JP7361357B2 - Semiconductor substrate cutting method and cutting device - Google Patents

Description

The present invention relates to a technique for dividing a semiconductor substrate.

The semiconductor manufacturing process consists of a process of manufacturing a substrate (wafer) that serves as a support for the semiconductor, a process of forming an electronic circuit on the substrate to manufacture elements (semiconductor chips), and a process of separating the manufactured semiconductor substrate. The process is divided into the process of cutting out the elements individually (chip-making) and the process of assembling a semiconductor using the elements.
Examples of methods for cutting out elements from a semiconductor substrate include forming scribe lines on the semiconductor substrate with a scribing wheel, dividing the substrate along the scribe lines, and cutting out the elements individually.

Incidentally, the surface of a semiconductor substrate is divided into a grid pattern, and a plurality of regions are formed. The lines in the grid are planned dividing lines called streets. Further, elements are formed in each divided area.
Various film-like laminates are formed on the upper surface of the street. If the film-like laminate remains, problems will occur when forming scribe lines on streets or when dividing a semiconductor substrate. Therefore, the film-like laminate is removed before forming the scribe line. Techniques for removing the film-like laminate are disclosed in, for example, Patent Documents 1 to 3.

Patent No. 5645593 Japanese Patent Application Publication No. 2013-197108 Patent No. 4741822

Now, various film-like laminates formed on the upper surface of a semiconductor substrate (for example, a street) include, for example, a metal film including a test circuit called TEG (Test Element Group), an alignment mark, a PL film, etc. (polarizing film), etc.
A laminated film (laminated film) is formed on the upper surface of the street. Since the stacked films have different stacking states, the streets of the semiconductor substrate have unevenness and are not uniform. That is, the structure (thickness) of the laminated film is different.

In the street, for example, basically only a Pl film is formed (thickness: about 2 μm). Further, in the portion where the alignment mark is formed on the street, for example, (Pl film+SiO ₂ ) is formed (thickness: about 3 μm).
In the portion where the TEG is formed on the street (Street TEG), for example, (Pl film+Metal Al+SiO ₂ ) is formed (thickness: about 5 μm).

Further, in the portion where the Pattern TEG is formed on the semiconductor substrate, for example, (Pl film+Metal Al+SiO ₂ +Poly Si+SiO ₂ ) is formed (thickness: about 10 μm).
As described above, when a TEG or the like is formed on a semiconductor substrate, the thickness becomes thicker than other parts. That is, in a semiconductor substrate, the thickness of the laminated film differs depending on the part, resulting in a difference in the structure.

Even if an attempt is made to remove TEG formed on a semiconductor substrate (for example, a street) using conventional techniques such as those disclosed in Patent Documents 1 to 3, it is not possible to uniformly remove TEG and the like. For example, if the laser output is increased, even if the TEG can be removed, the intersection of the streets (thin film such as Pl film only) will be etched more deeply, but the cross-cut In this case, the intersection portion will be cut deeper than necessary, which is not desirable (see FIG. 3). Therefore, when forming a scribe line, there is a possibility that the scribe line will not be a straight line but a broken line. When the semiconductor substrate breaks, it causes deformation and cracking.

Furthermore, if the laser output is lowered, TEG cannot be reliably removed. That is, the scribe line is formed on the semiconductor substrate, but since the TEG remains and the substrate portion is not exposed, it becomes difficult to form the scribe line.
That is, if a scribe line is not formed on the semiconductor substrate in the street, for example, when the semiconductor substrate is divided, there is a possibility that a problem such as a crack propagating toward the element side may occur.

Therefore, in view of the above problems, the present invention is capable of uniformly removing a film including a metal film such as TEG that is formed in a stacked manner on the upper surface of a semiconductor substrate, for example, on a street, and forms a scribe line. It is an object of the present invention to provide a semiconductor substrate cutting method and a cutting apparatus capable of cutting a semiconductor substrate along the scribe line.

In order to achieve the above object, the following technical measures were taken in the present invention.
A method for dividing a semiconductor substrate according to the present invention includes dividing a semiconductor substrate in which a plurality of elements are formed in a matrix on a substrate, and streets are provided between adjacent elements, and dividing the elements into individual parts. A method for dividing a semiconductor substrate includes a film removal step of removing a film including a metal film formed on the street by scanning a plurality of laser beams in parallel, and a semiconductor substrate after the film is removed. a scribing process in which the cutting edge of the scribing wheel is rolled under pressure against the street to form a scribe line; and a breaking process in which the semiconductor substrate is divided along the scribe line to separate the elements into individual parts. It is characterized by having a process.

Preferably, in the film removal step, a plurality of lasers each having a width smaller than the street may be scanned in parallel.
Preferably, in the coating removal step, when scanning a plurality of laser beams in parallel, striped protrusions are formed at intervals between adjacent laser removal parts where the coating is removed by irradiation with the laser. It is good.

Preferably, a convex portion is formed at the center where the plurality of laser removal portions intersect with each other at an intersection where two of the streets intersect.
Preferably, in the film removal step, at least two lasers are scanned, and the interval between the laser scans is at least 20 μm or more.
Preferably, the semiconductor substrate is a SiC substrate.

A semiconductor substrate cutting apparatus according to the present invention cuts a semiconductor substrate in which a plurality of elements are formed in a matrix on a substrate, and streets are formed between adjacent elements, and separates the elements into individual parts. In the semiconductor substrate cutting apparatus, a film removing unit removes the film including a metal film formed on the street by scanning a plurality of laser beams in parallel; and a semiconductor substrate after the film is removed. A scribing portion that forms a scribe line by bringing the cutting edge of the scribing wheel into vertical contact with the street, applying a load to the scribing wheel and causing it to roll, and dividing the semiconductor substrate along the scribe line. and a break part for dividing the element into individual parts, and in the film removing part, a plurality of the lasers narrower than the width of the street are scanned in parallel, and when the plurality of lasers are scanned in parallel, , a striped convex strip is formed at an interval between adjacent laser removed portions where the coating is removed by irradiation with the laser, and a plurality of the laser removed portions are formed at an intersection where two of the streets intersect. It is characterized by a structure in which a convex portion is formed at the center where they intersect with each other.

According to the present invention, it is possible to uniformly remove a film including a metal film such as TEG that is formed in a stacked manner on the upper surface of a semiconductor substrate, for example, on a street, and to form a scribe line, and to remove the film along the scribe line. A semiconductor substrate can be divided.

FIG. 2 is a diagram schematically showing an outline of a film removal step that constitutes the semiconductor substrate cutting method of the present invention. This is an image of a street showing the situation after a film containing a metal film has been removed by laser irradiation by scanning with one laser. These are an image showing the situation at the intersection of streets after one laser beam is scanned and a coating including a metal film is removed by laser irradiation, and a cross-sectional view (cross section AA) at the intersection. These are an image of a street showing the state after a film including a metal film has been removed by laser irradiation by scanning with two lasers, and a cross-sectional view (cross section BB) of the street. These are an image showing the situation at the intersection of streets after two laser beams are scanned and a coating including a metal film is removed by laser irradiation, and a cross-sectional view (cross section CC) at the intersection.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a method and a device for cutting a semiconductor substrate 1 according to the present invention will be described with reference to the drawings.
Note that the embodiment described below is an example of embodying the present invention, and the configuration of the present invention is not limited to the specific example.
The substrate 1 (wafer) serves as a support substrate for the element 2, and is formed into a disk shape. In this embodiment, the substrate is made of SiC and serves as a SiC layer that serves as a support substrate for the element 2.

As shown in FIG. 1, a semiconductor substrate 1 is formed by arranging a plurality of elements 2 (semiconductor chips) on which electronic circuits are formed in a grid pattern on the surface of a substrate made of SiC, for example. has been done.
That is, in the semiconductor substrate 1, a plurality of elements 2 are formed in a matrix on a SiC substrate, and streets 3 (dividing line) are provided between the adjacent elements 2. The streets 3 are formed in a lattice shape on the semiconductor substrate 1.

In such a semiconductor substrate 1, various treatments are performed on the surface of the substrate made of SiC in order to manufacture an element 2 (semiconductor chip) on which an electronic circuit is formed. Therefore, on the street 3, there are films (laminated films) having various structures, such as a metal film containing a test circuit called TEG (Test Element Group), an alignment mark, and a Pl film (polarizing film). It will be formed.

A scribe line is formed on the street 3 in a scribing process. If a laminated film exists on the street 3, it will be difficult to separate the semiconductor substrate 1 along the scribe line when it breaks, and there is a possibility that cracks will occur on the element 2 side.
Therefore, it is necessary to uniformly remove the laminated film formed on the streets 3. Among the laminated films, the TEG is thicker than the alignment mark or the Pl film. That is, on the street 3, laminated films having different thicknesses are formed, so that the situation is uneven. That is, the surface of street 3 is not in a uniform condition.

Therefore, in the present invention, the laminated films formed on the streets 3 and having different thicknesses, such as TEG, are reliably removed, and then a scribe line is formed on the streets 3, and the semiconductor substrate 1 is divided along the scribe lines. Thus, the elements 2 are individually divided.
A method for dividing a semiconductor substrate 1 according to the present invention includes a film removal step in which the film including a metal film formed on the streets 3 is removed by scanning a plurality of lasers 5 in parallel; There is a scribing process in which a scribe line is formed by rolling the cutting edge of a scribing wheel in pressure contact with the street 3 of the semiconductor substrate 1, and a scribing process in which the semiconductor substrate 1 is divided along the scribe line to form individual elements 2. and a breaking step of dividing into.

As shown in FIG. 1, the film removal process is performed on the streets 3 on which a film containing a metal film such as TEG is formed before performing the scribing process in a film removal section equipped with a laser irradiation unit 4. This is a step in which TEG and the like are removed by scanning a plurality of lasers 5 with narrow focus from the laser irradiation unit 4 in parallel. By performing this film removal step, the TEG is reliably removed, and a single scribe line can be formed for the street 3 in the scribing step.

In the film removal process, it is preferable to scan a plurality of lasers 5, which are narrower than the width of the street 3, in parallel. Preferably, in the film removal process, at least two or more lasers 5 are scanned.
In addition, in the film removal process, when scanning a plurality of lasers 5 in parallel, striped protrusions 7 are formed at intervals between adjacent laser removal parts 6 where the film is removed by irradiation with the laser 5. It is better to do this.

In the film removal step, a convex portion 8 may be formed at the intersection 3a where two streets 3 intersect, at the center where a plurality of laser removal portions 6 intersect.
Regarding the film removal process, verification was performed in which the film containing the metal film formed on the street 3 was scanned with the laser 5 to remove the film.
In this embodiment, the semiconductor substrate 1 in which the width of the streets 3 is 90 μm was used and verified.

The purpose was to replace the condensing lens with one with a shorter focal length and to verify the conditions under which TEG could be removed. In this embodiment, the condenser lens: F300mm was replaced with F150mm. Another purpose was to reduce the depth of processing by the laser 5 at the intersection 3a of the street 3.
As a goal, the removal width of the film on the street 3 was set to be 40 μm or more, and the processing width by the laser 5 was set to be less than 80 μm.

First, as a verification example, Pattern TEG (In-TEG) was processed to remove a film by scanning with one laser 5. At this time, the laser 5 was defocused (blurred) and the spot diameter was changed.
In this embodiment, the spot diameter of the laser 5 was changed to Φ35 μm and Φ40 μm. Furthermore, the processing conditions for removing the coating using the laser 5 are a scanning speed of 300 mm/s.

Note that in Pattern TEG, a film (thickness: about 10 μm) (Pl film+Metal Al+SiO ₂ +Poly Si+SiO ₂ ) is formed on the SiC layer.
As a result, the TEG (coating) could be uniformly removed with a spot diameter of Φ35 μm and an output of 5 W. Further, when the spot diameter was Φ40 μm, the TEG (coating) could be uniformly removed with an output of 6 W.

However, when the output of the laser 5 is lowered, problems such as the SiC layer not being exposed or the formation of burrs on the processing line occur.
Next, the street 3 was scanned with one laser 5 to remove the film on the street 3.
Note that the processing conditions for removing the coating using the laser 5 are a scanning speed of 300 mm/s. Regarding the laser 5, the spot diameter was set to Φ35 μm, and the output of the laser 5 was set to 5W. Furthermore, in street 3, a coating consisting only of a Pl film is formed on the SiC layer (thickness: approximately 2 μm).

As shown in Fig. 2, under the conditions of spot diameter = Φ35 μm and output = 5 W, only the Pl film was removed, the removal width of the film was 46 μm, and the processing width by laser 5 was 61 μm. . That is, the target film removal width = 40 μm or more and the processing width by the laser 5 = 80 μm or less were satisfied.
Furthermore, the intersection 3a where two streets 3 intersect was observed.

As shown in FIG. 3, as a result of observation, when the spot diameter=Φ35 μm and the output=5W, the size of the intersection portion 3a of the street 3 was 39 μm×35 μm.
Further, the processing depth of the laser 5 at the intersection 3a of the street 3 was 7.7 μm (cross section AA). In other words, it was found that although the area at the intersection 3a of the street 3 was smaller, the SiC layer was processed deeply.

Here, the repetition frequency, scanning speed, etc. of the laser 5 were changed, the pitch between pulses of the laser 5 was widened, and the laser 5 was scanned one by one to remove the TEG.
In this embodiment, the pitch between pulses of the laser 5 was changed from 3 μm to 6 μm. Further, the processing conditions for removing the coating using the laser 5 are as follows: repetition frequency = 80 kHz, scanning speed = 480 mm/s, and spot diameter = Φ40 μm. However, the scanning target was Pattern TEG.

As a result, it became difficult to uniformly remove the TEG in areas that were difficult to process with the laser 5. Moreover, even if the output of the laser 5 was increased, the processing state became unstable.
Therefore, the TEG on the street 3 was removed by just focusing on the street 3, shifting the laser 5, and scanning the two lasers 5.

Note that the processing conditions for removing the film using the laser 5 are: output of the laser 5 = 2 W, scanning speed = 300 mm/s, and spot diameter = 24 μm. Further, the shift width of the laser 5 is 20 μm.
As shown in FIG. 4, as a result, under the conditions of spot diameter = Φ24 μm and output = 2 W, the removal width of the film was 50 μm, and the processing width by the laser 5 was 59 μm. That is, the target removal width of the film was 40 μm or more, and the processing width by the laser 5 was 80 μm or less. The processing depth of the laser 5 in the street 3 was 4.3 μm (cross section BB).

When two lasers 5 are scanned in parallel with a shift width of 20 μm, two laser removed portions 6 are formed. It was confirmed that a striped protruding strip 7 was formed at the interval between the two laser-removed sections 6 adjacent to each other.
Similarly, when two laser beams 5 were scanned with a shift width of 30 μm, it was confirmed that the protruding stripes 7 were formed.

In other words, when the laser 5 scans two lines with a shift width of 20 μm or more, the SiC layer is not exposed at the interval between adjacent laser removed portions 6, and a convex strip 7 is formed where only the coating is removed. I understand. It is preferable that the scanning interval of the laser 5 is at least 20 μm or more.
Further, in order to allow the protruding portion 7 to pass straight through the cutting edge of the scribing wheel, the shift width of the laser 5 is preferably set to 30 μm.

Note that when the laser 5 scanned two lines with a shift width of 10 μm, no protruding stripes 7 were formed at intervals between adjacent laser-removed portions 6. In other words, the shift width of the laser 5 = 10 μm was almost unchanged from the situation when one laser 5 was scanned.
The protruding portion 7 becomes a line that guides the cutting edge of the scribing wheel when forming a scribing line. In other words, the protruding portion 7 serves as the basis for the cut line of the semiconductor substrate 1.

Furthermore, the intersection 3a where two streets 3 intersect was observed.
As shown in FIG. 5, as a result of observation, when the spot diameter=Φ24 μm and the output=3W, the size of the intersection portion 3a of the street 3 is 51 μm×53 μm.
Further, the processing depth of the laser 5 at the intersection 3a of the street 3 was 2.9 μm at the center (cross section CC). In other words, it was found that the processing depth of the laser 5 was shallow at the intersection 3a of the street 3.

However, at the intersection 3a where the two streets 3 intersect, a raised convex portion 8 is formed at the center (the center of the parallel cross) where the two laser removed portions 6 intersect (perpendicularly) each other. It was confirmed.
This convex portion 8 becomes a point in contact with the cutting edge of the scribing wheel, and a scribe line is also formed at the intersection portion 3a of the street 3. In other words, the convex portion 8 shortens the break in the line within the intersection portion 3a when forming the scribe line. Even if the cutting edge of the scribing wheel deviates from the convex part 8 and passes beside the convex part 8, both sides of the convex part 8 also become relatively convex parts, making it possible to shorten the break in the line when forming the scribe line. can.

By forming this convex portion 8, the cutting edge of the scribing wheel enters into the center of the intersection portion 3a of the street 3, thereby suppressing the formation of a scribe line without flying (in the shape of a broken line). You will be able to do this. That is, a scribe line equivalent to a continuous scribe line is formed. Thereby, when the semiconductor substrate 1 breaks, it is possible to reduce the occurrence of deformation and cracking due to skipped scribe lines.

A summary of the above verification is shown below.
Regarding Laser 5, we replaced the condensing lens with a shorter focal length (F300mm→F150mm) and verified the conditions under which TEG could be removed. Further, the output of the laser 5 was changed and verified with spot diameters of Φ35 μm and Φ40 μm, and it was confirmed that TEG could be uniformly removed.
Examples of processing conditions and processing results for film removal using the laser 5 are shown in (1) to (3) below.

(1) Spot diameter = Φ50 μm, output = 10 W, scanning speed = 300 mm/s, film removal width = 63 μm, processing width by laser 5 = 80 μm, size of intersection 3a of street 3 = 51 μm x 44 μm, intersection The processing depth of the laser 5 in 3a was 4.8 μm.
(2) Spot diameter = 40 μm, output = 6 W, scanning speed = 300 mm/s, film removal width = 53 μm, processing width by laser 5 = 67 μm, size of intersection 3a of street 3 = 41 μm x 33 μm, intersection The processing depth of the laser 5 in 3a was 7.3 μm.

(3) Spot diameter = Φ35 μm, output = 5 W, scanning speed = 300 mm/s, film removal width = 46 μm, processing width by laser 5 = 61 μm, size of intersection 3a of street 3 = 39 μm x 35 μm, intersection The laser processing depth in 3a was 7.7 μm.
According to the results (1) to (3), by reducing the spot diameter of the laser 5, it was possible to achieve a film removal width of 40 μm or more and a processing width of less than 80 μm by the laser 5.

However, although the size of the intersection portion 3a of the street 3 was reduced, the SiC layer was processed to be deep.
Therefore, we attempted to remove the TEG by widening the pitch between pulses of the laser 5 (from 3 μm to 6 μm), but in areas where the laser 5 is difficult to process, it was difficult to uniformly remove the TEG, so we increased the output of the laser 5. However, the machining condition became unstable.

From this, when the TEG (coating) on the street 3 was removed by shifting the laser 5 and scanning the laser 5 with just focus twice, the shift width of the laser 5 = 20 to 30 μm, and two The SiC layer was not exposed between the laser-removed portions 6, and protruding portions 7, which were portions where only the coating was removed, were formed.
Furthermore, at the intersection 3a of the street 3, a protrusion 8 was formed at a location where the two laser removed portions 6 (protruding stripes 7) intersect with each other.

By forming this convex portion 8, the cutting edge of the scribing wheel can enter the center of the intersection portion 3a of the street 3, and the occurrence of deformation and cracking due to skipping of the scribe line can be reduced. Even if the cutting edge of the scribing wheel deviates from the center of the intersection 3a of the street 3 and passes beside the center of the intersection 3a, both sides of the center of the intersection 3a will also become relatively convex, causing the scribe line to skip. It is possible to reduce the occurrence of deformation and cracking due to

In the present invention, when scanning the laser 5 to remove a film such as TEG in the street 3, the TEG is uniformly removed by scanning two focused lasers 5 at a certain interval. can do.
As described above, according to the knowledge of the present inventor, the spot diameter of the laser 5 is desirably Φ20 to 100 μm. Further, the shift width of the laser 5 is preferably 20 to 30 μm. That is, the spot diameter and shift width of the laser 5 are preferably large enough not to exceed the width of the street 3.

The output of the laser 5 is preferably 2 to 10W. Further, as the laser, UV laser, green laser, pulsed laser, etc. are preferable.
In this embodiment, the width of the street 3 was 90 μm, so the width of the film removed was set to be 40 μm or more, and the width processed by the laser 5 was set to 80 μm or less. This is just an example, and the width of the film to be removed and the width of processing by the laser 5 depend on the width of the street 3.

The device for cutting the semiconductor substrate 1 of the present invention includes a film removal unit that removes the film by scanning a plurality of lasers 5 in parallel on the film including the metal film formed on the streets 3; The cutting edge of the scribing wheel is brought into perpendicular contact with the street 3 of the semiconductor substrate 1 after the film has been removed, and the scribing part forms a scribe line by applying a load to the scribing wheel and rolling it, and the semiconductor along the scribe line. It is preferable to have a break part for dividing the substrate 1 and dividing the elements 2 into individual parts.

In the film removal part, a plurality of lasers 5 narrower than the width of the street 3 are scanned in parallel, and when the laser 5 is scanned in parallel, the film is removed by irradiation of the laser 5 between adjacent laser removal parts 6. A striped protruding portion 7 is formed at the interval, and a protruding portion 8 is formed at the center where the plurality of laser removal portions 6 intersect with each other at the intersection 3a where two streets 3 intersect. Good to have.

After completing the film removal process in the film removal section, the semiconductor substrate 1 is transferred to a scribing process.
The scribing step is a step of forming scribe lines, which serve as guides for dividing, on the streets 3 of the semiconductor substrate 1 at the scribe section. First, the semiconductor substrate 1 is installed in the scribe section. The scribing section is equipped with a scribing tool.
A rotatable scribing wheel is attached to the scribing tool. The outer periphery of the scribing wheel is a cutting edge that forms a scribe line. Note that the scribing wheel has a cutting edge whose outer periphery is coated with diamond (for example, single crystal diamond).

The cutting edge of the scribing wheel is brought into contact with the street 3 of the semiconductor substrate 1 perpendicularly. Specifically, the cutting edge of the scribing wheel is brought into contact with the protruding portion 7 formed between the two laser removed portions 6 .
When the scribing wheel is run while pressing with a predetermined load, the scribing wheel rolls on the convex strips 7 of the streets 3, and a single scribe line is formed on the surface of the semiconductor substrate 1. .

In other words, the scribe line is ideally formed on the protruding portion 7 formed between the two laser removed portions 6. Furthermore, even if the protruding portion 7 is shifted from the protruding portion 7 and is formed along either of the two laser removal portions 6 on both sides of the protruding portion 7, the side of the protruding portion 7 is relatively Therefore, similar effects can be achieved.
After completing the scribing process at the scribing section, the semiconductor substrate 1 is moved to a breaking process.

The breaking step is a step of cutting the semiconductor substrate 1 at the break portion along a scribe line that serves as a guide for cutting. First, a semiconductor substrate 1 on which a scribe line is formed is placed in a break portion.
In the break section, the semiconductor substrate 1 is installed with the scribe line facing downward so that the scribe line is at the center position. The break part is equipped with a break member having a blade at its tip. The breaking member is brought close to a position corresponding to the scribe line from the surface side where the scribe line is not formed.

Press the cutting edge of the break member to press the position corresponding to the scribe line. Then, the semiconductor substrate 1 is divided along the scribe lines.
According to the present invention, it is possible to uniformly remove a film including a metal film such as TEG that is formed in a laminated manner on the upper surface of the semiconductor substrate 1, for example, on the street 3, and to form a scribe line, and to form a scribe line in the scribe line. The semiconductor substrate 1 can be divided along the lines.

By uniformly removing the film containing the metal film such as TEG, the scribe line can be formed in a straight line, and the semiconductor substrate 1 can be divided without creating cracks on the element 2 side. .
It should be noted that the embodiments disclosed herein are illustrative in all respects and should not be considered restrictive.

In particular, in the embodiments disclosed herein, matters not explicitly stated, such as operating conditions, operating conditions, dimensions and weights of components, etc., do not deviate from the scope of those skilled in the art and are within the ordinary skill of those skilled in the art. We have adopted matters that can be easily assumed by a business operator.

1 Semiconductor substrate (SiC substrate)
2 Element 3 Street 3a Intersection 4 Laser irradiation unit 5 Laser 6 Laser removal section 7 Convex strip 8 Convex

Claims (7)

A method for dividing a semiconductor substrate in which a plurality of elements are formed in a matrix on a substrate, and streets are provided between adjacent elements, and the semiconductor substrate is divided into individual elements.
A film removal step of removing the film by scanning a plurality of laser beams in parallel on the film including a metal film formed on the street;
a scribing step of forming a scribe line by rolling the cutting edge of a scribing wheel in pressure contact with the street of the semiconductor substrate after the film has been removed;
A method for dividing a semiconductor substrate, comprising: a breaking step of dividing the semiconductor substrate along the scribe line to individually divide the elements. 2. The method for dividing a semiconductor substrate according to claim 1, wherein in the film removing step, a plurality of laser beams each having a width narrower than the street are scanned in parallel. In the film removal step, when scanning a plurality of laser beams in parallel, streak-like protrusions are formed at intervals between adjacent laser removal parts where the film is removed by irradiation with the laser. The method for dividing a semiconductor substrate according to claim 1 or 2. 4. The method for dividing a semiconductor substrate according to claim 3, wherein a convex portion is formed at the center where the plurality of laser removal portions intersect with each other at an intersection where two of the streets intersect. In the film removal step, at least two or more lasers are scanned,
5. The method for cutting a semiconductor substrate according to claim 1, wherein the laser scanning interval is at least 20 μm or more. 6. The method for dividing a semiconductor substrate according to claim 1, wherein the semiconductor substrate is a SiC substrate. A semiconductor substrate cutting apparatus for cutting a semiconductor substrate in which a plurality of elements are formed in a matrix on a substrate, and streets are formed between adjacent elements, and dividing the elements into individual parts,
a film removal unit that removes the film by scanning a plurality of laser beams in parallel on the film including a metal film formed on the street;
a scribing unit that forms a scribe line by bringing a cutting edge of a scribing wheel into vertical contact with the street of the semiconductor substrate after the film has been removed, applying a load to the scribing wheel and causing it to roll;
a break section that divides the semiconductor substrate along the scribe line to individually divide the elements;
In the film removal section,
scanning a plurality of the laser beams in parallel, which are narrower than the width of the street;
When scanning a plurality of laser beams in parallel, forming striped protrusions at intervals between adjacent laser removal portions where the coating is removed by irradiation with the laser;
A device for cutting a semiconductor substrate, characterized in that a convex portion is formed at the center where the plurality of laser removal portions intersect with each other at an intersection where two of the streets intersect.

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