Abstract: A buffer layer 2 made of aluminum nitride (AlN) is formed on a substrate 1 and is formed into an island pattern such as a dot pattern, a striped pattern, or a grid pattern such that substrate-exposed portions are formed in a scattered manner. A group III nitride compound semiconductor 3 grows epitaxially on the buffer layer 2 in a longitudinal direction, and grows epitaxially on the substrate-exposed portions in a lateral direction. As a result, a group III nitride compound semiconductor 3 which has little or no feedthrough dislocations 4 is obtained. Because the region where the group III nitride compound semiconductor 3 grows epitaxially in a lateral direction, on region 32, has excellent crystallinity, forming a group III nitride compound semiconductor device on the upper surface of the region results in improved device characteristics.

Abstract: On an upper surface of a silicon (Si) substrate, an Al0.2Ga0.8N layer having a film thickness of 0.2 &mgr;m to 0.3 &mgr;m and a GaN layer having a film thickness of 0.5 &mgr;m are formed successively. The resulting substrate is set in a halide VPE apparatus so that the resulting substrate can be independently etched with HCl gas from a rear surface of the resulting substrate. While a GaN layer is epitaxially grown on the GaN layer at 900° C. by a halide vapor-phase epitaxy method, the silicon (Si) substrate, the Al0.2Ga0.8N layer and the GaN layer are removed from the rear surface by gas etching. In this manner, the GaN layer having a film thickness of about 50 &mgr;m is obtained. While a GaN layer is epitaxially grown on the GaN layer at 1050° C. by a halide vapor-phase epitaxy method, the GaN layer is removed from the rear surface by gas etching. Finally, a substrate made of the GaN layer with a film thickness of 200 &mgr;m and free from any warp and any crack is obtained.

Abstract: An object of the invention is to produce, at high efficiency, semiconductor elements which are formed of a high-quality crystalline semiconductor having no cracks and a low dislocation density and which have excellent characteristics. Specifically, a mask formed from SiO2 film is provided on the Si(111) plane of an n-type silicon substrate, and a window portion (crystal growth region) in the shape of an equilateral triangle having a side of approximately 300 &mgr;m is formed through the mask. The three sides of the equilateral triangle are composed of three edges; each edge defined by the (111) plane and another crystal plane that is cleavable. Subsequently, a multi-layer structure of semiconductor crystals in an LED is formed through crystal growth of a Group III nitride compound semiconductor. Thus, limiting the area of one crystal growth region to a considerably small area weakens a stress applied to a semiconductor layer, thereby readily producing semiconductor elements having excellent crystallinity.

Abstract: A GaN layer 31 is subjected to etching, so as to form an island-like structure having, for example, a dot, stripe, or grid shape, thereby providing a trench/mesa structure including mesas and trenches whose bottoms sink into the surface of a substrate base 1. Subsequently, a GaN layer 32 is lateral-epitaxially grown with the top surfaces of the mesas and sidewalls of the trenches serving as nuclei, to thereby fill upper portions of the trenches (depressions of the substrate base 1), and then epitaxial growth is effected in the vertical direction. In this case, propagation of threading dislocations contained in the GaN layer 31 can be prevented in the upper portion of the GaN layer 32 that is formed through lateral epitaxial growth.

Abstract: An emission layer (5) for a light source device is formed to have a multi-layer structure, doped with an acceptor and a donor impurity. The multi-layer structure may include a quantum well (QW) structure or a multi quantum well (MQW) structure (50). With such a structure, a peak wavelength of the light source can be controlled, because the distances between atoms of the acceptor and the donor impurities are widened. Several arrangements can be made by, e.g., altering the thickness of each composite layer of the multi-layer structure, altering their composition ratio, forming undoped layer 5 between the impurity doped layers, and so forth. Further, luminous intensity of ultra violet color can be improved, because doping the donor impurity and the acceptor impurity realizes a donor-acceptor emission mechanism and abundant carriers. Several arrangements can be made by, e.g.

Abstract: A thick GaN layer is grown on sapphire through an Au layer at a temperature lower than the melting point of 1064° C. of the Au layer, and temperature of a sample is raised to reach and exceed the melting point of the Au layer so that the Au layer is dissolved. In this state, the sapphire and GaN layer are separated from each other.

Abstract: A semiconductor laser 101 comprises a sapphire substrate 1, an AlN buffer layer 2, Si-doped GaN n-layer 3, Si-doped Al0.1Ga0.9N n-cladding layer 4, Si-doped GaN n-guide layer 5, an active layer 6 having multiple quantum well (MQW) structure in which about 35 Å in thickness of GaN barrier layer 62 and about 35 Å in thickness of Ga0.95In0.05N well layer 61 are laminated alternately, Mg-doped GaN p-guide layer 7, Mg-doped Al0.1Ga0.9N p-cladding layer 8, and Mg-doped GaN p-contact layer 9 are formed successively thereon. A ridged hole injection part B which contacts to a ridged resonator part A is formed to have the same width as the width w of an Ni electrode 10. Holes transmitted from the Ni electrode 10 are injected to the active layer 6 with high current density, and electric current threshold for laser oscillation can be decreased. Electric current threshold can be improved more effectively by forming also the p-guide layer 7 to have the same width as the width w of the Ni electrode 10.

Abstract: A buffer layer 2 made of aluminum nitride (AlN) is formed on a substrate 1 and is formed into an island pattern such as a dot pattern, a striped pattern, or a grid pattern such that substrate-exposed portions are formed in a scattered manner. A group III nitride compound semiconductor 3 grows epitaxially on the buffer layer 2 in a longitudinal direction, and grows epitaxially on the substrate-exposed portions in a lateral direction. As a result, a group III nitride compound semiconductor 3 which has little or no feedthrough dislocations 4 is obtained. Because the region where the group III nitride compound semiconductor 3 grows epitaxially in a lateral direction, on region 32, has excellent crystallinity, forming a group III nitride compound semiconductor device on the upper surface of the region results in improved device characteristics.

Abstract: An emission layer (5) for a light source device is formed to have a multi-layer structure, doped with an acceptor and a donor impurity. The multi-layer structure may include a quantum well (QW) structure or a multi quantum well (MQW) structure (50). With such a structure, a peak wavelength of the light source can be controlled, because the distances between atoms of the acceptor and the donor impurities are widened. Several arrangements can be made by, e.g., altering the thickness of each composite layer of the multi-layer structure, altering their composition ratio, forming undoped layer 5 between the impurity doped layers, and so forth. Further, luminous intensity of ultra violet color can be improved, because doping the donor impurity and the acceptor impurity realizes a donor-acceptor emission mechanism and abundant carriers. Several arrangements can be made by, e.g.

Abstract: A Group III nitride compound semiconductor includes a multiple layer structure having an emission layer between an n-type cladding layer and a p-type cladding layer. The n-type cladding layer may be below the emission layer, having been formed on another n-type layer which was formed over a buffer layer and a sapphire substrate. The emission layer has a thickness which is wider than the diffusion length of holes within the emission layer. The n-type cladding layer is doped with a donor impurity and has a lattice constant substantially equal to a lattice constant of the emission layer. The p-type cladding layer is doped with an acceptor impurity and has a forbidden band sufficiently wider than the forbidden band of the emission layer in order to confine electrons injected into the emission layer.

Abstract: Aluminum gallium nitride (AlxGa1−xN, 0<x<1) is employed as a substrate of a Group III nitride compound semiconductor device. In light-emitting diodes and laser diodes employing the substrate, crack generation is prevented, even when a thick cladding layer formed of aluminum gallium nitride (AlxGa1−xN, 0<x<1) is stacked on the substrate. The smaller the difference in Al compositional proportion between the substrate and an aluminum gallium nitride (AlxGa1−xN, 0<x<1) layer, the less likely the occurrence of crack generation.

Abstract: A guide layer is formed to have a superlattice structure comprising five pairs of layers of AlGaN and InN, each having a thickness of about 10 nm. The guide layer has a total thickness of about 0.1 &mgr;m. The guide layer so structured has a reduced elastic constant such that the guide layer acts as a stress relieving layer.

Abstract: A group III nitride compound semiconductor light-emitting device provides a multiple quantum well (MQW) active layer formed on an intermediate layer. The MQW active layer may include, for example, five semiconductor layers having a thickness of approximately 500 Å. The five layers of the MQW active layer may comprise two gallium nitride (GaN) barrier layers each having a thickness of approximately 100 Å and three well layers having different emission wavelengths. The barrier layers and the well layers are stacked alternately. The three well layers may include, for example, an Al0.1In0.9N red-light-emitting well layer having a thickness of approximately 20 Å and doped with impurities (zinc (Zn) and silicon (Si)), a non-doped In0.2Ga0.8N green-light-emitting well layer having a thickness of approximately 50 Å and a non-doped In0.05Ga0.95N blue-light-emitting well layer having a thickness of approximately 30 Å, wherein the three well layers are stacked in the order given.

Abstract: A semiconductor laser comprises a sapphire substrate, an AlN buffer layer, Si-doped GaN n-layer, Si-doped Al0.1Ga0.9N n-cladding layer, Si-doped GaN n-guide layer, an active layer having multiple quantum well (MQW) structure in which about 35 Å in thickness of GaN barrier layer 62 and about 35 Å in thickness of Ga0.95In0.55N well layer 61 are laminated alternately, Mg-doped GaN p-guide layer, Mg-doped Al0.25Ga0.75N p-layer, Mg-doped Al0.1Ga0.9N p-cladding layer, and Mg-doped GaN p-contact layer are formed successively thereon. A ridged hole injection part B which contacts to a ridged laser cavity part A is formed to have the same width as the width w of an Ni electrode. Because the p-layer has a larger aluminum composition, etching rate becomes smaller and that can prevent from damaging the p-guide layer in this etching process.

Abstract: A clad layer is provided as a multilayer structure made of an alternate laminate of 20 layers of Al0.2Ga0.8N 50 nm thick and 20 layers of Ga0.99In0.01N 20 nm thick. The clad layer about 1.4 &mgr;m thick has a low elastic constant because the clad layer is provided as a multilayer structure. In a laser diode, it is useful that another layer such as a guide layer requiring a band gap of aluminum gallium nitride (AlxGa1-xN 0<x<1) is provided as a multilayer structure made of aluminum gallium nitride (AlxGa1-xN 0<x<1) and gallium indium nitride (GayGa1-yN 0<y<1).

Abstract: A first Group III nitride compound semiconductor layer 31 is etched, to thereby form an island-like structure such as a dot-like, stripe-shaped, or grid-like structure, so as to provide a trench/mesa such that layer different from the first Group III nitride compound semiconductor layer 31 is exposed at the bottom portion of the trench. Thus, a second Group III nitride compound layer 32 can be epitaxially grown, laterally, with a top surface of the mesa and a sidewall/sidewalls of the trench serving as a nucleus, to thereby bury the trench and also grow the layer in the vertical direction. In this case, propagation of threading dislocations contained in the first Group III nitride compound semiconductor layer 31 can be prevented in the upper portion of the second Group III nitride compound semiconductor 32 that is formed through lateral epitaxial growth. Etching may be performed until a cavity portion is provided in the substrate.

Abstract: A light-emitting element has a light-emitting layer and at lease one light-extracting portion. At least a partial part of the light-extracting portion is formed into a concave or convex surface for enhancing the efficiency of extracting light. Another light-emitting element has a light-emitting layer and a concave or convex surface for reflecting light emitted from the light-emitting layer toward one or more other surfaces of the light-emitting element through an inside of the light-emitting element.

Abstract: In a method of manufacturing a semiconductor light-emitting device involving the steps of: forming a first semiconductor layer; forming a light-emitting layer of superlattice structure by laminating a barrier layer being made of InY1Ga1−Y1N (Y1≧0) and a quantum well layer being made of InY2Ga1−Y2N (Y2>Y1 and Y2>0) on the first semiconductor layer; and forming a second semiconductor layer on the light-emitting layer, an uppermost barrier layer, which will become an uppermost layer of the light-emitting layer, is made thicker than the other barrier layers. Further, at the time of forming the second semiconductor layer, an upper surface of such uppermost barrier layer is caused to disappear so that the thickness of the uppermost barrier layer becomes substantially equal to those of the other barrier layers.

Abstract: The present invention provides a Group III nitride compound semiconductor with suppressed generation of threading dislocations.

Abstract: A first Group III nitride compound semiconductor layer 31 is etched, to thereby form an island-like structure such as a dot-like, stripe-shaped, or grid-like structure, so as to provide a trench/post. Thus, a second Group III nitride compound layer 32 can be epitaxially grown, vertically and laterally, from a top surface of the post and a sidewall/sidewalls of the trench serving as a nucleus for epitaxial growth, to thereby bury the trench and also grow the layer in the vertical direction. In this case, propagation of threading dislocations contained in the first Group III nitride compound semiconductor layer 31 can be prevented in the upper portion of the second Group III nitride compound semiconductor 32 that is formed through lateral epitaxial growth. As a result, a region having less threading dislocations is formed at the buried trench.