JP2018064061A - Semiconductor light-emitting element, illuminating device, head light, movable body, illuminating device, video device, projection type image display device and projector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor light-emitting device which enables the reduction in operation voltage.SOLUTION: The above problem is solved by a semiconductor light-emitting device comprising: a first semiconductor laminate structure formed from a group XIII nitride semiconductor and including an n-type semiconductor layer, an active layer, and a p-type semiconductor layer; a second semiconductor laminate structure formed from a group XIII nitride semiconductor, connected with the first semiconductor laminate structure, and forming a 2D hole gas, in which the 2D hole gas makes a current path; an n-side electrode connected to the first semiconductor laminate structure; and a p-side electrode connected to the second semiconductor laminate structure.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a semiconductor light emitting element, a lighting device, a headlight, a moving body, an illumination device, a video device, a projection type video device, and a projector.

  Conventionally, light emitting diodes and semiconductor lasers using group 13 nitride semiconductors are known. As a semiconductor laser, for example, a surface emitting laser having a structure in which the side of the current confinement portion is covered with a DBR made of a dielectric multilayer film and light loss is effectively reduced by confining light in the lateral direction is disclosed. (For example, refer to Patent Document 1).

  Further, for example, a surface-emitting laser having a periodic gain structure in which a plurality of active layers are arranged at peak positions of standing waves in a resonator is disclosed (for example, see Patent Document 2). This surface emitting laser has a structure in which an intermediate layer formed between active layers is laminated in the order of an Mg doped layer and a nitride semiconductor containing In.

  Further, for example, a surface emitting laser having a structure in which a conductive material is disposed on the outer periphery of a translucent electrode to make current injection into an active layer uniform is disclosed (for example, see Patent Document 3).

Incidentally, in the conventional surface emitting laser, a p-side _{electrode, ZnO, In 2 O 3,} SnO 2, ATO, ITO, MgO, is translucent electrode such as Ni / Au are used. Since these translucent electrodes absorb light not a little, the thickness cannot be increased. For this reason, when a current is passed in a direction perpendicular to the stacking direction of the stacked structure, the resistance increases and the operating voltage increases.

  Then, in view of the said subject, it aims at providing the semiconductor light-emitting device which can reduce an operating voltage.

  In order to achieve the above object, a semiconductor light emitting device according to one embodiment of the present invention has a first semiconductor stacked structure formed of a group 13 nitride semiconductor, and includes an n-type semiconductor layer, an active layer, and a p-type semiconductor layer. And a second semiconductor multilayer structure formed of a group 13 nitride semiconductor, the multilayer structure being connected to the first semiconductor multilayer structure and forming a two-dimensional hole gas A second semiconductor multilayer structure using the two-dimensional hole gas as a current path, an n-side electrode connected to the first semiconductor multilayer structure, and connected to the second semiconductor multilayer structure p-side electrode.

  According to the disclosed technology, it is possible to provide a semiconductor light emitting element capable of reducing the operating voltage.

Schematic sectional view showing an example of a semiconductor light emitting device according to an embodiment of the present invention Schematic sectional view showing an example of a first semiconductor laminated structure (1) Schematic sectional view showing an example of a first semiconductor laminated structure (2) Schematic sectional view showing an example of the second semiconductor laminated structure Schematic sectional view for explaining the arrangement of the p-side electrode Schematic sectional view (1) showing another example of the semiconductor light emitting device of the embodiment of the present invention Schematic sectional drawing (2) which shows another example of the semiconductor light-emitting device of embodiment of this invention. Schematic sectional view (3) showing another example of the semiconductor light emitting device of the embodiment of the present invention The figure for demonstrating the semiconductor light-emitting device of Example 1. FIG. The figure for demonstrating the semiconductor light-emitting device of Example 2. FIG. The figure for demonstrating the semiconductor light-emitting device of Example 3. The figure for demonstrating the semiconductor light-emitting device of Example 4. FIG. 6 is a diagram for explaining a semiconductor light emitting device of Example 5; The figure for demonstrating the semiconductor light-emitting device of Example 6. The figure for demonstrating the semiconductor light-emitting device of Example 7.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In addition, in this specification and drawing, about the substantially same structure, the duplicate description is abbreviate | omitted by attaching | subjecting the same code | symbol.

  A semiconductor light emitting device according to an embodiment of the present invention will be described. FIG. 1 is a schematic cross-sectional view showing an example of a semiconductor light emitting device according to an embodiment of the present invention. 2 and 3 are schematic cross-sectional views showing an example of the first semiconductor multilayer structure. FIG. 4 is a schematic cross-sectional view showing an example of the second semiconductor multilayer structure. FIG. 5 is a schematic cross-sectional view for explaining the arrangement of the p-side electrode.

  As shown in FIG. 1, the semiconductor light emitting device of the embodiment of the present invention includes a first semiconductor multilayer structure 10, a second semiconductor multilayer structure 20, an n-side electrode 30, and a p-side electrode 40. . The first semiconductor multilayer structure 10 includes an n-type semiconductor layer 11, an active layer 12, and a p-type semiconductor layer 13. The second semiconductor multilayer structure 20 includes a first group 13 nitride semiconductor 21 and a second group 13 nitride semiconductor 22. When a voltage is applied between the n-side electrode 30 and the p-side electrode 40, the semiconductor light emitting element injects electrons and holes into the active layer 12, and emits light by recombination of the electrons and holes.

  The first semiconductor multilayer structure 10 is a semiconductor multilayer structure formed of a group 13 nitride semiconductor, and includes an n-type semiconductor layer 11, an active layer 12, and a p-type semiconductor layer 13. The group 13 nitride semiconductor is a wurtzite nitride semiconductor composed of a group 13 metal selected from a group 13 metal element of boron (B), aluminum (Al), gallium (Ga), and indium (In) and nitrogen. It is.

  In the embodiment of the present invention, the direction from the nitrogen polar face of the c-plane, which is the polar face of the group 13 nitride semiconductor, to the group 13 metal polar face is referred to as a group 13 metal direction (+ c-axis direction (<0001> direction)). . In addition, a direction from the group 13 metal polar surface of the c-plane, which is a polar surface of the group 13 nitride semiconductor, to the nitrogen polar surface is referred to as a nitrogen polar direction (−c axis direction (<000-1> direction)). Further, the case of crystal growth in the + c axis direction is referred to as group 13 metal surface growth (for example, Ga surface growth), and the case of crystal growth in the −c axis direction is referred to as nitrogen surface growth.

  The stacking direction of the n-type semiconductor layer 11, the active layer 12, and the p-type semiconductor layer 13 is not particularly limited as long as electrons and holes are injected into the active layer 12 and light is emitted by recombination thereof. . For example, as shown in FIG. 2, the n-type semiconductor layer 11, the active layer 12, and the p-type semiconductor layer 13 may be arranged in the order along the + c-axis direction. As shown in FIG. The p-type semiconductor layer 13, the active layer 12, and the n-type semiconductor layer 11 may be in this order.

  The second semiconductor multilayer structure 20 is a semiconductor multilayer structure formed of a group 13 nitride semiconductor and has a multilayer structure that is connected to the first semiconductor multilayer structure 10 and forms the two-dimensional hole gas 23. The two-dimensional hole gas 23 is used as a current path. The formation of the two-dimensional hole gas can be confirmed by performing a band calculation of the second semiconductor multilayer structure 20. As shown in FIG. 4A, the second semiconductor stacked structure 20 includes a first group 13 nitride semiconductor 21 and a second group 13 nitride semiconductor 22 stacked in succession along the + c-axis direction. Including a structured.

  The first group 13 nitride semiconductor 21 is a high-resistance i-type semiconductor. The second group 13 nitride semiconductor 22 is an undoped n-type or p-type semiconductor. The first group 13 nitride semiconductor 21 and the second group 13 nitride semiconductor 22 have different lattice constants, and are caused by the lattice strain between the first group 13 nitride semiconductor 21 and the second group 13 nitride semiconductor 22. A piezoelectric field is generated in the first group 13 nitride semiconductor 21. Thus, the first group 13 nitride semiconductor 21 is polarized so that the c-plane group 13 metal polar surface 21a side is negative and the nitrogen polar surface 21b side is positive. Then, as shown in FIG. 4B, in the vicinity of the interface between the first group 13 nitride semiconductor 21 and the second group 13 nitride semiconductor 22 of the second group 13 nitride semiconductor 22, A high concentration two-dimensional hole gas 23 induced by the polarization of the first group 13 nitride semiconductor 21 is formed.

  The lattice constant of the first group 13 nitride semiconductor 21 and the lattice constant of the second group 13 nitride semiconductor 22 are the piezo electric field generated in the first group 13 nitride semiconductor 21 due to the strain caused by the difference between the two lattice constants. Is adjusted as appropriate so that the concentration of the two-dimensional hole gas 23 is increased. Preferably, the lattice constant of the second group 13 nitride semiconductor 22 is adjusted to be larger than the lattice constant of the first group 13 nitride semiconductor 21.

  The thickness of the first group 13 nitride semiconductor 21 and the thickness of the second group 13 nitride semiconductor 22 are increased so that cracks do not occur, and the concentration of the two-dimensional hole gas 23 increases. Is adjusted as appropriate.

  The n-side electrode 30 is connected to the first semiconductor multilayer structure 10. More specifically, the n-side electrode 30 is connected to the n-type semiconductor layer 11 of the first semiconductor multilayer structure 10.

  The p-side electrode 40 is connected to the second semiconductor multilayer structure 20. More specifically, the p-side electrode 40 may be formed on the second group 13 nitride semiconductor 22 as shown in FIG. 5A, as shown in FIG. 5B. Further, it may be formed on the second group 13 nitride semiconductor 22 via the p-type semiconductor 24. Further, as shown in FIG. 5C, the p-side electrode 40 is formed on the first group 13 nitride semiconductor 21 and the second group 13 nitride semiconductor 22 on the first group 13 nitride semiconductor 21. It may be formed so as to be in contact with the interface.

  As shown in FIG. 1, a part of the current path of the second semiconductor stacked structure 20 becomes a two-dimensional hole gas 23 formed in the second group 13 nitride semiconductor 22. In the portion of the two-dimensional hole gas 23, the current flows parallel to the interface between the first group 13 nitride semiconductor 21 and the second group 13 nitride semiconductor 22. When the two-dimensional hole gas 23 becomes a current path, the bulk portion of the second group 13 nitride semiconductor 22 where the two-dimensional hole gas is not formed and the p-type semiconductor layer 13 are laterally (perpendicular to the stacking direction). The resistance of the semiconductor light emitting element can be reduced as compared with the case where current flows in the right direction). In FIG. 1, the current flow is indicated by an arrow A.

  As described above, the first semiconductor multilayer structure 10 and the second semiconductor multilayer structure 20 are joined so that the active layer 12 is sandwiched between the n-side electrode 30 and the p-side electrode 40. As for the form of bonding between the first semiconductor multilayer structure 10 and the second semiconductor multilayer structure 20, the first semiconductor multilayer structure 10 and the second semiconductor multilayer structure 20 are electrically connected, and a current flows. If it is, it will not specifically limit. For example, the p-type semiconductor layer 13 included in the first semiconductor multilayer structure 10 and the second group 13 nitride semiconductor 22 included in the second semiconductor multilayer structure 20 are joined. At this time, the second semiconductor stacked structure 20 may be stacked on the + c axis direction side of the first semiconductor stacked structure 10, and the second semiconductor stacked structure 10 may be stacked on the −c axis direction side of the first semiconductor stacked structure 10. The semiconductor multilayer structure 20 may be laminated. Further, the c-axis direction of the first semiconductor multilayer structure 10 and the c-axis direction of the second semiconductor multilayer structure 20 may be the same direction or opposite directions.

  As shown in FIG. 1, when the second semiconductor multilayer structure 20 is formed on the nitrogen polar face side of the first semiconductor multilayer structure 10 with the c-axis direction being the same direction, the second semiconductor multilayer structure The first semiconductor stacked structure 10 may be stacked on the 20 second group 13 nitride semiconductor 22. In the semiconductor light emitting device having this structure, when a voltage is applied between the n-side electrode 30 and the p-side electrode 40, the current flows from the p-side electrode 40 to the second group 13 nitride semiconductor of the second semiconductor multilayer structure 20. It passes through the two-dimensional hole gas 23 formed on the surface 22. The current passing through the two-dimensional hole gas 23 flows from the second group 13 nitride semiconductor 22 to the p-type semiconductor layer 13 of the first semiconductor stacked structure 10, and the active layer 12, the n-type semiconductor layer 11, and n It flows in the order of the side electrodes 30. Then, holes and electrons are injected into the active layer 12 to emit light by recombination.

  6 to 8 are schematic cross-sectional views showing other examples of the semiconductor light emitting device according to the embodiment of the present invention. 6 to 8, the current flow is indicated by an arrow A.

  As shown in FIG. 6, the second semiconductor multilayer structure 20 has a c-axis direction opposite to the first semiconductor multilayer structure 10 on the side of the group 13 metal polar surface of the first semiconductor multilayer structure 10. It may be formed. In this case, the second group 13 nitride semiconductor 22 of the second semiconductor stacked structure 20 may be stacked on the p-type semiconductor layer 13 of the first semiconductor stacked structure 10. At the interface between the first semiconductor multilayer structure 10 and the second semiconductor multilayer structure 20, the polarity is reversed from the group 13 metal polar face to the nitrogen polar face. The method of reversing the polarity is not particularly limited. For example, each of the method of reversing from group 13 metal surface growth to nitrogen polar surface growth during crystal growth, each of the first semiconductor stacked structure 10 and the second semiconductor stacked structure 20. There is a method in which a group 13 metal polar surface is bonded as a bonding surface. In the semiconductor light emitting device having this structure, when a voltage is applied between the n-side electrode 30 and the p-side electrode 40, the current flows from the p-side electrode 40 to the second group 13 nitride semiconductor of the second semiconductor multilayer structure 20. It passes through the two-dimensional hole gas 23 formed on the surface 22. The current passing through the two-dimensional hole gas 23 flows from the second group 13 nitride semiconductor 22 to the p-type semiconductor layer 13 of the first semiconductor stacked structure 10, and the active layer 12, the n-type semiconductor layer 11, and n It flows in the order of the side electrodes 30. Then, holes and electrons are injected into the active layer 12 to emit light by recombination.

  Further, as shown in FIG. 7, the second semiconductor multilayer structure 20 has the c-axis direction on the side of the group 13 metal polar surface of the first semiconductor multilayer structure 10, and the c-axis direction of the first semiconductor multilayer structure 10. And may be laminated in the same direction. In this case, a part of the first group 13 nitride semiconductor 21 of the second semiconductor multilayer structure 20 is removed, and the second group 13 nitride is formed on the p-type semiconductor layer 13 of the first semiconductor multilayer structure 10. The physical semiconductor 22 may be crystal-grown. In the semiconductor light emitting device having this structure, when a voltage is applied between the n-side electrode 30 and the p-side electrode 40, the current flows from the p-side electrode 40 to the second group 13 nitride semiconductor of the second semiconductor multilayer structure 20. It passes through the two-dimensional hole gas 23 formed on the surface 22. The current passing through the two-dimensional hole gas 23 is generated from the second group 13 nitride semiconductor 22 in the region where the first high-resistance group 13 nitride semiconductor 21 has been removed, and p of the first semiconductor stacked structure 10. The active layer 12, the n-type semiconductor layer 11, and the n-side electrode 30 flow in this order. Then, holes and electrons are injected into the active layer 12 to emit light by recombination.

  Further, as shown in FIG. 8, the second semiconductor multilayer structure 20 has the c-axis direction opposite to the first semiconductor multilayer structure 10 on the nitrogen polar face side of the first semiconductor multilayer structure 10. May be laminated. In this case, a part of the first group 13 nitride semiconductor 21 of the second semiconductor multilayer structure 20 is removed, and the second group 13 nitride semiconductor 22 is exposed to make p of the first semiconductor multilayer structure 10. The type semiconductor layer 13 may be crystal-grown. In the semiconductor light emitting device having this structure, when a voltage is applied between the n-side electrode 30 and the p-side electrode 40, the current flows from the p-side electrode 40 to the second group 13 nitride semiconductor of the second semiconductor multilayer structure 20. It passes through the two-dimensional hole gas 23 formed on the surface 22. The current passing through the two-dimensional hole gas 23 is generated from the second group 13 nitride semiconductor 22 in the region where the first high-resistance group 13 nitride semiconductor 21 has been removed, and p of the first semiconductor stacked structure 10. It flows to the type semiconductor layer 13 and flows to the active layer 12, the n-type semiconductor layer 11, and the n-side electrode 30 in this order. Then, holes and electrons are injected into the active layer 12 to emit light by recombination.

  The first semiconductor multilayer structure 10 and the second semiconductor multilayer structure 20 may be continuously crystal-grown. After one of the crystals is grown, the crystal growth is interrupted and the wafer process is performed. The other crystal may be grown. Alternatively, the first semiconductor multilayer structure 10 and the second semiconductor multilayer structure 20 may be bonded to each other after crystal growth on separate substrates.

The material of the substrate on which the first semiconductor multilayer structure 10 and the second semiconductor multilayer structure 20 are crystal-grown is not particularly limited. Preferably, sapphire, GaN, AlN, Ga ₂ O ₃ , SiC, ZnO can be used. The plane orientation of the substrate may be other than the plane orientation in which the group 13 nitride semiconductor for crystal growth has a nonpolar plane (m-plane or a-plane) as the growth plane, but the plane orientation with the c-plane as the growth plane is preferable. It is.

  In addition, the semiconductor light emitting device of the embodiment of the present invention may be provided with a substrate, or may be removed during the manufacturing process of the light emitting device.

  As described above, in the semiconductor light emitting device according to the embodiment of the present invention, the two-dimensional hole gas in which a part of the current path of the second semiconductor multilayer structure 20 is formed in the second group 13 nitride semiconductor 22. 23. In the portion of the two-dimensional hole gas 23, the current flows parallel to the interface between the first group 13 nitride semiconductor 21 and the second group 13 nitride semiconductor 22. When the two-dimensional hole gas 23 becomes a current path, the bulk portion of the second group 13 nitride semiconductor 22 where the two-dimensional hole gas is not formed and the p-type semiconductor layer 13 are laterally (perpendicular to the stacking direction). The resistance of the semiconductor light emitting element can be reduced as compared with the case where current flows in the right direction). As a result, the operating voltage of the semiconductor light emitting element can be reduced.

  The semiconductor light emitting device according to the embodiment of the present invention may be a light emitting diode or a laser. Further, it may be an edge-emitting type or a surface-emitting type. As the surface emitting semiconductor light emitting element, for example, any of a surface emitting light emitting diode, a mirrored surface emitting light emitting diode, and a surface emitting laser may be used. The surface emitting laser may be a surface emitting laser having a vertical cavity structure including a first multilayer film reflecting mirror and a second multilayer film reflecting mirror with the active layer 12 interposed therebetween. Specifically, the second multilayer-film reflective mirror is formed on the side where the second semiconductor multilayer structure 20 is present as viewed from the active layer 12, and the first multilayer-film reflective mirror includes the second semiconductor multilayer structure 20 It is formed on one side and the other side. An active layer 12 is included between the first multilayer reflection mirror and the second multilayer reflection mirror, and all or part of the first semiconductor multilayer structure 10 and the second semiconductor multilayer structure 20 are included. A vertical resonator structure is included. The first multilayer film reflection mirror and the second multilayer film reflection mirror may be semiconductor multilayer film reflection mirrors or dielectric multilayer film reflection mirrors. Further, the first multilayer film reflection mirror may be a semiconductor multilayer film reflection mirror, and the second multilayer film reflection mirror may be a dielectric multilayer film reflection mirror, or vice versa. Furthermore, the semiconductor multilayer film reflecting mirror may be made conductive, and an electrode may be formed there. In addition, the light emitting diode or the laser may be a single light emitting element, or may be a one-dimensional or two-dimensional array of a plurality of light emitting elements.

  Since the semiconductor light emitting device of the embodiment of the present invention can reduce the operating resistance, the power consumption is low. For this reason, even if the operation is performed at a high output, heat generation can be suppressed to a low level, and a large output operation by arraying is also possible. Moreover, the group 13 nitride semiconductor used for the active layer can emit light from ultraviolet to infrared by changing the mixed crystal composition. The semiconductor light emitting device according to the embodiment of the present invention can be applied to various uses by utilizing such characteristics.

  For example, headlights of moving objects such as automobiles, motorcycles, trains, ships, etc., indoor lighting in buildings such as houses, offices, halls, etc., outdoor lighting such as construction sites, parks, roads, tunnels, and light decorations such as illumination It is used as a light source for an illumination device such as an illumination device (illumination device).

  It is also used as a light source for video devices. For example, it is also used as a light source for panel-type video devices such as televisions and displays, spatial projection-type stereoscopic televisions, projection mapping, projectors, head-up displays, and retinal scanning displays.

Example 1
The semiconductor light emitting device of Example 1 will be described. FIG. 9 is a diagram for explaining the semiconductor light emitting device of Example 1. FIG. FIG. 9A is a schematic cross-sectional view of the semiconductor light emitting device of Example 1 as viewed from the light emitting direction.

  As shown in FIG. 9A, the semiconductor light emitting device of Example 1 is an edge emitting semiconductor laser, which is a ridge stripe SCH LD (Separate Confinement Heterostructure Laser Diode). The SCH LD structure was formed by crystal growth using PA-MBE (Plasma-Assisted Molecular Beam Epitaxy).

  In the semiconductor laser stacked structure, the second semiconductor stacked structure 1002 and the first semiconductor stacked structure 1001 are formed in this order on the c-plane GaN substrate 100 in the Ga polarity direction <0001> direction.

The second semiconductor multilayer structure 1002 includes an undoped GaN layer 101 (300 nm), a high resistance Al _0.3 Ga _0.7 N layer 102 (50 nm), and a p-type GaN layer 103 (50 nm) stacked on the GaN substrate 100. )including.

The first semiconductor multilayer structure 1001 includes a p-type GaN layer 104 (500 nm) that is a clad layer stacked on the second semiconductor multilayer structure 1002 and a p-type In _0.01 Al _0.14 Ga that is an electron block layer. _0.85 N layer 105 (20 nm), In _0.08 Ga _0.92 N layer 106 (40 nm) as a guide layer, and multiple quantum well active layer (In _0.14 Ga _0.86 N (3 nm) / In _0.08 Ga _0.92 N (7 nm) 3QW) 107, In _0.08 Ga _0.92 N layer 108 (80 nm) as a guide layer, n-type GaN layer 109 (500 nm) as a cladding layer, and n-type The n-type GaN layer 110 (100 nm) which is a contact layer is included.

Then, the stacked structure of the semiconductor laser is etched until the first semiconductor stacked structure 1001 reaches the p-type GaN layer 103, leaving the laser waveguide structure, and the surface of the p-type GaN layer 103 is exposed. Yes. Further, the surface from the surface of the n-type contact layer 110 to the middle of the n-type cladding layer 109 is formed by etching into a ridge stripe shape. The ridge width is 3 μm. On the surface of the laser waveguide structure, the insulating film 111 on the contact layer 110 on the ridge where the insulating film SiO ₂ 111 is formed is etched into a stripe shape, and the surface of the contact layer 110 is exposed. A Ti / Au electrode layer 113 is deposited on the waveguide structure, and an n-side ohmic electrode 114 is formed on the exposed contact layer 110. A p-side ohmic electrode Ni / Au 112 is formed on the exposed p-type GaN layer 103 above the second semiconductor multilayer structure 1002. The light emitting end face is formed by cleavage, and the end face is reflectively coated. The element length is 700 μm.

  FIG. 9B is a diagram for explaining a polarization structure of a portion surrounded by a broken line in the second semiconductor multilayer structure 1002 in FIG.

As shown in FIG. 9B, the high-resistance Al _0.3 Ga _0.7 N layer 102 grown on the undoped GaN layer 101 has a negative polarity on the Ga polar plane side and a nitrogen polar plane side due to lattice strain. The side is positively polarized. Due to this polarization, a two-dimensional electron gas is formed in the GaN layer 101 in the vicinity of the interface between the GaN layer 101 and the Al _0.3 Ga _0.7 N layer 102. On the other hand, a two-dimensional hole gas is formed in the GaN layer 103 in the vicinity of the interface between the p-type GaN layer 103 and the Al _0.3 Ga _0.7 N layer 102.

  In the semiconductor laser of Example 1, a two-dimensional hole gas is caused to act as a current path, a current is caused to flow laterally from the p-side electrode 112 through the two-dimensional hole gas, and holes are injected into the active layer. Since the current passes through the two-dimensional hole gas, the resistance is lower than that when the current is passed in the lateral direction through the portion of the p-type GaN layer 103 where the two-dimensional hole gas is not formed. By applying a voltage between the n-side electrode and the p-side electrode, holes and electrons are injected into the active layer, and light is emitted by recombination, resulting in laser oscillation. The oscillation wavelength was 430 nm.

(Example 2)
The semiconductor light emitting device of Example 2 will be described. FIG. 10 is a diagram for explaining the semiconductor light emitting device of the second embodiment. FIG. 10A is a schematic cross-sectional view of the semiconductor light emitting device of Example 2.

As shown in FIG. 10A, the semiconductor light emitting device of Example 2 is a surface emitting light emitting diode. The semiconductor laminated structure of the surface-emitting light-emitting diode of Example 2 was formed by crystal growth by metal organic chemical vapor deposition (MOCVD).
In the semiconductor multilayer structure, the second semiconductor multilayer structure 2002 and the first semiconductor multilayer structure 2001 are stacked in this order on the c-plane sapphire substrate 200 in the Ga polarity direction <0001> direction. The second semiconductor multilayer structure 2002 includes a low-temperature GaN buffer layer 201 (50 nm), an undoped GaN layer 202 (300 nm), and a high resistance Al _0.3 Ga _0.7 N layer 203 (50 nm) stacked on the sapphire substrate 200. ) And a p-type GaN layer 204 (50 nm). The first semiconductor multilayer structure 2001 includes a p-type GaN layer 205 (500 nm) which is a p-type cladding layer stacked on the second semiconductor multilayer structure 2002, and a p-type In _0.01 Al _{0. 14} Ga _0.85 N layer 206 (20 nm), multiple quantum well active layer (In _0.14 Ga _0.86 N (3 nm) / In _0.08 Ga _0.92 N (7 nm) 3QW) 207, clad An n-type GaN layer 208 (500 nm) as a layer and an n-type GaN layer 209 (100 nm) as an n-type contact layer are included.

The surface-emitting light-emitting diode of Example 2 is etched until the first semiconductor multilayer structure 2001 reaches the p-type GaN layer 204 so that the light-emitting region becomes a square of 300 × 300 μm ² , and the p-type GaN is etched. The surface of the layer 204 is exposed. An insulating film SiO ₂ 210 is formed on the surface of the light emitting diode laser. The insulating film 210 around the contact layer 209 is etched, and the surface of the contact layer 209 is exposed. Ti / Au is deposited on the exposed contact layer 209, and an n-side ohmic electrode 212 is formed. A p-side ohmic electrode Ni / Au 211 is formed on the exposed p-type GaN layer 204 above the second semiconductor multilayer structure 2002.

  FIG. 10B is a diagram for explaining a polarization structure of a portion surrounded by a broken line in the second semiconductor multilayer structure 2002 in FIG.

As shown in FIG. 10B, the high resistance Al _0.3 Ga _0.7 N layer 203 grown on the undoped GaN layer 202 is negative on the Ga polar plane side and has a nitrogen polar plane side due to lattice strain. The side is positively polarized. Due to this polarization, a two-dimensional electron gas is formed in the GaN layer 202 in the vicinity of the interface between the GaN layer 202 and the Al _0.3 Ga _0.7 N layer 203. On the other hand, a two-dimensional hole gas is formed in the GaN layer 204 near the interface between the p-type GaN layer 204 and the Al _0.3 Ga _0.7 N layer 203.

  In the surface-emitting light emitting diode of Example 2, a two-dimensional hole gas is caused to act as a current path, and a current is allowed to flow laterally from the p-side electrode 211 through the two-dimensional hole gas. Since the current passes through the two-dimensional hole gas, the resistance is lower than when the current is passed in the lateral direction through the portion of the p-type GaN layer 204 where the two-dimensional hole gas is not formed. By applying a voltage between the n-side electrode and the p-side electrode, holes and electrons are injected into the active layer and light is emitted by recombination. The emission peak wavelength was 430 nm.

(Example 3)
The semiconductor light emitting device of Example 3 will be described. FIG. 11 is a diagram for explaining the semiconductor light emitting device of Example 3. FIG. FIG. 11A is a schematic cross-sectional view of the semiconductor light emitting device of Example 3.

  As shown in FIG. 11A, the semiconductor light-emitting element of Example 3 is a surface-emitting light-emitting diode. In the surface-emitting light-emitting diode, the first semiconductor multilayer structure 3001 and the second semiconductor multilayer structure 3002 are crystal-grown on different substrates by MOCVD and bonded to the wafer.

The first semiconductor multilayer structure 3001 includes an n-type GaN layer 301 (300 m) and an n-type GaN layer 302 (an n-type cladding layer) in the Ga polarity direction <0001> direction on an n-type c-plane GaN substrate 300. 500 nm), a multi-quantum well active layer (In _0.14 Ga _0.86 N (3 nm) / In _0.08 Ga _0.92 N (7 nm) 3QW) 303, and a p-type In _{0. A 01} Al _0.14 Ga _0.85 N layer 304 (20 nm) and a p-type GaN layer 305 (500 nm) which is a p-type cladding layer are stacked in this order.

As shown in FIG. 11C, the second semiconductor multilayer structure 3002 includes a low-temperature GaN buffer layer (50 nm) 309 and an undoped GaN layer 308 on the c-plane sapphire substrate 310 in the Ga polarity direction <0001> direction. (1000 nm), a high resistance Al _0.3 Ga _0.7 N layer 307 (50 nm) and a p-type GaN layer 306 (300 nm) are stacked in this order.

  The first semiconductor multilayer structure 3001 and the second semiconductor multilayer structure 3002 are subjected to p-type activation heat treatment after their crystal growth. Subsequently, wafer bonding is performed using the p-type GaN layer 305 of the first semiconductor stacked structure 3001 and the p-type GaN layer 306 of the second semiconductor stacked structure 3002 as bonding surfaces. Thereafter, the sapphire substrate 310, the low-temperature GaN buffer layer 309, and the undoped GaN layer 308 are polished and removed leaving only 100 nm of the undoped GaN layer 308, thereby forming a stacked structure of light emitting diodes.

In this manner, on the first semiconductor multilayer structure 3001, the p-type GaN layer 306 (300 nm) whose polarity is inverted, the high resistance Al _0.3 Ga _0.7 N layer 307 (50 nm), and the undoped as a cap layer. A second semiconductor stacked structure 3002 in which the GaN layer 308 (100 nm) is stacked is formed.

Part of the second semiconductor multilayer structure 3002 is etched to the surface of the p-type GaN layer 306, and the p-side ohmic electrode 312 made of Ni / Au is formed on the exposed surface of the p-type GaN layer 306. An insulating film SiO ₂ 313 is formed on the exposed surface other than the portion where the p-side ohmic electrode 312 is formed above the second semiconductor multilayer structure. Further, Ti / Au is deposited on the back surface of the GaN substrate 300, and an n-side ohmic electrode 311 is formed.

  FIG. 11B is a diagram for explaining a polarization structure of a portion surrounded by a broken line in the second semiconductor multilayer structure 3002 in FIG.

As shown in FIG. 11B, the high resistance Al _0.3 Ga _0.7 N layer 307 grown on the undoped GaN layer 308 has a negative polarity on the Ga polar plane side and a nitrogen polar plane side due to lattice distortion. The side is positively polarized. Due to this polarization, a two-dimensional electron gas is formed in the GaN layer 308 in the vicinity of the interface between the GaN layer 308 and the Al _0.3 Ga _0.7 N layer 307. On the other hand, a two-dimensional hole gas is formed in the GaN layer 306 in the vicinity of the interface between the p-type GaN layer 306 and the Al _0.3 Ga _0.7 N layer 307.

  In the surface-emitting light-emitting diode of Example 3, a two-dimensional hole gas is caused to act as a current path, and a current is allowed to flow laterally from the p-side ohmic electrode 312 through the two-dimensional hole gas. Since the current passes through the two-dimensional hole gas, the resistance is lower than that in the case where the current flows in the lateral direction through the portion of the p-type GaN layer 306 where the two-dimensional hole gas is not formed. Less light is absorbed than when a conductive electrode is formed. By applying a voltage between the n-side electrode and the p-side electrode, holes and electrons are injected into the active layer and light is emitted by recombination. The emission peak wavelength was 430 nm.

Example 4
The semiconductor light emitting device of Example 4 will be described. FIG. 12 is a diagram for explaining the semiconductor light emitting device of Example 4. FIG. FIG. 12A is a schematic cross-sectional view of the semiconductor light emitting device of Example 4.

  As shown in FIG. 12A, the semiconductor light emitting device of Example 4 is a surface emitting light emitting diode. The semiconductor multilayer structure of the surface-emitting light-emitting diode of Example 4 was formed by crystal growth using PA-MBE.

  The first semiconductor multilayer structure 4001 and the second semiconductor multilayer structure 4002 have different growth polarities. The first semiconductor multilayer structure 4001 has a Ga polar plane as a growth plane and crystal growth in the <0001> direction, and the second semiconductor multilayer structure 4002 has a nitrogen polar plane as a growth plane in the <000-1> direction. Crystals are growing.

A first semiconductor multilayer structure 4001 is formed on an n-type c-plane GaN substrate 400, an n-type GaN layer 401 (300 nm) and an n-type GaN layer 402 (an n-type cladding layer) in the Ga polarity direction <0001> direction. 500 nm), (In _0.14 Ga _0.86 N (3 nm) / In _0.08 Ga _0.92 N (7 nm) 3QW) 403 which is a multiple quantum well active layer, and p-type In _{0. A 01} Al _0.14 Ga _0.85 N layer 404 (20 nm) and a p-type GaN layer 405 (500 nm) which is a p-type cladding layer are stacked in this order.

The second semiconductor multilayer structure 4002 is inverted in polarity by growing eight atomic layers of aluminum on the p-type GaN layer 405 (500 nm), and the p-type GaN layer 406 (300 nm) in the nitrogen polarity direction <000-1> direction. ), A high resistance Al _0.3 Ga _0.7 N layer 407 (50 nm) and an undoped GaN layer 408 (100 nm) are stacked in this order.

Part of the second semiconductor multilayer structure 4002 is etched to the surface of the p-type GaN layer 406, and the p-side ohmic electrode 410 made of Ni / Au is formed on the exposed surface of the p-type GaN layer 406. An insulating film SiO ₂ 411 is formed on the exposed surface other than the portion where the p-side ohmic electrode 410 is formed above the second semiconductor multilayer structure 4002. Further, Ti / Au is deposited on the back surface of the GaN substrate 400, and an n-side ohmic electrode 409 is formed.

  FIG. 12B is a diagram for explaining a polarization structure of a portion surrounded by a broken line in the second semiconductor multilayer structure 4002 in FIG.

As shown in FIG. 12B, the high resistance Al _0.3 Ga _0.7 N layer 407 grown on the undoped GaN layer 408 has a negative polarity on the Ga polar plane side and a nitrogen polar plane side due to lattice distortion. The side is positively polarized. Due to this polarization, a two-dimensional electron gas is formed in the GaN layer 408 in the vicinity of the interface between the GaN layer 408 and the Al _0.3 Ga _0.7 N layer 407. On the other hand, a two-dimensional hole gas is formed in the GaN layer 406 in the vicinity of the interface between the p-type GaN layer 406 and the Al _0.3 Ga _0.7 N layer 407.

  In the surface-emitting light-emitting diode of Example 4, a two-dimensional hole gas is caused to act as a current path, and a current is allowed to flow laterally from the p-side ohmic electrode 410 through the two-dimensional hole gas. Since the current passes through the two-dimensional hole gas, the resistance is lower than when a current is passed through the portion of the p-type GaN layer 406 where the two-dimensional hole gas is not formed in the lateral direction. Less light is absorbed than when a conductive electrode is formed. By applying a voltage between the n-side electrode and the p-side electrode, holes and electrons are injected into the active layer and light is emitted by recombination. The emission peak wavelength was 430 nm.

(Example 5)
The semiconductor light emitting device of Example 5 will be described. FIG. 13 is a diagram for explaining the semiconductor light emitting element of Example 5. FIG. FIG. 13A is a schematic cross-sectional view of the semiconductor light-emitting device of Example 5.

  As shown in FIG. 13A, the semiconductor light emitting device of Example 5 is a surface emitting laser (VCSEL). The semiconductor multilayer structure of the surface emitting laser of Example 5 was formed by crystal growth using PA-MBE.

  In the semiconductor multilayer structure, the second semiconductor multilayer structure 5002 and the first semiconductor multilayer structure 5001 are formed in this order on the c-plane GaN substrate 500 in the Ga polarity direction <0001> direction.

The second semiconductor multilayer structure 5002 includes an Al _0.8 In _0.2 N / GaN DBR (41.5 pair) 501 laminated in the Ga polarity direction <0001> direction on the c-plane GaN substrate 500, undoped. It includes a GaN layer 502 (350 nm), a high resistance Al _0.3 Ga _0.7 N layer 503 (50 nm), and a p-type GaN layer 504 (50 nm).

The first semiconductor stacked structure 5001 includes a p-type GaN layer 505 (300 nm) that is a p-type cladding layer stacked on the second semiconductor stacked structure 5002, and a p-type Al _0.2 Ga _{0. 8} N layer 506 (20 nm), multiple quantum well active layer In _0.10 Ga _0.90 N (5 nm) / In _0.01 Ga _0.99 N (5 nm) 5QW) 507, n-type cladding layer It includes an n-type GaN layer 508 (250 nm), a p-type GaN layer 509 (100 nm) that is a current blocking layer, and an n-type GaN layer 510 (100 nm) that is an n-type contact layer.

The p-type GaN layer 509 that is a current blocking layer has a φ8 μm hole, and the n-type GaN layer 508 that is an n-type cladding layer and the n-type GaN layer 510 that is an n-type contact layer are connected through the hole. doing. A dielectric multilayer film DBR511 formed of TiO ₂ / SiO ₂ (7 pairs) is formed on the first semiconductor multilayer structure 5001.

In the surface emitting laser of Example 5, the first semiconductor multilayer structure 5001 is etched to form a mesa shape with a diameter of 100 μm. The etching is performed until the p-type GaN layer 504 having the second semiconductor multilayer structure is reached, and the surface of the p-type GaN layer 504 is exposed. An insulating film SiO ₂ 512 is formed on the surface of the surface emitting laser. The insulating film 512 around the n-type contact layer 510 is etched into a ring shape, and the surface of the contact layer 510 is exposed. Ti / Au is deposited on the exposed contact layer 510, and an n-side ohmic electrode 513 is formed. A wiring electrode 514 made of Cr / Au is formed on the n-side ohmic electrode 513, and the electrode is arranged to the bottom of the mesa shape. A p-side ohmic electrode Ni / Au 515 is formed on the exposed p-type GaN layer 504 above the second semiconductor multilayer structure 5002.

  FIG. 13B is a diagram for explaining a polarization structure of a portion surrounded by a broken line in the second semiconductor multilayer structure 5002 in FIG.

As shown in FIG. 13B, the high-resistance Al _0.3 Ga _0.7 N layer 503 grown on the undoped GaN layer 502 has a negative Ga-polarity side and a nitrogen-polarity side due to lattice distortion. The side is positively polarized. Due to this polarization, a two-dimensional electron gas is formed in the GaN layer 502 in the vicinity of the interface between the GaN layer 502 and the Al _0.3 Ga _0.7 N layer 503. On the other hand, a two-dimensional hole gas is formed in the GaN layer 504 in the vicinity of the interface between the p-type GaN layer 504 and the Al _0.3 Ga _0.7 N layer 503.

In the surface emitting laser of Example 5, a two-dimensional hole gas is caused to act as a current path, and a current is caused to flow laterally from the p-side electrode 515 through the two-dimensional hole gas. Since the current passes through the two-dimensional hole gas, the resistance is lower than when the current is passed in the lateral direction through the portion of the p-type GaN layer 504 where the two-dimensional hole gas is not formed. A p-type GaN layer 505 that is a p-type cladding layer, a p-type Al _0.2 Ga _0.8 N layer 506 that is an electron blocking layer, an active layer 507, an n-type GaN layer 508 that is an n-type cladding layer, a current A current is passed in the order of the p-type GaN layer 509 that is the block layer, the n-type GaN layer 510 that is the n-type contact layer, and the n-side ohmic electrode 513. Then, holes and electrons are injected into the active layer, light is emitted by recombination, and laser oscillation occurs. The oscillation wavelength was 420 nm.

(Example 6)
A semiconductor light emitting device of Example 6 will be described. FIG. 14 is a diagram for explaining the semiconductor light-emitting element of Example 6. FIG. 14A is a schematic cross-sectional view of the semiconductor light emitting device of Example 6.

  As shown in FIG. 14A, the semiconductor light emitting device of Example 6 is a surface emitting laser (VCSEL). In the surface emitting laser of Example 6, the first semiconductor multilayer structure 6001 and the second semiconductor multilayer structure 6002 are crystal-grown on different substrates by MOCVD and bonded to the wafer.

The first semiconductor stacked structure 6001 includes an n-type Al _0.8 In _0.2 N / GaN DBR doped with Si stacked on the n-type c-plane GaN substrate 600 in the Ga polar direction <0001> direction. 41.5 pairs) 601, n-type GaN layer 602 (100 nm), n-type cladding layer n-type GaN 603 (250 nm), multiple quantum well active layer (In _0.10 Ga _0.90 N (5 nm) / In _0.01 Ga _0.99 N (5 nm) 5QW) 604, a p-type Al _0.2 Ga _0.8 N layer 605 (20 nm) as an electron blocking layer, and a p-type GaN layer 606 (a p-type cladding layer) 300 nm). In the p-type cladding layer 606 of the first semiconductor multilayer structure 6001, a current blocking region 617 in which boron (B) is implanted is formed, and a current confinement structure is formed. This is formed by using a circular mask of φ8 μm and implanting boron (B) into a region 610 other than the mask to increase the resistance of this region. The first semiconductor multilayer structure 6001 is subjected to a heat treatment for p-type activation after boron (B) is ion-implanted.

As shown in FIG. 14C, the second semiconductor stacked structure 6002 includes a low-temperature GaN buffer layer (50 nm) 610 stacked on the c-plane sapphire substrate 611 in the Ga polarity direction <0001> direction, a cap layer. An undoped GaN layer 609 (1000 nm), a high-resistance Al _0.3 Ga _0.7 N layer 608 (50 nm), and a p-type GaN layer 607 (300 nm). The second semiconductor multilayer structure 6002 is subjected to p-type activation heat treatment after crystal growth. Subsequently, wafer bonding is performed using the p-type GaN layer 605 of the first semiconductor multilayer structure 6001 and the p-type GaN layer 607 of the second semiconductor multilayer structure 6002 as bonding surfaces. Thereafter, the sapphire substrate 611, the low-temperature GaN buffer layer 610, and the undoped GaN layer 609 are polished and removed leaving only 130 nm of the undoped GaN layer 609 as a cap layer, thereby forming a stacked structure of a surface emitting laser.

In this way, on the first semiconductor multilayer structure 6001, the p-type GaN layer 607 (300 nm) whose polarity is inverted, the high resistance Al _0.3 Ga _0.7 N layer 608 (50 nm), and the undoped as a cap layer. A second semiconductor multilayer structure 6002 in which the GaN layer 609 (130 nm) is laminated is formed.

A dielectric multilayer film DBR616 made of TiO ₂ / SiO ₂ (7 pairs) is formed on the second semiconductor multilayer structure 6002.

In the surface emitting laser of Example 6, the first semiconductor multilayer structure 6001 and the second semiconductor multilayer structure 6002 are etched to form a mesa shape with a diameter of 100 μm. Etching is performed until the n-type DBR 601 of the first semiconductor multilayer structure is reached, and the surface of the n-type DBR 601 is exposed. The second semiconductor multilayer structure 6002 is etched up to the p-type GaN layer 607 to form a mesa shape with a diameter of 20 μm. An insulating film SiO ₂ 612 is formed on the surface of the surface emitting laser. The insulating film 612 around the p-type GaN layer 607 is etched into a ring shape, and the surface of the p-type GaN layer 607 is exposed. Ni / Au is deposited on the exposed p-type GaN layer 607, and a p-side ohmic electrode 613 is formed. A wiring electrode 615 made of Cr / Au is formed on the p-side ohmic electrode 613, and the electrode is arranged to the bottom of the mesa shape. Further, Ti / Au is deposited on the back surface of the GaN substrate 600, and an n-side ohmic electrode 614 is formed.

  FIG. 14B is a diagram for explaining a polarization structure of a portion surrounded by a broken line in the second semiconductor multilayer structure 6002 in FIG.

As shown in FIG. 14B, the high-resistance Al _0.3 Ga _0.7 N layer 608 grown on the undoped GaN layer 609 has a negative polarity on the Ga polar plane side and a nitrogen polar plane side due to lattice distortion. The side is positively polarized. Due to this polarization, a two-dimensional electron gas is formed in the GaN layer 609 in the vicinity of the interface between the GaN layer 609 and the Al _0.3 Ga _0.7 N layer 608. On the other hand, two-dimensional hole gas is formed in the GaN layer 607 near the interface between the p-type GaN layer 607 and the Al _0.3 Ga _0.7 N layer 608.

In the surface emitting laser of Example 6, a two-dimensional hole gas is caused to act as a current path, and a current is caused to flow laterally from the p-side electrode 613 through the two-dimensional hole gas. Since the current passes through the two-dimensional hole gas, the resistance is lower than the case where the current flows in the lateral direction through the portion of the p-type GaN layer 607 where the two-dimensional hole gas is not formed. Less light is absorbed than when a conductive electrode is formed. Then, the p-type GaN layer 607 to the p-type GaN layer 606, the p-type Al _0.2 Ga _0.8 N layer 605 (20 nm) that is an electron blocking layer, the active layer 604, and the n-type GaN 603 that is an n-type cladding layer ( 250 nm), n-type GaN layer 602, n-type Al _0.8 In _0.2 N / GaN DBR (41.5 pairs) 601, GaN substrate 600 and n-side ohmic electrode 614 are passed in this order. Then, holes and electrons are injected into the active layer, light is emitted by recombination, and laser oscillation occurs. The oscillation wavelength was 420 nm.

(Example 7)
A semiconductor light emitting device of Example 7 will be described. FIG. 15 is a diagram for explaining the semiconductor light emitting element of Example 7. FIG. FIG. 15A is a schematic cross-sectional view of the semiconductor light emitting device of Example 7.

  As shown in FIG. 15A, the semiconductor light emitting device of Example 7 is a surface emitting laser (VCSEL). The semiconductor laminated structure of the surface emitting laser of Example 7 was formed by crystal growth using PA-MBE.

  In the semiconductor multilayer structure of the surface emitting laser, a first semiconductor multilayer structure 7001 and a second semiconductor multilayer structure 7002 are formed in this order on the c-plane n-type GaN substrate in the Ga polarity direction <0001> direction. .

The first semiconductor multilayer structure 7001 includes an n-type GaN contact layer 700 (160 nm) grown as a crystal and laminated in the Ga polarity direction <0001> direction on an c-plane n-type GaN substrate, and an n-type cladding layer n. Type GaN 701 (200 nm), multiple quantum well active layer (In _0.10 Ga _0.90 N (5 nm) / In _0.01 Ga _0.99 N (5 nm) 5QW) 702, p-type electron blocking layer An Al _0.2 Ga _0.8 N layer 703 (20 nm) and a p-type GaN layer 704 (200 nm) which is a p-type cladding layer are included.

The second semiconductor multilayer structure 7002 includes an undoped GaN layer 705 (50 nm), a high resistance Al _0.3 Ga _0.7 N layer 706 (50 nm), and a p-type GaN layer stacked on the first semiconductor multilayer structure 7001. 707 (110 nm).

The undoped GaN layer 705 and the high resistance Al _0.3 Ga _0.7 N layer 706 have φ8 μm holes, and the p-type GaN layer 704 and the p-type GaN layer 707 that are p-type cladding layers are formed through the holes. It is connected.

The semiconductor multilayer structure is separated from the GaN substrate, and a dielectric multilayer film DBR (710, 711) made of TiO ₂ / SiO ₂ (7 pairs) is formed below the n-type GaN contact layer 700 and the p-type GaN layer 707. ) Is formed. Ti / Au is deposited on the n-type GaN contact layer 700, and an n-side ohmic electrode 709 is formed. In addition, a p-side ohmic electrode Ni / Au 708 is formed on the p-type GaN layer 707.
FIG. 15B is a diagram for explaining a polarization structure of a portion surrounded by a broken line in the second semiconductor multilayer structure 7002 in FIG.

As shown in FIG. 15B, the high resistance Al _0.3 Ga _0.7 N layer 706 grown on the undoped GaN layer 705 has a negative polarity on the Ga polar plane side and a nitrogen polar plane side due to lattice distortion. The side is positively polarized. Due to this polarization, a two-dimensional electron gas is formed in the GaN layer 705 near the interface between the GaN layer 705 and the Al _0.3 Ga _0.7 N layer 706. On the other hand, a two-dimensional hole gas is formed in the GaN layer 707 near the interface between the p-type GaN layer 707 and the Al _0.3 Ga _0.7 N layer 706.

In the surface emitting laser of Example 7, a two-dimensional hole gas is caused to act as a current path, and a current is caused to flow laterally from the p-side electrode 708 through the two-dimensional hole gas. Since the current passes through the two-dimensional hole gas, the resistance is lower than the case where the current flows in the lateral direction through the portion of the p-type GaN layer 707 where the two-dimensional hole gas is not formed. Less light is absorbed than when a conductive electrode is formed. Then, it flows from the p-type GaN layer 707 to the p-type GaN layer 704 in the region where the Al _0.3 Ga _0.7 N layer 706 and the undoped GaN layer 705 are removed, and the electron blocking layer p-type Al _0.2 Ga _{0. .8 A} current flows through the N layer 703, the active layer 702, the n-type GaN 701, the n-type GaN contact layer 700, and the n-side ohmic electrode 709 in this order. Then, holes and electrons are injected into the active layer, light is emitted by recombination, and laser oscillation occurs. The oscillation wavelength was 420 nm.

  As mentioned above, although embodiment of this invention was described, the said content does not limit the content of invention, Various deformation | transformation and improvement are possible within the scope of the present invention.

DESCRIPTION OF SYMBOLS 10 1st semiconductor laminated structure 11 n-type semiconductor layer 12 Active layer 13 p-type semiconductor layer 20 2nd semiconductor laminated structure 21 1st group 13 nitride semiconductor 22 2nd group 13 nitride semiconductor 23 Two-dimensional hole Gas 30 n-side electrode 40 p-side electrode

Japanese Patent No. 5633435 JP 2014-112654 A Japanese Patent No. 5707742

Claims (14)

A first semiconductor multilayer structure formed of a group 13 nitride semiconductor, the first semiconductor multilayer structure including an n-type semiconductor layer, an active layer, and a p-type semiconductor layer;
A second semiconductor multilayer structure formed of a group 13 nitride semiconductor, wherein the two-dimensional hole gas has a multilayer structure connected to the first semiconductor multilayer structure to form a two-dimensional hole gas; A second semiconductor multilayer structure with a current path as
An n-side electrode connected to the first semiconductor multilayer structure;
A p-side electrode connected to the second semiconductor multilayer structure;
Having
Semiconductor light emitting device. By applying a voltage between the n-side electrode and the p-side electrode, electrons and holes are injected into the active layer, and light is emitted by recombination of the electrons and holes.
The semiconductor light emitting device according to claim 1. The c-axis direction of the second semiconductor multilayer structure is the same direction as the c-axis direction of the first semiconductor multilayer structure.
The semiconductor light emitting element according to claim 1. The c-axis direction of the second semiconductor multilayer structure is opposite to the c-axis direction of the first semiconductor multilayer structure.
The semiconductor light emitting element according to claim 1. The second semiconductor multilayer structure includes a first group 13 nitride semiconductor and a second group 13 nitride semiconductor having different lattice constants.
The semiconductor light emitting element according to claim 1. Emitting light in a direction in which the first semiconductor multilayer structure and the second semiconductor multilayer structure are stacked;
The semiconductor light emitting element according to claim 1. A surface emitting laser having a vertical cavity structure including a multilayer reflection mirror,
The semiconductor light emitting device according to claim 6.   The illuminating device which uses the semiconductor light-emitting device as described in any one of Claims 1 thru | or 7 as a light source.   A headlight using the semiconductor light-emitting device according to claim 1 as a light source.   A moving body comprising the headlight according to claim 9.   An illumination apparatus using the semiconductor light-emitting element according to claim 1 as a light source.   An image device using the semiconductor light-emitting element according to claim 1 as a light source.   A projection-type video apparatus using the semiconductor light-emitting element according to claim 1 as a light source.   The projector which uses the semiconductor light-emitting device as described in any one of Claims 1 thru | or 7 as a light source.

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