Sumitomo Electric Industries, Limited

Sony Corporation

Itoki Crebio Corporation

Panasonic Corporation

Koji Katayama

Takao Nakamura

Takeshi Takagi

Masaki Ueno

Yusuke Yoshizumi

Takatoshi Ikegami

Shimpei Takagi

Takashi Kyono

Shinji Tokuyama

Masahiro Adachi

Katsushi Akita

Yohei Enya

Youichi Nagai

Kazuhiko Shimakawa

Shunsaku Muraoka

Satoru Fujii

Takamichi Sumitomo

Hiroyuki Kitabayashi

Koji Uematsu

Makoto Kiyama

Takashi Sakurada

Hideki Matsubara

Susumu Yoshimoto

Ayako Ikeda

Katsunori Yanashima

Kazuhide Sumiyoshi

Nobuhiro Saga

Akihiko Saegusa

Hiroshi Nakajima

Hiroki Mori

Hiroshi Takeuchi

Yoshihiko Kanzawa

Satoru Mitani

Tatsushi Hamaguchi

Koichi Osano

Ryoko Miyanaga

Yoshihiro Saito

Satoshi Arakawa

Toshihiko Takebe

Shigenori Takehara

In a group III nitride semiconductor device according to one aspect of the present invention, in a p-type group III nitride semiconductor region formed on a semi-polar plane substrate, the concentration of hydrogen (H) contained in the p-type group III nitride semiconductor region is 25% or less of the concentration of a p-type dopant therein, and the concentration of oxygen contained in the p-type group III nitride semiconductor region is 5&#xd7;10atoms/cmor lower, and an angle between a normal axis of a primary surface of the semi-polar plane substrate and a c-axis of the semi-polar plane substrate is not lower than 45 degrees and not higher than 80 degrees or not lower than 100 degrees and not higher than 135 degrees in a waveguide axis direction of the group III nitride semiconductor device.

Group III nitride semiconductor device, and method for fabricating group III nitride semiconductor device

A III-nitride semiconductor laser device including: a laser structure including a support base and a semiconductor region, the support base including a hexagonal III-nitride semiconductor and having a semipolar primary surface, and the semiconductor region being provided on the semipolar primary surface of the support base; and an electrode provided on the semiconductor region of the laser structure, the semiconductor region including a first cladding layer, a second cladding layer, and an active layer.

Group-III nitride semiconductor laser device, and method for fabricating group-III nitride semiconductor laser device

Provided is a III-nitride semiconductor laser diode which is capable of lasing at a low threshold. A support base has a semipolar or nonpolar primary surface. The c-axis Cx of a III-nitride is inclined relative to the primary surface. An n-type cladding region and a p-type cladding region are provided above the primary surface of the support base. A core semiconductor region is provided between the n-type cladding region and the p-type cladding region. The core semiconductor region includes a first optical guide layer, an active layer, and a second optical guide layer. The active layer is provided between the first optical guide layer and the second optical guide layer. The thickness of the core semiconductor region is not less than 0.5 &#x3bc;m. This structure allows the confinement of light into the core semiconductor region without leakage of light into the support base, and therefore enables reduction in threshold current.

III-nitride semiconductor laser diode

A group-III nitride semiconductor laser device comprises: a laser structure including a semiconductor region and a support base having a semipolar primary surface of group-III nitride semiconductor; a first reflective layer, provided on a first facet of the region, for a lasing cavity of the laser device; and a second reflective layer, provided on a second facet of the region, for the lasing cavity. The laser structure includes a laser waveguide extending along the semipolar surface. A c+ axis vector indicating a &#x3c;0001&#x3e; axial direction of the base tilts toward an m-axis of the group-III nitride semiconductor at an angle of not less than 63 degrees and less than 80 degrees with respect to a vector indicating a direction of an axis normal to the semipolar surface. The first reflective layer has a reflectance of less than 60% in a wavelength range of 525 to 545 nm.

Group-III nitride semiconductor laser device

A method of fabricating a III-nitride semiconductor laser device includes: preparing a substrate having a hexagonal III-nitride semiconductor and having a semipolar primary surface; forming a substrate product having a laser structure, an anode electrode and a cathode electrode, the laser structure including a substrate and a semiconductor region formed on the semipolar primary surface; scribing a first surface of the substrate product in part in a direction of the a-axis of the hexagonal III-nitride semiconductor; and carrying out breakup of the substrate product by press against a second surface of the substrate product, to form another substrate product and a laser bar.

Group-III nitride semiconductor laser device, and method of fabricating group-III nitride semiconductor laser device

Provided is a group-III nitride semiconductor laser device with a laser cavity of high lasing yield, on a semipolar surface of a support base in which the c-axis of a hexagonal group-III nitride is tilted toward the m-axis. First and second fractured faces to form the laser cavity intersect with an m-n plane. The group-III nitride semiconductor laser device has a laser waveguide extending in a direction of an intersecting line between the m-n plane and the semipolar surface. In a laser structure, a first surface is opposite to a second surface. The first and second fractured faces extend from an edge of the first surface to an edge of the second surface. The fractured faces are not formed by dry etching and are different from conventionally-employed cleaved facets such as c-planes, m-planes, or a-planes.

Provided is a group-III nitride semiconductor laser device with a laser cavity allowing for a low threshold current, on a semipolar surface of a support base in which the c-axis of a hexagonal group-III nitride is tilted toward the m-axis. First and second fractured facesto form the laser cavity intersect with an m-n plane. The group-III nitride semiconductor laser devicehas a laser waveguide extending in a direction of an intersecting line between the m-n plane and the semipolar surface. For this reason, it is feasible to make use of emission by a band transition enabling the low threshold current. In a laser structure, a first surfaceis opposite to a second surface. The first and second fractured facesextend from an edgeof the first surfaceto an edgeof the second surface. The fractured faces are not formed by dry etching and are different from conventionally-employed cleaved facets such as c-planes, m-planes, or a-planes.

A III-nitride semiconductor laser device includes a laser structure including a support base, a semiconductor region, and an electrode. The support base includes a hexagonal III-nitride semiconductor and a semipolar primary surface. The semiconductor region includes first and second cladding layers and an active layer arranged along an axis normal to the semipolar primary surface. A c-axis of the hexagonal III-nitride semiconductor is inclined at an angle ALPHA with respect to the normal axis toward an m-axis of the hexagonal III-nitride semiconductor. The laser structure includes first and second fractured faces that intersect with an m-n plane defined by the normal axis and the m-axis of the hexagonal III-nitride semiconductor. A laser cavity of the laser device includes the first and second fractured faces. Each of the first and second fractured faces have a stripe structure on an end face of the support base.

A compound semiconductor device having reduced contact resistance to an electrode is provided. The compound semiconductor device includes an n-substratecomprising a hexagonal compound semiconductor GaN and having surfaces Sand S; an n-electrodeformed on the surface Sof the n-substrate; a layered product having an n-cladding layer, an active layer, a p-cladding layer, and a contact layerformed on the surface Sof the n-substrate; and a p-electrodeformed on the p-cladding layer. The number of N atoms contained on the surface Sof the n-substrateis more than the number of Ga atoms contained on the surface S. The electrode formed on the surface Sis an n-electrode. The surface Shas an oxygen concentration of not more than 5 atomic percent. The number of Ga atoms contained on the surface Sof the contact layeris more than the number of N atoms contained on the surface S. The electrode formed on the surface Sis a p-electrode. The surface Shas an oxygen concentration of not more than 5 atomic percent.

Compound semiconductor device

Provided is a group-III nitride semiconductor laser device with a laser cavity allowing for a low threshold current, on a semipolar surface of a support base in which the c-axis of a hexagonal group-III nitride is tilted toward the m-axis. First and second fractured facesto form the laser cavity intersect with an m-n plane. The group-III nitride semiconductor laser devicehas a laser waveguide extending in a direction of an intersecting line between the m-n plane and the semipolar surface. In a laser structure, a first surfaceis opposite to a second surface. The first and second fractured facesextend from an edgeof the first surface to an edgeof the second surface. The fractured faces are not formed by dry etching and are different from conventionally-employed cleaved facets such as c-planes, m-planes, or a-planes.

A method of fabricating a III-nitride semiconductor laser device includes: preparing a substrate with a semipolar primary surface, the semipolar primary surface including a hexagonal III-nitride semiconductor; forming a substrate product having a laser structure, an anode electrode, and a cathode electrode, the laser structure including a substrate and a semiconductor region, and the semiconductor region being formed on the semipolar primary surface; after forming the substrate product, forming first and second end faces; and forming first and second dielectric multilayer films for an optical cavity of the nitride semiconductor laser device on the first and second end faces, respectively.

III-nitride semiconductor laser device, and method of fabricating the III-nitride semiconductor laser device

A III-nitride semiconductor laser device is provided with a laser structure and an electrode. The laser structure includes a support base which includes a hexagonal III-nitride semiconductor and a semipolar primary surface, and a semiconductor region provided on the semipolar primary surface. The electrode is provided on the semiconductor region. The semiconductor region includes a first cladding layer of a first conductivity type GaN-based semiconductor, a second cladding layer of a second conductivity type GaN-based semiconductor, and an active layer provided between the first cladding layer and the second cladding layer.

Group-III nitride semiconductor laser device, method of fabricating group-III nitride semiconductor laser device, and epitaxial substrate

A method of fabricating a III-nitride semiconductor laser device includes: preparing a substrate product, where the substrate product has a laser structure, the laser structure includes a semiconductor region and a substrate of a hexagonal III-nitride semiconductor, the substrate has a semipolar primary surface, and the semiconductor region is formed on the semipolar primary surface; scribing a first surface of the substrate product to form a scribed mark, the scribed mark extending in a direction of an a-axis of the hexagonal III-nitride semiconductor; and after forming the scribed mark, carrying out breakup of the substrate product by press against a second region of the substrate product while supporting a first region of the substrate product but not supporting the second region thereof, to form another substrate product and a laser bar.

A Group III nitride semiconductor device has a semiconductor region, a metal electrode, and a transition layer. The semiconductor region has a surface comprised of a Group III nitride crystal. The semiconductor region is doped with a p-type dopant. The surface is one of a semipolar surface and a nonpolar surface. The metal electrode is provided on the surface. The transition layer is formed between the Group III nitride crystal of the semiconductor region and the metal electrode. The transition layer is made by interdiffusion of a metal of the metal electrode and a Group III nitride of the semiconductor region.

Group III nitride semiconductor device

In a III-nitride semiconductor laser device, a laser structure includes a support base comprised of a hexagonal III-nitride semiconductor and having a semipolar primary surface, and a semiconductor region provided on the semipolar primary surface of the support base. An electrode is provided on the semiconductor region of the laser structure. The c-axis of the hexagonal III-nitride semiconductor of the support base is inclined at an angle ALPHA with respect to a normal axis toward the m-axis of the hexagonal III-nitride semiconductor. The angle ALPHA is in the range of not less than 45 degrees and not more than 80 degrees or in the range of not less than 100 degrees and not more than 135 degrees. The laser structure includes first and second fractured faces that intersect with an m-n plane defined by the m-axis of the hexagonal III-nitride semiconductor and the normal axis. A laser cavity of the III-nitride semiconductor laser device includes the first and second fractured faces. The laser structure includes first and second surfaces, and the first surface is opposite to the second surface. Each of the first and second fractured faces extends from an edge of the first surface to an edge of the second surface. The support base of the laser structure has a recess provided at a portion of the edge of the first surface in the first fractured face. The recess extends from a back surface of the support base, and an end of the recess is apart from the edge of the second surface of the laser structure.

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Osaka, Japan

Koji Katayama