Mitsubishi Chemical Corporation

Tohoku University

The Japan Steel Works, Ltd.

Yutaka Mikawa

Hideo Fujisawa

Kazunori Kamada

Tae Mochizuki

Shinichiro Kawabata

Hirotaka Ikeda

Hideo Namita

Yusuke Tsukada

Shuichi Kubo

Satoru Nagao

Kenji Fujito

Yuji Kagamitani

Hirobumi Nagaoka

Atsuhiko Kojima

Hajime Matsumoto

Tatsuhiro Ohata

Masayuki Tashiro

Toru Ishiguro

Tetsuharu Kajimoto

Takashi Fukada

Makiko Kiyomi

Yoshihiko Yamamura

Tetsuo Okano

An object is to provide a nonpolar or semipolar GaN substrate having improved size and crystal quality. A self-standing GaN substrate has an angle between the normal of the principal surface and an m-axis of 0 degrees or more and 20 degrees or less, wherein: the size of the projected image in a c-axis direction when the principal surface is vertically projected on an M-plane is 10 mm or more; and when an a-axis length is measured on an intersection line between the principal surface and an A-plane, a low distortion section with a section length of 6 mm or more and with an a-axis length variation within the section of 10.0×10Å or less is observed.

Self-standing GaN substrate, GaN crystal, method for producing GaN single crystal, and method for producing semiconductor device

Provided is a bulk GaN crystal in which the degree of curvature of the c-plane is reduced. The bulk GaN crystal includes a main surface selected from a surface inclined at 0° to 10° from the (0001) crystal plane and a surface inclined at 0° to 10° from the (000-1) crystal plane, and the main surface is a specific main surface A that satisfies the following conditions (i) and (ii): (i) a first line, which is a 80 mm-long virtual line segment extending in a first direction on the specific main surface A, can be drawn, and a difference between a maximum value and a minimum value of peak angles in (002) XRD rocking curves of the GaN crystal, which is measured between 17 measurement points arranged at a 5-mm pitch on the first line with the omega axis being perpendicular to the first direction, is 0.05° or less; and (ii) a second line, which is a 80 mm-long virtual line segment extending in a second direction perpendicular to the first direction on the specific main surface A, can be drawn, and a difference between a maximum value and a minimum value of peak angles in (002) XRD rocking curves of the GaN crystal, which is measured between 17 measurement points arranged at a 5-mm pitch on the second line with the omega axis being perpendicular to the second direction, is 0.05° or less.

Bulk GaN crystal, c-plane GaN wafer, and method for manufacturing bulk GaN crystal

A conductive C-plane GaN substrate has a resistivity of 2&#xd7;10&#x3a9;&#xb7;cm or less or an n-type carrier concentration of 1&#xd7;10cmor more at room temperature. At least one virtual line segment with a length of 40 mm can be drawn at least on one main surface of the substrate. The line segment satisfies at least one of the following conditions (A1) and (B1): (A1) when an XRC of (004) reflection is measured at 1 mm intervals on the line segment, a maximum value of XRC-FWHMs across all measurement points is less than 30 arcsec; and (B1) when an XRC of the (004) reflection is measured at 1 mm intervals on the line segment, a difference between maximum and minimum values of XRC peak angles across all the measurement points is less than 0.2&#xb0;.

Conductive C-plane GaN substrate

A gallium nitride substrate comprising a first main surface and a second main surface opposite thereto, wherein the first main surface is a non-polar or semi-polar plane, a dislocation density measured by a room-temperature cathode luminescence method in the first main surface is 1&#xd7;10cmor less, and an averaged dislocation density measured by a room-temperature cathode luminescence method in an optional square region sizing 250 &#x3bc;m&#xd7;250 &#x3bc;m in the first main plan is 1&#xd7;10cmor less.

Gallium nitride substrate and manufacturing method of nitride semiconductor crystal

An object is to provide a nonpolar or semipolar GaN substrate having improved size and crystal quality. A self-standing GaN substrate has an angle between the normal of the principal surface and an m-axis of 0 degrees or more and 20 degrees or less, wherein: the size of the projected image in a c-axis direction when the principal surface is vertically projected on an M-plane is 10 mm or more; and when an a-axis length is measured on an intersection line between the principal surface and an A-plane, a low distortion section with a section length of 6 mm or more and with an a-axis length variation within the section of 10.0&#xd7;10&#x212b; or less is observed.

A GaN single crystal having a gallium polar surface which is a main surface on one side and a nitrogen polar surface which is a main surface on the opposite side, wherein on the gallium polar surface is found at least one square area, an outer periphery of which is constituted by four sides of 2 mm or more in length, and, when the at least one square area is divided into a plurality of sub-areas each of which is a 100 &#x3bc;m&#xd7;100 &#x3bc;m square, pit-free areas account for 80% or more of the plurality of sub-areas.

GaN single crystal and method for manufacturing GaN single crystal

A method for growing a GaN crystal suitable as a material of GaN substrates including C-plane GaN substrates includes: a first step of preparing a GaN seed having a nitrogen polar surface; a second step of arranging a pattern mask on the nitrogen polar surface of the GaN seed, the pattern mask being provided with a periodical opening pattern comprising linear openings and including intersections, the pattern mask being arranged such that longitudinal directions of at least part of the linear openings are within &#xb1;3&#xb0; from a direction of an intersection line between the nitrogen polar surface and an M-plane; and a third step of ammonothermally growing a GaN crystal through the pattern mask such that a gap is formed between the GaN crystal and the pattern mask.

Method for growing GaN crystal and c-plane GaN substrate

A high-quality nitride crystal can be produced efficiently by charging a nitride crystal starting material that contains tertiary particles having a maximum diameter of from 1 to 120 mm and formed through aggregation of secondary particles having a maximum diameter of from 100 to 1000 &#x3bc;m, in the starting material charging region of a reactor, followed by crystal growth in the presence of a solvent in a supercritical state and/or a subcritical state in the reactor, wherein the nitride crystal starting material is charged in the starting material charging region in a bulk density of from 0.7 to 4.5 g/cmfor the intended crystal growth.

Method for producing nitride crystal and nitride crystal

A new GaN single crystal is provided. A GaN single crystal according to the present embodiment comprises a gallium polar surface which is a main surface on one side and a nitrogen polar surface which is a main surface on the opposite side, wherein on the gallium polar surface is found at least one square area, an outer periphery of which is constituted by four sides each with a length of 2 mm or more, and, when the at least one square are is divided into a plurality of sub-areas each of which is a square of 100 &#x3bc;m&#xd7;100 &#x3bc;m, pit-free areas account for 80% or more of the sub-areas.

An object of the present invention is to provide a crystal of a nitride of a Group-13 metal on the Periodic Table which has good crystallinity and has no crystal strain, and to provide a production method for the crystal. The crystal of a nitride of a Group-13 metal on the Periodic Table of the present invention, comprises oxygen atom and hydrogen atom in the crystal and has a ratio of a hydrogen concentration to an oxygen concentration therein of from 0.5 to 4.5.

Crystal of nitride of group-13 metal on periodic table, and method for producing the same

The main purpose of the present invention is to provide: a nonpolar or semipolar GaN substrate, in which a nitride semiconductor crystal having a low stacking fault density can be epitaxially grown on the main surface of the substrate, and a technique required for the production of the substrate. This invention provides: a method for manufacturing an M-plane GaN substrate comprising;

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Ushiku, Japan

Yutaka Mikawa