Ricoh Company, Ltd.

Hiroshi Nambu

Seiji Sarayama

Hirokazu Iwata

Masahiro Hayashi

Takashi Satoh

Chiharu Kimura

A gallium nitride crystal having a hexagonal crystal structure includes a first region located on an inner side of a cross section intersecting c-axis of the hexagonal crystal structure, and a second region surrounding at least a part of the outer periphery of the first region in the cross section. An emission spectrum of each of the first region and the second region with electron beam or ultraviolet light excitation has a first peak including a band edge emission of gallium nitride and a second peak located in a longer wavelength area than the first peak. A peak intensity of the first peak is smaller than a peak intensity of the second peak in the first region, and a peak intensity of the first peak is greater than a peak intensity of the second peak in the second region.

Gallium nitride crystal, group 13 nitride crystal, group 13 nitride crystal substrate, and manufacturing method

A group 13 nitride crystal having a hexagonal crystal structure and containing at least a nitrogen atom and at least a metal atom selected from a group consisting of B, Al, Ga, In, and Tl. The group 13 nitride crystal includes a first region disposed on an inner side in a cross section intersecting c-axis, a third region disposed on an outermost side in the cross section and having a crystal property different from that of the first region, and a second region disposed at least partially between the first region and the third region in the cross section, the second region being a transition region of a crystal growth and having a crystal property different from that of the first region and that of the third region.

Group 13 nitride crystal and group 13 nitride crystal substrate

A method of manufacturing a group 13 nitride crystal includes a crystal growth process to form the group 13 nitride crystal by growing the group 13 nitride crystal having a hexagonal crystal structure from a seed crystal which is a gallium nitride crystal having a hexagonal crystal structure in which a length 'L' in a c-axis direction is 9.7 mm or more, and a ratio L/d of the length 'L' to a crystal diameter &#x201c;d&#x201d; in a c-plane is larger than 0.813. The crystal growth process includes a process of forming an outer periphery containing a {10-10} plane and an outer periphery containing a {10-11} plane at side surfaces of the group 13 nitride crystal, and forming an outer periphery containing a {0001} plane at a bottom surface of the group 13 nitride crystal.

Manufacturing method of group 13 nitride crystal

A group 13 nitride crystal has a hexagonal crystal structure and at least contains nitrogen atom and at least a kind of metal atoms selected from a group consisting of B, Al, Ga, In, and Tl. The group 13 nitride crystal includes a first region located at an inner side of a cross section intersecting a c-axis, and a second region surrounding at least a part of an outer periphery of the first region, having a thickness larger than a maximum diameter of the first region, and having a carrier density higher than that of the first region.

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Kanagawa, Japan

Hiroshi Nambu