Ricoh Company, Ltd.

Osaka University

Japan Atomic Energy Agency

Sciocs Company Limited

Seiji Sarayama

Hirokazu Iwata

Hisanori Yamane

Masahiko Shimada

Akihiro Fuse

Takashi Satoh

Masahiro Hayashi

Naoya Miyoshi

Chiharu Kimura

Masato Aoki

Hiroshi Nambu

Masafumi Kumano

Junichi Wada

Akira Takahashi

Minoru Fukuda

Tetsuya Takahashi

Yasuo Kitaoka

Yusuke Mori

Junichi Saito

Tetsuya Toshine

Akishige Murakami

Kuniaki Ara

Takashi Araki

In a method for manufacturing a group 13 nitride crystal, a seed crystal made of a group 13 nitride crystal is arranged in a mixed melt containing an alkali metal and a group 13 element, and nitrogen is supplied to the mixed melt to grow the group 13 nitride crystal on a principal plane of the seed crystal. The seed crystal is manufactured by vapor phase epitaxy. At least a part of contact members coming into contact with the mixed melt in a reaction vessel accommodating the mixed melt is made of AlO. An interface layer having a photoluminescence emission peak whose wavelength is longer than the wavelength of a photoluminescence emission peak of the grown group 13 nitride crystal is formed between the seed crystal and the grown group nitride crystal.

Method for manufacturing group 13 nitride crystal and group 13 nitride crystal

A method for producing a gallium nitride crystal includes growing a gallium nitride crystalby dissolving nitrogen in a mixed melt including gallium and sodium, and collecting the galliumseparated from an alloyincluding the gallium and the sodium by reacting the alloyand a liquidthat ionizes the sodium and separating sodium ions and the galliumfrom the alloy.

Method for producing gallium nitride crystal

A crystal has a diameter of 1 cm or more and shows a strongest peak in cathode luminescent spectrum at a wavelength of 360 nm in correspondence to a band edge.

Production of a GaN bulk crystal substrate and a semiconductor device formed on a GaN bulk crystal substrate

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 crystal growth apparatus comprises a reaction vessel holding a melt mixture containing an alkali metal and a group III metal, a gas supplying apparatus supplying a nitrogen source gas to a vessel space exposed to the melt mixture inside the reaction vessel, a heating unit heating the melt mixture to a crystal growth temperature, and a support unit supporting a seed crystal of a group III nitride crystal inside the melt mixture.

Crystal growth apparatus and manufacturing method of group III nitride crystal

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 method for manufacturing a group III nitride crystal on a seed crystal in a holding vessel holding therein a melt containing a group III metal, an alkali metal and nitrogen. The manufacturing method comprises the steps of causing the seed crystal to make a contact with the melt, setting an environment of the seed crystal to a first state offset from a crystal growth condition while in a state in which said seed crystal is in contact with the melt, increasing a nitrogen concentration in the melt, and setting the environment of the seed crystal to a second state suitable for crystal growth when the nitrogen concentration of the melt has reached a concentration suitable for growing the seed crystal.

Manufacturing method and manufacturing apparatus of a group III nitride crystal, utilizing a melt containing a group III metal, an alkali metal, and nitrogen

A group III nitride crystal containing therein an alkali metal element comprises a base body, a first group III nitride crystal formed such that at least a part thereof makes a contact with the base body, the first group III nitride crystal deflecting threading dislocations in a direction different from a direction of crystal growth from the base body and a second nitride crystal formed adjacent to the first group III nitride crystal, the second nitride crystal having a crystal growth surface generally perpendicular to the direction of the crystal growth.

Group III nitride crystal and manufacturing method thereof

A crystal manufacturing apparatus for manufacturing a group III nitride crystal includes a crucible that holds a mixed molten liquid including an alkali metal and a group III metal; a reaction vessel accommodating the crucible in the reaction vessel; a heating device that heats the crucible with the reaction vessel; a holding vessel having a lid that is capable of opening and closing, accommodating the reaction vessel and the heating device in the holding vessel; a sealed vessel accommodating the holding vessel in the sealed vessel, having an operating device that enables opening the lid of the holding vessel for supplying source materials into the crucible and taking out a manufactured GaN crystal under a sealed condition, and closing the lid of the holding vessel that is sealed in the sealed vessel, the sealed vessel including an inert gas atmosphere or a nitrogen atmosphere; and a gas supplying device for supplying a nitrogen gas to the mixed molten liquid through each of the vessels.

Crystal manufacturing apparatus

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.

Group 13 nitride crystal and substrate thereof

A nitride crystal which encircles an outer periphery of a seed crystal, the nitride crystal in an embodiment includes: a first partial region, and a second partial region that has optical characteristics different from those of the first partial region and has optical characteristics which indicate the crystal orientation.

Nitride crystal and method for producing the same

In a method of producing a group III nitride crystal in which a melt holding vessel where a melt containing a group III metal and flux is held is accommodated in a reaction vessel and a group III nitride crystal is produced as a substance containing nitrogen is supplied from an outside to the reaction vessel through a pipe, the method includes a step of forming an accumulated part of a liquid in the pipe to thereby temporarily close the pipe before growing the group III nitride crystal in the melt holding vessel.

Method of producing group III nitride crystal, apparatus for producing group III nitride crystal, and group III nitride crystal

A crystal producing apparatus includes a crystal forming unit and a crystal growing unit. The crystal forming unit forms a first gallium nitride (GaN) crystal by supplying nitride gas into melt mixture containing metal sodium (Na) and metal gallium (Ga). The first GaN crystal is sliced and polished to form GaN wafers. The crystal growing unit grows a second GaN crystal on a substrate formed by using a GaN wafer, by the hydride vapor phase epitaxy method, thus producing a bulked GaN crystal.

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Miyagi, Japan

Seiji Sarayama