Mitsubishi Chemical Corporation

Yusuke Tsukada

Yutaka Mikawa

Hideo Fujisawa

Kazunori Kamada

Shuichi Kubo

Hirotaka Ikeda

Satoru Nagao

Kenji Fujito

Tae Mochizuki

Masayuki Tashiro

Hajime Matsumoto

Tatsuhiro Ohata

Tetsuharu Kajimoto

Takashi Fukada

Hideo Namita

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

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 method for producing a GaN crystal is provided. In the method, front surfaces of a plurality of tiling GaN seeds closely arranged side by side on a flat surface of a plate are planarized. An aggregated seed is formed by arranging the tiling GaN seeds closely side by side on a susceptor of an HVPE apparatus in the same arrangement as when fixed on the plate, with the front planarized surfaces facing upward. A bulk GaN crystal is grown epitaxially on the aggregated seed by an HVPE method.

Non-polar or semi-polar GaN wafer

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;

A disc-like GaN substrate is a substrate produced by a tiling method and having an angel between the normal line and m-axis on the main surface of the substrate of 0 to 20&#xb0; inclusive and a diameter of 45 to 55 mm, to 4 or less. In a preferred embodiment, a disc-like GaN substrate has a first main surface and a second main surface that is opposite to the first main surface, and which has an angle between the normal line and m-axis on the first main surface of 0 to 20&#xb0; inclusive and a diameter of 45 mm or more. The disc-like GaN substrate comprises at least four crystalline regions each being exposed to both of the first main surface and the second main surface, wherein the four crystalline regions are arranged in line along the direction of the orthogonal projection of c-axis on the first main surface.

GaN substrate, method for producing GaN substrate, method for producing GaN crystal, and method for manufacturing semiconductor device

A disk-shaped GaN substrate has a diameter of 2 inches or more has a front surface tilted with a tilt angle of 45&#xb0; or more and 135&#xb0; or less relative to the (0001) plane in a tilt direction within a range of &#xb1;5&#xb0; around the &#x3c;10-10&#x3e; direction, and a back surface which is a main surface opposite to the front surface. The GaN substrate has a first point positioned in a direction perpendicular to the c-axis when viewed from the center thereof, on the side surface thereof. A single diffraction peak appears in an X-ray diffraction pattern obtained by &#x3b8; scan in which an X-ray (CuK&#x3b1;: wavelength: 0.1542 nm) is incident to the first point and the incident angle &#x3b8; of the incident X-ray is varied while the 2&#x3b8; angle of the diffracted X-ray is fixed to twice the Bragg angle of 28.99&#xb0; of the {11-20} plane.

GaN substrate

The invention provides 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 method for manufacturing an M-plane GaN substrate by forming a mask pattern having a line-shaped opening parallel to an a-axis of a C-plane GaN substrate on an N-polar plane of the C-plane GaN substrate, growing a plane-shape GaN crystal of which thickness direction is an m-axis direction from the opening of the mask pattern by an ammonothermal method, and cutting out the M-plane GaN substrate from the plane-shape GaN crystal.

Growing community of inventors

Ushiku, Japan

Yusuke Tsukada