Method for manufacturing semiconductor laser device and manufacturing apparatus

Abstract

The present invention comprises: a step for preparing a semiconductor substrate which is provided with a first substrate and a plurality of semiconductor parts that are formed in stripes on the first substrate by means of crystal growth; a step for obtaining a group of individual pieces by dividing, on the first substrate, a plurality of structures each containing one of the plurality of semiconductor parts such that each of the structures have end faces which are parallel to each other in the short-side direction; a step for transferring a plurality of individual pieces contained in the group of individual pieces to a second substrate; and a step for obtaining a plurality of element substrates each comprising one or more individual pieces by dividing the second substrate.

Description

Technical Field

[0001] The present disclosure relates to a method for manufacturing a semiconductor laser device and the like.

Background Art

[0002] Patent Document 1 discloses a method in which an element structure wafer having a laser element structure formed on a growth substrate is bonded to a support substrate, the bonded wafer thus obtained is diced, and a laser element with a support substrate having a light emitting end face and a light reflecting end face is obtained.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

[0004] A method for manufacturing a semiconductor laser device according to the present disclosure includes a step of preparing a semiconductor substrate including a first substrate and a plurality of stripe-shaped semiconductor portions crystal-grown on the first substrate, a step of dividing, on the first substrate, a plurality of structures each including one of the plurality of semiconductor portions so that end faces parallel to the short side direction protrude from each structure to obtain a group of individuals, a step of transferring the plurality of individuals included in the group of individuals to a second substrate, and a step of dividing the second substrate to obtain a plurality of element substrates each including one or more individuals.

Brief Description of the Drawings

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Embodiments for Carrying Out the Invention

[0006] (Method for Manufacturing a Semiconductor Laser Device) FIG. 1 is a perspective view showing a method for manufacturing a semiconductor laser device according to an embodiment. FIG. 2 is a flowchart showing a method for manufacturing a semiconductor laser device according to an embodiment.

[0007] The method for manufacturing a semiconductor laser device described in FIGS. 1 and 2 includes a step (S10) of preparing a semiconductor substrate 10 including a first substrate FK and a plurality of stripe-shaped semiconductor portions 8 grown on the first substrate FK, and a step of forming a plurality of structures JT each including a plurality of semiconductor portions 8 on the first substrate FK. (S20) of dividing the individual group LA by dividing the individual group LA so that end faces CF parallel to the short-side direction (X direction) are formed in each structure JT, and a step (S30) of transferring a plurality of individuals LT included in the individual group LA to a second substrate SK, and a step (S40) of dividing the second substrate SK to obtain a plurality of element substrates 30 each including one or more individuals LT.

[0008] The population LA refers to, for example, four or more individuals. After dividing the semiconductor substrate 10 into a plurality of individual substrate pieces 10D, a plurality of individuals LT of the individual substrate pieces 10D may be transferred to the second substrate SK. In the semiconductor substrate 10, the direction from the first substrate FK to the semiconductor portion 8 is set to "upward". Viewing an object with a line of sight parallel to the normal direction of the semiconductor substrate 10 (including the case of perspective) may be referred to as "plan view". A semiconductor substrate means a substrate including a semiconductor portion, and the first substrate FK (which may be referred to as a template substrate) may include a non-semiconductor (for example, an insulator).

[0009] In the method for manufacturing a semiconductor laser device according to the present embodiment, a plurality of individuals LT are transferred from a population LA obtained by dividing a plurality of structures JT to a second substrate SK, and then the second substrate SK is divided, so that the manufacturing yield of the semiconductor laser device (for example, the element substrate 30) is increased. Since the plurality of stripe-shaped structures JT along the crystal orientation of the semiconductor portion 8 are divided on the first substrate FK without transferring, for the plurality of structures JT, the end face CF can be formed in a desired shape and at a desired position.

[0010] The semiconductor portion 8 may be a semiconductor layer including a nitride semiconductor (for example, a nitride semiconductor crystal). The nitride semiconductor can be represented by, for example, AlxGayInzN (0≦x≦1; 0≦y≦1; 0≦z≦1; x + y + z = 1), and specific examples include GaN-based semiconductors, AlN (aluminum nitride), InAlN (indium aluminum nitride), and InN (indium nitride). A GaN-based semiconductor is a semiconductor containing gallium atoms (Ga) and nitrogen atoms (N), and typical examples include GaN, AlGaN, AlGaInN, and InGaN. The semiconductor portion 8 may be of a doped type (for example, an n-type including donors) or a non-doped type.

[0011] The division of the plurality of stripe-shaped structures JT may be performed by cleavage or by etching (dry or wet etching). The end face CF formed by the division of the structure JT may include the resonator end face of the individual LT (laser body).

[0012] In step S30, selective transfer can be performed such that the number of transferred individuals per unit area onto the second substrate SK is smaller than the number of individuals per unit area in the population LA. For example, the interval in the Y direction of a plurality of individuals LT may be equal to or greater than the size in the Y direction (resonator length) of each individual LT (laser body). In step S40, the second substrate SK can be divided without dividing any of the individuals LT. By doing so, contamination of the end faces (resonator end faces of the laser bodies) of the individuals LT due to the division of the second substrate SK can be reduced.

[0013] (Manufacturing apparatus for semiconductor laser device) FIG. 3 is a block diagram showing a manufacturing apparatus for a semiconductor device according to an embodiment. The manufacturing apparatus 50 for a semiconductor device in FIG. 3 includes an apparatus A10 that performs the step of S10, an apparatus A20 that performs the step of S20, an apparatus A30 that performs the step of S30, an apparatus A40 that performs the step of S40, and an apparatus A50 that controls the apparatus A10, the apparatus A20, the apparatus A30, and the apparatus A40.

[0014] (Examples) FIG. 4 is a flowchart showing a method for manufacturing a semiconductor laser device according to an embodiment. FIG. 5 is a plan view showing a method for manufacturing a semiconductor laser device according to an embodiment. FIG. 6 is a cross-sectional view showing a method for manufacturing a semiconductor laser device according to an embodiment. FIG. 7 is a perspective view showing the arrangement of individuals on a second substrate according to an embodiment. FIG. 8A is a cross-sectional view perpendicular to the resonator length direction showing a configuration example of an individual (laser body) according to an embodiment. FIG. 8B is a cross-sectional view parallel to the resonator length direction showing a configuration example of an individual (laser body) according to an embodiment. FIG. 9 is a perspective view showing the configuration of an element substrate and a laser element according to an embodiment.

[0015] The manufacturing method of the semiconductor laser device described in FIGS. 4 to 6 includes a first substrate FK including a mask pattern 6 including a mask portion 5 and an opening K, and a semiconductor substrate 10 including a plurality of stripe-shaped semiconductor portions 8 grown on the first substrate FK. A step of preparing a semiconductor substrate 10, a step of dividing a plurality of structures JT each including a plurality of semiconductor portions 8 on the first substrate FK in the short side direction (X direction) so that an end face CF parallel to the short side direction is formed in each structure JT to obtain an individual group LA, a step of removing the mask pattern 6, a step of transferring a plurality of individuals LT included in the individual group LA to a second substrate SK to obtain an element substrate 20 (semiconductor device) in which the plurality of individuals LT are arranged in a matrix, a step of dividing the second substrate SK to obtain a plurality of element substrates 30 (semiconductor devices) each including two or more individuals arranged in a row, a step of forming a dielectric film (reflective mirror film) RF on the end face CF of each individual LT on the element substrate 30, and a step of dividing the element substrate 30 to obtain a plurality of laser elements 40 (semiconductor devices) each including one or more individuals. Here, the mask pattern 6 is removed before transfer, but transfer may be performed without removing the mask pattern 6.

[0016] The first substrate FK (template substrate) may include a base substrate BS, and the mask pattern 6 may be formed on the base substrate BS. The semiconductor portion 8 can be formed by the ELO (Epitaxial Lateral Overgrowth) method starting from a region where the base substrate BS is exposed by the opening K (the seed region of the first substrate FK). For the ELO method, vapor growth such as metalorganic chemical vapor deposition, hydride vapor deposition, and molecular beam epitaxy can be applied.

[0017] The mask portion 5 may be a selective growth mask (growth suppression region of the first substrate FK) for laterally growing the semiconductor portion 8. The thickness direction of the semiconductor portion 8 may be the c-axis direction (<0001> direction). The opening K has a longitudinal shape, and its width direction may be the a-axis direction (<11-20> direction) of the semiconductor portion 8 which is, for example, a nitride semiconductor crystal, and its longitudinal direction may be the m-axis direction. In the mask pattern 6, a plurality of openings K may be arranged in the a-axis direction (X direction) of the semiconductor portion 8.

[0018] In the ELO method of this embodiment, before crystals growing in opposite directions (a-axis direction) on the mask portion 5 meet each other, growth is stopped, whereby a plurality of stripe-shaped semiconductor portions 8 can be formed. The mask portion 5 is located below the gap G between adjacent semiconductor portions 8.

[0019] As shown in FIGS. 5 and 6, the structure JT may include a semiconductor portion 8 and an upper layer portion 9 located on the semiconductor portion 8. The upper layer portion 9 may include a functional semiconductor layer 9S containing a nitride semiconductor, an insulating film 9Z, and electrodes 9A and 9C. Since the mask portion 5 exists below the gap G between adjacent semiconductor portions 8, the functional semiconductor layer 9S (for example, a nitride semiconductor crystal) grows selectively on the semiconductor portion 8 and hardly forms (films) on the mask portion 5 facing the gap G and on the side surfaces of the semiconductor portion 8 in the X direction. Therefore, the plurality of structures JT have a stripe shape along the crystal orientation (for example, m-axis orientation) of the semiconductor portion 8. The functional semiconductor layer 9S may include a ridge RJ (a convex current constriction portion). In the semiconductor portion 8 formed by the ELO method, since the portion on the mask portion 5 has low defects (described later), the ridge RJ may have a longitudinal shape with the m-axis direction as the longitudinal direction so as to overlap the mask portion 5 in plan view.

[0020] In the embodiment, each of the plurality of structures JT may be divided by cleavage. The semiconductor portion 8 may include a nitride semiconductor, and the end face CF that is the cleavage plane may be parallel to the m-plane of the nitride semiconductor (crystal).

[0021] Scrivening for starting cleavage may be performed on each structure JT. The semiconductor portion 8 may include a GaN-based semiconductor, and the first substrate FK may include a wafer (for example, a silicon substrate) made of a material having a smaller coefficient of thermal expansion than this GaN-based semiconductor. In this case, by performing scrivening on the semiconductor crystal of each structure JT, the internal stress of the semiconductor substrate 10 is released, so that cleavage can proceed naturally. By performing this scrivening on the side surface closer to the ridge RJ of the structure JT, the flatness of the resonator end face (cross section of the ridge RJ) included in the end face CF can be enhanced.

[0022] Each of the first substrate FK and the second substrate SK may include a silicon substrate, or each of the first substrate FK and the second substrate SK may include a silicon carbide substrate. If the materials of both substrates are the same, the bonding accuracy can be enhanced. Therefore, the process of transferring a plurality of individual LT onto the second substrate SK by bonding the plurality of individual LT on the first substrate FK to the heated second substrate SK is facilitated. When transferring the plurality of individual LT onto the second substrate SK, the connection crystal part 8U between the individual LT and the first substrate FK may break naturally. Of course, the connection crystal part 8U may be broken by an external force before transferring the plurality of individual LT onto the second substrate SK.

[0023] Simultaneously with transferring the plurality of individual LT onto the second substrate SK, each individual LT may be electrically connected to the electrode pads (P1·P2) of the second substrate SK. For example, the electrodes of each individual LT can be connected to the electrode pads (P1·P2) via solder H (see FIG. 9).

[0024] As shown in FIG. 5, regarding the transfer of the plurality of individual LT, thinning type selective transfer can be performed such that the number of transferred individuals NS per unit area onto the second substrate SK is smaller than the number of individuals NA per unit area in the individual group LA. NS / NA can be set to 1 / 4, 1 / 8, 1 / 12, etc. The thinning number in the first direction (X direction) may be made larger than the thinning number in the second direction (Y direction). Taking the direction corresponding to the short side direction of the plurality of semiconductor parts LT on the second substrate SK as the first direction (X direction) and the direction corresponding to the long side direction as the second direction (Y direction), the plurality of individual LT transferred onto the second substrate SK may be arranged in a matrix in the X direction and the Y direction. The interval d1 in the Y direction of the plurality of individual LT may be equal to or greater than the size (resonator length) of each individual LT (laser body) in the Y direction. The interval d1 in the Y direction of the plurality of individual LT may be a natural multiple of the size (resonator length) of each individual LT in the Y direction. In this case, the second substrate SK can be easily divided. For example, the end face contamination of the individual LT can be reduced without applying a technique such as stealth dicing.

[0025] In this embodiment, for example, even when the resonator length L (size in the Y direction) of the individual LT is a short resonator length of 200 μm or less, the distance d2 between the end face CF and the cut face CL can be ensured, so there is an advantage that the end face is difficult to be contaminated. The distance d2 between the end face CF and the (substrate) cut face CL may be set to be 1 / 2 or more of the resonator length L. Note that a plurality of element substrates 30 may be obtained by dividing the second substrate SK by stealth dicing. In this way, the contamination of the end face of the individual LT can be further reduced.

[0026] As shown in FIGS. 5 and 7, the second substrate SK may have a plurality of recesses UB arranged in a matrix in the first direction (X direction) and the second direction (Y direction). As shown in FIGS. 5 and 9, the end face CF parallel to the short side direction (X direction) of each of the plurality of individual LTs transferred to the second substrate SK may be located above one of the plurality of recesses UB of the second substrate KS. In this case, there are advantages such as facilitating the formation of the dielectric film on the end face CF and making it difficult for the laser light from the individual LT to hit the second substrate SK.

[0027] The cross section (substrate cross section) formed by dividing the second substrate SK may include at least one of the plurality of recesses UB. Since the recess UB has a small thickness, substrate cutting becomes easy.

[0028] As shown in FIGS. 5 and 9, in each of the plurality of element substrates 30, two or more individual LTs may be arranged in a row in the first direction (X direction). By arranging the plurality of individual LTs in a row, the formation of the dielectric film RF on the end face CF becomes easy. In addition, since the end faces of the plurality of individual LTs are aligned in a row, the element substrate 30 itself can function as a semiconductor laser device. The dielectric film RF may be a light reflection including at least one of Al2O3, AlN, MgF2, MgO, Nb2O5, SiO2, Si3N4, TiO2, Ta2O5, Y2O3, ZnO, and ZrO2.

[0029] As shown in FIG. 8A, the laser body LT may include a semiconductor part 8, a functional semiconductor layer 9S (n-type semiconductor layer 9N, active layer 9K, p-type semiconductor layer 9P) located above the semiconductor part 8, an electrode 9A (anode) in contact with the p-type semiconductor layer 9P of the ridge RJ, an electrode 9C (cathode) in contact with the n-type semiconductor layer 9N, and an insulating film 9Z located on the side of the ridge RJ.

[0030] An optical guide layer located on the inner side (active layer 9K side) and a cladding layer located on the outer side may be provided in each of the n-type semiconductor layer 9N and the p-type semiconductor layer 9P sandwiching the active layer 9K. The active layer 9K can be, for example, a quantum well structure, and light is generated by the recombination of holes supplied from the electrode 9A and electrons supplied from the electrode 9C in the active layer 9K. As shown in FIGS. 8A and 8B, the light generated in the active layer 9K is confined by two cladding layers (n-type and p-type) with a small refractive index, amplified by stimulated emission in the process of reciprocating between the end faces (resonator end faces) RE of the resonator RK, and emitted as laser light from one of the resonator end faces RE. The end face CF of the body LT (laser body) may include the resonator end face RE, and the resonator end face RE may be covered with a dielectric film RF that is a mirror film.

[0031] The semiconductor part 8 may include a first region A1 that overlaps the ridge RJ in plan view and a second region A2 that does not overlap the ridge RJ in plan view and has a higher threading dislocation density than the first region A1. As shown in FIG. 8A, a region 8C (a surface roughened region where the surface is rougher than the surroundings) with a locally increased surface roughness may be included on the lower surface (back surface) of the semiconductor part 8. At least one of protrusions and depressions may be formed in the region 8C. For example, a plurality of protrusions with a random shape and a plurality of depressions with a random shape may be formed. The region 8C may be formed on the lower surface of the second region A2. The region 8C may be formed so as not to overlap the ridge part RJ in plan view. The heat dissipation property may be enhanced by the region 8C. A protective film made of the same material as the dielectric film RF may be formed on at least a part of the region 8C.

[0032] FIG. 10 is a plan view showing a method of manufacturing a semiconductor laser device according to an embodiment. Each structure JT includes a ridge RJ, electrodes 9A and 9C, and an insulating film 9Z. In the semiconductor portion 8 formed by the ELO method, since the portion on the mask portion 5 has low defects, the ridge RJ has a longitudinal shape with the m-axis direction as the longitudinal direction so as to overlap the mask portion 5 in plan view. The ridge RJ, which is a part of the functional semiconductor layer 9S, may be included in the end face CF, and the cross section (parallel to the a-axis) of the ridge RJ functions as a resonator end face. That is, the structure JT may be cut so as to be orthogonal to the extending direction of the ridge RJ.

[0033] FIG. 11 is a plan view showing a method of manufacturing a semiconductor laser device according to an embodiment. In FIG. 5, the structure JT is divided by cleavage, but it is not limited thereto. As shown in FIG. 11, the structure JT can be divided by etching, and the end face (including the resonator end face) of the individual LT can be used as an etched mirror. In this case, dry etching such as inductively coupled plasma reactive ion etching, wet etching using a solution such as KOH, etc. can be applied. In the embodiment, since each of the plurality of structures JT is formed along the crystal orientation (m-axis orientation, Y direction), a high-quality etched mirror can be obtained.

[0034] FIG. 12 is a plan view showing a method of manufacturing a semiconductor laser device according to an embodiment. In FIG. 5, in the element substrate in which two or more individuals LT are arranged in a row, the end face coat (formation of a dielectric film) of the individual LT is performed, but it is not limited thereto. As shown in FIG. 12, a dielectric film RF can also be formed on the end face CF of each of the plurality of individuals LT arranged in a matrix on the second substrate SK. By performing selective transfer to the second substrate SK, the end face interval is widened compared to before transfer, so that the dielectric film RF can be formed even in a state where a plurality of individuals LT are arranged in a matrix.

[0035] FIG. 13 is a cross-sectional view showing a configuration example of a base substrate included in the first substrate. The base substrate BS may have a semiconductor portion 8 and a main substrate 1 which is a different substrate having a different lattice constant. The semiconductor portion 8 may include a GaN-based semiconductor, and the main substrate 1 which is a different substrate may be a silicon substrate. Examples of the different substrate include a sapphire (Al2O3) substrate, a silicon carbide (SiC) substrate, etc. in addition to the silicon substrate. The plane orientation of the main substrate 1 is, for example, the (111) plane of the silicon substrate, the (0001) plane of the sapphire substrate, and the 6H-SiC(0001) plane of the SiC substrate. These are examples, and any substrate and plane orientation capable of growing the semiconductor portion 8 by the ELO method may be used.

[0036] The base substrate BS includes the main substrate 1 and an underlying portion 4 on the main substrate 1, and the semiconductor portion 8 may grow from the upper surface (seed region) of the underlying portion 4 exposed in the opening K. The underlying portion 4 may contain a nitride semiconductor. The underlying portion 4 may include at least one of a buffer portion and a seed portion. That is, the underlying portion 4 may be composed of a seed portion, or the underlying portion 4 may be composed of a buffer portion (main substrate side) and a seed portion (semiconductor portion side). As the buffer portion, a GaN-based semiconductor, AlN, SiC, etc. can be used. As the seed portion, a nitride semiconductor (for example, a GaN-based semiconductor) can be used. The base substrate BS may be composed of a self-supporting single crystal substrate such as GaN or SiC (for example, a wafer cut out from a bulk crystal), and a mask pattern 6 may be arranged on the single crystal substrate.

[0037] FIG. 14 is a cross-sectional view showing a method for manufacturing a semiconductor substrate according to an embodiment. In FIG. 14, a mask pattern 6 including a plurality of stripe-shaped mask portions 5 is provided on the base substrate BS. The mask portion 5 is made of, for example, a laminated insulating film (SiOx / SiNx) having a width of 52 μm, and has the m-axis direction of the semiconductor portion 8 as the longitudinal direction. The pitch of the stripes of the mask portion 5 is 55 μm. On the mask pattern 6, the semiconductor portion 8 (nitride semiconductor portion) is grown (ELO method) by, for example, metalorganic chemical vapor deposition (MOCVD) using trimethylgallium (TMG) and ammonia (NH3).

[0038] The initial growth portion 8p serves as the starting point for the lateral growth of the semiconductor portion 8. The initial growth portion 8p can be formed, for example, with a thickness of 30 nm to 1000 nm, or 50 nm to 400 nm, or 70 nm to 350 nm. By performing lateral growth starting from a state where the initial growth portion 8p slightly protrudes from the mask portion 5, the growth of the semiconductor portion 8 in the c-axis direction (thickness direction) can be suppressed, and the semiconductor portion 8 can be laterally grown at high speed with high crystallinity, reducing the consumption of raw materials. As a result, a semiconductor portion 8 (crystal of a nitride semiconductor such as GaN) with low defects can be formed thinly and widely at low cost.

[0039] By ensuring that semiconductor portions 8 that have grown laterally in opposite directions from two adjacent openings K do not contact (meet) on the mask portion 5 and have a gap G, the internal stress of the semiconductor portion 8 can be reduced. As a result, cracks and defects (dislocations) generated in the semiconductor portion 8 can be reduced. This effect is particularly effective when the main substrate 1 is a heterogeneous substrate. The width of the gap G can be, for example, 10 μm or less, 5 μm or less, 3 μm or less, or 2 μm or less.

[0040] Among the semiconductor portion 8, the portion located on the initial growth portion 8p becomes a dislocation inheritance portion with many through dislocations, and the portion on the mask portion 5 (wing portion) becomes a low defect portion YS (the first region A1 in FIG. 8) where the through dislocation density is 1 / 10 or less compared to the dislocation inheritance portion. A through dislocation is a dislocation (defect) that extends in the c-axis direction (<0001> direction) in the semiconductor portion 8. The through dislocation density of the low defect portion YS can be, for example, 5×10 6 〔pieces / cm 2 〕or less. As described above, when forming an active layer 9K including a light emitting portion above the semiconductor portion 8, the light emitting portion can be disposed above the low defect portion YS (so as to overlap the low defect portion YS in plan view).

[0041] Regarding the low defect portion YS, the ratio (W1 / d1) of the size W1 in the a-axis direction to the thickness d1 can be, for example, 2.0 or more. Using the method of the embodiment, W1 / d1 can be 1.5 or more, 2.0 or more, 4.0 or more, 5.0 or more, 7.0 or more, or 10.0 or more. By setting W1 / d1 to 1.5 or more, it becomes easier to perform the division process of the semiconductor portion 8 (for example, the division process with the cross-section being the m-plane) in the subsequent process. Also, the internal stress of the semiconductor portion 8 is reduced, and the warp of the semiconductor substrate 10 is reduced.

[0042] The aspect ratio of the semiconductor portion 8 (the ratio of the size in the X direction to the thickness = WL / d1) can be 3.5 or more, 5.0 or more, 6.0 or more, 8.0 or more, 10 or more, 15 or more, 20 or more, 30 or more, or 50 or more. Also, using the method of the embodiment, the ratio (WL / WK) of the size WL in the X direction of the semiconductor portion 8 to the width WK of the opening K can be 3.5 or more, 5.0 or more, 6.0 or more, 8.0 or more, 10 or more, 15 or more, 20 or more, 30 or more, or 50 or more, and the ratio of the low defect portion can be increased. The semiconductor portion 8 (including the initial growth portion 8p) shown in FIG. 14 can be a nitride semiconductor crystal (for example, a GaN crystal, an AlGaN crystal, an InGaN crystal, or an InAlGaN crystal).

[0043] (Other Embodiments) In the above-described embodiment, the semiconductor laser device including the individual LT having a single-sided two-electrode structure in which the electrodes 9A and 9C are provided on the same side with respect to the semiconductor portion 8 has been described. However, in another embodiment, the individual LT may have a structure (double-sided electrode structure) in which the electrode 9C is on the side opposite to the side where the electrode 9A is provided. For example, after transferring the individual LT to the second substrate SK, an electrode 9C that is electrically connected to the semiconductor portion 8 may be formed on the surface of the individual LT opposite to the side where the electrode 9A is provided.

[0044] The above dislocation inheritance part may be removed by etching or the like. In this case, the structure JT may be formed using the low defect part YS. By increasing the width of the low defect part YS (that is, increasing the above size WL), the individual LT of the single-sided two-electrode structure can be formed from the structure JT formed using the low defect part YS.

[0045] FIG. 15 is a plan view showing a method for manufacturing a semiconductor laser device according to an embodiment. As shown in FIG. 15, crystals growing in opposite directions (a-axis direction) on the mask part 5 may be joined together to form a planar semiconductor layer PS, and a plurality of stripe-shaped semiconductor parts 8 may be formed by removing the joining part (longitudinal high defect region) of the planar semiconductor layer PS. In the method for manufacturing a semiconductor laser device according to an aspect of the present disclosure, it is sufficient to prepare a semiconductor substrate 10 including a first substrate FK and a plurality of stripe-shaped semiconductor parts 8 crystal-grown on the first substrate FK, and the specific method is not particularly limited.

[0046] Alternatively, after dividing the structure JT by etching or the like, the end face CF may be formed by cleavage. The semiconductor substrate 10 may be divided into a plurality of individual substrate pieces 10D so that a cross section is formed in the portion of the trench formed by etching or the like.

[0047] In the known technique of Patent Document 1, it is necessary to precisely align the cleavage easy surfaces of the element structure wafer and the support substrate and then cleave the element structure wafer and the support substrate together. Further, it is required that the support substrate has a cleavage easy surface. Furthermore, it is also necessary to remove the support substrate after the light emitting end face is formed and the individualization is performed. On the one hand, according to the foregoing embodiments, since the laser end face (resonator end face) is formed on the first substrate FK (growth substrate), a precise alignment process as in the prior art is not required, and the problem of cleavage failure is less likely to occur. Further, since the second substrate SK is transferred after the laser end face is formed, the second substrate SK does not need to have an easy cleavage surface, and precise alignment (for laser end face formation) is not required during transfer. Furthermore, the removal of the first substrate FK is performed in the form of transfer to the second substrate SK (submount substrate) in the wafer state before singulation, so the manufacturing process is simple and suitable for mass production. Thus, according to the foregoing embodiments, the manufacturing yield of the semiconductor laser device is improved.

[0048] Figs. 16 to 18 are cross-sectional views showing a method of manufacturing a semiconductor laser device according to an embodiment. In Fig. 16, a first individual LT, which is one of a plurality of individuals to be transferred, includes an anode 9A, and the second substrate SK has a first convex portion T1 corresponding to the first individual LT. At the time of transfer, at least a part (all in Fig. 16) of the first convex portion T1 is located inside the anode 9A (closer to the center of the first individual LT). The second substrate SK has a second convex portion T2 corresponding to the first individual LT. At the time of transfer, the second convex portion T2 is located outside the anode 9A (farther from the center of the first individual LT). The anode 9A may be joined to the electrode pad P1 of the second substrate SK via a solder H. In Fig. 16, at least one of the first convex portion T1 and the second convex portion T2 may function as a shielding wall for the solder H.

[0049] In FIG. 17, a first individual LT, which is one of a plurality of individuals to be transferred, includes an anode 9A. The second substrate SK has a first groove G1 corresponding to the first individual LT. At the time of transfer, at least a part (all in FIG. 17) of the first groove G1 is located inside the anode 9A (closer to the center of the first individual LT). The second substrate SK has a second groove G2 corresponding to the first individual LT. At the time of transfer, the second groove G2 is located outside the anode 9A (farther from the center of the first individual LT). The anode 9A may be joined to the electrode pad P1 of the second substrate SK via solder H. In FIG. 17, at least one of the first groove G1 and the second groove G2 may function as a trap groove for the solder H. At least one of the first groove G1 and the second groove G2 may have a side wall containing metal. At least one of the first groove G1 and the second groove G2 may have a tapered shape (for example, a shape that becomes narrower downward). In plan view, the second groove G2 and the anode 9A may be parallel in the Y direction.

[0050] The second substrate SK in FIG. 18 has a first groove G1 (at least a part of which is located inside the anode 9A at the time of transfer) and a second convex portion T2 (at least a part of which is located outside the anode 9A at the time of transfer). The first groove G1 may have a side wall MF containing metal. The first groove G1 may have a forward tapered shape (a shape that becomes narrower downward).

[0051] FIG. 19 is a cross-sectional view showing a method of manufacturing a semiconductor laser device according to an embodiment. In FIG. 17, the second groove G2 extending in the Y direction (parallel to the resonator length direction) is formed outside in the X direction. However, as shown in FIG. 19, the second groove G2 extending in the X direction (orthogonal to the resonator length direction) may be formed outside in the Y direction.

[0052] FIG. 20 is a perspective view showing a method of manufacturing a semiconductor laser device according to an embodiment. FIG. 21 is a cross-sectional view showing a method of manufacturing a semiconductor laser device according to an embodiment. As shown in FIGS. 20 and 21, among a plurality of inner walls formed by the recess UB (second groove G2), the inner wall MF located under the first body LT may contain a metal. The anode 9A may be joined to the electrode pad P1 of the second substrate SK via the solder H. Further, the inner wall MF may be a tapered surface. According to the configurations of FIGS. 20 and 21, it is possible to reduce the problem that the solder H flows out into an unintended region during transfer.

[0053] FIG. 22 is a cross-sectional view showing a method of manufacturing a semiconductor laser device according to an embodiment. FIG. 23 is a perspective view showing a method of manufacturing a semiconductor laser device according to an embodiment. In FIGS. 22 and 23, the second substrate SK has a mound Q corresponding to the first body LT which is one of a plurality of bodies to be transferred, and the first body LT is disposed above the mound Q during transfer. During transfer, the non-selected body LN in the body group may not contact the second substrate SK. The second substrate SK includes the electrode pad P1, and at least a part of the electrode pad P1 may be located on the mound Q. The first body LT includes the anode 9A, and the anode 9A and the electrode pad P1 may be in contact. FIG. 24 is a cross-sectional view showing a method of manufacturing a semiconductor laser device according to an embodiment. As shown in FIG. 24, the electrode pad P1 may have a thick film portion PD located on the mound Q and a thin film portion PF having a smaller film thickness than the thick film portion PD. Since the second substrate SK has the mound Q, when selectively transferring a plurality of bodies to the second substrate SK by a bonding method that does not use solder such as Au (gold)-Au (gold) bonding, the possibility that a body that is not a transfer target is transferred to the second substrate SK is reduced.

[0054] 〔Supplementary Notes〕 The present disclosure is not limited to the above-described embodiments and examples. Forms obtained by appropriately combining the technical means separately described in the embodiments and examples are also included in the scope of the present disclosure. It should be noted that it is easy for those skilled in the art to make various modifications or corrections based on the present disclosure, and the forms obtained by these modifications or corrections are also included in the scope of the present disclosure.

[0055] 〔Summary〕 The method for manufacturing a semiconductor laser device according to Embodiment 1 of the present disclosure includes a step of preparing a semiconductor substrate including a first substrate and a plurality of stripe-shaped semiconductor parts grown on the first substrate, and a step of forming, on the first substrate, a plurality of structures each including one of the plurality of semiconductor parts, and dividing the structures in a short-side direction so that end faces parallel to the short-side direction are exposed from each structure to obtain a group of individual structures. The method further includes a step of transferring the plurality of individual structures included in the group of individual structures to a second substrate, and a step of dividing the second substrate to obtain a plurality of element substrates each including one or more individual structures.

[0056] The method for manufacturing a semiconductor laser device according to Embodiment 2 of the present disclosure is the method according to Embodiment 1, wherein the end face functions as a resonator end face, and selective transfer is performed such that the number of transferred individual structures per unit area on the second substrate is smaller than the number of individual structures per unit area in the group of individual structures, and the second substrate is divided without dividing any of the individual structures.

[0057] The method for manufacturing a semiconductor laser device according to Embodiment 3 of the present disclosure is the method according to Embodiment 2, wherein, in the second substrate, a direction corresponding to the short-side direction of the plurality of semiconductor parts is defined as a first direction, and a direction corresponding to the long-side direction is defined as a second direction, and the plurality of individual structures transferred to the second substrate are arranged in a matrix in the first and second directions.

[0058] The method for manufacturing a semiconductor laser device according to Embodiment 4 of the present disclosure is the method according to Embodiment 3, wherein the interval between the plurality of individual structures in the second direction is equal to or greater than the size of each individual structure in the second direction.

[0059] The method for manufacturing a semiconductor laser device according to Embodiment 5 of the present disclosure is the method according to Embodiment 4, wherein the interval between the plurality of individual structures in the second direction is a natural number multiple of the size.

[0060] The method for manufacturing a semiconductor laser device according to Embodiment 6 of the present disclosure is the method according to any one of Embodiments 3 to 5, wherein the second substrate has a plurality of recesses arranged in a matrix in the first and second directions.

[0061] In the method for manufacturing a semiconductor laser device according to Embodiment 7 of the present disclosure, in the above-described Embodiment 6, the end face parallel to the short side direction of each individual transferred to the second substrate is located above one of the plurality of recesses.

[0062] In the method for manufacturing a semiconductor laser device according to Embodiment 8 of the present disclosure, in the above-described Embodiment 6 or 7, the cross section formed by dividing the second substrate includes at least one of the plurality of recesses.

[0063] In the method for manufacturing a semiconductor laser device according to Embodiment 9 of the present disclosure, in any one of the above-described Embodiments 3 to 8, in each of the plurality of element substrates, two or more individuals are arranged in a row in the first direction.

[0064] In the method for manufacturing a semiconductor laser device according to Embodiment 10 of the present disclosure, in the above-described Embodiment 9, a dielectric film is formed on the end face of each of two or more individuals arranged in a row on each element substrate.

[0065] In the method for manufacturing a semiconductor laser device according to Embodiment 11 of the present disclosure, in the above-described Embodiment 4 or 5, before the step of obtaining the plurality of element substrates, a dielectric film is formed on the end face of each of the plurality of individuals arranged in a matrix on the second substrate.

[0066] In the method for manufacturing a semiconductor laser device according to Embodiment 12 of the present disclosure, in any one of the above-described Embodiments 1 to 11, the resonator length of each individual is 200 μm or less.

[0067] In the method for manufacturing a semiconductor laser device according to Embodiment 13 of the present disclosure, in any one of the above-described Embodiments 1 to 12, the plurality of substrates are obtained by stealth dicing the second substrate.

[0068] In the method for manufacturing a semiconductor laser device according to Embodiment 14 of the present disclosure, in any one of the above-described Embodiments 1 to 13, the end face is formed by cleavage or etching.

[0069] In the method for manufacturing a semiconductor laser device according to Embodiment 15 of the present disclosure, in any one of Embodiments 1 to 14 described above, each semiconductor portion includes a nitride semiconductor, and the end face is parallel to the m-plane of the nitride semiconductor.

[0070] In the method for manufacturing a semiconductor laser device according to Embodiment 16 of the present disclosure, in any one of Embodiments 1 to 15 described above, each of the first and second substrates includes a silicon substrate or a silicon carbide substrate.

[0071] In the method for manufacturing a semiconductor laser device according to Embodiment 17 of the present disclosure, in any one of Embodiments 1 to 16 described above, when transferring the plurality of individuals to the second substrate, each individual is electrically connected to the electrode pads of the second substrate.

[0072] In the method for manufacturing a semiconductor laser device according to Embodiment 18 of the present disclosure, in any one of Embodiments 1 to 17 described above, the method includes a step of dividing a semiconductor substrate including the plurality of individuals into a plurality of individual pieces.

[0073] In the method for manufacturing a semiconductor laser device according to Embodiment 19 of the present disclosure, in any one of Embodiments 1 to 18 described above, the method includes a step of scribing each structure.

[0074] In the method for manufacturing a semiconductor laser device according to Embodiment 20 of the present disclosure, in any one of Embodiments 1 to 19 described above, each of the plurality of semiconductor portions includes a GaN-based semiconductor, and the first substrate includes a wafer made of a material having a coefficient of thermal expansion smaller than that of the GaN-based semiconductor.

[0075] In the method for manufacturing a semiconductor laser device according to Embodiment 21 of the present disclosure, in any one of Embodiments 1 to 20 described above, when transferring the plurality of individuals to the second substrate, the connection crystal portion between each individual and the first substrate breaks.

[0076] In the method for manufacturing a semiconductor laser device according to Embodiment 22 of the present disclosure, in any one of Embodiments 1 to 21 described above, each structure includes a ridge including a nitride semiconductor, an electrode, and an insulating film.

[0077] In the method for manufacturing a semiconductor laser device according to Embodiment 23 of the present disclosure, in the above-described Embodiment 22, at least one of the electrode and the insulating film is not included in the end face formed by dividing each structure.

[0078] In the method for manufacturing a semiconductor laser device according to Embodiment 24 of the present disclosure, in the above-described Embodiment 22 or 23, a cross section of the ridge is included in the end face, and the cross section functions as a resonator end face.

[0079] In the method for manufacturing a semiconductor laser device according to Embodiment 25 of the present disclosure, in the above-described Embodiment 1, a first individual, which is one of the plurality of individuals to be transferred, includes an anode, the second substrate has a first convex portion corresponding to the first individual, and at the time of transfer, the first convex portion is located inside the anode.

[0080] In the method for manufacturing a semiconductor laser device according to Embodiment 26 of the present disclosure, in the above-described Embodiment 1, a first individual, which is one of the plurality of individuals to be transferred, includes an anode, the second substrate has a second convex portion corresponding to the first individual, and at the time of transfer, the second convex portion is located outside the anode.

[0081] In the method for manufacturing a semiconductor laser device according to Embodiment 27 of the present disclosure, in the above-described Embodiment 1, a first individual, which is one of the plurality of individuals to be transferred, includes an anode, the second substrate has a first groove portion corresponding to the first individual, and at the time of transfer, the first groove portion is located inside the anode.

[0082] In the method for manufacturing a semiconductor laser device according to Embodiment 28 of the present disclosure, in the above-described Embodiment 1, a first individual, which is one of the plurality of individuals to be transferred, includes an anode, the second substrate has a second groove portion corresponding to the first individual, and at the time of transfer, the second groove portion is located outside the anode.

[0083] In the method for manufacturing a semiconductor laser device according to Embodiment 29 of the present disclosure, in Embodiment 27 described above, the first groove portion has side walls containing a metal.

[0084] In the method for manufacturing a semiconductor laser device according to Embodiment 30 of the present disclosure, in Embodiment 28 described above, the second groove portion has side walls containing a metal.

[0085] In the method for manufacturing a semiconductor laser device according to Embodiment 31 of the present disclosure, in any one of Embodiments 25 to 30 described above, the anode is joined to the second substrate via solder.

[0086] In the method for manufacturing a semiconductor laser device according to Embodiment 32 of the present disclosure, in Embodiment 1 described above, the second substrate has a mound portion corresponding to a first individual that is one of the plurality of individuals to be transferred, and at the time of transfer, the first individual is disposed above the mound portion.

[0087] In the method for manufacturing a semiconductor laser device according to Embodiment 33 of the present disclosure, in Embodiment 32 described above, at the time of transfer, non-selected individuals in the group of individuals do not come into contact with the second substrate.

[0088] In the method for manufacturing a semiconductor laser device according to Embodiment 34 of the present disclosure, in Embodiment 32 or 33 described above, the second substrate includes electrode pads, and at least a part of the electrode pads is located on the mound portion.

[0089] In the method for manufacturing a semiconductor laser device according to Embodiment 35 of the present disclosure, in Embodiment 34 described above, the electrode pads have a thick film portion located on the mound portion and a thin film portion having a smaller film thickness than the thick film portion.

[0090] In the method for manufacturing a semiconductor laser device according to Embodiment 36 of the present disclosure, in Embodiment 34 or 35 described above, the first individual includes an anode, and the anode comes into contact with the electrode pads.

[0091] The manufacturing apparatus for a semiconductor laser device according to Embodiment 25 of the present disclosure performs each step described in any one of Embodiments 1 to 24 above.

Explanation of Symbols

[0092] 1 Main substrate 4 Underlayer 5 Mask part 6 Mask pattern 8 Semiconductor part 10 Semiconductor substrate 20 Element substrate (semiconductor laser device) 30 Element substrate (semiconductor laser device) 40 Laser element (semiconductor laser device) JT structure CF end face LT body (laser body) BS base substrate FK First substrate SK Second substrate K Opening G Gap

Claims

1. Preparing a semiconductor substrate including a first substrate and a plurality of stripe-shaped semiconductor portions that have grown crystallographically on the first substrate; On the first substrate, dividing a plurality of structures each including one of the plurality of semiconductor portions such that end faces thereof protrude from each structure to obtain a group of individuals; Transferring the plurality of individuals included in the group of individuals onto a second substrate; and Dividing the second substrate to obtain a plurality of element substrates each including one or more individuals, the method for manufacturing a semiconductor laser device.

2. The transfer step onto the second substrate is a selective transfer performed such that the number of transferred individuals per unit area on the second substrate is smaller than the number of individuals per unit area in the group of individuals, the method for manufacturing a semiconductor laser device according to Claim 1.

3. The end face includes a resonator end face, Dividing the second substrate without dividing any of the individuals, the method for manufacturing a semiconductor laser device according to Claim 2.

4. The end face of each individual is formed along the crystal orientation of each semiconductor portion, the method for manufacturing a semiconductor laser device according to any one of Claims 1 to 3.

5. The end face of each individual is parallel to the short side direction of each semiconductor portion, the method for manufacturing a semiconductor laser device according to any one of Claims 1 to 3.

6. Each semiconductor portion includes a nitride semiconductor, The longitudinal direction of the plurality of stripe-shaped semiconductor portions is the m-axis direction of the nitride semiconductor, the method for manufacturing a semiconductor laser device according to any one of Claims 1 to 3.

7. Each semiconductor portion includes a nitride semiconductor, The end face of each individual is parallel to the m-plane of the nitride semiconductor, the method for manufacturing a semiconductor laser device according to Claim 1.

8. In the second substrate, with the direction corresponding to the short side direction of the plurality of semiconductor portions as a first direction and the direction corresponding to the longitudinal direction as a second direction, The plurality of individuals transferred onto the second substrate are arranged in a matrix in the first direction and the second direction, the method for manufacturing a semiconductor laser device according to Claim 2.

9. The interval in the second direction of the plurality of individuals is equal to or greater than the size of each individual in the second direction, the method for manufacturing a semiconductor laser device according to Claim 8.

10. The interval in the second direction of the plurality of individuals is a natural number multiple of the size, the method for manufacturing a semiconductor laser device according to Claim 9.

11. The manufacturing method of the semiconductor laser device according to claim 8, wherein the second substrate has a plurality of recesses arranged in a matrix in the first direction and the second direction.

12. The manufacturing method of the semiconductor laser device according to claim 11, wherein the end face of each individual transferred to the second substrate is located above one of the plurality of recesses.

13. The manufacturing method of the semiconductor laser device according to claim 11, wherein the cross section formed by dividing the second substrate includes at least one of the plurality of recesses.

14. The manufacturing method of the semiconductor laser device according to claim 8, wherein in each of the plurality of element substrates, two or more individuals are arranged in a row in the first direction.

15. The manufacturing method of the semiconductor laser device according to claim 14, wherein a dielectric film is formed on the end face of each of two or more individuals arranged in a row in each element substrate.

16. The manufacturing method of the semiconductor laser device according to claim 9, wherein a dielectric film is formed on the end face of each of the plurality of individuals arranged in a matrix on the second substrate before the step of obtaining the plurality of element substrates.

17. The manufacturing method of the semiconductor laser device according to claim 1, wherein the resonator length of each individual is 200 μm or less.

18. The manufacturing method of the semiconductor laser device according to claim 1, wherein the plurality of element substrates are obtained by stealth dicing the second substrate.

19. The manufacturing method of the semiconductor laser device according to claim 1, wherein the end face is formed by cleavage or etching.

20. The manufacturing method of the semiconductor laser device according to claim 1, wherein each of the first substrate and the second substrate includes a silicon substrate or a silicon carbide substrate.

21. The manufacturing method of the semiconductor laser device according to claim 1, wherein the plurality of individuals are transferred to the second substrate and at the same time, each individual is electrically connected to the electrode pad of the second substrate.

22. The manufacturing method of the semiconductor laser device according to claim 1, including a step of dividing a semiconductor substrate including the plurality of individuals into a plurality of individual pieces.

23. The manufacturing method of the semiconductor laser device according to claim 1, including a step of scribing each structure.

24. Each of the plurality of semiconductor parts includes a GaN-based semiconductor, The manufacturing method of the semiconductor laser device according to claim 1, wherein the first substrate includes a wafer made of a material having a smaller thermal expansion coefficient than the GaN-based semiconductor.

25. The method for manufacturing a semiconductor laser device according to claim 1, wherein when transferring the plurality of individuals to the second substrate, the connection crystal part between each individual and the first substrate is broken.

26. The method for manufacturing a semiconductor laser device according to claim 1, wherein each structure includes a ridge containing a nitride semiconductor, an electrode, and an insulating film.

27. The method for manufacturing a semiconductor laser device according to claim 26, wherein at least one of the electrode and the insulating film is not included in the end face formed by dividing each structure.

28. The method for manufacturing a semiconductor laser device according to claim 26, wherein the cross section of the ridge is included in the end face, and the cross section functions as a resonator end face.

29. A first individual, which is one of the plurality of individuals to be transferred, includes an anode, the second substrate has a first convex portion corresponding to the first individual, and at the time of transfer, the first convex portion is located inside the anode. The method for manufacturing a semiconductor laser device according to claim 1.

30. A first individual, which is one of the plurality of individuals to be transferred, includes an anode, the second substrate has a second convex portion corresponding to the first individual, and at the time of transfer, the second convex portion is located outside the anode. The method for manufacturing a semiconductor laser device according to claim 1.

31. A first individual, which is one of the plurality of individuals to be transferred, includes an anode, the second substrate has a first groove portion corresponding to the first individual, and at the time of transfer, the first groove portion is located inside the anode. The method for manufacturing a semiconductor laser device according to claim 1.

32. A first individual, which is one of the plurality of individuals to be transferred, includes an anode, the second substrate has a second groove portion corresponding to the first individual, and at the time of transfer, the second groove portion is located outside the anode. The method for manufacturing a semiconductor laser device according to claim 1.

33. The method for manufacturing a semiconductor laser device according to claim 31, wherein the first groove portion has side walls containing metal.

34. The method for manufacturing a semiconductor laser device according to claim 32, wherein the second groove portion has side walls containing metal.

35. The method for manufacturing a semiconductor laser device according to any one of claims 29 to 34, wherein the anode is joined to the second substrate via solder.

36. The manufacturing method of the semiconductor laser device according to claim 1, wherein the second substrate has a mound portion corresponding to a first individual that is one of the plurality of individuals to be transferred, and the first individual is disposed above the mound portion during transfer.

37. The manufacturing method of the semiconductor laser device according to claim 36, wherein non-selected individuals in the group of individuals do not come into contact with the second substrate during transfer.

38. The second substrate includes electrode pads, The manufacturing method of the semiconductor laser device according to claim 36 or 37, wherein at least a part of the electrode pads is located on the mound portion.

39. The manufacturing method of the semiconductor laser device according to claim 38, wherein the electrode pads have a thick film portion located on the mound portion and a thin film portion having a smaller film thickness than the thick film portion.

40. The first individual includes an anode, The manufacturing method of the semiconductor laser device according to claim 38, wherein the anode is in contact with the electrode pad.

41. A manufacturing apparatus for a semiconductor laser device that performs each step according to claim 1.

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