Hitachi Cable, Inc.

Sumitomo Chemical Company, Limited

Nec Corporation

Sciocs Company Limited

Osaka University

Other

Hosei University

Itochu Plastics Inc.

Masatomo Shibata

Takehiro Yoshida

Yuichi Oshima

Akira Usui

Masashi Yoshimura

Mamoru Imade

Toshio Kitamura

Fumimasa Horikiri

Takashi Sato

Yusuke Mori

Yukio Abe

Hiroshi Ohta

Hajime Fujikura

Tomoyoshi Mishima

Masayuki Imanishi

Takayuki Suzuki

Naotaka Kuroda

Takeshi Eri

Takashi Furuya

Masashi Isemura

Tetsuji Fujimoto

Haruo Sunagawa

Naoya Miyoshi

Akishige Murakami

Seiji Sarayama

There is provided a gallium nitride single crystal substrate, which is a gallium nitride single crystal substrate that has a diameter of 50 mm or more and whose low index crystal plane closest to a main surface is a (0001) plane, wherein a density of etch pits when applying etching to the main surface with an alkaline etching solution is less than 1×10cm, and among peaks appearing in a histogram of diameters of the etch pits, when a diameter of a first peak appearing on a smallest diameter-side is a, a total number of the etch pits with a diameter exceeding 4is 1/1000 or less of a number of etch pits forming the first peak.

Gallium nitride single crystal substrate

There is provided a method of manufacturing a crystal substrate, including: preparing a first crystal body which is a substrate comprising a single crystal of group III nitride produced by a vapor phase method and having a first main surface, and in which c-plane of the single crystal is curved in a concave spherical shape with a predetermined curvature; and growing a second crystal body comprising a single crystal of group III nitride on the first main surface, in a mixed melt containing an alkali metal and a group III element.

Group III nitride crystal substrate having a diameter of 4 inches or more and a curved c-plane with a radius of curvature of 15 m or more

There is provided a gallium nitride laminated substrate including: an n-type gallium nitride layer containing an n-type impurity; a p-type gallium nitride layer provided on the n-type gallium nitride layer, containing a p-type impurity, forming a pn-junction at an interface with the n-type gallium nitride layer, and having a p-type impurity concentration and a thickness such that, when a reverse bias voltage is applied to the pn-junction, a breakdown occurs due to a punchthrough phenomenon before occurrence of a breakdown due to an avalanche phenomenon; and an intermediate level layer provided on the p-type gallium nitride layer, containing a p-type gallium nitride which contains the p-type impurity at a higher concentration than the p-type gallium nitride layer, having at least one or more intermediate levels between a valence band and a conduction band, and configured to suppress an overcurrent resulting from a breakdown due to the punchthrough phenomenon in the p-type gallium nitride layer.

Gallium nitride laminated substrate and semiconductor device

To provide a technique of increasing a radius of curvature of (0001) plane, and narrowing an off-angle distribution, there is provided a nitride semiconductor substrate containing a group III nitride semiconductor crystal and having a main surface in which a nearest low index crystal plane is (0001) plane, wherein (0001) plane in one of a direction along &#x3c;1-100&#x3e; axis and a direction along &#x3c;11-20&#x3e; axis orthogonal to the &#x3c;1-100&#x3e; axis, is curved in a concave spherical shape with respect to the main surface, and a radius of curvature of the (0001) plane in one of the direction along the &#x3c;1-100&#x3e; axis and the direction along the &#x3c;11-20&#x3e; axis orthogonal to the &#x3c;1-100&#x3e; axis is different from a radius of curvature of at least a part of the (0001) plane in the other direction.

Nitride semiconductor substrate, semiconductor laminate, laminated structure, method for manufacturing nitride semiconductor substrate and method for manufacturing semiconductor laminate

There is provided a nitride crystal substrate made of a nitride crystal with a diameter of 100 mm or more, having on its main surface: a continuous high dislocation density region and a plurality of low dislocation density regions divided by the high dislocation density region, with the main surface not including a polarity inversion domain.

Nitride crystal substrate

A method for manufacturing a group III nitride semiconductor crystal substrate includes providing, as a seed crystal substrate, a group III nitride single crystal grown by a liquid phase growth method, and homoepitaxially growing a group III nitride single crystal by a vapor phase growth method on a principal surface of the seed crystal substrate. The principal surface of the seed crystal substrate is a +c-plane, and the seed crystal substrate has an atomic oxygen concentration of not more than 1&#xd7;10cmin a crystal near the principal surface over an entire in-plane region thereof.

Method for manufacturing group-III nitride semiconductor crystal substrate

There is provided a method for manufacturing a group-III nitride substrate, including: (a) preparing a substrate which is made of a group III-nitride crystal and which has a high oxygen concentration domain where an oxygen concentration is higher than that of a matrix of the crystal; (b) irradiating the substrate with laser beam aiming at the high oxygen concentration domain, forming a through-hole penetrating the substrate in a thickness direction, and removing at least a part of the high oxygen concentration domain from the substrate; and (c) embedding at least a part of an inside of the through-hole by growing the group-III nitride crystal in the through-hole.

Method for manufacturing group-III nitride substrate and group-III nitride substrate

A large Group III nitride crystal of high quality with few defects such as a distortion, a dislocation, and warping is produced by vapor phase epitaxy. A method for producing a Group III nitride crystal includes: a first Group III nitride crystal production process of producing a first Group III nitride crystalby liquid phase epitaxy; and a second Group III nitride crystal production process of producing a second Group III nitride crystalon the first crystalby vapor phase epitaxy. In the first Group III nitride crystal production process, the surfaces of seed crystals(preliminarily provided Group III nitride) are brought into contact with an alkali metal melt, a Group III element and nitrogen are cause to react with each other in a nitrogen-containing atmosphere in the alkali metal melt, and the Group III nitride crystals are bound together by growth of the Group III nitride crystals grown from the seed crystalsto produce a first crystal

Method for producing group-III nitride crystal, group-III nitride crystal, semiconductor device, and device for producing group-III nitride crystal

There is provided a method for manufacturing a nitride crystal substrate, including: arranging a plurality of seed crystal substrates made of a nitride crystal in a planar appearance, so that their main surfaces are parallel to each other and their lateral surfaces are in contact with each other; growing a first crystal film using a vapor-phase growth method on a surface of the plurality of seed crystal substrates arranged in the planar appearance, and preparing a combined substrate formed by combining the adjacent seed crystal substrates each other by the first crystal film; growing a second crystal film using a liquid-phase growth method on a main surface of the combined substrate so as to be embedded in a groove that exists at a combined part of the seed crystal substrates, and preparing a substrate for crystal growth having a smoothened main surface; and growing a third crystal film using the vapor-phase growth method, on the smoothed main surface of the substrate for crystal growth.

Method for manufacturing nitride crystal substrate and substrate for crystal growth

A semiconductor substrate manufacturing method includes: epitaxially growing a columnar III nitride semiconductor single crystal on a principal place of a circular substrate; removing a hollow cylindrical region at an outer peripheral edge side of the III nitride semiconductor single crystal to leave a solid columnar region at an inside of the hollow cylindrical region of the III nitride semiconductor single crystal; and slicing the solid columnar region after removing the hollow cylindrical region. The hollow cylindrical region is removed such that the shape of the III nitride semiconductor single crystal is always keeps an axial symmetry that a center axis of the III nitride semiconductor single crystal is defined as a symmetric axis.

Semiconductor substrate manufacturing method

A nitride semiconductor single crystal substrate manufacturing method includes providing a template that a first nitride semiconductor single crystal layer is hetero-epitaxially grown on a heterogeneous substrate, forming a plurality of linear grooves on a surface of the template that have a depth reaching an inside of the heterogeneous substrate, wherein a pattern of the plurality of the linear grooves has three-fold or six-fold rotational symmetry with respect to a central axis of the template, epitaxially growing a second nitride semiconductor single crystal layer on the template with the plurality of the linear grooves formed thereon, and cutting a nitride semiconductor single crystal substrate from the second nitride semiconductor single crystal layer.

Nitride semiconductor single crystal substrate manufacturing method

A III group nitride semiconductor substrate according to the present invention is fabricated by forming a metal film or metal nitride filmwith mesh structure in which micro voids are provided on a starting substrate, and growing a III group nitride semiconductor crystal layervia the metal film or metal nitride film

Group III nitride semiconductor substrate, substrate for group III nitride semiconductor device, and methods of making same

A GaN single-crystal substrate has a substrate surface in which polarity inversion zones are included. The number density of the polarity inversion zones in the substrate surface is not more than 20 cm. A GaN single crystal production method includes introducing group III and V raw material gases on a substrate, and growing a GaN single crystal on the substrate. The growth temperature is within the range of not less than 1100&#xb0; C. and not more than 1400&#xb0; C., the group V to III raw material gas partial pressure ratio (V/III ratio) is within the range of not less than 0.4 and not more than 1, and the number density of polarity inversion zones in a surface of the substrate is not more than 20 cm.

GaN single-crystal substrate and method for producing GaN single crystal

A group III-V nitride-based semiconductor substrate has: a first layer made of GaN single crystal; and a second layer formed on the first layer, the second layer made of group III-V nitride-based semiconductor single crystal represented by AlGaN, where 0.9&#x3c;x&#x2266;1, wherein a top surface and a back surface of the substrate are flattened.

Group III-V nitride-based semiconductor substrate, group III-V nitride-based device and method of fabricating the same

A self-supported III-V nitride semiconductor substrate having a substantially uniform carrier concentration distribution in a surface layer existing from a top surface to a depth of at least 10 &#x3bc;m is produced by growing a III-V nitride semiconductor crystal while forming a plurality of projections on a crystal growth interface at the initial or intermediate stage of crystal growth; conducting the crystal growth until recesses between the projections are buried, so that the crystal growth interface becomes flat; and continuing the crystal growth to a thickness of 10 &#x3bc;m or more while keeping the crystal growth interface flat.

Growing community of inventors

Tokyo, Japan

Masatomo Shibata