Abstract: When a p-layer 4 composed of GaN is maintained at ordinary temperature and TNO is sputtered thereon by an RF magnetron sputtering method, a laminated TNO layer 5 is in an amorphous state. Then, there is included a step of thermally treating the amorphous TNO layer in a reduced-pressure atmosphere where hydrogen gas is substantially absent to thereby crystallize the TNO layer. At the sputtering, an inert gas is passed through together with oxygen gas, and volume % of the oxygen gas contained in the gas passed through is 0.10 to 0.15%. In this regard, oxygen partial pressure is 5×10?3 Pa or lower. The temperature of the thermal treatment is 500° C. for about 1 hour.

Abstract: Provided is a method for producing a Group III nitride semiconductor light-emitting device including a GaN substrate serving as a growth substrate, which method facilitates tapering of a bottom portion of the GaN substrate. In the production method, firstly, a Group III nitride semiconductor layer, an ITO electrode, a p-electrode, and an n-electrode are formed on the top surface of a GaN substrate through MOCVD. Thereafter, the GaN substrate is thinned through mechanical polishing of the bottom surface thereof, and then scratches formed by mechanical polishing are removed through chemical mechanical polishing, to thereby planarize the bottom surface. Subsequently, a mask is formed on the bottom surface of the GaN substrate, followed by wet etching with phosphoric acid. By virtue of anisotropy in etching of GaN with phosphoric acid, a tapered surface is exposed so as to be inclined by about 60° with respect to the GaN substrate.

Abstract: Provided is a method for producing a Group III nitride-based compound semiconductor having an M-plane main surface. The method employs a sapphire substrate having a main surface which is inclined by 30° with respect to R-plane about a line of intersection Lsapph-AM formed by R-plane and A-plane perpendicular thereto. R-plane surfaces of the sapphire substrate are exposed, and a silicon dioxide mask is formed on the main surface of the substrate. AlN buffer layers are formed on the exposed R-plane surfaces. A GaN layer is formed on the AlN buffer layers. At an initial stage of GaN growth, the top surface of the sapphire substrate is entirely covered with the GaN layer through lateral growth.

Abstract: Provided is a GaN-based semiconductor light-emitting device which does not require an external constant-current circuit. The light-emitting device of the present invention includes a sapphire substrate; an AlN buffer layer formed on the substrate; and an HEMT structure formed on the buffer layer, the HEMT structure including a GaN layer and an Al0.2Ga0.8N layer. On the Al0.2Ga0.8N layer are sequentially formed an n-GaN layer, an MQW light-emitting layer including an InGaN well layer and an AlGaN barrier layer, and a p-GaN layer. A source electrode and an HEMT/LED connection electrode are formed on an exposed portion of the Al0.2Ga0.8N layer. The HEMT/LED connection electrode serves as both the corresponding drain electrode and an electrode for injecting electrons into the n-GaN layer. An ITO transparent electrode is formed on the top surface of the p-GaN layer, and a gold pad electrode is formed on a portion of the top surface of the transparent electrode.

Abstract: The refractive index of a titanium oxide layer is modified by adding an impurity (e.g., niobium (Nb)) thereto within a range where good electrical conductivity is obtained. The Group III nitride-based compound semiconductor light-emitting device of the invention includes a sapphire substrate, an aluminum nitride (AlN) buffer layer, an n-contact layer, an n-cladding layer, a multiple quantum well layer (emission wavelength: 470 nm), a p-cladding layer, and a p-contact layer. On the p-contact layer is provided a transparent electrode made of niobium titanium oxide and having an embossment. An electrode is provided on the n-contact layer. An electrode pad is provided on a portion of the transparent electrode. Since the transparent electrode is formed from titanium oxide containing 3% niobium, the refractive index with respect to light (wavelength: 470 nm) becomes almost equal to that of the p-contact layer.

Abstract: A method for forming an electrode for Group-III nitride compound semiconductor light-emitting devices includes a step of forming a first electrode layer having an average thickness of less than 1 nm on a Group-III nitride compound semiconductor layer, the first electrode layer being made of a material having high adhesion to the Group-III nitride compound semiconductor layer or low contact resistance with the Group-III nitride compound semiconductor layer and also includes a step of forming a second electrode layer made of a highly reflective metal material on the first electrode layer.

Abstract: A semiconductor light emitting element has an electrode formed on a semiconductor layer, a passivation film covering a part of a top surface of the electrode, and a multilayer film formed on the electrode. The multilayer film has at least one pair of a Ti layer and a Ni layer, the Ti layer and the Ni layer being stacked alternately in the multilayer film.

Abstract: A foam-holding body 52 having a large difference in refractive index between foams 521 and the surrounding material is disposed on the major light extraction surface of the sapphire substrate 50. The foam-holding body 52 has translucency to light of a light-emitting wavelength and is formed of a material such as a silicone or the like, having a refractive index equal to or more than 1.77, and includes a foam-holding layer holding a plurality of foams made of an air or an inactive gas having a refractive index of about one. Therefore, when the light emitted in the light-emitting portion scatters in the foam-holding body 52, the spread of the scattered light becomes wide, which restricts repetition of the total reflection in the light-emitting device to improve an efficiency of the light extraction.

Abstract: A foam-holding body 52 having a large difference in refractive index between foams 521 and the surrounding material is disposed on the major light extraction surface of the sapphire substrate 50. The foam-holding body 52 has translucency to light of a light-emitting wavelength and is formed of a material such as a silicone or the like, having a refractive index equal to or more than 1.77, and includes a foam-holding layer holding a plurality of foams made of an air or an inactive gas having a refractive index of about one. Therefore, when the light emitted in the light-emitting portion scatters in the foam-holding body 52, the spread of the scattered light becomes wide, which restricts repetition of the total reflection in the light-emitting device to improve an efficiency of the light extraction.