer, a step of forming a metal film on the first surface is further included.

4. The production method according to any one of claims 1 to 3, characterized in that The semiconductor wafer is made of SiC.

5. The manufacturing method according to claim 4, characterized in that: The above-mentioned crystal axis is the c-axis.

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