JP3812356B2 - Semiconductor light emitting device and manufacturing method thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a gallium nitride (GaN) short wavelength semiconductor laser expected to be applied in the field of optical information processing and the like, and a method for manufacturing the same.
[0002]
[Prior art]
Nitride semiconductors having nitrogen (N) as a group V element are regarded as promising materials for short-wavelength light-emitting devices because of their large band gap. In particular, a semiconductor laser having an oscillation wavelength in the 400 nm band has been eagerly aimed at increasing the capacity of an optical disk device such as a DVD. In particular, a laser composed of a GaN-based nitride semiconductor (Al _x Ga _y In _z N (0 ≦ x, y, z ≦ 1, x + y + z = 1)) has been actively researched and is now reaching a practical level. is there.
[0003]
FIG. 1 is a structural diagram of a cross section orthogonal to a resonator of a GaN-based semiconductor laser device. An n-AlGaN contact layer 102, an n-AlGaN cladding layer 103, an n-GaN light guide layer 104, Ga _1-x In _x N / Ga _1-y In _y N are formed on the GaN substrate 101 by metal organic chemical vapor deposition. A multiple quantum well (MQW) active layer 105, a p-GaN light guide layer 106, a p-AlGaN cladding layer 107, and a p-GaN contact layer 108 made of (0 <y <x <1) are grown. A ridge stripe having a width of about 2 μm is formed on the p-GaN contact layer 108, and both sides thereof are buried with the insulating film 110. Thereafter, a p-electrode 109 made of, for example, Ni / Au is formed on the ridge stripe and the insulating film 110, and an n-electrode 111 made of, for example, Ti / Al is formed on the surface etched partially until the n-AlGaN contact layer 102 is exposed. The
[0004]
When the n-electrode 111 is grounded and a voltage is applied to the p-electrode 109 to inject current, electrons and holes recombine in the MQW active layer 105 to emit light, resulting in optical gain, and lasing at a wavelength of around 400 nm. Wake up. The oscillation wavelength is controlled by the composition and thickness of the Ga _{1 -x} In _x N / Ga _{1 -y} In _y N thin film constituting the MQW active layer 105.
[0005]
For example, “Jpn. J. Appl. Phys. Vol. 39, page L647” discloses that the estimated lifetime of a GaN-based semiconductor laser as described above is 15000 hours at 60 ° C. and 30 mW output CW operation. . In this example, prior to crystal growth of the laser structure, selective lateral growth is performed on the GaN substrate 101, and the dislocation density existing in the stripe-shaped active layer region into which current is injected is reduced to 7 × 10 ⁵ cm ⁻² . By doing so, the reliability of the element is improved.
[0006]
In general, the size of a semiconductor laser element is several hundred μm square, and the laser resonator surface is produced by cleaving a semiconductor crystal. In the crystal growth process and device fabrication process, the substrate thickness is selected to be about several hundreds of μm for reasons such as easy handling of the substrate, but in order to cleave a resonator length of several hundreds of μm with a high yield. Prior to the cleavage step, it is necessary to polish or etch the back side of the substrate until the thickness of the substrate reaches about 50 to 150 μm. The surface thus obtained is usually flat. The electrode on the back side of the substrate is formed on this flat surface.
[0007]
When the semiconductor laser element is energized, the temperature of the pn junction increases. The temperature rise not only changes the oscillation characteristics such as the light output and the oscillation wavelength, but also has a great influence on the device life. Therefore, when a laser element that requires a high operating current, such as a high-power laser, is mounted on a package, the pn junction surface side of the element is bonded to a heat sink in order to improve heat dissipation characteristics, that is, the back side of the element substrate In general, it is mounted in a so-called junction down arrangement that exposes. An example is shown in FIG. This is an example in which the heat sink 114 is mounted via the submount 113.
[0008]
[Problems to be solved by the invention]
Compared to conventional semiconductor laser elements using GaAs, InP, or the like as the substrate, the semiconductor laser element using a nitride semiconductor such as GaN as the substrate has a thermal conductivity of about 1.5 W / cmK, which is about twice as high. Since it is high and has good heat dissipation characteristics, the thermal management of the semiconductor laser device is relatively easy.
[0009]
However, it is predicted that higher temperature operation and higher output operation will be required for nitride semiconductor lasers in the future. Therefore, as a result of examination by the inventors of the present application, it has been found that, in the GaN-based semiconductor laser device configured by the above-described conventional technology, the device lifetime is extremely shortened when operating at 80 ° C. and 60 mW compared to operating at 60 ° C. and 30 mW, for example. It was. In the current-light output characteristics in the high temperature region, the increase of the oscillation threshold current value is not significant (that is, the characteristic temperature is not significantly decreased), but the slope efficiency may decrease at a high output of about 50 to 100 mW. As a result, it was considered that thermal saturation had begun to occur. This phenomenon is considered to be caused by insufficient heat dissipation characteristics.
[0010]
The present invention has been made in view of the above circumstances, and provides a semiconductor laser device using a nitride semiconductor laser element having high reliability even during high-temperature and high-power operation and a method for manufacturing the same. This is particularly effective in application to a laser device for optical disks.
[0011]
[Means for Solving the Problems]
To solve the above problems, a semiconductor light-emitting device of the present invention includes a substrate made of a nitride semiconductor, and a semiconductor multilayer structure provided on the substrate possess, semiconductors stacked structure of a nitride semiconductor p A semiconductor layer structure of a substrate, comprising an n-type semiconductor layer made of a nitride semiconductor, an n-type semiconductor layer made of a nitride semiconductor, and an active layer made of a nitride semiconductor sandwiched between a p-type semiconductor layer and an n-type semiconductor layer and the back surface of the surface on the side that includes a plurality, six-sided pyramid-shaped facets, truncated hexagonal pyramid shaped facets, or uneven surfaces der the hexagonal columnar hole is formed is, the substrate and the semiconductor multilayer backside is uneven surface It is a semiconductor light emitting device manufactured by cleaving the structure .
[0012]
In the above structure, the p-type semiconductor layer preferably includes a ridge, and the semiconductor stacked structure preferably includes a resonator surface manufactured by cleavage. Moreover, it is preferable that the surface on which the semiconductor laminated structure of the substrate is formed is a + C polarity surface. Moreover, it is preferable that the surface orientation of the back surface of a board | substrate is a -C polarity direction. Moreover, it is preferable that the electrical conductivity type of the substrate is n-type. The hexagonal pyramid or hexagonal frustum facet formed on the back surface of the substrate preferably has a diameter of 10 μm to several hundreds of μm and a depth of 1 μm to 10 μm. The hexagonal columnar hole formed on the back surface of the substrate preferably has a depth of 10 μm to 20 μm. Moreover, it is preferable that the electrode is formed in the back surface of a board | substrate so that the uneven surface of a back surface may be covered. The electrode preferably contains Ti.
[0013]
The semiconductor light-emitting device of the present invention is a semiconductor light-emitting device in which any one of the semiconductor light-emitting elements described above is mounted, and the light-emitting element has a submount or a heat sink on the side of the substrate where the semiconductor multilayer structure is formed. It is fixed. Another semiconductor light-emitting device of the present invention is a semiconductor light-emitting device in which any one of the above semiconductor light-emitting elements is mounted, and the back surface side of the light-emitting element is fixed to a submount or a heat sink.
[0014]
The method for manufacturing a semiconductor light emitting device of the present invention includes a p-type semiconductor layer made of a nitride semiconductor, an n-type semiconductor layer made of a nitride semiconductor, a p-type semiconductor layer, and an n-type semiconductor layer on a substrate. A plurality of hexagonal pyramid facets, hexagonal frustum facets, or six by forming a semiconductor laminated structure having an active layer made of a nitride semiconductor and anisotropic wet etching of the back surface of the substrate. including a step of obtaining an irregular surface to which columnar hole of square are formed, and a step of cleaving the substrate and the semiconductor multilayer structure.
[0015]
The method of manufacturing a semiconductor light emitting device of the present invention includes a p-type semiconductor layer made of a nitride semiconductor, an n-type semiconductor layer made of a nitride semiconductor, and the p-type semiconductor layer and the n-type semiconductor layer on a substrate. Forming a semiconductor multilayer structure having an active layer made of a nitride semiconductor, and treating the back surface of the substrate with a chemical solution containing at least phosphoric acid, thereby forming a plurality of hexagonal pyramid facets, six Including a step of obtaining an uneven surface in which a truncated pyramid facet or a hexagonal columnar hole is formed, and a step of cleaving the substrate and the semiconductor laminated structure. In the above production method, the phosphoric acid contained in the chemical solution is preferably at least one selected from triphosphoric acid, metaphosphoric acid, trimetaphosphoric acid, tetrametaphosphoric acid, pyrophosphoric acid, and orthophosphoric acid. Moreover, it is preferable that a chemical | medical solution contains orthophosphoric acid, nitric acid, and water. Moreover, it is preferable that the temperature of a chemical | medical solution is 100 degreeC or more and 250 degrees C or less.
[0016]
In the method for manufacturing a semiconductor light emitting device of the present invention, a step of forming a ridge in a p-type semiconductor layer, and a step of forming a resonator surface in the semiconductor multilayer structure by cleaving the substrate and the semiconductor multilayer structure Are preferably included.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0018]
(Example 1)
FIG. 3 is a diagram schematically showing a semiconductor laser device according to an embodiment of the present invention. A state in which a GaN-based semiconductor laser element is mounted on a heat sink 114 in a junction-down arrangement via a submount 113 is schematically shown in a cross section orthogonal to the resonator. The semiconductor laser element includes an n-AlGaN cladding layer 103, an n-GaN light guide layer 104, an MQW active layer 105 made of GaInN / GaN, a p-GaN light guide layer 106, a ridge-shaped p-AlGaN on an n-AlGaN substrate 115. A clad layer 107 and a p-GaN contact layer 108 are sequentially laminated, and both sides of the ridge are filled with an insulating film 110, a p-electrode 109 is on the p-GaN contact layer 108, and an n-electrode 111 is an n-AlGaN substrate 115. Each is formed on a back surface (that is, a surface different from the surface on which the active layer is formed).
[0019]
The point of this embodiment is that the back surface of the n-AlGaN substrate 115 is an uneven surface. The concavo-convex surface is composed of a hexagonal frustum facet 116, a hexagonal frustum facet 117 or a columnar hole 118. The manufacturing process of this laser device is made up of processes such as crystal growth, dry etching, p-electrode deposition, substrate back surface polishing, substrate back surface processing, n-electrode deposition, cleavage, end surface coating, element separation, and mounting. The point is in the substrate back surface processing step.
[0020]
The n-AlGaN substrate 115 used for manufacturing the laser element has, for example, a diameter of 2 inches, a thickness of about 300 μm, an Al mixed crystal ratio of 3%, a carrier concentration of 1 × 10 ¹⁸ cm ⁻³ (dopant is Si), and a plane orientation (0001). is there. A laser element structure is formed on the surface side of the n-AlGaN substrate 115 that has been completed up to the substrate back surface polishing step, and the substrate thickness is about 100 μm by the back surface polishing. The substrate back surface treatment is performed, for example, by immersing in orthophosphoric acid at 160 ° C. for 2 minutes. The p-electrode 109 and the (0001) plane of the GaN-based semiconductor that cover the entire surface are hardly affected by orthophosphoric acid under these conditions, but when an element structure different from this embodiment is adopted or a harsher process than this When the conditions are adopted, the entire surface can be protected with a SiO ₂ film or the like as necessary so as not to be affected by orthophosphoric acid.
[0021]
4 and 5 show optical microscope images of the back surface of the n-AlGaN substrate 115 after the treatment. 4 shows a hexagonal frustum facet 116, a hexagonal frustum facet 117, or a columnar hole 118 schematically shown in cross section in FIG. It can be seen that the entire back surface of the substrate is covered with a hexagonal pyramid having a diameter of about several tens to several hundreds μm and a depth of about several to 10 μm. Further, FIG. 5 shows a columnar hole 118. The columnar hole 118 has a hexagonal or circular shape with a diameter of about 5 μm and a depth of about 10 to 20 μm. The density is about 2 × 10 ⁶ cm ⁻² . In the dense part, independent columnar holes overlap to form a large hole.
[0022]
The plane orientation of the back surface of the substrate is a (000-1) plane, that is, a -c polar plane. The -c polarity plane is the plane in which three of the four Ga-N bonds face downward in the hexagonal GaN crystal structure shown in FIG. Although the surface atomic rearrangement structure of GaN-based semiconductors is unknown, the -c polar plane is more susceptible to orthophosphoric acid than the + c polar plane because of the difference in the configuration of dangling bonds. This is because it is easier to react with orthophosphoric acid, and gallium phosphate salts such as Ga ₃ PO ₄ are more likely to be produced. The reason why the columnar holes 118 are formed is unknown, but considering the density, it can be considered that dislocations were etched quickly.
[0023]
When the surface area of the back surface of the n-AlGaN substrate 115 was measured, it was found to be 20.1 cm ² before the treatment, but increased by 7 times or more to 75.6 cm ² after the treatment. It is assumed that the contribution of the surface area increase due to the formation of the columnar holes 118 is large.
[0024]
After the substrate back surface treatment step, an n electrode 111 was deposited on the back surface of the n-AlGaN substrate 115 and cleaved into bars at intervals of 750 μm. The cleave yield was not affected by the unevenness of the backside of the substrate. Further, high-reflectance coating and element separation were performed on the rear end face, and the substrate was mounted on the heat sink 114 via the submount 113 in a junction-down arrangement.
[0025]
When the thermal resistance was measured in order to evaluate the heat dissipation characteristics of the semiconductor laser device, the semiconductor laser device manufactured without performing the substrate back surface processing for comparison had a temperature of about 25 to 35 ° C./W, In the case where the substrate back surface treatment according to the present invention was performed, it was improved to about 15 to 25 ° C./W. For this reason, for example, the current-light output characteristics at the time of 100 ° C. CW operation have been improved, and the reduction in slope efficiency at the time of 50-100 mW output operation, which has been a conventional problem, has not been recognized. Furthermore, the lifetime of the device at 80 ° C. and 60 mW output operation was extended.
[0026]
As described above, based on this example, the heat radiation characteristics were improved by increasing the surface area of the back surface of the substrate, and the reliability during high-temperature and high-output operation could be improved.
[0027]
In this embodiment, the case where n-AlGaN is used as the substrate has been described. However, similar effects can be obtained even when GaN or other nitride semiconductors such as GaInN are used. Furthermore, a substrate other than a nitride semiconductor, for example, SiC, Si, Al ₂ O ₃ or the like may be used. In this case, an appropriate back surface processing method for forming an uneven surface on each substrate is used.
[0028]
The conductivity type of the substrate may be not only n-type but also p-type or semi-insulating. The polarity of the substrate may be not only when the back surface of the nitride semiconductor substrate is a −c polarity plane but also when it is a + c polarity plane. However, in this case, as described above, more severe back surface processing conditions are required.
[0029]
Further, in this embodiment, the element in which the electrode is formed on the back surface of the substrate has been described, but the element in which both the p-type and n-type electrodes are formed on the substrate surface side as shown in FIGS. Even in the case, the same effect can be obtained.
[0030]
In this example, orthophosphoric acid was used for the rear surface treatment of the nitride semiconductor substrate, but orthophosphoric acid (H ₃ PO ₄ ) was dehydrated and condensed by heating to form pyrophosphoric acid (H ₄ P ₂ O ₇ ) and triphosphoric acid (H ₅ P ₃ O ₁₀ ), metaphosphoric acid (HPO ₃ ), and metaphosphoric acid multimerizes and usually exists as trimetaphosphoric acid (H ₃ P ₃ O ₉ ) and tetrametaphosphoric acid (H ₄ P ₄ O ₁₂ ). Even when a chemical solution containing at least these phosphoric acids is used, the same effect can be obtained. This is because a nitride semiconductor easily reacts with these phosphoric acids to generate a chelate compound of gallium phosphate.
[0031]
In order to suppress dehydration condensation of orthophosphoric acid, it is preferable to add nitric acid and water thereto. Thereby, the back surface of the substrate made of a nitride semiconductor can be etched stably and with good reproducibility to obtain an uneven surface. When the temperature of this chemical solution is less than 100 ° C., the reactivity is poor, and when it exceeds 250 ° C., dehydration condensation proceeds, so that it is preferably used at 100 ° C. or more and 250 ° C. or less.
[0032]
Furthermore, as a method of providing the uneven surface on the back surface of the substrate, a wet etching method that easily reacts with a nitride semiconductor such as a molten alkali treatment can be selected in addition to the phosphoric acid treatment. Moreover, you may use the dry etching which has the reactivity which becomes anisotropic etching.
[0033]
(Example 2)
FIG. 7 is a view schematically showing a semiconductor laser device according to another embodiment of the present invention. A state in which a GaN-based semiconductor laser element is mounted on a heat sink 114 in a junction-down arrangement via a submount 113 is schematically shown in a cross section orthogonal to the resonator. The semiconductor laser device includes an n-AlGaN contact layer 102, an n-AlGaN cladding layer 103, an n-GaN light guide layer 104, an MQW active layer 105 made of GaInN / GaN, a p-GaN light guide layer 106, a ridge on a GaN substrate 101. A p-AlGaN cladding layer 107 and a p-GaN contact layer 108 are sequentially stacked, and both sides of the ridge are filled with an insulating film 110, a p-electrode 109 is on the p-GaN contact layer 108, and an n-electrode 111 is The n-AlGaN contact layer 102 is formed on the etched surface.
[0034]
The point of this embodiment is that a heat sink 114 is also provided on the back surface of the GaN substrate 101. Thereby, the heat dissipation characteristic from the back surface is improved. The submount 113 and the heat sink 114 are selected from a group of materials having high thermal conductivity in consideration of the difference in thermal expansion coefficient with the semiconductor laser element so as to suppress the occurrence of thermal distortion accompanying mounting. Usually, diamond, SiC, Si, AlN or the like is used for the submount 113. The heat sink 114 is a portion corresponding to a post in the package of the semiconductor laser device, but a metal such as Cu or Kovar is used. Furthermore, it is desirable that the heat sink 114 provided on the back surface of the substrate has a high emissivity, and may be usually a metal.
[0035]
The shape of the heat sink provided on the back surface of the substrate may be a flat plate shape as shown in FIG. 7, but may be a comb shape to increase the surface area of the heat sink as shown in FIG. In addition, as shown in FIG. 9, in order to increase thermal conductivity, a post heat sink 114 may be connected via a metal pad 119 covering the back surface of the substrate.
[0036]
When thermal resistance was measured to evaluate the heat dissipation characteristics of the semiconductor laser device, it was about 25 to 35 ° C./W in the semiconductor laser device manufactured without providing a heat sink on the back surface of the substrate for comparison. When the heat sink was fixed based on this example, the temperature was improved to about 15 to 25 ° C./W. For this reason, for example, the current-light output characteristics at the time of 100 ° C. CW operation have been improved, and the reduction in slope efficiency at the time of 50-100 mW output operation, which has been a conventional problem, has not been recognized. Furthermore, the lifetime of the device at 80 ° C. and 60 mW output operation was extended.
[0037]
As described above, according to the present invention, the heat radiation characteristic is improved by fixing the heat sink to the back surface of the substrate, and the reliability at the time of high temperature and high output operation can be improved.
[0038]
In this embodiment, the case where GaN is used as the substrate has been described. However, other nitride semiconductors such as AlGaN and GaInN, or substrates other than nitride semiconductors such as SiC, Si, and Al ₂ O ₃ are used. May be used.
[0039]
Further, in this embodiment, the element in which both the p-type and n-type electrodes are formed on the front surface side of the substrate has been described. it can.
[0040]
In the present embodiment, the case where the semiconductor laser element is mounted in a junction-down arrangement has been described. However, even when the semiconductor laser element is mounted in a junction-up arrangement, a large effect can be obtained by fixing the heat sink to the substrate surface. be able to.
[0041]
The present invention relates to a laser element, but can also be applied to other semiconductor elements such as electronic elements that require high-temperature and high-power operation and a method for manufacturing the same, and provides high reliability.
[0042]
【The invention's effect】
As described above, according to the semiconductor laser device and the manufacturing method thereof of the present invention, it is possible to provide a highly reliable GaN-based semiconductor laser device with good heat dissipation characteristics even during high-temperature and high-power operation.
[Brief description of the drawings]
FIG. 1 is a structural diagram of a cross section orthogonal to a resonator of a GaN-based semiconductor laser device. FIG. 2 is a cross-sectional view orthogonal to the resonator showing a state in which a conventional GaN-based semiconductor laser device is mounted via a submount. Fig. 3 is a schematic diagram of a cross section perpendicular to a resonator showing a state in which a GaN-based semiconductor laser device according to an embodiment of the present invention is mounted via a submount. Fig. 4 is an embodiment of the present invention. FIG. 5 is a diagram showing an optical microscope image of the back surface of the GaN-based semiconductor laser device according to the embodiment of the present invention. FIG. 5 is a diagram showing an optical microscope image of the back surface of the GaN-based semiconductor laser device according to the embodiment of the present invention. FIG. 7 is a schematic diagram showing the polarities of the crystal GaN crystal (0001) plane and the (000-1) plane. FIG. 7 shows a state in which a GaN-based semiconductor laser device according to an embodiment of the present invention is mounted via a submount. FIG. 8 is a schematic diagram of a cross section perpendicular to the resonator showing a state in which the GaN-based semiconductor laser device according to one embodiment of the present invention is mounted via a submount. 9 is a schematic diagram of a cross section orthogonal to a resonator showing a state in which a GaN-based semiconductor laser device according to an embodiment of the present invention is mounted via a submount.
101 GaN substrate 102 n-AlGaN contact layer 103 n-AlGaN cladding layer 104 n-GaN light guide layer 105 active layer 106 p-GaN light guide layer 107 p-AlGaN cladding layer 108 p-GaN contact layer 109 p electrode 110 insulating film 111 n-electrode 112 solder 113 submount 114 heat sink 115 n-AlGaN substrate 116 hexagonal frustum facet 117 hexagonal frustum facet 118 columnar hole 119 metal pad

Claims (17)

A substrate made of a nitride semiconductor;
Have a semiconductor multilayer structure provided on said substrate, before Symbol semiconductor multilayer structure includes a p-type semiconductor layer made of a nitride semiconductor, and the n-type semiconductor layer made of a nitride semiconductor, the p-type semiconductor layer And an active layer made of a nitride semiconductor sandwiched between n-type semiconductor layers,
Rear surface of the surface on which the semiconductor layer structure is formed of the substrate, a plurality, six-sided pyramid-shaped facets, Ri uneven surface der the truncated hexagonal pyramid shaped facets, or hexagonal columnar hole is formed,
A semiconductor light emitting device manufactured by cleaving the substrate and the semiconductor multilayer structure, the back surface of which is the uneven surface .   The semiconductor light-emitting element according to claim 1, wherein the p-type semiconductor layer has a ridge, and the semiconductor multilayer structure has a resonator surface fabricated by cleavage.   The semiconductor light emitting element according to claim 1, wherein a surface of the substrate on which the semiconductor multilayer structure is formed is a + C polarity surface.   The semiconductor light emitting element according to claim 1, wherein a surface orientation of a back surface of the substrate is a −C polarity direction.   The semiconductor light-emitting device according to claim 1, wherein an electrical conductivity type of the substrate is n-type.   6. The hexagonal pyramid or hexagonal frustum facet formed on the back surface of the substrate comprises a hexagonal pyramid or a hexagonal frustum having a diameter of 10 μm to several hundreds of μm and a depth of 1 μm to 10 μm. The semiconductor light emitting element in any one. 7. The semiconductor light emitting element according to claim 1, wherein the hexagonal columnar hole formed on the back surface of the substrate has a depth of 10 μm to 20 μm.   The semiconductor light emitting element according to any one of claims 1 to 7, wherein an electrode is formed on a back surface of the substrate so as to cover an uneven surface of the back surface.   The semiconductor light emitting element according to claim 8, wherein the electrode contains Ti.   10. A semiconductor light-emitting device in which the semiconductor light-emitting element according to claim 1 is mounted, wherein the light-emitting element is fixed to a submount or a heat sink on a surface side of the substrate where the semiconductor multilayer structure is formed. Semiconductor light emitting device.   10. A semiconductor light-emitting device in which the semiconductor light-emitting element according to claim 1 is mounted, wherein the back surface side of the substrate is fixed to a submount or a heat sink. A p-type semiconductor layer made of a nitride semiconductor, an n-type semiconductor layer made of a nitride semiconductor, and an active layer made of a nitride semiconductor sandwiched between the p-type semiconductor layer and the n-type semiconductor layer on a substrate. A step of forming a semiconductor laminated structure, and an uneven surface on which a plurality of hexagonal pyramid facets, hexagonal frustum facets, or hexagonal columnar holes are formed by anisotropic wet etching of the back surface of the substrate And a method of manufacturing a semiconductor light emitting device, comprising: cleaving the substrate and the semiconductor multilayer structure. A p-type semiconductor layer made of a nitride semiconductor, an n-type semiconductor layer made of a nitride semiconductor, and an active layer made of a nitride semiconductor sandwiched between the p-type semiconductor layer and the n-type semiconductor layer on a substrate. A plurality of hexagonal pyramid facets, hexagonal frustum facets, or hexagonal columnar holes are formed by processing the back surface of the substrate using a chemical solution containing at least phosphoric acid, and a step of forming a semiconductor multilayer structure having A method for manufacturing a semiconductor light emitting device, comprising: a step of obtaining a formed uneven surface; and a step of cleaving the substrate and the semiconductor multilayer structure. The method for manufacturing a semiconductor light-emitting element according to claim 13 , wherein the phosphoric acid contained in the chemical solution is at least one selected from triphosphoric acid, metaphosphoric acid, trimetaphosphoric acid, tetrametaphosphoric acid, pyrophosphoric acid, and orthophosphoric acid. The method of manufacturing a semiconductor light emitting element according to claim 13 or 14 , wherein the chemical solution contains orthophosphoric acid, nitric acid, and water. The method of manufacturing a semiconductor light emitting element according to claim 15 , wherein the temperature of the chemical solution is 100 ° C. or higher and 250 ° C. or lower.   17. The method according to claim 12, comprising a step of forming a ridge in the p-type semiconductor layer, and a step of forming a resonator surface in the semiconductor multilayer structure by cleaving the substrate and the semiconductor multilayer structure. A method for manufacturing a semiconductor light emitting device.

Images