JP2020119956A - Manufacturing method and manufacturing apparatus of semiconductor element - Google Patents

Abstract

To provide a manufacturing method of a semiconductor element which improves the accuracy of position that is a starting point of cleavage, and reduces the load when cleavage is performed to suppress generation of a foreign matter, and improves the yield.SOLUTION: A manufacturing method of a semiconductor element which divides a semiconductor substrate along a planned dividing line includes the steps of: preparing a semiconductor substrate including a first semiconductor layer having a front surface and a back surface, and a second semiconductor layer provided on the front surface of the first semiconductor layer; partially removing the second semiconductor layer using the second semiconductor layer remaining on the planned dividing line as an absorption layer; forming a groove on the planned dividing line on the surface of the semiconductor substrate; and dividing the semiconductor substrate along the planned dividing line while applying bending stress to the semiconductor substrate, and irradiating the absorption layer with laser light to heat the absorption layer, and the width of the absorption layer is smaller than the width of the groove.SELECTED DRAWING: Figure 1

Description

The present invention relates to a semiconductor element manufacturing method and a manufacturing apparatus, and more particularly to a semiconductor element manufacturing method and a manufacturing apparatus for dividing a semiconductor substrate into individual semiconductor elements.

As a method of dividing the semiconductor substrate into individual semiconductor elements, a method using cleavage, which is a method of dividing the semiconductor substrate along the crystal orientation, has been used. As such a cleavage method, for example, a first step of forming a plurality of semiconductor elements on the surface of the semiconductor substrate, a second step of forming a cleavage groove for cleavage by etching or the like between the plurality of semiconductor elements, A method including a third step of cleaving a semiconductor substrate by pressing a jig along the cleavage groove is known (see, for example, Patent Document 1).
A method is also known in which a groove is formed in a semiconductor substrate, a light absorbing material is attached in the groove, light is irradiated, and the semiconductor substrate is cleaved by utilizing the volume expansion of the light absorbing material that has absorbed the light. (For example, see Patent Document 2).

JP, 2003-86900, A Japanese Patent No. 3816147

However, in the method described in Patent Document 1, the cleavage is performed using the groove formed in the semiconductor substrate, so that the starting point when the cleavage is performed is difficult to determine and the crack may progress from a position other than the groove. Further, it is necessary to press the cleavage jig with a relatively large load, and the divided substrates rub against each other after the cleavage to generate foreign matter, and there is also a problem that the foreign matter adheres to the semiconductor element and the yield decreases. ..

In addition, the method described in Patent Document 2 requires a step for attaching the light absorbing material in the groove, which causes a problem that the manufacturing process is complicated. Further, since the light absorbing material remaining after the cleavage becomes a pollution source of the vacuum device, there is a problem that a step of removing the light absorbing material is further required.

Therefore, an object of the present invention is to improve the accuracy of the position that is the starting point of cleavage, reduce the load when performing cleavage, suppress the generation of foreign matter, and improve the yield.

A first aspect of the present invention is
A method of manufacturing a semiconductor device, wherein a semiconductor substrate is divided along a dividing line,
Providing a semiconductor substrate including a first semiconductor layer having a front surface and a back surface, and a second semiconductor layer provided on the front surface of the first semiconductor layer;
Partially removing the second semiconductor layer and using the second semiconductor layer remaining on the planned dividing line as an absorption layer;
Forming a groove on the planned dividing line on the surface of the semiconductor substrate;
While applying bending stress to the semiconductor substrate, by irradiating the absorption layer with laser light to heat the absorption layer, dividing the semiconductor substrate at the dividing line,
In the manufacturing method, the width of the absorption layer is smaller than the width of the groove.

The second aspect of the present invention is
A method of manufacturing a semiconductor device, wherein a semiconductor substrate is divided along a dividing line,
Providing a semiconductor substrate including a first semiconductor layer having a front surface and a back surface;
Forming a groove on the planned dividing line on the surface of the first semiconductor layer;
A step of selectively forming an absorption layer inside the groove,
Dividing the semiconductor substrate along the dividing line by irradiating the absorption layer with laser light to heat the absorption layer while applying bending stress to the semiconductor substrate. It is a manufacturing method.

A third aspect of the present invention is
A method of manufacturing a semiconductor device, wherein a semiconductor substrate is divided along a dividing line,
Providing a semiconductor substrate including a first semiconductor layer having a front surface and a back surface, and a second semiconductor layer provided on the front surface of the first semiconductor layer;
Bonding a sheet to the back surface of the first semiconductor layer,
Partially removing the second semiconductor layer and using the second semiconductor layer remaining on the planned dividing line as an absorption layer;
Forming a groove on the planned dividing line on the surface of the semiconductor substrate;
While applying bending stress to the semiconductor substrate, by irradiating the absorption layer with laser light from the back surface side of the semiconductor substrate to heat the absorption layer, dividing the semiconductor substrate at the dividing line, Including
The width of the absorption layer is smaller than the width of the groove,
The focused spot of the laser light overlaps with the interface between the first semiconductor layer and the sheet, and at the focused spot, the laser light is absorbed by the first semiconductor layer and heats the first semiconductor layer. It is a manufacturing method characterized by the above.

A fourth aspect of the present invention is
A semiconductor device manufacturing apparatus for dividing a semiconductor substrate along a dividing line,
Two parallel receiving blades for mounting the semiconductor substrate,
A pressing blade that presses the semiconductor substrate to apply bending stress,
A laser light source for irradiating the semiconductor substrate with laser light,
A lens that collects the laser light to form a condensed spot that overlaps the semiconductor substrate,
And a position moving unit that adjusts the position of the focused spot by changing the relative position between the laser light source and the semiconductor substrate.

A fifth aspect of the present invention is
A method of manufacturing a semiconductor device, wherein a semiconductor substrate is divided along a dividing line,
Providing a semiconductor substrate including a first semiconductor layer having a front surface and a back surface, and a second semiconductor layer provided on the front surface of the first semiconductor layer;
Partially removing the second semiconductor layer and using the second semiconductor layer remaining on the planned dividing line as an absorption layer;
Forming a groove on the planned dividing line on the surface of the semiconductor substrate;
Irradiating the absorption layer of the semiconductor substrate with a laser beam to heat the absorption layer,
Applying a bending stress to the semiconductor substrate, and dividing the semiconductor substrate at the dividing line,
In the manufacturing method, the width of the absorption layer is smaller than the width of the groove.

With the method and the apparatus for manufacturing a semiconductor element according to the present invention, the starting point of cleavage when dividing a semiconductor substrate can be accurately controlled, and the dividing line can be controlled with high precision. Further, by reducing the load required for cleavage, it is possible to prevent the generation of foreign matter due to the rubbing of the semiconductor substrates during cleavage, and improve the yield of semiconductor elements.

It is a perspective view which shows the outline of the manufacturing device of the semiconductor element concerning Embodiment 1 of this invention. FIG. 3 is a schematic diagram of a method for manufacturing a semiconductor element using the manufacturing apparatus according to the first embodiment of the present invention. FIG. 3 is a schematic diagram of a method for manufacturing a semiconductor element using the manufacturing apparatus according to the first embodiment of the present invention. FIG. 3 is a schematic diagram of a method for manufacturing a semiconductor element using the manufacturing apparatus according to the first embodiment of the present invention. FIG. 3 is a schematic diagram of a method for manufacturing a semiconductor element using the manufacturing apparatus according to the first embodiment of the present invention. FIG. 3 is a schematic diagram of a method for manufacturing a semiconductor element using the manufacturing apparatus according to the first embodiment of the present invention. It is a schematic diagram of a manufacturing method of a semiconductor element using a manufacturing device concerning a 2nd embodiment of the present invention. It is a schematic diagram of a manufacturing method of a semiconductor element using a manufacturing device concerning a 2nd embodiment of the present invention. It is a schematic diagram of a manufacturing method of a semiconductor element using a manufacturing device concerning a 2nd embodiment of the present invention. It is a schematic diagram of a manufacturing method of a semiconductor element using a manufacturing device concerning a 3rd embodiment of the present invention. It is a schematic diagram of a manufacturing method of a semiconductor element using a manufacturing device concerning a 4th embodiment of the present invention. It is a schematic diagram of a manufacturing method of a semiconductor element using a manufacturing device concerning a 4th embodiment of the present invention. It is a schematic diagram of a manufacturing method of a semiconductor element using a manufacturing device concerning a 5th embodiment of the present invention. It is a schematic diagram of a manufacturing method of a semiconductor element using a manufacturing device concerning a 5th embodiment of the present invention.

In the drawings of this specification, the same reference numerals indicate the same or corresponding portions. Further, in this specification, a “crack” is defined as a surface of a separated portion where a bond between atoms of a semiconductor substrate is cut off. When there is no possibility of confusion, the line of intersection between the crack and the semiconductor substrate surface is also described as a crack.

Embodiment 1.
FIG. 1 is a perspective view showing the outline of a semiconductor device manufacturing apparatus according to a first embodiment of the present invention, which is wholly represented by 100. The manufacturing apparatus 100 includes a laser irradiation unit 40 for irradiating the semiconductor substrate 1 with the laser light L. The laser irradiation means 40 includes a laser light source 42 that emits laser light L and a mirror 43. The laser light source 42 is, for example, a YAG pulse laser.

The laser light L emitted from the laser light source 42 is reflected by the mirror 43 and goes toward the semiconductor substrate 1 to be divided. Further, the laser irradiation means 40 includes cylindrical lenses 411 and 412 and an objective lens 413. The laser light L reflected by the mirror 43 enters the cylindrical lens 411, then passes through the cylindrical lens 412, and travels toward the objective lens 413 in the direction of the semiconductor substrate 1.

The cross-sectional shape (shape on the XY plane) of the laser light L emitted from the laser light source 42 and before entering the cylindrical lens 411 is a perfect circle. The focal length of the cylindrical lens 411 is f _C1 , and the focal length of the cylindrical lens 412 is f _C2 (|f _C1 |>|f _C2 |). Here, it is defined that the focal length is negative when the lens is a concave lens.

When the cylindrical lenses 411 and 412 are arranged such that the inter-lens distance Dc is D _C =f _C1 +f _C2 , the laser light L becomes a parallel light beam, and the cross section perpendicular to the traveling direction thereof has a short diameter and a long diameter. The elliptical shape is 1/e times (here, e=|f _C1 |).

In the manufacturing apparatus 100 according to the first embodiment, the cylindrical lenses 411 and 412 are arranged such that the short diameter is parallel to the Y axis and the long diameter is parallel to the X axis. In this specification, e may be referred to as an ellipticity ratio. In the case where the cylindrical lenses 411 and 412 are not provided, the shape of the cross section (XY plane) perpendicular to the traveling direction of the laser light L remains a perfect circle, and this case can be understood as the ellipticity ratio e=1.

The light that has passed through the cylindrical lens 412 then enters the objective lens 413 and is condensed on the condensing spot L1. When the cylindrical lenses 411 and 412 are installed as described above, the condensed spot L1 has an elliptical shape whose major axis is parallel to the Y axis and whose major axis is e times the minor axis. By forming the converging spot L1 into an elliptical shape, cracks are easily formed along the major axis direction of the ellipse.

The manufacturing apparatus 100 preferably includes a lens barrel (not shown) that integrally holds the cylindrical lenses 411 and 412 and the objective lens 413. The mirror 43 is preferably held by a mirror holder (not shown). In order to adjust both the position of the laser light L and the laser beam direction, the manufacturing apparatus 100 preferably has a plurality of sets of the mirror 43 and the mirror holder. Here, the configuration in which the manufacturing apparatus 100 includes the mirror 43 has been described, but the configuration may be such that the laser light L from the laser light source 42 is directly incident on the cylindrical lens 411 without the mirror 43.

Further, the manufacturing apparatus 100 has two receiving blades 32 and a pressing blade 31, the semiconductor substrate 1 is placed on the receiving blade 32, and is arranged between the receiving blade 32 and the pressing blade 31. It Here, in order to facilitate understanding, the direction perpendicular to the surface of the semiconductor substrate 1 is defined as the Z-axis (the upward direction in the vertical direction is positive), and the X-axis and the Y-axis orthogonal to each other are within the surface of the semiconductor substrate 1. Shall be included. The receiving blade 32 has a prismatic shape whose longitudinal direction is parallel to the Y axis. The two receiving blades 32 have the same shape, and are arranged in parallel at the same position in the Y-axis direction and apart from each other in the X-axis direction.

On the other hand, the pressing blade 31 is arranged with its longitudinal direction parallel to the Y axis, and has a side or a surface that functions as a blade on the lower side. The cross section in the XZ plane has a substantially triangular prism shape. The pressing blade 31 is arranged such that the position in the X-axis direction is between the positions of the two receiving blades 32 in the X-axis direction. In this way, the semiconductor substrate 1 is arranged between the two receiving blades 32 and the pressing blade 31, and the pressing blade 31 is pressed upward, so that the pressing blade is the load point and the receiving blade is the supporting point. The three-point bending can be performed to give the semiconductor substrate 1 a mechanical bending whose lower side is a mountain.

Furthermore, the manufacturing apparatus 100 includes a positioning unit (not shown) for irradiating the desired position with the laser light L and dividing the semiconductor substrate 1 at the desired position. The positioning means includes a receiving blade stage + (not shown) that supports the receiving blade 32. The receiving blade stage preferably has a mechanism for adjusting the distance between the two receiving blades 32. Further, the positioning means preferably includes, for example, a pressing blade stage (not shown) that moves the pressing blade 31 in the Z-axis direction. Since the manufacturing conditions vary depending on the conditions such as the material and size of the semiconductor substrate 1, the pressing blade stage further adjusts the rotation of the pressing blade 31 about the X axis (the inclination of the pressing blade 31) ( (Not shown).

Further, the positioning means of the manufacturing apparatus 100 includes, for example, a work stage (not shown) for moving the semiconductor substrate 1 in the X-axis and Y-axis directions and rotating it around the Z-axis. Specifically, after the sheet 20 is attached to the semiconductor substrate 1, the sheet 20 (and the semiconductor substrate 1) is attached to the ring. The ring is attached to the work stage, and the work stage moves the ring in the XY axis directions and rotates about the Z axis. The receiving blade stage, the pressing blade stage, and the work stage are preferably electric stages in order to improve production efficiency.

The manufacturing apparatus 100 may include an upper unit support material (not shown) that supports the laser irradiation means 40 and the pressing blade stage. The receiving blade stage, the work stage, and the upper unit support material are fixed on a base (not shown).

In the above description, the work stage for moving the semiconductor substrate 1 has been described as a means for changing the relative position between the semiconductor substrate 1 and the condensing point L1. However, the manufacturing apparatus 100 according to the first embodiment is not limited to this. The present invention is not limited to this, and a known optical system capable of adjusting the position of the focal point L1 such as a galvano scan mirror may be used.

Next, a method of manufacturing a semiconductor element using the manufacturing apparatus 100 will be described with reference to FIGS. For easy understanding, FIG. 2 is upside down from FIG.

First, as shown in FIG. 2, the sheet 20 is attached to the back surface of the semiconductor substrate 1 having a front surface and a back surface. One or more semiconductor elements are formed on the surface of the semiconductor substrate 1, and the semiconductor substrate 1 is divided for each semiconductor element along a dividing line 14.

In the process of FIG. 2, the semiconductor substrate 1 having the sheet 20 attached to the back surface is placed between the pressing blade 31 and the two receiving blades 32. Here, in order to facilitate understanding, the direction perpendicular to the surface of the semiconductor substrate 1 is defined as the Z axis (the downward direction in the vertical direction is positive), and the two axes orthogonal to each other in the surface of the semiconductor substrate 1 are defined as the X axis and The Y axis is used. The receiving blade 32 has a prismatic shape whose longitudinal direction is parallel to the Y axis. The two receiving blades 32 have the same shape and are arranged in parallel at the same position in the X-axis direction and apart from each other in the Y-axis direction.

The semiconductor substrate 1 has an element forming region 1b in which a semiconductor element is formed and an ear portion 1a around the element forming region 1b. In the element forming region 1b, the epitaxial layer 12b is formed on the substrate layer 11. On the other hand, the ear layer 1a also has the epitaxial layer 12a formed on the substrate layer 11. However, as can be seen from FIG. 2, the width of the epitaxial layer 12a in the X-axis direction is smaller than the width of the epitaxial layer 12b in the X-axis direction. It is getting smaller. In this specification, the "width" of the epitaxial layer 12a and the groove portion means the length in the X-axis direction.

The substrate layer 11 is made of, for example, InP (indium phosphide), Si (silicon), or GaAs (gallium arsenide), although the material is not particularly limited. On the other hand, the epitaxial layer 12 is formed of, for example, InGaAsP (indium gallium arsenide phosphide) or InGaAs (indium gallium arsenide). If the epitaxial layer 12 is a layer made of InGaAsP or InGaAs, after the epitaxial layer 12 is formed on the entire substrate layer 11, the epitaxial layer 12 of the ear portion (peripheral portion where no semiconductor element is formed) 1a is wet-etched or dry-etched. By doing so, the epitaxial layer 12a having a desired width may be formed. As a result, the epitaxial layer 12a of the ear 1a can be formed without increasing the number of steps.

The groove portion 13 may be formed by using one or both of dry etching and wet etching. Although the cross-sectional shape in the XZ plane is V-shaped in FIG. 2, it may be pentagonal. In particular, a shape having a corner at the tip in the Z-axis direction is preferable. This is because it is possible to prevent the bending stress due to the pressing blade 31 from being concentrated on the tip end and the division of the semiconductor substrate 1 from deviating from the planned dividing line 14.

The semiconductor substrate 1 is attached and fixed to the sheet adhesive layer 22 of the sheet 20 including the sheet base material 21 and the sheet adhesive layer 22. For example, YAG pulse laser light is used as the laser light L. When such light is selected, the laser light L is transmitted through the substrate layer 11 and absorbed by the epitaxial layer 12 when the wavelength is 1064 nm. It

The material of the sheet base material 21 of the sheet 20 is, for example, polyvinyl chloride. Polyvinyl chloride is a material for the sheet base material 21 because it transmits light having a wavelength of 1064 nm and can be easily deformed or expanded when the semiconductor substrate 1 is separated and collected from the sheet base material 21 after division. preferable.

As can be seen from FIG. 2, the semiconductor substrate 1 is irradiated with the laser light L through the pressing blade 31. Therefore, the pressing blade 31 needs to be made of a material that transmits the laser light L. The material of the pressing blade 31 is preferably glass or acrylic. When glass is used as the material of the pressing blade 31, there is an advantage that it is excellent in durability and is hard to be deformed and scratched by a bending load, for example. The use of acrylic has the advantage that it can be easily processed.

FIG. 3 is a perspective view of the semiconductor substrate 1 when FIG. 2 is viewed from different directions, and the two receiving blades 32 are omitted. 4 is a cross-sectional view taken along the line AA when a load is applied to the semiconductor substrate 1 of FIG. 3, and the top and bottom (Z-axis direction) is opposite to that of FIG.

In FIG. 4, the semiconductor substrate 1 and the sheet 20 are pressed by the pressing blade 31 in the Z-axis direction and pressed against the receiving blade 32, so that a bending load is applied. In this state, the laser light L is condensed by the lens 40 and irradiated onto the epitaxial layer 12a from the substrate layer 11 side, so that the laser light L is transmitted through the substrate layer 11 and absorbed by the epitaxial layer 12a.

By absorbing the laser light L, the epitaxial layer 12a is rapidly heated and expanded. The substrate layer 11 near the epitaxial layer 12a is also rapidly heated and expanded. This causes cracks 15 in the substrate layer 11. At this time, the laser light L also has a constant spot diameter L2 in the X-axis direction even in the condensed spot L1. Here, the diameter of the beam at the focus where the laser light L is condensed by the lens is called the spot diameter. On the other hand, the irradiation position of the laser light L usually shifts. Therefore, by making the width of the epitaxial layer 12a in the X-axis direction smaller than the total of the spot diameter L2 and the assumed irradiation position shift, the positional accuracy of the crack 15 in the X-axis direction can be improved.

As shown in FIG. 4, the crack 15 generated in the epitaxial layer 12 in the focused spot L1 of the laser light L and the substrate layer 11 around the epitaxial layer 12 is guided by the groove portion 13 and progresses to divide the semiconductor substrate 1 by cleavage. To do.

The bending load required for the crack 15 to be generated by the pressing blade 31 at this time is smaller than that in the case where only the groove 13 is provided and the laser beam L is not irradiated.

5 and 6 are schematic views of the semiconductor substrate 1 of FIG. 4 when viewed in the axial direction from the back surface. As shown in FIG. 5, the width of the epitaxial layer 12a in the direction (X-axis direction) perpendicular to the propagation direction of the crack 15 is equal to the width (X-axis direction) of the groove portion 13 perpendicular to the propagation direction of the crack 15 (X-axis direction). It is desirable that the width is smaller than the width in (direction). Under such a condition, even if the crack 15 occurs at a position away from the center in the epitaxial layer 12a, the crack 15 can be brought close to the planned dividing line 14 by passing through the groove 13.

On the other hand, as shown in FIG. 6, the width of the epitaxial layer 12 in the direction perpendicular to the progress direction of the crack is larger than the width of the crack in the groove portion 13 in the direction perpendicular to the progress direction. In the case of a large crack, when the crack 15 is formed at a position away from the center of the epitaxial layer 12, the crack 15 is not guided by the groove portion 13 and largely deviates from the planned dividing line 14.

As described above, in the method of manufacturing the semiconductor element according to the first embodiment of the present invention, since both the laser light L and the load are used, it is possible to divide the semiconductor substrate with a load smaller than the conventional one. Further, by forming the epitaxial layer 12a, even if there is a spread of the spot diameter L2 of the laser light L or a deviation of the irradiation position of the laser light L, it is possible to perform division near the planned division line 14.

Embodiment 2.
A method of manufacturing a semiconductor device according to the second embodiment of the present invention will be described with reference to FIGS. 7 to 9 are cross-sectional views corresponding to the AA direction (see FIG. 3) when a load is applied to the substrate layer 11 in the manufacturing method according to the second embodiment. 7 to 9, the same reference numerals as those in FIG. 4 indicate the same or corresponding portions.

In the second embodiment, the focused spot L1 of the laser light L is the interface between the substrate layer 11 and the sheet 20, and the spot diameter in the X-axis direction at the interface is L2. Here, the substrate layer 11 is transparent to the laser light L, but when the laser power density P of the laser light L exceeds a certain threshold P _th , multiphoton absorption occurs in the substrate layer 11.

In the second embodiment, the laser power density P of the laser light L is set to a value larger than the threshold value P _th to cause multiphoton absorption in the substrate layer 11 in the vicinity of the focused spot L1. The amount of energy absorbed by multiphoton absorption is proportional to the n-th power of the energy density of the irradiated laser light L (n is the number of photons). For example, in the case of two-photon absorption, the energy absorption amount is proportional to the square of the energy density of the laser light L.

In order to increase the laser power density P of the laser light L, in the second embodiment, a laser light source (not shown) is used to change the Q value of the optical resonator at high speed to achieve high-power pulse oscillation. A Q switch element (not shown) having a function is provided. As a result, Q-switched laser light having a high peak value is emitted. The pulse width of the Q-switched laser light is preferably 1 μs or less so that the energy per pulse is sufficiently large.

The laser parameters of the laser light L (pulse width, repetition frequency, pulse energy, peak output, etc., if the laser light L is a pulse laser) are set to values that can vaporize (or thermally decompose) the substrate layer 11. It

As shown in FIG. 8, a part of the substrate layer 11 is vaporized by the irradiation of the laser beam L, so that gas is trapped between the sheet 20 and the substrate layer 11 and the sheet 20 is removed from the substrate layer 11. A load is generated in the opposite direction (the positive direction of the Z axis).

Light of the laser light L that is not absorbed by multiphoton absorption reaches the epitaxial layer 12a and is absorbed. As a result, the epitaxial layer 12a and the substrate layer 11 in the vicinity thereof are partially vaporized. As a result, as shown in FIG. 9, a crack 15 is generated from the epitaxial layer 12 and the substrate layer 11 in the vicinity thereof, and the substrate layer 11 is divided.

As described above, in the manufacturing method according to the second embodiment, not only the load from the pressing blade 31 but also the pressure from the gas generated between the substrate layer 11 and the sheet 20 is applied to the division of the substrate. The applied load can be reduced.

Embodiment 3.
FIG. 10 is a perspective view of a manufacturing apparatus 200 used in the method of manufacturing a semiconductor device according to the third embodiment of the present invention, and the same reference numerals as those in FIGS. In the manufacturing apparatus 200, the pressing blade 31 is arranged so as to avoid the optical path of the laser light L. In addition, in order to display the shape of the pressing blade 31 in an easy-to-understand manner, the top and bottom of the drawing are inverted.

In the manufacturing apparatus 200, since the pressing blade 31 is out of the optical path of the laser light, the material of the pressing blade 31 may be a material that absorbs the laser light, and for example, a material such as a metal that can be easily processed can be selected. Using a metal for the pressing blade 31 has the advantages of excellent durability and easy processing.

Further, for the pressing, the shape of the pressing blade 31 can be changed from a quadrangular prism whose base is trapezoidal (see FIG. 2) to a triangular prism by making the material of the hard metal 31. Thereby, the stress applied to the substrate layer 11 from the pressing blade 31 can be concentrated in the vicinity of the planned dividing line 14, and the crack can be prevented from coming off the planned dividing line 14 due to the stress dispersion.

Fourth Embodiment
FIG. 11 is a perspective view of the semiconductor substrate 1, and the two receiving blades 32 are omitted. Further, FIG. 12 is a sectional view taken along the line BB when a load is applied to the substrate layer 11 of FIG. 11, and the Y-axis direction is opposite to that of FIG.

In the fourth embodiment, the epitaxial layer 12c is formed inside the groove 13. Specifically, wet etching, dry etching, or both are used to form the groove 13 in the substrate layer 11, and then a protective film (not shown) is formed in a portion other than the groove 13. By growing the epitaxial layer 12 in this state, the epitaxial layer 12c can be selectively formed inside the groove portion 13.

In the fourth embodiment, the epitaxial layer 12 is selectively formed inside the groove 13 and the laser light L is condensed at the bottom of the groove 13, so that the absorption of the laser light L inside the groove 13 is maximized. As a result, the inside of the groove 13 becomes the starting point of the crack 15, and the positional accuracy of the starting point of the crack 15 can be improved.

Embodiment 5.
13 and 14 are schematic views of a method of manufacturing a semiconductor element using the manufacturing apparatus according to the fifth embodiment of the present invention. 13 and 14 are cross-sectional views when viewed in the same direction as the AA direction in FIG. The same reference numerals as those in FIG. 4 indicate the same or similar portions, and 33 indicates a pressing plate.

In the manufacturing method of the fifth embodiment, as shown in FIG. 13, a bending load is not applied when irradiating the laser beam L, the surface of the sheet 20 is pressed by the pressing plate 33, and the evaporation pressure due to heating is set inside. I'm only confining it. As a result, cracks are generated only in the vicinity of the laser light irradiation portion, but they do not propagate enough to divide the substrate.

Subsequently, as shown in FIG. 14, the pressing blade 31 is used to apply a bending load to the surface of the sheet 20 to divide the substrate 1. By dividing the step of irradiating the laser beam and the step of applying the bending load in this way, the material of the pressing blade 31 may be a material that absorbs the laser beam, and for example, a material such as a metal that can be easily processed can be selected. Further, by using metal or the like for the material of the pressing blade 31, the shape of the tip of the pressing blade 31 can be made into a sharp shape. As a result, the stress applied to the substrate 1 by the bending load can be concentrated in a limited narrow range. Moreover, the flatness of the end face can be improved by gradually applying the bending load.

1 semiconductor substrate, 1a ear part, 1b element part, 11 substrate layer, 12, 12a, 12b, 12c epitaxial layer, 13 groove part, 14 planned dividing line, 15 cracks, 20 sheet, 21 sheet base material, 22 sheet adhesive layer, 31 pressing blade, 32 receiving blade, 33 pressing plate, 40 lens, 411, 412 cylindrical lens, 413 objective lens, 42 laser light source, 43 mirror, 100, 200 manufacturing device, L laser beam, L1 condensing spot, L2 spot diameter ..

Claims (14)

A method of manufacturing a semiconductor device, wherein a semiconductor substrate is divided along a dividing line,
Providing a semiconductor substrate including a first semiconductor layer having a front surface and a back surface, and a second semiconductor layer provided on the front surface of the first semiconductor layer;
Partially removing the second semiconductor layer and using the second semiconductor layer remaining on the planned dividing line as an absorption layer;
Forming a groove on the planned dividing line on the surface of the semiconductor substrate;
While applying bending stress to the semiconductor substrate, by irradiating the absorption layer with laser light to heat the absorption layer, dividing the semiconductor substrate at the dividing line,
The width of the absorption layer is smaller than the width of the groove portion. A method of manufacturing a semiconductor device, wherein a semiconductor substrate is divided along a dividing line,
Providing a semiconductor substrate including a first semiconductor layer having a front surface and a back surface, and a second semiconductor layer provided on the front surface of the first semiconductor layer;
Partially removing the second semiconductor layer and using the second semiconductor layer remaining on the planned dividing line as an absorption layer;
Forming a groove on the planned dividing line on the surface of the semiconductor substrate;
Irradiating the absorption layer of the semiconductor substrate with a laser beam to heat the absorption layer,
Dividing the semiconductor substrate along the dividing line by applying bending stress to the semiconductor substrate,
The width of the absorption layer is smaller than the width of the groove portion. A method of manufacturing a semiconductor device, wherein a semiconductor substrate is divided along a dividing line,
Providing a semiconductor substrate including a first semiconductor layer having a front surface and a back surface;
Forming a groove on the planned dividing line on the surface of the first semiconductor layer;
A step of selectively forming an absorption layer inside the groove,
Dividing the semiconductor substrate along the dividing line by irradiating the absorption layer with laser light to heat the absorption layer while applying bending stress to the semiconductor substrate. Production method. The manufacturing method according to claim 1, wherein the focused spot of the laser light overlaps the absorption layer. The said laser beam is irradiated from the back surface side of the said semiconductor substrate, is not absorbed by the said 1st semiconductor substrate, but is absorbed by the said absorption layer, The manufacturing in any one of the Claims 1-4 characterized by the above-mentioned. Method. A method of manufacturing a semiconductor device, wherein a semiconductor substrate is divided along a dividing line,
Providing a semiconductor substrate including a first semiconductor layer having a front surface and a back surface, and a second semiconductor layer provided on the front surface of the first semiconductor layer;
Bonding a sheet to the back surface of the first semiconductor layer,
Partially removing the second semiconductor layer and using the second semiconductor layer remaining on the planned dividing line as an absorption layer;
Forming a groove on the planned dividing line on the surface of the semiconductor substrate;
While applying bending stress to the semiconductor substrate, by heating the absorption layer by irradiating the absorption layer with laser light from the back surface side of the semiconductor substrate, a step of dividing the semiconductor substrate along the dividing line, Including
The width of the absorption layer is smaller than the width of the groove,
The focused spot of the laser light overlaps with the interface between the first semiconductor layer and the sheet, and at the focused spot, the laser light is absorbed by the first semiconductor layer and heats the first semiconductor layer. A manufacturing method characterized by the above. 7. The laser light is not absorbed by the first semiconductor layer, but is absorbed by the first semiconductor layer at the focused spot where the laser power density of the laser light increases. Production method. The manufacturing method according to claim 6, wherein the laser light is pulsed laser light. The front surface of the semiconductor substrate is supported by two receiving blades that are parallel to each other, and the back surface of the semiconductor substrate is pressed by a pressing blade between the receiving blades to apply bending stress to the semiconductor substrate. The manufacturing method according to claim 1. The pressing blade is arranged in the optical path of the laser light and is made of a material that does not absorb the laser light, or the pressing blade is arranged outside the optical path of the laser light and absorbs the laser light. The manufacturing method according to claim 9, wherein the manufacturing method is made of a material. 11. The manufacturing method according to claim 1, wherein the irradiation of the laser beam is performed only on a peripheral portion of the semiconductor substrate where the semiconductor element is not formed. The said semiconductor element is an element selected from the group which consists of a semiconductor laser, a light emitting diode, and a transistor, The manufacturing method in any one of Claims 1-11 characterized by the above-mentioned. A semiconductor device manufacturing apparatus for dividing a semiconductor substrate along a dividing line,
Two parallel receiving blades for mounting the semiconductor substrate,
A pressing blade that presses the semiconductor substrate to apply bending stress,
A laser light source for irradiating the semiconductor substrate with laser light,
A lens that collects the laser light to form a condensed spot that overlaps the semiconductor substrate,
A manufacturing apparatus comprising: a position moving unit that adjusts a position of the focused spot by changing a relative position between the laser light source and the semiconductor substrate. The manufacturing apparatus according to claim 13, wherein the pressing blade has a triangular or pentagonal sectional shape.

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