JP2024081494A - Semiconductor device manufacturing method - Google Patents

Abstract

To provide a manufacturing method of a semiconductor device in which a semiconductor substrate having an electrode layer formed is appropriately divided using a scribe and break construction method.SOLUTION: A manufacturing method of a semiconductor device comprises the steps of: forming a trench G on a surface of a metal film 8 that is an electrode layer which covers a first surface 2a of a semiconductor substrate 2; forming, in the semiconductor substrate 2, a crack 5 that extends in a thickness direction of the semiconductor substrate 2, by pressing a scribing wheel 33 on a bottom surface of the trench G; and dividing the semiconductor substrate 2 by pressing a break plate being a division member along the trench on a second surface 2b of the semiconductor substrate 2 which is positioned on the opposite side of the first surface 2a after the step of forming the crack 5.SELECTED DRAWING: Figure 6

Description

The technology disclosed in this specification relates to a method for manufacturing a semiconductor device.

The manufacturing method of a semiconductor device includes a process for dividing a semiconductor substrate on which multiple element structures are formed. Patent Document 1 discloses a process called scribe and break. In this process, a scribing wheel is first pressed against the surface of the semiconductor substrate on which the electrode layer is formed, and a load is applied in the thickness direction of the semiconductor substrate (hereinafter simply referred to as the thickness direction), forming a crack that extends in the thickness direction of the semiconductor substrate along the boundary. Next, a dividing member is pressed against the boundary, and the semiconductor substrate is divided and divided along the boundary, starting from the crack.

JP 2021-193746 A

In some cases, an electrode layer is provided on the surface of a semiconductor substrate. When a scribing wheel is pressed against the electrode layer of such a semiconductor substrate, the load is distributed because the electrode layer is relatively soft. As a result, cracks extending along the thickness direction of the semiconductor substrate cannot be properly formed, and cracks may be formed in a direction other than the thickness direction. In this case, when the semiconductor substrate is subsequently singulated, the cracks remain in the singulated semiconductor device. This specification provides a technology for properly dividing a semiconductor substrate on which an electrode layer is formed, using a scribe-and-break method.

This specification discloses a method for manufacturing a semiconductor device. The manufacturing method includes the steps of forming a groove (G) on the surface of an electrode layer (8) covering a first surface (2a) of a semiconductor substrate (2), forming a crack (5) in the semiconductor substrate extending in the thickness direction of the semiconductor substrate by pressing a scribing wheel (33) against the bottom surface of the groove, and dividing the semiconductor substrate by pressing a dividing member (35) along the groove against a second surface (2b) of the semiconductor substrate located opposite the first surface after the step of forming the crack.

In this manufacturing method, first, a groove is formed in an electrode layer provided on a first surface of a semiconductor substrate. Then, a scribing wheel is pressed against the bottom surface of the groove to form a crack in the semiconductor substrate. In this way, the scribing wheel is pressed along the groove, so the load is not distributed by the electrode layer. As a result, a crack extending along the thickness direction of the semiconductor substrate can be appropriately formed. Then, the dividing member is pressed against the second surface side to divide the semiconductor substrate. In this way, the above manufacturing method can appropriately form a crack extending along the thickness direction of the semiconductor substrate, so that the semiconductor substrate on which the electrode layer is formed can be appropriately divided.

FIG. 2 is a plan view of a semiconductor substrate. 13A and 13B are diagrams for explaining a support plate attaching step. FIG. 13 is a diagram for explaining a grinding process before cracks are formed. FIG. 11 is a diagram for explaining an electrode forming step. FIG. 11 is a diagram for explaining a groove forming step. FIG. 13 is a diagram for explaining a crack forming process. FIG. 13 is a diagram for explaining how cracks are formed in Example 1. FIG. 13 is a diagram for explaining a dicing tape attaching step. 11A and 11B are diagrams for explaining a support plate peeling step. FIG. 11 is a diagram for explaining a protective member covering step. FIG. 13 is a diagram for explaining a division step. FIG. 11 is a diagram for explaining a pick-up process. FIG. 11 is a diagram for explaining how cracks are formed in Example 2.

In one example of the manufacturing method disclosed in this specification, the tip angle (A2) of the scribing wheel may be smaller than the angle (A1) defined by two straight lines connecting each of the two upper ends of the groove to the lower end of the groove in a cross section perpendicular to the groove.

With this configuration, the scribing wheel is less likely to come into contact with the electrode layer, and cracks that extend along the thickness direction can be more appropriately formed.

In one example manufacturing method disclosed in this specification, the first scribing wheel is rotatably supported by a first support (133a), the second scribing wheel is rotatably supported by a second support (132a), and the play (C2) of the first scribing wheel relative to the first support in a direction along the rotation axis of the first scribing wheel may be greater than the play (C1) of the second scribing wheel relative to the second support in a direction along the rotation axis of the second scribing wheel.

This configuration allows the first scribing wheel to move easily in accordance with the groove. This prevents the movement path of the first scribing wheel from deviating from the groove.

Example 1
The manufacturing method of the first embodiment will be described with reference to the drawings. FIG. 1 is a plan view of a semiconductor substrate 2 in which a plurality of element regions 3 are formed in a matrix. In FIG. 1, each element region 3 is shown typically by a solid line. For convenience of explanation, a boundary between adjacent element regions 3 and a line that will become an edge of each element region (semiconductor device) obtained by dividing the semiconductor substrate 2 into each element region 3 later will be referred to as a division line 4. The division line 4 is not a line actually drawn on the semiconductor substrate 2, but a virtual line. The division line 4 may be a line or a groove actually drawn on the semiconductor substrate 2 so that it can be seen with the naked eye. A semiconductor element having a function such as a transistor or a diode is formed in each element region 3.

The semiconductor substrate 2 is made of silicon carbide (SiC). The semiconductor substrate 2 may be made of other semiconductor materials such as silicon (Si) or gallium nitride (GaN). As shown in FIG. 2 etc., the semiconductor substrate 2 has a first surface 2a and a second surface 2b located on the back side of the first surface 2a. A main electrode 6 (source electrode, anode electrode, etc.) is formed on the second surface 2b of the semiconductor substrate 2.

The manufacturing method of the embodiment includes a support plate attachment process, a metal film formation process, a groove formation process, a crack formation process, a dicing tape attachment process, a support plate peeling process, a protective material coating process, and a division process.

(Support plate attachment process)
In the support plate attachment step, as shown in FIG. 2, a support plate 12 is attached to the second surface 2b of the semiconductor substrate 2. The support plate 12 is attached to 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 silicon-based adhesive, and in addition to the function of adhering the semiconductor substrate 2 to the support plate 12, it also has the function of protecting the second surface 2b of the semiconductor substrate 2. Therefore, here, the adhesive 11 is applied so that the thickness of the adhesive 11 is thicker than the thickness of the main electrode 6. Thereafter, as shown in FIG. 3, the first surface 2a of the semiconductor substrate 2 is ground by a grinding wheel 31 as necessary. This makes the semiconductor substrate 2 thinner.

(Metal film forming process)
Next, the metal film formation step shown in Fig. 4 is performed. In the metal film formation step, a metal film 8 is formed on the first surface 2a of the semiconductor substrate 2. The material constituting the metal film 8 is not particularly limited, but it is, for example, a multi-layer film in which titanium, nickel, and gold are laminated. The metal film 8 is formed so as to cover substantially the entire area of the first surface 2a. In other words, the metal film 8 is formed on the first surface 2a so as to span a plurality of element regions 3. The metal film 8 functions as an electrode of the completed semiconductor device.

(Groove forming process)
Next, a groove forming process shown in FIG. 5 is performed. In the groove forming process, the scribing wheel 32 is pressed against the metal film 8 to form a groove G in the metal film 8. The scribing wheel 32 is a disk-shaped member and is supported by a pair of supports 132a so as to be rotatable around its central axis. Specifically, the scribing wheel 32 has a central hole (not shown), and a shaft 132b is inserted through the central hole. On both sides of the scribing wheel 32, supports 132a are fixed to the shaft 132b. Therefore, the scribing wheel 32 rotates relative to the shaft 132b. In addition, there is a clearance of a distance C1 between the scribing wheel 32 and each support 132a. In FIG. 5, the distance between the scribing wheel 32 and the left support 132a is B1, the distance between the scribing wheel 32 and the right support 132a is B2, and the sum of these (B1+B2) is the clearance C1. The scribing wheel 32 can move relative to the support 132a along the shaft 132b within the range of the clearance C1. That is, the clearance C1 is the play of the scribing wheel 32 relative to the support 132a. The outer peripheral surface of the scribing wheel 32 protrudes radially outward in an angular shape. Hereinafter, the angle of the outer peripheral surface in a cross section along the radial direction of the scribing wheel is referred to as the tip angle. The scribing wheel 32 has a tip angle A1. Hereinafter, the outer peripheral surface of the scribing wheel 32 is pressed against the metal film 8 while moving (scanning) along the planned division line 4. When moving along the planned division line 4, the scribing wheel 32 rolls (rolls) on the metal film 8 like a tire rolling on a road surface. The scribing wheel 32 does not slide against the metal film 8, but rotates (in a gripping state) as it moves. In this way, a V-shaped groove G that conforms to the shape of the tip of the scribing wheel 32 is formed in the metal film 8. The angle of the V-shaped groove G (i.e., the angle formed by both side surfaces of the groove G) is equal to the tip angle A1 of the scribing wheel 32. In the groove forming process, no cracks are formed in the semiconductor substrate 2. The scribing wheel 32 is an example of a "second scribing wheel." The support 132a is an example of a "second support."

(Crack formation process)
Next, the crack forming process shown in FIG. 6 is performed. In the crack forming process, a scribe line accompanied by a crack 5 is formed in the semiconductor substrate 2 by pressing a scribing wheel 33 against the bottom surface of the groove G. The scribing wheel 33 is a disk-shaped member and is supported by a pair of supports 133a so as to be rotatable around its central axis. Specifically, the scribing wheel 33 has a central hole (not shown), and a shaft 133b is inserted through the central hole. On both sides of the scribing wheel 33, supports 133a are fixed to the shaft 133b. Therefore, the scribing wheel 33 rotates relative to the shaft 133b. In addition, there is a clearance of a distance C2 between the scribing wheel 33 and each support 133a. In FIG. 6, the distance between the scribing wheel 33 and the left support 133a is B3, the distance between the scribing wheel 33 and the right support 133a is B4, and the sum of these (B3+B4) is the clearance C2. The scribing wheel 33 can move relative to the support 133a along the shaft 133b within the range of the clearance C2. In other words, the clearance C2 is the play of the scribing wheel 33 relative to the support 133a. The outer peripheral surface of the scribing wheel 32 protrudes in an angular shape radially outward. The scribing wheel 33 has a tip angle A2. The tip angle A2 of the scribing wheel 33 is smaller than the tip angle A1 of the scribing wheel 32.

Here, the scribing wheel 33 is moved (scanned) along the planned division line 4 while pressing the outer peripheral surface of the scribing wheel 33 against the bottom surface of the groove G. When the scribing wheel 32 moves along the planned division line 4, it rolls (rolls) on the bottom surface of the groove G (i.e., the first surface 2a of the semiconductor substrate 2) like a tire rolling on a road surface. The scribing wheel 32 does not slide against the bottom surface of the groove G, but rotates (in a gripping state) as it moves. Since the distance C2 (i.e., the play of the scribing wheel 33) is large, the scribing wheel 33 can move along the axial direction. Therefore, when the scribing wheel 33 is pressed against the bottom surface of the groove G and moved, the scribing wheel 33 moves in the axial direction by being guided by the groove G. Therefore, the scribing wheel 33 can be moved accurately along the lower end of the groove G. In other words, the movement path of the scribing wheel 33 can be prevented from deviating from the groove G. In addition, at this time, since the tip angle A2 of the scribing wheel 33 is smaller than the tip angle (i.e., the groove angle) A1 of the scribing wheel 32, the tip of the scribing wheel 33 can be properly brought into contact with the bottom surface of the groove G. That is, as shown in FIG. 7, the tip of the scribing wheel 33 can be pressed against the semiconductor substrate 2 with almost no contact of the inclined surface of the scribing wheel 33 with the metal film 8.

As shown in FIG. 7, when the bottom surface of the groove G (i.e., the first surface 2a) is pressed by the scribing wheel 33, compressive stress is generated in the surface region R near the first surface 2a inside the semiconductor substrate 2. The compressive stress is generated isotropically from the point pressed by the scribing wheel 33 (the contact point between the periphery of the scribing wheel 33 and the first surface 2a) as shown by the arrow 20 in FIG. 7. A scribe line is formed at the point pressed by the scribing wheel 33, while tensile stress is generated inside the semiconductor substrate 2 immediately below the region R where the compressive stress is generated. The tensile stress is generated in a direction away from the planned division line 4 along the first surface 2a of the semiconductor substrate 2 immediately below the region R where the compressive stress is generated, as shown by the arrow 22. This tensile stress forms a crack 5 extending in the thickness direction of the semiconductor substrate 2 inside the semiconductor substrate 2. Here, the crack 5 is formed so as to extend along the boundary between the adjacent element regions 3 and in the thickness direction of the semiconductor substrate 2. Crack 5 is formed near the surface layer of first surface 2a of semiconductor substrate 2. In general, compressive stress inhibits the formation and extension of cracks, so crack 5 is formed so as to extend from the outside of region R where compressive stress occurs at the point pressed by scribing wheel 33 on first surface 2a of semiconductor substrate 2 to the region where tensile stress occurs directly below region R where compressive stress occurs, since compressive stress generally inhibits the formation and extension of cracks.

Here, a comparative example is considered in which cracks 5 are formed without forming grooves G in the metal film 8. In the comparative example, since the metal film 8 is relatively soft, when the scribing wheel 33 is pressed against the metal film 8, the load is dispersed. Therefore, cracks 5 extending in the thickness direction of the semiconductor substrate 2 cannot be properly formed, and there is a risk that cracks will be formed in directions other than the thickness direction. On the other hand, in this embodiment, the tip of the scribing wheel 33 can be pressed against the surface 2a of the semiconductor substrate 2 with almost no contact between the inclined surface of the scribing wheel 33 and the metal film 8. As a result, cracks 5 extending in the thickness direction of the semiconductor substrate 2 can be properly formed.

(Dicing tape application process)
Next, a dicing tape application step shown in Fig. 8 is performed. In the dicing tape application step, a dicing tape 13 is applied to the surface of the metal film 8. The dicing tape 13 is applied so as to cover substantially the entire area of the metal film 8. The dicing tape 13 is fixed to a dicing frame (not shown). Note that in Fig. 8 and subsequent figures, the semiconductor substrate 2 is depicted with the second surface 2b facing up.

(Support plate peeling process)
9 is performed. In the support plate peeling step, the support plate 12 and the adhesive 11 are peeled off from the second surface 2b of the semiconductor substrate 2. Here, for example, the adhesive 11 is dissolved by a solvent, thereby peeling the support plate 12 together with the adhesive 11 from the second surface 2b. As a result, the semiconductor substrate 2 is supported by the dicing tape 13.

(Protective member coating process)
Next, a protective member covering step shown in Fig. 10 is performed. In the protective member covering step, the protective member 15 is attached so as to straddle the surface of each main electrode 6 of each element region 3 of the semiconductor substrate 2, thereby covering the second surface 2b of the semiconductor substrate 2 with the protective member 15. The material of the protective member 15 is not particularly limited, but for example, a resin or the like can be used. By covering the second surface 2b of the semiconductor substrate 2 with the protective member 15, the second surface 2b of the semiconductor substrate 2 is protected in a subsequent division step or the like.

(Dividing step)
Next, the division step shown in FIG. 11 is performed. In the division step, the break plate 34 is pressed along the division planned line 4 (the crack 5 formed in the crack formation step), and the semiconductor substrate 2 is divided along the division planned line 4 (along the boundary of the element region 3). Here, the semiconductor substrate 2 is first placed on two support stands 35. The two support stands 35 are arranged with a gap between them. When the semiconductor substrate 2 is placed on the support stand 35, the semiconductor substrate 2 is placed so that the gap is located below the position to be divided (the position where the break plate 34 is pressed). Then, the break plate 34 is pressed against the second surface 2b of the semiconductor substrate 2 via the protective member 15. The break plate 34 is a plate-shaped member, and the lower end (the edge pressed against the second surface 2b) is ridge-shaped (sharp blade-shaped), but the semiconductor substrate 2 is only pressed against it without cutting it.

Because there is no support base 35 below the break plate 34 (there is a gap between the two support bases 35), when the break plate 34 is pressed against the second surface 2b, the semiconductor substrate 2 is bent so as to enter the gap between the two support bases 35. Here, the crack 5 is formed on the first surface 2a side of the semiconductor substrate 2. Therefore, when the break plate 34 is pressed against the semiconductor substrate 2 from the second surface 2b side, the semiconductor substrate 2 is bent with the pressed part (line) as an axis, and on the first surface 2a side, a force is applied to the crack 5 in a direction that separates the two element regions 3 adjacent to the split position. Also, as described above, tensile stress is applied around the crack 5. Therefore, when the break plate 34 is pressed against the second surface 2b, the crack 5 extends in the thickness direction of the semiconductor substrate 2, and the semiconductor substrate 2 is split along the planned split line 4. In addition, since the metal film 8 is formed on the first surface 2a of the semiconductor substrate 2, a force is applied to the metal film 8 in a direction that separates the two element regions 3 adjacent to the split position, and the metal film 8 is deformed and split. Instead of the two support bases 35, the entire first surface 2a of the semiconductor substrate 2 may be supported by one elastic support plate (or one or more support bases via one elastic support plate). In this case, an elastic support plate is present below the break plate 34, but when the semiconductor substrate 2 bends, the elastic support plate deforms in response to the bending of the semiconductor substrate 2. Therefore, when the break plate 34 is pressed against the second surface 2b, a force is applied to the crack 5 in a direction that separates the two element regions 3 adjacent to the split position, as in the case where the break plate 34 is supported by two support bases 35 (when there is no support base 35 below the break plate 34). The break plate 34 is an example of a "splitting member".

In the division process, the above-mentioned process of pressing the break plate 34 against the second surface 2b is repeated along each planned division line 4. This allows the semiconductor substrate 2 and the metal film 8 to be divided along the boundaries of each element region 3. Thereafter, as shown in FIG. 12, the individual element regions 3 and the metal film 8 are peeled off from the dicing tape 13. When peeling the individual element regions 3 and the metal film 8 from the dicing tape 13, the dicing tape 13 is expanded so that the individual element regions 3 and the metal film 8 can be peeled off while being separated from each other. This completes a number of semiconductor devices.

As described above, in this embodiment, first, the crack 5 is formed on the first surface 2a side of the semiconductor substrate 2 by pressing the scribing wheel 33 against the bottom surface of the groove G (i.e., the first surface 2a of the semiconductor substrate 2). Since the crack 5 is formed on the first surface 2a side of the semiconductor substrate 2, when the break plate 34 is pressed against the second surface 2b side, the semiconductor substrate 2 bends along the crack 5. Therefore, a force is applied from the first surface 2a side along the crack 5 in a direction to open the semiconductor substrate 2. As a result, the crack 5 extends in the thickness direction of the semiconductor substrate 2, and the semiconductor substrate 2 can be easily divided along the boundary of the element region 3. In addition, since the metal film 8 is formed on the first surface 2a of the semiconductor substrate 2, a force is also applied to the metal film 8 on both sides of the crack 5 in a direction to pull the metal film 8 apart, the metal film 8 is deformed, and the metal film 8 can be easily divided. Thus, in this embodiment, the metal film 8 can be divided together with the semiconductor substrate 2 by the simple process of pressing the scribing wheel 33 and the break plate 34 against the semiconductor substrate 2.

In addition, in this embodiment, the crack 5 is formed on the first surface side of the semiconductor substrate 2 with the support plate 12 made of glass attached to the semiconductor substrate 2. Because the support plate 12 is made of a relatively hard material, when the scribing wheel 33 is pressed against the semiconductor substrate 2, the crack 5 can be formed on the first surface side of the semiconductor substrate 2 with a relatively low load.

In addition, in this embodiment, the semiconductor substrate 2 and the metal film 8 are divided while the dicing tape 13 is attached. Since the semiconductor substrate 2 (metal film 8) is fixed to the dicing tape 13, it is possible to suppress the positional deviation of the semiconductor substrate 2 when the break plate 34 is pressed against the semiconductor substrate 2, and it is possible to prevent the resulting semiconductor device from scattering.

In addition, in this embodiment, the break plate 34 is pressed against the semiconductor substrate 2 while the second surface 2b is covered with the protective member 15. Since the second surface 2b is protected by the protective member 15, it is possible to prevent the break plate 34 from damaging the second surface 2b.

Example 2
Next, with reference to FIG. 13, Example 2 will be described. Example 2 differs from Example 1 in that, as shown in FIG. 13, a U-shaped groove G is formed in the metal film 8. In Example 2, the angle A1 of the groove G is an angle defined by two straight lines (dashed line 100 in FIG. 13) connecting the two upper ends U1 and U2 of the groove G and the lower end L of the groove G in a cross section perpendicular to the groove G. The tip angle A2 of the scribing wheel 33 is smaller than the angle A1 of the groove G. Even with this configuration, the scribing wheel 33 is less likely to come into contact with the metal film 8, and a crack 5 extending along the thickness direction can be more appropriately formed.

In the above-mentioned embodiment, the support plate attachment process, the dicing tape attachment process, and the protective material coating process do not have to be performed.

In addition, in the groove forming process of the above embodiment, the groove G is formed in the metal film 8 using a scribing wheel 32, but the groove G may be formed in the metal film 8 using other methods, such as etching.

The configurations of the manufacturing method disclosed in this specification are listed below.
(Configuration 1)
A method for manufacturing a semiconductor device, comprising:
forming a groove (G) on a surface of an electrode layer (8) covering a first surface (2a) of a semiconductor substrate (2);
forming a crack (5) in the semiconductor substrate extending in a thickness direction of the semiconductor substrate by pressing a scribing wheel (33) against a bottom surface of the groove;
a step of dividing the semiconductor substrate by pressing a dividing member (35) along the groove against a second surface (2b) of the semiconductor substrate located opposite to the first surface after the step of forming the crack;
A manufacturing method comprising:
(Configuration 2)
The manufacturing method described in configuration 1, wherein the tip angle (A2) of the scribing wheel is smaller than the angle (A1) defined by two straight lines connecting each of the two upper ends of the groove to the lower end of the groove in a cross section perpendicular to the groove.
(Configuration 3)
the scribing wheel is a first scribing wheel (33);
In the step of forming the groove, the groove is formed by pressing a second scribing wheel (32) against the electrode layer.
The method for producing the method according to claim 1 or 2.
(Configuration 4)
4. The manufacturing method of claim 3, wherein the tip angle (A2) of the first scribing wheel is smaller than the tip angle (A1) of the second scribing wheel.
(Configuration 5)
The first scribing wheel is rotatably supported by a first support (133a);
The second scribing wheel is rotatably supported by a second support (132a);
The play (C2) of the first scribing wheel relative to the first support in a direction along the rotation axis of the first scribing wheel is greater than the play (C1) of the second scribing wheel relative to the second support in a direction along the rotation axis of the second scribing wheel;
The method for producing the method according to configuration 3 or 4.
(Configuration 6)
6. The method of claim 1, wherein the semiconductor substrate is made of SiC.

Specific examples of the technology disclosed in this specification have been described in detail above, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and variations of the specific examples exemplified above. The technical elements described in this specification or drawings exhibit technical utility 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 exemplified in this specification or drawings can achieve multiple objectives simultaneously, and achieving one of those objectives is itself technically useful.

2: semiconductor substrate, 2a: first surface, 2b: second surface, 3: element region, 4: planned division line, 5
: Crack, 6: Main electrode, 8: Metal film, 11: Adhesive, 12: Support plate, 13: Dicing tape, 15: Protective member, 31: Grinding wheel, 32, 33: Scribing wheel, 34: Break plate, G: Groove

Claims (6)

A method for manufacturing a semiconductor device, comprising:
forming a groove (G) on a surface of an electrode layer (8) covering a first surface (2a) of a semiconductor substrate (2);
forming a crack (5) in the semiconductor substrate extending in a thickness direction of the semiconductor substrate by pressing a scribing wheel (33) against a bottom surface of the groove;
a step of dividing the semiconductor substrate by pressing a dividing member (35) along the groove against a second surface (2b) of the semiconductor substrate located opposite to the first surface after the step of forming the crack;
A manufacturing method comprising: The manufacturing method according to claim 1, wherein the tip angle (A2) of the scribing wheel is smaller than the angle (A1) defined by two straight lines connecting each of the two upper ends of the groove to the lower end of the groove in a cross section perpendicular to the groove. the scribing wheel is a first scribing wheel (33);
In the step of forming the groove, the groove is formed by pressing a second scribing wheel (32) against the electrode layer.
The method according to claim 1 or 2. The manufacturing method according to claim 3, wherein the tip angle (A2) of the first scribing wheel is smaller than the tip angle (A1) of the second scribing wheel. The first scribing wheel is rotatably supported by a first support (133a);
The second scribing wheel is rotatably supported by a second support (132a);
The play (C2) of the first scribing wheel relative to the first support in a direction along the rotation axis of the first scribing wheel is greater than the play (C1) of the second scribing wheel relative to the second support in a direction along the rotation axis of the second scribing wheel;
The method according to claim 3. The manufacturing method according to claim 1 or 2, wherein the semiconductor substrate is made of SiC.

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