Ngk Insulators, Inc.

Tomohiko Sugiyama

Mitsuhiro Tanaka

Makoto Miyoshi

Mikiya Ichimura

Yoshitaka Kuraoka

Shigeaki Sumiya

Takashi Yoshino

Yukihisa Takeuchi

Tsutomu Nanataki

Morimichi Watanabe

Katsuhiro Imai

Jun Yoshikawa

Kei Sato

Sota Maehara

Kentaro Nonaka

A vertical external-cavity surface-emitting laser (VECSEL) whose blueshift is reduced also in a high intensity range of emitted laser light is realized. A surface-emitting device for VECSEL includes a base substrate made of GaN and c-axis oriented, and an emitter structure formed of a group 13 nitride semiconductor and provided on the base substrate. The emitter structure is formed of unit deposition parts, each of which is provided on the base substrate and includes a DBR layer having a distributed Bragg reflection structure and an active layer that has a multiple quantum well structure and generates excitation emission in response to irradiation with external laser light. A c-axis orientation of each of the unit deposition parts conforms to the c-axis orientation of the base substrate located directly below the unit deposition parts. Grooves are formed between the unit deposition parts.

Surface-emitting device, vertical external-cavity surface-emitting laser, and method for manufacturing surface-emitting device

Provided is a light emitting device composite substrate suitable for manufacturing large-area light emitting devices at low cost. The light emitting device composite substrate comprises a substrate composed of an oriented polycrystalline alumina sintered body, and a light emitting functional layer formed on the substrate and having two or more layers composed of semiconductor single crystal grains, wherein each of the two or more layers has a single crystal structure in a direction approximately normal to the substrate.

Composite substrate for light-emitting element and production method therefor

Provided is a self-supporting gallium nitride substrate useful as an alternative material for a gallium nitride single crystal substrate, which is inexpensive and also suitable for having a large area. This substrate is composed of a plate composed of gallium nitride-based single crystal grains, wherein the plate has a single crystal structure in the approximately normal direction. This substrate can be manufactured by a method comprising providing an oriented polycrystalline sintered body; forming a seed crystal layer composed of gallium nitride on the sintered body so that the seed crystal layer has crystal orientation mostly in conformity with the crystal orientation of the sintered body; forming a layer with a thickness of 20 &#x3bc;m or greater composed of gallium nitride-based crystals on the seed crystal layer so that the layer has crystal orientation mostly in conformity with crystal orientation of the seed crystal layer; and removing the sintered body.

Gallium nitride self-supported substrate, light-emitting device and manufacturing method therefor

Provided is a semiconductor device in which a reverse leakage current is suppressed and the mobility of a two-dimensional electron gas is high. A semiconductor device includes: an epitaxial substrate in which a group of group-III nitride layers are laminated on a base substrate such that a (0001) crystal plane is substantially in parallel with a substrate surface; and a Schottky electrode. The epitaxial substrate includes: a channel layer made of a first group-III nitride having a composition of InAlGaN (x1+y1+z1=1, z1&#x3e;0); a barrier layer made of a second group-III nitride having a composition of InAlN (x2+y2=1, x2&#x3e;0, y2&#x3e;0); an intermediate layer made of GaN adjacent to the barrier layer; and a cap layer made of AlN and adjacent to the intermediate layer. A Schottky electrode is bonded to the cap layer.

Semiconductor device, HEMT device, and method of manufacturing semiconductor device

Provided is a method for treating a group III nitride substrate capable of obtaining, in the case where a group III nitride layer is laminated thereon, a group III nitride substrate that can form an electronic device having excellent characteristics. The method for treating a group III nitride substrate includes the steps of CMPing a surface of a substrate, elevating a temperature of the group III nitride substrate after the CMP process to a predetermined annealing temperature under a nitrogen gas atmosphere, and holding the group III nitride substrate whose temperature has been elevated to the annealing temperature for four minutes or more and eight minutes or less in a first mixed atmosphere of a hydrogen gas and a nitrogen gas or a second mixed atmosphere of a hydrogen gas and an ammonia gas.

Method for treating group III nitride substrate and method for manufacturing epitaxial substrate

Provided is a crack-free epitaxial substrate with reduced warping, in which a silicon substrate is used as a base substrate. The epitaxial substrate includes a (111) single crystal Si substrate, a superlattice layer group in which a plurality of superlattice layers are laminated, and a crystal layer. The superlattice layer is formed of a first unit layer and a second unit layer made of group-III nitrides having different compositions being alternately and repeatedly laminated. The crystal layer is made of a group-III nitride and formed above the base substrate so as to be positioned at an upper side of the superlattice layer group relative to the base substrate. The superlattice layer group has a compressive strain contained therein. In the superlattice layer group, the more distant the superlattice layer is from the base substrate, the greater the compressive strain becomes.

Epitaxial substrate comprising a superlattice group and method for manufacturing the epitaxial substrate

Provided is an epitaxial substrate for use in a semiconductor element, having excellent characteristics and capable of suitably suppressing diffusion of elements from a cap layer. An epitaxial substrate for use in a semiconductor element, in which a group of group-III nitride layers are laminated on a base substrate such that a (0001) crystal plane of the group of group-III nitride layers is substantially in parallel with a substrate surface of the base substrate, includes: a channel layer made of a first group-III nitride having a composition of InAlGaN (x1+y1+z1=1, z1&#x3e;0); a barrier layer made of a second group-III nitride having a composition of InAlN (x2+y2=1, x2&#x3e;0, y2&#x3e;0); an anti-diffusion layer made of AlN and having a thickness of 3 nm or more; and a cap layer made of a third group-III nitride having a composition of InAlGaN (x3+y3+z3=1, z3&#x3e;0).

Epitaxial substrate for semiconductor element, semiconductor element, PN junction diode, and method for manufacturing an epitaxial substrate for semiconductor element

Provided is an epitaxial substrate for a semiconductor device, which has excellent schottky contact characteristics that are stable over time. The epitaxial substrate for a semiconductor device includes a base substrate, a channel layer formed of a first group III nitride containing at least Ga and having a composition of InAlGaN (x1+y1+z1=1), and a barrier layer formed of a second group III nitride containing at least In and Al and having a composition of InAlGaN (x2+y2+z2=1), wherein the barrier layer has tensile strains in an in-plane direction, and pits are formed on a surface of the barrier layer at a surface density of 5&#xd7;10/cmor more and 1&#xd7;10/cmor less.

Epitaxial substrate for semiconductor device and semiconductor device

An epitaxial substrate, in which a group of group-III nitride layers is formed on a single-crystal silicon substrate so that a crystal plane is approximately parallel to a substrate surface, comprises: a first group-III nitride layer formed of AlN on the base substrate; a second group-III nitride layer formed of InAlGaN (xx+yy+zz=1, 0&#x2266;xx&#x2266;1, 0&#x3c;yy&#x2266;1 and 0&#x3c;zz&#x2266;1) on the first group-III nitride layer; and at least one third group-III nitride layer epitaxially-formed on the second group-III nitride layer, wherein: the first group-III nitride layer is a layer containing multiple defects including at least one type of a columnar crystal, a granular crystal, a columnar domain and a granular domain; and an interface between the first group-III nitride layer and the second group-III nitride layer is a three-dimensional asperity surface.

Epitaxial substrate for semiconductor device, method for manufacturing epitaxial substrate for semiconductor device, and semiconductor device

Provided is an epitaxial substrate for semiconductor device that is capable of achieving a semiconductor device having high reliability in reverse characteristics of schottky junction. An epitaxial substrate for semiconductor device obtained by forming, on a base substrate, a group of group III nitride layers by lamination such that a (0001) crystal plane of each layer is approximately parallel to a substrate surface includes: a channel layer formed of a first group III nitride having a composition of InAlGaN (x1+y1+z1=1, z1&#x3e;0); and a barrier layer formed of a second group III nitride having a composition of InAlN (x2+y2=1, x2&#x3e;0, y2&#x3e;0), wherein the second group III nitride is a short-range-ordered mixed crystal having a short-range order parameter &#x3b1; satisfying a range where 0&#x2266;&#x3b1;&#x2266;1.

Epitaxial substrate for semiconductor device, schottky junction structure, and leakage current suppression method for schottky junction structure

Provided is an epitaxial substrate capable of achieving a semiconductor device that has excellent schottky contact characteristics as well as satisfactory device characteristics. On a base substrate, a channel layer formed of a first group III nitride that contains at least Al and Ga and has a composition of InAlGaN (x1+y1+z1=1) is formed. On the channel layer, a barrier layer formed of a second group III nitride that contains at least In and Al and has a composition of InAlGaN (x2+y2+z2=1) is formed such that an In composition ratio of a near-surface portion is smaller than an In composition ratio of a portion other than the near-surface portion.

Epitaxial substrate for semiconductor device, semiconductor device, and method of manufacturing epitaxial substrate for semiconductor device

Provided is an epitaxial substrate capable of achieving a semiconductor device that has excellent ohmic contact characteristics as well as satisfactory device characteristics. On a base substrate, a channel layer formed of a first group III nitride that contains at least Al and Ga and has a composition of InAlGaN (x1+y1+z1=1) is formed. On the channel layer, a barrier layer formed of a second group III nitride that contains at least In and Al and has a composition of InAlGaN (x2+y2+z2=1) is formed such that an In composition ratio of a near-surface portion is larger than an In composition ratio of a portion other than the near-surface portion.

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Nagoya, Japan

Tomohiko Sugiyama