Sumitomo Electric Industries, Limited

Hideki Osada

Seiji Nakahata

Shinsuke Fujiwara

Koji Uematsu

Yusuke Yoshizumi

Katsushi Akita

Keiji Ishibashi

Naoki Matsumoto

Masaki Ueno

Takashi Kyono

Yohei Enya

Yoshiki Miura

Hitoshi Kasai

Yoshiaki Hagi

Hidenori Mikami

Shugo Minobe

Sayuri Yamaguchi

A gallium nitride crystal substrate has a diameter of 50-155 mm and a thickness of 300-800 &#x3bc;m and includes any of a flat portion and a notch portion in a part of an outer edge. The gallium nitride crystal substrate contains any of oxygen atoms, silicon atoms, and carriers at a concentration of 2&#xd7;10to 4&#xd7;10cm, and has an average dislocation density of 1000 to 5&#xd7;10cmin any of a first flat region extending over a width from the flat portion to a position at a distance of 2 mm in a direction perpendicular to a straight line indicating the flat portion in a main surface and a first notch region extending over a width from the notch portion to a position at a distance of 2 mm in a direction perpendicular to a curve indicating the notch portion in the main surface.

Gallium nitride crystal substrate

Group III nitride crystal produced by cutting, from III nitride bulk crystal, a plurality of Group III nitride crystal substrates with major-surface plane orientation misoriented five degrees or less with respect to a crystal-geometrically equivalent plane orientation selected from the group consisting of {20-21}, {20-2-1}, {22-41}, and {22-4-1}, transversely arranging the substrates adjacent to each other such that their major surfaces are parallel to each other and such that their [0001] directions coincide with each other, and growing a Group III nitride crystal on the major surfaces. The Group III nitride crystal substrates are further characterized by satisfying at least either an oxygen-atom concentration of 1&#xd7;10cmto 4&#xd7;10cmor a silicon-atom concentration of 6&#xd7;10cmto 5&#xd7;10cm, and by having a carrier concentration of 1&#xd7;10cmto 6&#xd7;10cm.

Group III nitride crystal substrates and group III nitride crystal

A method for producing a Group III nitride crystal includes the steps of cutting a plurality of Group III nitride crystal substratesandhaving a major surface from a Group III nitride bulk crystal, the major surfacesandhaving a plane orientation with an off-angle of five degrees or less with respect to a crystal-geometrically equivalent plane orientation selected from the group consisting of {20&#x2212;21}, {20&#x2212;2&#x2212;1}, {22&#x2212;41}, and {22&#x2212;4&#x2212;1}, transversely arranging the substratesandadjacent to each other such that the major surfacesandof the substratesandare parallel to each other and each [0001] direction of the substratesandcoincides with each other, and growing a Group III nitride crystalon the major surfacesandof the substratesand

Method for producing group III nitride crystal

A GaN single crystal substrate has a main surface with an area of not less than 10 cm, the main surface has a plane orientation inclined by not less than 65&#xb0; and not more than 85&#xb0; with respect to one of a (0001) plane and a (000-1) plane, and the substrate has at least one of a substantially uniform distribution of a carrier concentration in the main surface, a substantially uniform distribution of a dislocation density in the main surface, and a photoelasticity distortion value of not more than 5&#xd7;10, the photoelasticity distortion value being measured by photoelasticity at an arbitrary point in the main surface when light is applied perpendicularly to the main surface at an ambient temperature of 25&#xb0; C. Thus, the GaN single crystal substrate suitable for manufacture of a GaN-based semiconductor device having a small variation of characteristics can be obtained.

GaN single crystal substrate having a large area and a main surface whose plane orientation is other than (0001) and (000-1)

GaN single crystal substrate and method of manufacturing thereof and GaN-based semiconductor device and method of manufacturing thereof

A method for producing a group III nitride crystal in the present invention includes the steps of cutting a plurality of group III nitride crystal substratesandhaving a main plane from a group III nitride bulk crystal, the main planesandhaving a plane orientation with an off-angle of five degrees or less with respect to a crystal-geometrically equivalent plane orientation selected from the group consisting of {20-21}, {20-2-1}, {22-41}, and {22-4-1}, transversely arranging the substratesandadjacent to each other such that the main planesandof the substratesandare parallel to each other and each [0001] direction of the substratesandcoincides with each other, and growing a group III nitride crystalon the main planesandof the substratesand

Group III nitride crystal and method for producing the same

A nitride semiconductor device includes a main surface and an indicator portion. The main surface is a plane inclined by at least 71&#xb0; and at most 79&#xb0; in a [1-100] direction from a (0001) plane or a plane inclined by at least 71&#xb0; and at most 79&#xb0; in a [&#x2212;1100] direction from a (000-1) plane. The indicator portion indicates a (&#x2212;1017) plane, a (10-1-7) plane, or a plane inclined by at least &#x2212;4&#xb0; and at most 4&#xb0; in the [1-100] direction from these planes and inclined by at least &#x2212;0.5&#xb0; and at most 0.5&#xb0; in a direction orthogonal to the [1-100] direction.

Nitride semiconductor substrate

A gallium nitride-based semiconductor optical device is provided that includes an indium-containing gallium nitride-based semiconductor layer that exhibit low piezoelectric effect and high crystal quality. The gallium nitride-based semiconductor optical deviceincludes a GaN support base, a GaN-based semiconductor region, and well layers. A primary surfacetilts from a surface orthogonal to a reference axis that extends in a direction from one crystal axis of the m-axis and the a-axis of GaN toward the other crystal axis. The tilt angle Ais 0.05 degree or more to less than 15 degrees. The angle Ais equal to the angle defined by a vector VM and a vector VN. The inclination of the primary surface is shown by a typical m-plane Sand m-axis vector VM. The GaN-based semiconductor regionis provided on the primary surface. In the well layersin an active layer, both the m-plane and the a-plane of the well layerstilt from a normal axis Aof the primary surface. The indium content of the well layersis 0.1 or more.

Gallium nitride-based semiconductor optical device, method of fabricating gallium nitride-based semiconductor optical device, and epitaxial wafer

A GaN substrate having a large diameter of two inches or more by which a semiconductor device such as a light emitting element with improved characteristics such as luminance efficiency, an operating life and the like can be obtained at low cost industrially, a substrate having an epitaxial layer formed on the GaN substrate, a semiconductor device, and a method of manufacturing the GaN substrate are provided. A GaN substrate has a main surface and contains a low-defect crystal region and a defect concentrated region adjacent to low-defect crystal region. Low-defect crystal region and defect concentrated region extend from the main surface to a back surface positioned on the opposite side of the main surface. A plane direction [0001] is inclined in an off-angle direction with respect to a normal vector of the main surface.

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Itami, Japan

Hideki Osada