Abstract: In the present invention, (Ti1?xAx)N [in which A is at least one kind of metal selected from the group consisting of Al, Ga, and In] is used as a metal nitride layer, so that a Group III nitride compound semiconductor layer is formed on the metal nitride layer. When a Ti layer is formed between the metal nitride layer having a sufficient thickness and a substrate and the titanium layer is removed, a Group III nitride compound semiconductor device using metal nitride as a substrate can be obtained.

Abstract: A method including the steps of: modifying at least one part of a sapphire substrate by dry etching to thereby form any one of a dot shape, a stripe shape, a lattice shape, etc. as an island shape on the sapphire substrate; forming an AlN buffer layer on the sapphire substrate; and epitaxially growing a desired Group III nitride compound semiconductor vertically and laterally so that the AlN layer formed on a modified portion of the surface of the sapphire substrate is covered with the desirably Group III nitride compound semiconductor without any gap while the AlN layer formed on a non-modified portion of the surface of the sapphire substrate is used as a seed, wherein the AlN buffer layer is formed by means of reactive sputtering with Al as a target in an nitrogen atmosphere.

Abstract: A p-GaN layer 5 comprising materials such as a Group III nitride compound semiconductor is formed on a sapphire substrate 1 through MOVPE treatment, and a first metal layer 6 made of Co/Au is formed thereon. Then in a planar electron beam irradiation apparatus using plasma, electron beams are irradiated to the p-GaN layer 5 through the first metal layer 6. Accordingly, the first metal layer 6 prevents the surface of the p-GaN layer 5 from being damaged and resistivity of the p-GaN layer 5 can be lowered. Next, a second metal (Ni) layer 10 is formed on the first metal layer 6. And the first metal layer 6 is etched through the second metal layer 10 by using fluoric nitric acid. As a result, the first metal layer is almost completely removed. Then a light-transmitting p-electrode 7 made of Co/Au is formed thereon. As a result, a p-type semiconductor having decreased contact resistance and lower driving voltage can be obtained and optical transmittance factor of the p-type semiconductor improves.

Abstract: A group III nitride compound semiconductor device is produced according to the following manner. A separation layer made of a material which prevents group III nitride compound semiconductors from being grown thereon is formed on a substrate. Group III nitride compound semiconductors is grown on a surface of the substrate uncovered with the separation layer while keeping the uncovered substrate surface separated by the separation layer.

Abstract: To lower the electrical resistance of a p-type semiconductor or the operation voltage of a light-emitting/light-receiving semiconductor device. An ion-plasma-type electron-beam irradiation apparatus 100 generates wide-area-radiation electron beams. The thus-generated electron beams are radiated to the outside through a thin metallic plate 108 formed on the outer surface of a beam extraction window 107. A p-type semiconductor is disposed below the beam extraction window 107 such that the p-type semiconductor is disposed about 20 mm away from the electron extraction window so as to be almost parallel to the metallic plate 108. When the surface of the p-type semiconductor is irradiated with electron beams by use of this apparatus, the electrical resistance of the p-type semiconductor can be effectively lowered within a short period of time; i.e., within about three minutes, which is considerably shorter than the time required in the case where a conventional electron-beam irradiation apparatus is employed.

Abstract: A first group III nitride compound layer, which is formed on a substrate by a method not using metal organic compounds as raw materials, is heated in an atmosphere of a mixture gas containing a hydrogen or nitrogen gas and an ammonia gas, so that the crystallinity of a second group III nitride compound semiconductor layer formed on the first group III nitride compound layer is improved. When the first group III nitride compound layer is formed on a substrate by a sputtering method, the thickness of the first group III nitride compound layer is set to be in a range of from 50 ? to 3000 ?.

Abstract: A group III nitride compound semiconductor device has a substrate and an AlN single crystal layer formed on the substrate. The AlN single crystal layer has a thickness of from 0.5 to 3 ?m and has a substantially flat surface. The half-value width of an X-ray rocking curve of the AlN single crystal layer is not longer than 50 sec. In another device, a group III nitride compound semiconductor layer having a thickness of from 0.01 to 3.2 ?m is grown at a temperature of from 1000 to 1180° C. on a sapphire substrate having a surface nitride layer having a thickness of not larger than 300 ?.

Abstract: A method including the steps of: modifying at least one part of a sapphire substrate by dry etching to thereby form any one of a dot shape, a stripe shape, a lattice shape, etc. as an island shape on the sapphire substrate; forming an AlN buffer layer on the sapphire substrate; and epitaxially growing a desired Group III nitride compound semiconductor vertically and laterally so that the AlN layer formed on a modified portion of the surface of the sapphire substrate is covered with the desirably Group III nitride compound semiconductor without any gap while the AlN layer formed on a non-modified portion of the surface of the sapphire substrate is used as a seed, wherein the AlN buffer layer is formed by means of reactive sputtering with Al as a target in an nitrogen atmosphere.

Abstract: A separator layer of Ti is formed on an auxiliary substrate of sapphire or the like. An undercoat layer of TiN is formed on the separator layer. The undercoat layer is provided so that a Group III nitride compound semiconductor layer can be grown with good crystallinity on the undercoat layer. TiN is sprayed on the undercoat layer to form a thermal spray depositing layer. Then, the separator layer is chemically etched to reveal the undercoat layer. Then, a Group III nitride compound semiconductor layer is grown on a surface of the undercoat layer.

Abstract: An undercoat layer inclusive of a metal nitride layer is formed on a substrate. Group III nitride compound semiconductor layers are formed on the undercoat layer continuously.

Abstract: A method of producing a Group III nitride compound semiconductor device, has the following steps of: forming an n-type layer on a substrate; forming a layer containing a light emitting layer on the n-type layer; forming a p-type layer being doped with a p-type impurity on the layer; etching at least a portion of the n-type layer and at least a portion of the layer to reveal at least a part of the n-type layer and an end surface of the layer; forming a p-electrode on a surface side of the p-type layer; forming an n-electrode on the revealed part of the n-type layer; irradiating the p-type layer with an electron beam to make resistance of the p-type layer low; and acidizing at least the revealed end surface of the layer after the electron beam irradiating step.

Abstract: An AlN layer having a surface of a texture structure is formed on a sapphire substrate. Then, a growth suppressing material layer is formed on the AlN layer so that the AlN layer is partially exposed to the outside. Then, group III nitride compound semiconductor layers are grown on the AlN layer and on the growth suppressing material layer by execution of an epitaxial lateral overgrowth method. Thus, a group III nitride compound semiconductor device is produced. An undercoat layer having convex portions each shaped like a truncated hexagonal pyramid is formed on a substrate. Group III nitride compound semiconductor layers having a device function are laminated successively on the undercoat layer.

Abstract: A preferred condition for forming a Group III nitride compound semiconductor layer on a substrate by a sputtering method is proposed. When a first Group III nitride compound semiconductor layer is formed on a substrate by a sputtering method, an initial voltage of a sputtering apparatus is selected to be not higher than 110% of a sputtering voltage.

Abstract: A separator layer of Ti is formed on an auxiliary substrate of sapphire or the like. An undercoat layer of TiN is formed on the separator layer. The undercoat layer is provided so that a Group III nitride compound semiconductor layer can be grown with good crystallinity on the undercoat layer. TiN is sprayed on the undercoat layer to form a thermal spray depositing layer. Then, the separator layer is chemically etched to reveal the undercoat layer. Then, a Group III nitride compound semiconductor layer is grown on a surface of the undercoat layer.

Abstract: A p-GaN layer 5 comprising materials such as a Group III nitride compound semiconductor is formed on a sapphire substrate 1 through MOVPE treatment, and a first metal layer 6 made of Co/Au is formed thereon. Then in a planar electron beam irradiation apparatus using plasma, electron beams are irradiated to the p-GaN layer 5 through the first metal layer 6. Accordingly, the first metal layer 6 prevents the surface of the p-GaN layer 5 from being damaged and resistivity of the p-GaN layer 5 can be lowered. Next, a second metal (Ni) layer 10 is formed on the first metal layer 6. And the first metal layer 6 is etched through the second metal layer 10 by using fluoric nitric acid. As a result, the first metal layer is almost completely removed. Then a light-transmitting p-electrode 7 made of Co/Au is formed thereon. As a result, a p-type semiconductor having decreased contact resistance and lower driving voltage can be obtained and optical transmittance factor of the p-type semiconductor improves.

Abstract: A first group III nitride compound layer, which is formed on a substrate by a method not using metal organic compounds as raw materials, is heated in an atmosphere of a mixture gas containing a hydrogen or nitrogen gas and an ammonia gas, so that the crystallinity of a second group III nitride compound semiconductor layer formed on the first group III nitride compound layer is improved. When the first group III nitride compound layer is formed on a substrate by a sputtering method, the thickness of the first group III nitride compound layer is set to be in a range of from 50 Å to 3000 Å.

Abstract: In the present invention, (Ti1−xAx)N [in which A is at least one kind of metal selected from the group consisting of Al, Ga, and In] is used as a metal nitride layer, so that a Group III nitride compound semiconductor layer is formed on the metal nitride layer. When a Ti layer is formed between the metal nitride layer having a sufficient thickness and a substrate and the titanium layer is removed, a Group III nitride compound semiconductor device using metal nitride as a substrate can be obtained.

Abstract: A first group III nitride compound layer, which is formed on a substrate by a method not using metal organic compounds as raw materials, is heated in an atmosphere of a mixture gas containing a hydrogen or nitrogen gas and an ammonia gas, so that the crystallinity of a second group III nitride compound semiconductor layer formed on the first group III nitride compound layer is improved. When the first group III nitride compound layer is formed on a substrate by a sputtering method, the thickness of the first group III nitride compound layer is set to be in a range of from 50 Å to 3000 Å.

Abstract: A group III nitride compound semiconductor device has a substrate and an AlN single crystal layer formed on the substrate. The AlN single crystal layer has a thickness of from 0.5 to 3 &mgr;m and has a substantially flat surface. The half-value width of an X-ray rocking curve of the AlN single crystal layer is not longer than 50 sec. In another device, a group III nitride compound semiconductor layer having a thickness of from 0.01 to 3.2 &mgr;m is grown at a temperature of from 1000 to 1180° C. on a sapphire substrate having a surface nitride layer having a thickness of not larger than 300 Å.

Abstract: A method of producing a Group III nitride compound semiconductor device, has the following steps of: forming an n-type layer on a substrate; forming a layer containing a light emitting layer on the n-type layer; forming a p-type layer being doped with a p-type impurity on the layer; etching at least a portion of the n-type layer and at least a portion of the layer to reveal at least a part of the n-type layer and an end surface of the layer; forming a p-electrode on a surface side of the p-type layer; forming an n-electrode on the revealed part of the n-type layer; irradiating the p-type layer with an electron beam to make resistance of the p-type layer low; and acidizing at least the revealed end surface of the layer after the electron beam irradiating step.