JP7277782B2 - Semiconductor device manufacturing method - Google Patents

Description

The present invention relates to a method of manufacturing a semiconductor device.

Conventionally, wafers on which semiconductor layers are laminated are made into chips by a dicer, a scriber, a laser scriber, or the like.
Furthermore, a method has been proposed for forming split grooves on the surface of the nitride semiconductor layer and/or the sapphire substrate and irradiating the inside of the sapphire substrate with a laser to form chips from a wafer on which semiconductor layers are laminated (for example, patent Reference 1).

JP-A-2006-245043

It is an object of the present invention to provide a method for manufacturing a semiconductor light emitting device, which can accurately chip a substrate having a nitride semiconductor layer laminated thereon with an extremely high yield.

The present disclosure includes the following embodiments.
A substrate having a first principal surface and a second principal surface opposite to the first principal surface is focused with a laser beam to a certain depth close to the first principal surface to form a first process-altered portion. , forming a first line arranged linearly in plan view,
The substrate on which the first line of the first work-affected part is formed is placed at a certain depth close to the second main surface and at a line-symmetrical position with respect to the first line in plan view. forming a second line and a third line in which the second work-affected portion and the third work-affected portion are arranged in a broken line shape in a plan view by condensing the laser beam;
By applying an external force to the obtained substrate, the substrate is bent along the direction of inclination from the first line to the second line and the direction of inclination from the first line to the third line in the substrate. A method of manufacturing a semiconductor device, comprising: dividing a substrate and forming one side surface of the divided substrate into an inclined surface.

According to the method for manufacturing a semiconductor light-emitting device according to an embodiment of the present invention, a semiconductor light-emitting device can be accurately chipped as intended with a high yield from a substrate having a nitride semiconductor layer laminated thereon. can provide a manufacturing method of

It is a schematic sectional drawing for demonstrating the manufacturing method of the semiconductor element of one Embodiment of this invention. It is a schematic sectional drawing for demonstrating the manufacturing method of the semiconductor element of one Embodiment of this invention. It is a schematic sectional drawing for demonstrating the manufacturing method of the semiconductor element of one Embodiment of this invention. It is a schematic sectional drawing for demonstrating the manufacturing method of the semiconductor element of one Embodiment of this invention. FIG. 1C is an enlarged schematic cross-sectional view of the main part of FIG. 1C; Fig. 1D is a schematic plan view of the entire substrate shown in Fig. 1D; FIG. 1D is a schematic plan view showing the entirety of another substrate shown in FIG. 1D; 1 is a schematic plan view showing a semiconductor device obtained by a method for manufacturing a semiconductor device according to one embodiment of the present invention; FIG. 4B is a schematic cross-sectional view taken along the line I-I' of FIG. 4A; FIG. It is a schematic sectional drawing for demonstrating the manufacturing method of the semiconductor device of other embodiment of this invention. It is a schematic sectional drawing for demonstrating the manufacturing method of the semiconductor device of other embodiment of this invention. It is a schematic sectional drawing for demonstrating the manufacturing method of the semiconductor device of other embodiment of this invention. It is a schematic sectional drawing for demonstrating the manufacturing method of the semiconductor device of other embodiment of this invention. FIG. 5D is an enlarged schematic cross-sectional view of the main part of FIG. 5C; It is a schematic plan view showing a semiconductor device obtained by a method for manufacturing a semiconductor device according to another embodiment of the present invention. 7B is a schematic cross-sectional view taken along line II-II' of FIG. 7A; FIG.

Hereinafter, embodiments of the present application will be described with reference to the drawings as appropriate. However, the embodiments described below are for embodying the technical idea of the present invention, and unless there is a specific description, the present invention is not limited to the following. The sizes and positional relationships of members shown in each drawing may be exaggerated for clarity of explanation. In the following description, the same or similar members are denoted by the same names and symbols, and detailed description thereof will be omitted as appropriate.
In the embodiment, the thickness direction of the substrate is the Z direction, the direction parallel to the main surface of the substrate and perpendicular to the Z direction is the X direction, and the Z direction and the X direction are parallel to the main surface of the substrate and are perpendicular to the Z direction. The vertical direction is sometimes described as the Y direction. 1B, 1C, 1D, and 2, the first work-affected portion, the second work-affected portion, and the third work-affected portion are shown in one section, but this is for convenience of explanation. Therefore, the first work-affected portion, the second work-affected portion, and the third work-affected portion do not necessarily have to be arranged on one two-dimensional plane (cross section) obtained by cutting the substrate in the Z direction.

In the conventional method of manufacturing a semiconductor light emitting device, a nitride semiconductor layer is usually laminated on a wafer made of a sapphire substrate, and the sapphire substrate has an orientation flat (mostly A plane and M plane. Also called orientation flat or OF). ), the sapphire substrate cracks obliquely in the film thickness direction, that is, in a manner that is inclined, and cracks extend to a part of the semiconductor layer that functions as an element. There was a case that the product was defective.
In order to avoid such cracks, a split groove is formed on the surface of the nitride semiconductor layer and/or the sapphire substrate, and the semiconductor layer laminated wafer is chipped by irradiating the inside of the sapphire substrate with a laser. A method is proposed.
However, there is a problem that the sapphire substrate is not cleaved as intended and cracks in oblique directions still appear. In addition, there is also a problem that the luminous efficiency of the obtained semiconductor device is lowered due to the deterioration part due to the multistage and intermittent laser irradiation over almost the entire thickness direction of the sapphire substrate.

On the other hand, in the method for manufacturing a semiconductor light emitting device according to the embodiment of the present application, the first line is formed at a predetermined position on the substrate having the nitride semiconductor layer laminated on the first main surface. The second line and the third line are respectively formed at predetermined positions with respect to the substrate, and an external force is applied to the obtained substrate so that the direction of inclination in the substrate from the first line toward the second line and the direction of inclination from the first line to the second line and the The substrate is divided along the direction of inclination from the first line to the third line. As a result, the side surfaces of the divided substrates are inclined.
By such a manufacturing method, the substrate having the nitride semiconductor layer laminated thereon can be divided easily and accurately with the side surfaces being inclined surfaces. As a result, a semiconductor device with improved light extraction efficiency can be efficiently manufactured.

[Method 1 for manufacturing a semiconductor light emitting device]
In the method for manufacturing a semiconductor light emitting device according to one embodiment of the present application,
A substrate having a first principal surface and a second principal surface opposite to the first principal surface is focused with a laser beam to a certain depth close to the first principal surface to form a first process-altered portion. , forming a first line arranged linearly in plan view,
The substrate on which the first line of the first work-affected part is formed is placed at a certain depth close to the second main surface and at a line-symmetrical position with respect to the first line in plan view. forming a second line and a third line in which the second work-affected portion and the third work-affected portion are arranged linearly in a plan view by condensing the laser beam;
By applying an external force to the obtained substrate, the substrate is bent along the direction of inclination from the first line to the second line and the direction of inclination from the first line to the third line in the substrate. It is characterized in that it is divided and one side surface of the divided substrate is inclined.
Forming the first line, the second line, and the third line linearly means that when forming the first work-affected portion, the second work-affected portion, and the third work-affected portion, for example, the first work-affected portion When forming, a plurality of first work-affected parts are formed in a certain direction, but at that time, the first line is formed by connecting the adjacent first work-affected parts by cracks . In addition, the crack may appear on the surface of the first main surface or the second main surface that is closer to the first work-affected portion. The same applies to the second line and the third line. In addition, since the lines are connected by cracks, the term "linear" refers to a connected state, and is not limited to a straight line.

(Formation of first breaking line)
In order to form the first break line, first, as shown in FIG. 1A, substrate 10 having nitride semiconductor layer 14 laminated on first main surface 101 is prepared.
The substrate 10 has a first major surface 101 and a second major surface 102 opposite the first major surface 101 . The first main surface 101 and the second main surface 102 are preferably parallel to each other. The first principal surface and/or the second principal surface may be flat or may have convex portions. The shape, size, etc. of the projections here are not particularly limited, and examples thereof include those described in Japanese Patent Laid-Open No. 2003-318441.
Various substrates such as an insulating substrate and a semiconductor substrate can be used as the substrate 10, but a substrate that does not have a remarkable cleavage property is preferable. This is because a substrate having a remarkable cleavability is easily cleaved by a slight external force, but it may not be possible to divide at the intended portion with high accuracy. In other words, the division of the substrate in the present application does not utilize the cleavage property, but utilizes the work-affected portion formed in the substrate, the fracture line, and the connection of cracks extending therefrom. The substrate is preferably, for example, a sapphire substrate or a silicon substrate. By using such a substrate, a nitride semiconductor layer can be grown with good crystallinity on the first main surface. In addition, since the cleavability is weak, the substrate can be divided at the intended portion with high accuracy by the process described later.

A substrate 10 such as a sapphire substrate, a silicon substrate, or the like is generally a wafer having an approximately disc shape and an orientation flat, as shown in FIG. 3A. The sapphire substrate is made of, for example, hexagonal Al ₂ O ₃ and has a C plane, A plane, R plane, or M plane, or a plane having an off angle of 1° to 5° with respect to these planes. may be used as the first main surface and the second main surface. In particular, the C-plane and a plane having an off angle of 1° to 5° with respect to the C-plane are preferably used as the first principal surface and the second principal surface. The orientation flat surface may be the A surface or the M surface, preferably the A surface.
The thickness of the substrate is, for example, 20 μm to 2 mm, preferably 50 μm to 500 μm, more preferably 80 μm to 160 μm. Further, a wafer-like one having a diameter of 50 mm to 150 mm is also included.
Examples of the nitride semiconductor layer ₁₄ include those represented by _{InxAlyGa1 -xyN} (0≤x≤1, 0≤y≤1, 0≤x+y≤1). In the nitride semiconductor layer, a first semiconductor layer, a light emitting layer, and a second semiconductor layer are laminated in this order from the substrate side. The thickness of the nitride semiconductor layer 14 can be set arbitrarily. A first electrode is electrically connected to the first semiconductor layer, and a second electrode is electrically connected to the second semiconductor layer.

Next, as shown in FIG. 1B, a first work-affected portion 11 is formed in the substrate 10 on the side closer to the first main surface 101 and at a certain depth. The side close to the first main surface 101 refers to the first main surface 101 side of the center of the total thickness of the substrate 10 .
The first work-affected portion 11 can be formed by, for example, a laser. That is, the laser beam is condensed with respect to a certain depth in the substrate 10 to form the first process-altered portion 11 . Then, the first main surface 101 of the substrate 10 is scanned with laser light in a predetermined direction, for example, the X direction. As the laser light for forming the first breaking line 111, a pulse laser, a continuous wave laser, or the like, which can process the substrate by causing multiphoton absorption, can be used. Among them, it is preferable to generate a pulse laser such as a femtosecond laser, a picosecond laser, or a nanosecond laser, which has a high peak output and can easily generate multiphoton absorption.
Thereby, a plurality of first work-affected portions 11 can be formed in an arbitrary direction, for example, the X direction. Then, the first work-affected parts 11 are arranged in a broken line shape to form a first broken line 111 as shown in FIG. 3A in plan view. The first breaking line 111 is preferably formed by one-step irradiation of laser light, that is, by one scanning.
The first work-affected portion 11 formed here can have a width w ₁ of, for example, 1 μm to 5 μm, and a length L ₁ of, for example, , 3 μm to 50 μm.
Due to the first work-affected portion 11 formed here, a part of the first work-affected portion 11 becomes a void on the first main surface 101 side of the substrate 10, and a crack extending from the first work-affected portion 11 is formed. It is formed. Further, cracks extending from the first work-affected portion 11 to the adjacent first work-affected portion 11 are formed in a plane parallel or substantially parallel to the first major surface 101 of the substrate 10 .
Note that the X direction can be, for example, a direction parallel or perpendicular to the orientation flat surface.

Various wavelengths of laser light for forming the first breaking line 111 can be used, for example, Nd:YAG laser, Nd: _YVO4 laser, Nd:YLF laser, titanium sapphire laser, and the like. The output power of the laser beam can be set to about 0.5 to 5W, for example. The frequency of the laser light can be, for example, 5-200 kHz. The pulse width of the laser light can be, for example, 100 fs to 50000 fs (femtoseconds). Specifically, a femtosecond laser with a center wavelength of 1030 nm is used. The wavelength of the laser light can be from 250 nm to 1100 nm. The irradiation scanning speed of the laser light can be 20 mm/sec to 2000 mm/sec.
The laser light may be applied from either the first main surface 101 or the second main surface 102, and for example, can be applied from the second main surface 102 side. The fixed depth here is the position of the depth d ₁ from the first main surface 101 of the substrate 10 as shown in FIG. 1B. The depth d ₁ can be appropriately adjusted depending on the thickness of the substrate 10, and is 2% to 49% of the thickness of the substrate 10 from the surface of the substrate 10 on which the laser light is irradiated, for example, the first main surface 101. Positions are mentioned, and positions of 3% to 20% are preferred. Specifically, when the thickness of the substrate 10 is 50 μm to 500 μm, the depth d ₁ can be 15 μm to 245 μm, and the depth d ₁ can be 30 μm to 150 μm.

Scanning with laser light can be performed by using a laser light irradiation device known in the art. In this case, the laser light irradiation device may be one that moves the stage on which the wafer is placed, one that moves the laser light source, or one that moves both the stage and the laser light source.
The scanning of the laser beam may be performed only once in order to form only one first breaking line 111 in the X direction. can be adjusted. For example, in addition to the X direction, the first breaking line may be formed in the Y direction by irradiating the laser light in the Y direction, that is, in a direction perpendicular to or parallel to the orientation flat surface. Moreover, when the planar shape of the semiconductor element to be obtained is a square, it is preferable to form the first breaking lines in both the X direction and the Y direction. Here, the formation of the first breaking line in the Y direction may be performed before or after the formation of the first breaking line in the X direction. You can go before or after.
As shown in FIGS. 3A and 3B, when forming a plurality of first breaking lines 111, the pitch _P1 can be appropriately set depending on the size of the semiconductor device to be obtained. Examples include 80 μm to 2000 μm.

(Formation of second breaking line and third breaking line)
Subsequently, as shown in FIG. 1C, a second breaking line 112 and a third breaking line 113 are formed on the substrate 10 on which the first breaking line 111 of the first work-affected portion 11 is formed. That is, at a constant depth close to the second main surface 102, in plan view, the second work-affected portion 12 and the third work-affected portion 13 are spaced apart by a distance P ₃ and A second work-affected portion 12 and a third work-affected portion 13 are formed by condensing laser beams at axisymmetric positions. As a result, in plan view, it is possible to form the second breaking line 112 and the third breaking line 113 in which the second work-affected portion 12 and the third work-affected portion are arranged in the form of breaking lines, respectively. The second breaking line 112 and the third breaking line 113 are preferably formed by one stage irradiation of laser light, that is, by one scanning.
The second work-affected portion 12 and the third work-affected portion 13 can be formed by a method similar to the method for forming the first work-affected portion. The second work-affected portion 12 and the third work-affected portion 13 may be formed by irradiating laser light from either the first main surface 101 side or the second main surface 102 side of the substrate 10. It can be formed by irradiating laser light from the main surface 102 side. In particular, it is preferable to irradiate the laser beam for forming the second work-affected portion 12 and the third work-affected portion 13 from the same side as the laser light irradiation for forming the first work-affected portion 11 .

As shown in FIG. 1C, the constant depth may be different depths in the second work-affected portion 12 and the third work-affected portion 13, but preferably the same depth. Then, it is positioned at a depth d ₂ from the second main surface 102 of the substrate 10 . The depth d ₂ can be appropriately adjusted depending on the thickness of the substrate 10, and is 2% to 45% of the thickness of the substrate 10 from the surface of the substrate 10 on which the laser light is irradiated, for example, the second main surface 102. Positions are mentioned, and positions of 3% to 20% are preferred. Specifically, when the thickness of the substrate 10 is 50 μm to 500 μm, the depth d ₂ can be 15 μm to 245 μm, and the depth d ₂ can be 30 μm to 150 μm.

The second breaking line 112 and the third breaking line 113 are preferably formed at positions symmetrical with respect to the first breaking line 111 in plan view. In other words, in a plan view, the second breaking line 112 is positioned at a position where the distance between the first breaking line 111 and the second breaking line 112 is the same as the distance between the first breaking line 111 and the third breaking line 113. and a third breaking line 113 is preferably formed. By setting in this way, the side surfaces of the semiconductor light emitting device after manufacture can be made to have the same inclination angle, and the uniformity of the light extraction efficiency on the light emitting surface and its periphery can be achieved. These distances P ₂ (see FIG. 3A) can be appropriately adjusted depending on the thickness of the substrate 10 to be used and the like. From another point of view, for example, as shown in FIG. A connecting line Q can be set at α degrees with respect to a perpendicular line R to the first main surface of the substrate passing through the first work-affected portion 11 . The α degree is, for example, 10° to 30°, preferably about 8°±5°. Although it is preferable that the angle formed by the line S and the perpendicular R and the angle formed by the line Q and the perpendicular R are the same, it is not excluded that they are different.

In this way, by forming the first break line 111 by the first work-affected portion 11, the second break line 112 by the second work-affected portion 12, and the third break line 113 by the third work-affected portion 13, FIG. , the crack extending from the first work-affected portion 11 in the thickness direction of the substrate, particularly toward the second main surface 102 side, is connected to the crack extending from the second work-affected portion 12 in the thickness direction of the substrate. A crack extending from the first work-affected portion 11 in the thickness direction of the substrate, particularly toward the second main surface 102 side, is connected to a crack extending from the third work-affected portion 13 in the thickness direction of the substrate. Further, the crack extending in the in-plane direction of the substrate from the first work-affected portion 11 is connected to the crack extending in the in-plane direction of the substrate from the adjacent first work-affected portion 11, and the second work-affected portion 12 extends to the substrate. A crack extending in the in-plane direction is connected to a crack extending in the in-plane direction of the substrate from the adjacent second work-affected portion 12, and a crack extending in the in-plane direction of the substrate from the third work-affected portion 13 is adjacent. It connects with the crack extending in the in-plane direction of the substrate from the third work-affected portion 13 . Such cracks can be effectively connected, for example, by appropriately adjusting conditions such as laser light output. Thereby, the division of the substrate, which will be described later, can be performed at the intended portion with high accuracy.
As described above, when a plurality of first breaking lines 111 are formed, it is preferable to similarly form a plurality of second breaking lines 112 and third breaking lines 113 . In that case they may or may not be parallel to each other. Moreover, in a part thereof, the angle formed by the line S and the perpendicular line R and the angle formed by the line Q and the perpendicular line R may be different from each other.

(substrate division)
The substrate obtained is divided. Dividing can be performed by applying an external force to the substrate 10 without using the cleavage property of the substrate. That is, the crack between the first work-affected portion 11 and the second work-affected portion 12, the crack between the first work-affected portion 11 and the third work-affected portion 13, and the second work-affected portion 12 shown in FIG. A crack between the second work-affected portions 12, a crack between the third work-affected portions 13 adjacent to the third work-affected portion 13, and a crack extending from the first work-affected portion 11 to the second main surface side described above. Even if a crack extending from the first work-affected portion 11 to the adjacent first work-affected portion 11 is formed, an external force is applied to the substrate that has not yet been cut so that the substrate is divided from each other at the cracks. In addition, divide the substrate. Such an external force is applied in the thickness direction of the substrate using a chip breaker using a knife, blade, roller, notch, or the like. Also, by attaching the substrate to, for example, a stretchable sheet and stretching the stretchable sheet, an external force can be applied to the substrate. As a result, the substrate can be cut at the intended site.

The side surface of the divided substrate can be an inclined surface along the direction of the crack between the first work-affected portion 11 and the second work-affected portion 12 . Alternatively, it can be an inclined surface along the crack direction between the first work-affected portion 11 and the third work-affected portion 13 . In other words, as shown in FIG. 2, it can be an inclined surface along the line S connecting the first work-affected portion 11 and the second work-affected portion 12 . Alternatively, it can be an inclined surface along the line Q connecting the first work-affected portion 11 and the third work-affected portion 13 . In other words, it can be an inclined surface along the direction of inclination from the first breaking line 111 to the second breaking line 112 . Alternatively, it can be an inclined surface along the direction of inclination from the first breaking line 111 to the third breaking line 113 .
As shown in FIG. 3A, when a plurality of first breaking lines 111, second breaking lines 112, and third breaking lines 113 are formed in the X direction, the divided substrate is tilted on two opposite sides. can be a face. Further, as shown in FIG. 3B, when a plurality of first breaking lines 111, second breaking lines 112, and third breaking lines 113 are formed in the X direction and the Y direction, the divided substrates face each other. In addition, two pairs of two side surfaces can be inclined surfaces. Then, as shown in FIGS. 4A and 4B, a semiconductor device having a square planar shape can be obtained.
Note that the first breaking line 111, the second breaking line 112 and the third breaking line 111, according to the planar shape of the semiconductor device to be obtained (for example, a polygon such as a triangle, a rhombus, a trapezoid, a hexagon, or a substantially polygonal shape). The formation direction and number of the breaking lines 113 can be arbitrarily set. For example, by arranging them not only parallel or perpendicular to the orientation flat, but also at an angle of 60°, 120°, etc., the planar shape of the semiconductor element can be set to a triangle, rhombus, trapezoid, hexagon, etc. .

In this embodiment, the second main surface side of the substrate may be ground and/or polished at any stage such as before and after irradiation with laser light and before division of the substrate. The thinner the final thickness after grinding and/or polishing, the less damage to the semiconductor laminate and the like at the time of cutting the wafer, and the more efficiently the light emitting device can be manufactured. Wafer grinding and polishing may utilize any of the methods known in the art. Among them, grinding and polishing using abrasive grains such as diamond are preferable.

When the planar shape of the semiconductor device manufactured in this way is square, for example, as shown in FIGS. can be done. However, the inclination angles of all the side surfaces do not necessarily have to be the same. In this way, by forming the side surfaces of the substrate into inclined surfaces, particularly by forming the entire side surfaces of the substrate into inclined surfaces, the substrate becomes shaped like a convex lens. Therefore, the light emitted by the nitride semiconductor layer can be reduced from being reflected at the substrate side surface at the critical angle, re-reflected inside the semiconductor element, becoming stray light, and lost or lost. That is, even when the light emitted by the nitride semiconductor layer is reflected by the side surface of the substrate and returns to the inside, the light incident on the side surface of the substrate again is reflected in a different direction. Extraction efficiency can be increased. As a result, the light extraction efficiency can be improved.

[Manufacturing Method 2 of Semiconductor Light Emitting Device]
A method for manufacturing a semiconductor light emitting device according to another embodiment includes:
A substrate having a nitride semiconductor layer laminated on a first main surface is focused with a laser beam to a certain depth close to a second main surface opposite to the first main surface to form a first process-affected portion. , in plan view, forming a first break line arranged in the form of a break line,
A laser beam is applied to the substrate on which the breaking line of the first work-affected part is formed, at a certain depth close to the first main surface and at a line-symmetrical position with respect to the first breaking line in plan view. Condensing light to form a second break line and a third break line in which the second work-affected portion and the third work-affected portion are arranged in a plan view, respectively,
An external force is applied to the obtained substrate along the inclination direction from the first breaking line to the second breaking line and the inclination direction from the first breaking line to the third breaking line in the substrate. and dividing the substrate by using a slanted surface.

(Formation of first breaking line)
In order to form the first break line, first, as shown in FIG. 5A, substrate 10 having nitride semiconductor layer 14 laminated on first main surface 101 is prepared.
Next, as shown in FIG. 5B, a first work-affected portion 11 is formed at a constant depth d ₁ on the side closer to the second main surface 102 in the substrate 10 . The side close to the second main surface 102 refers to the second main surface 102 side of the center of the total thickness of the substrate 10 . The depth d ₁ can be appropriately set within the range described above.

(Formation of second breaking line and third breaking line)
Subsequently, as shown in FIG. 5C, a second breaking line 112 and a third breaking line 113 are formed on the substrate 10 on which the first breaking line 111 of the first work-affected portion 11 is formed. That is, at a certain depth close to the first main surface 101, in plan view, the second work-affected portion 12 and the third work-affected portion 13 are spaced apart by a distance P ₃ and A second work-affected portion 12 and a third work-affected portion 13 are formed by condensing laser beams at axisymmetric positions. As a result, in plan view, it is possible to form the second breaking line 112 and the third breaking line 113 in which the second work-affected portion 12 and the third work-affected portion are arranged in the form of breaking lines, respectively. The second breaking line 112 and the third breaking line 113 are preferably formed by one stage irradiation of laser light, that is, by one scanning.
The second work-affected portion 12 and the third work-affected portion 13 can be formed by a method similar to the method for forming the first work-affected portion. The second work-affected portion 12 and the third work-affected portion 13 may be formed by irradiating laser light from either the first main surface 101 side or the second main surface 102 side of the substrate 10. It can be formed by irradiating laser light from the main surface 101 side. In particular, it is preferable to irradiate the laser beam for forming the second work-affected portion 12 and the third work-affected portion 13 from the same side as the laser light irradiation for forming the first work-affected portion 11 .

As shown in FIG. 5C, the constant depth may be different depths in the second work-affected portion 12 and the third work-affected portion 13, but preferably the same depth. Then, it is positioned at a depth d ₂ from the first main surface 101 of the substrate 10 . The depth d ₂ can be appropriately adjusted depending on the thickness of the substrate 10, and is 2% to 45% of the thickness of the substrate 10 from the surface of the substrate 10 on which the laser light is irradiated, for example, the first main surface 101. Positions are mentioned, and positions of 3% to 20% are preferred. Specifically, when the thickness of the substrate 10 is 50 μm to 500 μm, the depth d ₂ can be 15 μm to 245 μm, and the depth d ₂ can be 30 μm to 150 μm.

The second breaking line 112 and the third breaking line 113 are preferably formed at positions symmetrical with respect to the first breaking line 111 in plan view. In other words, in a plan view, the second breaking line 112 is positioned at a position where the distance between the first breaking line 111 and the second breaking line 112 is the same as the distance between the first breaking line 111 and the third breaking line 113. and a third breaking line 113 is preferably formed. By setting in this way, the side surfaces of the semiconductor light emitting element after manufacture can be made to have the same inclination angle, and the uniformity of the light extraction efficiency on the light emitting surface and its periphery can be achieved. These distances P ₂ (see FIG. 3A) can be appropriately adjusted depending on the thickness of the substrate 10 to be used and the like. From another point of view, for example, as shown in FIG. A connecting line Q can be set at α degrees with respect to a perpendicular line R to the first main surface of the substrate passing through the first work-affected portion 11 . The α degree is, for example, 10° to 30°, preferably about 8°±5°. Although it is preferable that the angle formed by the line S and the perpendicular R and the angle formed by the line Q and the perpendicular R are the same, it is not excluded that they are different.

In this way, by forming the first break line 111 by the first work-affected portion 11, the second break line 112 by the second work-affected portion 12, and the third break line 113 by the third work-affected portion 13, FIG. , the crack extending from the first work-affected portion 11 in the thickness direction of the substrate, particularly toward the first main surface 101 side, is connected to the crack extending from the second work-affected portion 12 in the thickness direction of the substrate. A crack extending from the first work-affected portion 11 in the thickness direction of the substrate, particularly toward the first main surface 101 side, is connected to a crack extending from the third work-affected portion 13 in the thickness direction of the substrate. Further, the crack extending in the in-plane direction of the substrate from the first work-affected portion 11 is connected to the crack extending in the in-plane direction of the substrate from the adjacent first work-affected portion 11, and the second work-affected portion 12 extends to the substrate. A crack extending in the in-plane direction is connected to a crack extending in the in-plane direction of the substrate from the adjacent second work-affected portion 12, and a crack extending in the in-plane direction of the substrate from the third work-affected portion 13 is adjacent. It connects with the crack extending in the in-plane direction of the substrate from the third work-affected portion 13 . Such cracks can be effectively connected, for example, by appropriately adjusting conditions such as laser light output. Thereby, the division of the substrate, which will be described later, can be performed at the intended portion with high accuracy.

As described above, when a plurality of first breaking lines 111 are formed, it is preferable to similarly form a plurality of second breaking lines 112 and third breaking lines 113 . In that case they may or may not be parallel to each other. Moreover, in a part thereof, the angle formed by the line S and the perpendicular line R and the angle formed by the line Q and the perpendicular line R may be different from each other.

(substrate division)
The substrate obtained is divided. Division of the substrate is the same as in one embodiment.
When the planar shape of the semiconductor device manufactured in this way is a square, for example, as shown in FIGS. be able to. However, the inclination angles of all the side surfaces do not necessarily have to be the same. In this way, by forming the side surfaces of the substrate into inclined surfaces, particularly by forming the entire side surfaces of the substrate into inclined surfaces, the substrate becomes shaped like a convex lens. Therefore, the light emitted by the nitride semiconductor layer can be reduced from being reflected at the substrate side surface at the critical angle, re-reflected inside the semiconductor element, becoming stray light, and lost or lost. That is, even when the light emitted by the nitride semiconductor layer is reflected by the side surface of the substrate and returns to the inside, the light incident on the side surface of the substrate again is reflected in a different direction. Extraction efficiency can be increased. As a result, the light extraction rate can be improved.

According to the method for manufacturing a semiconductor light emitting device according to another embodiment of the present invention, as in the one embodiment of the present invention, a substrate in which a nitride semiconductor layer is laminated on a substrate is intended with an extremely high yield. It is possible to provide a method for manufacturing a semiconductor light emitting device that can be accurately chipped as described above.

Finally, according to one embodiment of the present application, at least one of the following (1) to (9) includes a method for manufacturing a semiconductor device.

(1) A substrate having a first principal surface and a second principal surface opposite to the first principal surface is focused with a laser beam at a constant depth close to the first principal surface to perform a first processing. Forming a first breaking line in which the altered portion is arranged in a breaking line shape in a plan view,
A laser beam is applied to the substrate on which the breaking line of the first work-affected portion is formed, at a certain depth near the second main surface and at a line-symmetrical position with respect to the first breaking line in plan view. Condensing light to form a second break line and a third break line in which the second work-affected portion and the third work-affected portion are arranged in a plan view, respectively,
An external force is applied to the obtained substrate along the inclination direction from the first breaking line to the second breaking line and the inclination direction from the first breaking line to the third breaking line in the substrate. and dividing the substrate by using a slanted surface.
(2) The method of manufacturing a semiconductor device according to (1), wherein a nitride semiconductor layer is stacked on the first main surface of the substrate.
(3) In (1) or (2), the substrate is a sapphire substrate or a silicon substrate.
(4) Any one of (1) to (3), wherein the first break line is formed at a constant depth in the range of 15 μm to 245 μm from the second main surface of the substrate,
The second breaking line and the third breaking line are each formed at a constant depth ranging from 15 μm to 245 μm from the first major surface of the substrate.
(5) In any one of (1) to (4), one side surface of the divided substrate is inclined by 10° to 30°.
(6) In any one of (1) to (5), the substrate is a wafer having an orientation flat, and the first, second and third break lines are aligned with respect to the orientation flat. parallel or perpendicular to each other.
(7) In any one of (1) to (6), by scanning a plurality of each of the first breaking line, the second breaking line, and the third breaking line with a pulse laser to the substrate a plurality of times, form respectively.
(8) In (7), the planar shape of the semiconductor element is a quadrangle,
The substrate is divided into two opposing sides or two pairs of opposing sides, each of which is inclined.
(9) In (7) or (8), the plurality of side surfaces of the divided substrate are inclined by 10° to 30°.

10 substrate 101 first principal surface 102 second principal surface 11 first work-affected portion 111 first break line 12 second work-affected portion 112 second break line 13 third work-affected portion 113 third break line 14 nitride semiconductor layer

Claims (10)

A substrate having a first principal surface and a second principal surface opposite to the first principal surface is focused with a laser beam to a certain depth close to the first principal surface to form a first process-altered portion. , in plan view, forming a first line arranged linearly by one stage of irradiation,
The substrate on which the first line of the first work-affected part is formed is placed at a certain depth close to the second main surface and at a line-symmetrical position with respect to the first line in plan view. A laser beam is focused to form a second line and a third line in which the second work-affected portion and the third work-affected portion are arranged in the form of a breaking line by only one stage of irradiation in a plan view, and a cross-sectional view is performed. wherein only the first work-affected portion and the second work-affected portion are formed as work-affected portions on a line connecting the first work-affected portion and the second work-affected portion; and forming only the first work-affected portion and the third work-affected portion as work-affected portions on a line connecting the part and the third work-affected portion;
By applying an external force to the obtained substrate, the substrate is bent along the direction of inclination from the first line to the second line and the direction of inclination from the first line to the third line in the substrate. A method of manufacturing a semiconductor device, comprising: dividing a substrate and forming one side surface of the divided substrate into an inclined surface. 2. The method of manufacturing a semiconductor device according to claim 1, wherein a nitride semiconductor layer is laminated on said first main surface of said substrate. 3. The method of manufacturing a semiconductor device according to claim 1, wherein said substrate is a sapphire substrate or a silicon substrate. forming the first line to a constant depth ranging from 15 μm to 245 μm from the first major surface of the substrate;
4. The method of manufacturing a semiconductor device according to claim 1, wherein said second line and said third line are each formed at a constant depth ranging from 15 [mu]m to 245 [mu]m from said second main surface of said substrate. . forming the first line at a position from 2% to 49% of the thickness of the substrate from the first main surface of the substrate;
4. The semiconductor device according to claim 1, wherein the second line and the third line are formed at positions 2% to 45% of the thickness of the substrate from the second main surface of the substrate. manufacturing method. 6. The method of manufacturing a semiconductor device according to claim 1, wherein one side surface of said divided substrate is inclined by 10[deg.] to 30[deg.] with respect to a line perpendicular to said first main surface of said substrate. . 7. A semiconductor device according to any one of claims 1 to 6, wherein said substrate is a wafer having an orientation flat and said first, second and third lines are formed parallel or perpendicular to said orientation flat. manufacturing method. 8. The method of manufacturing a semiconductor device according to claim 1, wherein a plurality of each of the first lines, the second lines and the third lines are formed by scanning the substrate with a pulsed laser a plurality of times. The planar shape of the semiconductor element is a quadrangle,
9. The method of manufacturing a semiconductor device according to claim 8, wherein the substrate is divided into two opposing side surfaces or two pairs of opposing two side surfaces, each of which is a slanted surface. 10. The method of manufacturing a semiconductor device according to claim 8, wherein a plurality of side surfaces of said divided substrate are inclined by 10[deg.] to 30[deg.] with respect to a perpendicular to said first main surface of said substrate.

Images