Sharp Kabushiki Kaisha Corporation

501 Sharp Kabushiki Kaisha

Masafumi Kondo

Takahiro Suyama

Toshiro Hayakawa

Saburo Yamamoto

Kosei Takahashi

Kohsei Takahashi

Sadayoshi Matsui

Kazuaki Sasaki

Hiroyuki Hosoba

Toshio Hata

Taiji Morimoto

Masaki Kondo

Masahiro Hosoda

Mitsuhiro Matsumoto

Shinji Kaneiwa

Akinori Seki

Daisuke Hanaoka

Atsuo Tsunoda

Kunihiro Takatani

Susumu Ohmi

Yoshika Kaneko

The nitride semiconductor device includes an insulating layer and a metal layer formed on a nitride semiconductor layer. The insulating layer makes contact with the nitride semiconductor layer. A separation preventing layer is formed between the insulating layer and the metal layer so as to make contact with each of these layers. The separation preventing layer includes, as a main component, at least one oxide of a metal selected from a group of metals consisting of tungsten, molybdenum, chromium, titanium, nickel, hafnium, zinc, indium and yttrium.

Nitride semiconductor devices including a separation preventing layer

A method for growing a compound semiconductor layer of Al.sub.x Ga.sub.1-x As (0.ltoreq.x.ltoreq.1) on a compound semiconductor substrate uses a molecular beam epitaxial apparatus, the method including the steps of providing the substrate having a GaAs layer on an upper surface thereof, thermally etching the GaAs layer by heating the substrate at a temperature and irradiating the GaAs layer with a gallium molecular beam and an arsenic molecular beam to expose the upper surface of the substrate, and growing the Al.sub.x Ga.sub.1-x As (0.ltoreq.x.ltoreq.1) layer on the upper surface of the substrate.

Method for growing a compound semiconductor and a method for producing a

A semiconductor laser device which can effectively confine electrons and positive holes is disclosed. The semiconductor laser device includes a semiconductor substrate of a first conductivity type, a current blocking layer of a second conductivity type, a first semiconductor layer of the first conductivity type made of a III-V group compound semiconductor, an active layer made of a III-V group compound semiconductor, and a second semiconductor layer. The semiconductor substrate has a ridge-type mesa having (n11)A planes. The current blocking layer is formed on the semiconductor substrate other than the top face of the mesa. The first semiconductor layer is formed on the entire surface of the current blocking layer and on the top face of the mesa. The active layer is formed on the first semiconductor layer. The second semiconductor layer is formed on the active layer. The second semiconductor layer has inclined portions, and is made of a III-V group compound semiconductor containing an amphoteric element as an impurity so that the inclined portions are of the first conductivity type and the other portions are of the second conductivity type.

Semiconductor laser device

A semiconductor laser device and a method for the production of the semiconductor laser device are provided, which semiconductor laser device includes a striped channel formed in a semiconductor substrate through a current blocking layer on the substrate and at least two dummy grooves formed in the current blocking layer on each side of the striped channel. Also provided are a semiconductor wafer prepared for the purpose of producing optical devices with an optical waveguide, and a method for the production of the semiconductor wafer. The semiconductor wafer includes a semiconductor substrate, the surface of which has an orientation inclined from the [100] direction to one of the [011] and [011] directions of an angle .theta. satisfying the relationship 0.1.degree.&lt;.vertline..theta..vertline.&lt;4.degree.; a plurality of striped channels formed in a substrate through a current blocking layer in the direction of the other of the [011] and [011] directions; and at least one dummy side groove formed between the striped channels, having a combined cross-sectional area on the plane perpendicular to the other direction greater than that of each of the striped channels.

Semiconductor laser device, a semiconductor wafer

A semiconductor device comprising a (111)B single-crystalline semiconductor substrate which is misoriented toward (110), and epitaxial layers grown on the substrate by molecular beam epitaxy, whereby the crystallinity and luminescence efficiency of epitaxial layers are significantly improved.

Semiconductor device with substrate misorientation

A semiconductor laser device is disclosed which comprises a semiconductor substrate and a multi-layered crystal structure disposed on the substrate, the multi-layered crystal structure containing a first cladding layer, a quantum-well active layer for laser oscillation, and a second cladding layer with a striped ridge portion for current injection, wherein the difference in the effective refractive index between the region underneath the striped ridge portion and the adjacent regions thereto is greater in the vicinity of at least one of the facets than inside of the facets.

An optical semiconductor device is disclosed that comprises a quantum-well structure as an active region and exhibits a nonlinear optical effect with regard to light of energy near the band gap between the allowed band edges in the active region. The quantum-well structure of this device is composed of alternate layers consisting of at least one first semiconductor layer with a thickness smaller than the de Broglie wavelength of carriers and at least two second semiconductor layers with a band gap greater than that of the first semiconductor layer, the alternate layers being formed along a crystal orientation in the zinc-blende structure. The second semiconductor layers mentioned above are of an indirect transition type.

Optical semiconductor device

A semiconductor laser device is disclosed which comprises a semiconductor substrate, a striped mesa disposed on the substrate and having an active layer for laser oscillation, a current injection layer disposed on the striped mesa and having a width smaller than that of the striped mesa, and a burying layer disposed on both sides of the current injection layer so as to come into contact with the side walls of the current injection layer, the burying layer being capable of absorbing laser light produce in the active layer and of preventing current from flowing through the outside of the striped mesa.

A semiconductor laser device comprising a substrate of a first conductivity type having a mesa; a first semiconductor layer of a second conductivity type which is formed on the upper surface of the substrate other than the mesa to form a flat plane including the top face of the mesa; a laser oscillation region which is formed on the flat plane and includes an active area for laser oscillation; and a multi-layer structure burying the laser oscillation region, the multi-layer structure comprising a high resistance layer formed on the first semiconductor layer and burying both sides of the laser oscillation region, and a second semiconductor layer of the first conductivity type formed on the high resistance layer.

A semiconductor laser device containing a laser oscillation-operating area which comprises a Ga.sub.1-x Al.sub.x As (0.ltoreq.x.ltoreq.1) quantum well active layer, Ga.sub.1-y Al.sub.y As optical guiding layers interposing the quantum well active layer therebetween, and Ga.sub.1-z Al.sub.z As cladding layers superposed on the optical guiding layers, respectively, wherein the AlAs mole fraction y at the area of each of the optical guiding layers positioned in the vicinity of the interface of the optical guiding layers and the quantum well active layer meets the relationships y-z.gtoreq.0.3 and z-y.ltoreq.0.25.

A semiconductor laser device of this invention comprises a plurality of semiconductor epitaxial layers grown on a semiconductor substrate, wherein the growth plane of said substrate is substantially the (111) plane.

A double-heterostructure multilayered crystal structure in a semiconductor laser device contains an active layer for laser oscillation. A striped etching-protective thin layer is formed on the double-heterostructure multilayered crystal. A striped-mesa multilayered crystal is formed on the striped etching-protective thin layer. A burying layer is formed on the double-heterostructure multilayered crystal outside of both the striped thin layer and striped-mesa multilayered crystal. This provides refractive index distributions within the active layer corresponding to the inside and the outside of the striped-mesa multilayered crystal. Further, it provides a striped structure which functions as a current path composed of the striped-mesa multilayered crystal.

A semiconductor device using the quantum effect of one dimension that arises in the direction vertical to the plane of a substrate on which the device structure is disposed, wherein the plane of the substrate is substantially the (111) plane.

Semiconductor device

A Semiconductor laser device comprising a quantum well region with a superlattice structure that functions as an active region, wherein the superlattice quantum well region is composed of alternate layers consisting of a plurality of first Al.sub.x Ga.sub.1-x As thin films and a plurality of second Al.sub.y Ga.sub.1-y As thin films (0&lt;x&lt;y.ltoreq.1).

Deterioration-resistant superlattice semiconductor laser device

A semiconductor laser device comprising an active layer, optical guiding layers sandwiching the active layer therebetween, and a cladding layer disposed on each of the optical guiding layers, wherein the refractive index of each of the optical guiding layers gradually varies in the direction of the thickness of the optical guiding layer, and the thickness of each of the cladding layers is 0.5 um or less.

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Nara, Japan

Masafumi Kondo