Matsushita Electric Industrial Co., Ltd.

Matsushita Electronics Corporation

Panasonic Corporation

Masahiro Kume

Isao Kidoguchi

Akihiko Ishibashi

Yuzaburo Ban

Ryoko Miyanaga

Ayumu Tsujimura

Masakatsu Suzuki

Yoshiaki Hasegawa

Hirokazu Shimizu

Nobuyuki Uemura

Toru Takayama

Kunio Itoh

Gaku Sugahara

Satoshi Kamiyama

Hiroki Naito

Yoshihiro Hara

Hidemi Takeisi

Yuuzaburou Ban

Kiyoyuki Morita

Akio Yoshikawa

Ken Hamada

Issei Ohta

Hideyuki Sugiura

Yusaburo Ban

Fukukazu Hirayama

Kazuhisa Yamamoto

Hideo Nagai

Yasuo Kitaoka

Masaaki Yuri

Tooru Aoyagi

Osamu Imafuji

Kenji Harafuji

Shinichi Takigawa

Kiyoshi Fujihara

Akihiko Murai

Tetsuo Ueda

Toshiya Kawata

Shouichi Takasuka

Takao Shibutani

Issei Ota

Hiroki Naitou

Masuru Wada

Fumiko Tajiri

Akiko Nakamura

A light distribution controller of a light-emitting device includes a first optical member formed of ZnO disposed over an LED interposing a transparent adhesive, and a second optical member which covers the first optical member. The first optical member includes a first concave portion having an opening in a regular hexagon shape whose area gradually increases. In the first concave portion, inner wall surfaces having inclined surfaces, each of whose bases is formed by one side of the hexagon of the opening shape, are formed. Outside of the first optical member, outer wall surfaces each having a trapezoidal shape are formed. The second optical member includes a second concave portion arranged so that light at an annular peak in the light distribution characteristic of the light traveled through the first optical member is totally reflected.

Light distribution controller, light-emitting device using the same, and method for fabricating light distribution controller

In a dual-wavelength semiconductor laser in which a first semiconductor laser element and a second semiconductor laser element are integrated onto a substrate made of a compound semiconductor, a constituent material of an etching stopper of the first semiconductor laser element is a material which allows diffusion of impurities less easily than a constituent material of an etching stopper of the second semiconductor laser element.

Dual-wavelength semiconductor laser device and method for fabricating the same

A semiconductor laser device includes: a first cladding layer, which is made of a nitride semiconductor of a first conductivity type and is formed over a substrate; an active layer, which is made of another nitride semiconductor and is formed over the first cladding layer; and a second cladding layer, which is made of still another nitride semiconductor of a second conductivity type and is formed over the active layer. A spontaneous-emission-absorbing layer, which is made of yet another nitride semiconductor of the first conductivity type and has such an energy gap as absorbing spontaneous emission that has been radiated from the active layer, is formed between the substrate and the first cladding layer.

Semiconductor laser device, optical disk apparatus and optical integrated unit

A semiconductor laser device () includes a resonant cavity () in which a quantum well active layer () made up of barrier layers of gallium nitride and well layers of indium gallium nitride is vertically sandwiched between at least light guide layers of n- and p-type aluminum gallium nitride. An end facet reflective film () is formed on a reflective end facet () opposite to a light-emitting end facet () in the resonant cavity (). The end facet reflective film () has a structure including a plurality of unit reflective films (), each of which is made up of a low-refractive-index film () of silicon dioxide and a high-refractive-index film () of niobium oxide. The low-and high-refractive-index films are deposited in this order on the end facet of the resonant cavity ().

Semiconductor laser device, method for fabricating the same, and optical disk apparatus

Semiconductor laser device optical disk apparatus and optical integrated unit

In a semiconductor laser, a current blocking layercovers a p-type 2cladding layerand a p-type cap layerthat extend in a lengthwise direction of an optical resonator, at both a light-emission end and an end opposite the light-emission end, to thus form non-current injection regions in an optical waveguide. By making current blocking layerat the light-emission end large enough that carriers flowing from a current injection region do not reach the light-emission end surface, the light intensity distribution in the near field at the light-emission end surface is strongly concentrated, allowing the horizontal divergence angle of an emerging laser beam to be enlarged. This structure makes it possible to enlarge the horizontal divergence angle independently after having optimized the thickness of cladding layers and the size of the current injection region.

Semiconductor laser

The method of fabricating a nitride semiconductor of this invention includes the steps of forming, on a substrate, a first nitride semiconductor layer of AlGaInN, wherein 0&#x2266;u, v, w&#x2266;1 and u+v+w=1; forming, in an upper portion of the first nitride semiconductor layer, plural convexes extending at intervals along a substrate surface direction; forming a mask film for covering bottoms of recesses formed between the convexes adjacent to each other; and growing, on the first nitride semiconductor layer, a second nitride semiconductor layer of AlGaInN, wherein 0&#x2266;x, y, z&#x2266;1 and x+y+z=1, by using, as a seed crystal, C planes corresponding to top faces of the convexes exposed from the mask film.

Method of fabricating nitride semiconductor, method of fabricating nitride semiconductor device, nitride semiconductor device, semiconductor light emitting device and method of fabricating the same

A semiconductor laser device ( ) includes a resonant cavity ( ) in which a quantum well active layer ( ) made up of barrier layers of gallium nitride and well layers of indium gallium nitride is vertically sandwiched between at least light guide layers of n- and p-type aluminum gallium nitride. An end facet reflective film ( ) is formed on a reflective end facet ( ) opposite to a light-emitting end facet ( ) in the resonant cavity ( ). The end facet reflective film ( ) has a structure including a plurality of unit reflective films ( ), each of which is made up of a low-refractive-index film ( ) of silicon dioxide and a high-refractive-index film ( ) of niobium oxide. The low-and high-refractive-index films are deposited in this order on the end facet of the resonant cavity ( ).

The method of fabricating a nitride semiconductor of this invention includes the steps of forming, on a substrate, a first nitride semiconductor layer of Al Ga In N, wherein 0&lE;u, v, w &lE;1 and u&plus;v&plus;w&equals;1; forming, in an upper portion of the first nitride semiconductor layer, plural convexes extending at intervals along a substrate surface direction; forming a mask film for covering bottoms of recesses formed between the convexes adjacent to each other; and growing, on the first nitride semiconductor layer, a second nitride semiconductor layer of Al Ga In N, wherein 0&lE;x, y, z&lE;1 and x&plus;y&plus;z&equals;1, by using, as a seed crystal, Cplanes corresponding to top faces of the convexes exposed from the mask film.

First, the substrate temperature is set to 1020&deg; C., and an n-type cladding layer ( ) made of n-type Al Ga N, an n-type optical guide layer ( ) made of n-type GaN, and a flatness maintenance layer ( ) made of n-type Al Ga N for maintaining the surface flatness of the n-type optical guide layer ( ) by suppressing re-evaporation of the constituent atoms of the n-type optical guide layer ( ), are grown in this order on a substrate ( ) made of sapphire. Then, the supply of a group III material gas is stopped, the substrate temperature is decreased to 780&deg; C., and the carrier gas is switched from a hydrogen gas to a nitrogen gas. Then, an active layer ( ) having a multiple quantum well structure is grown by introducing NH as a group V source and selectively introducing TMI and TMG as a group III source.

Method for fabricating nitride semiconductor device

A nitride semiconductor laser device includes an n-type contact layer of n-type GaN and an n-type cladding layer of n-type Al Ga N formed on a substrate of sapphire. On the n-type cladding layer, a multiple quantum well active layer of Al Ga N/Al Ga N, a p-type leak barrier layer of p-type Al Ga N P and a p-type cladding layer of p-type Al Ga N P are successively formed. The p-type leak barrier layer has a wider energy gap than the n-type cladding layer, and the p-type leak barrier layer and the p-type cladding layer include phosphorus for making an acceptor level shallow with keeping a wide energy gap.

Semiconductor laser device

Laser light emitted from the wavelength-locked GaN semiconductor laser is collimated through a collimation lens, led through a polarization beam splitter and a &frac14; wavelength plate, and converged by a focus lens so as to be radiated on pits formed in an optical disk medium. The signal light from the optical disk medium is collimated by the focus lens, and has its polarization direction turned by the &frac14; wavelength plate by 90&deg; relative to its polarization direction before being returned from the optical disk medium. As a result, the signal light is reflected from the polarization beam splitter so as to be converged on the optical detector by the focus lens.

Optical pickup and optical disk apparatus using the same

A GaN buffer layer and an Si-doped n-type GaN contact layer are formed in this order on a sapphire substrate. An n-type Al,Ga,N cladding layer, an n-type Al,Ga,N optical guide layer, a multi-quantum well active layer, in which Al,Ga,N well layers and Al,Ga,N barrier layers are alternately stacked, an Mg-doped p-type Al,Ga,N optical guide layer, a p-type Al,Ga,N,P,cladding layer and a p-type GaN contact layer are stacked in this order on an active region on the upper surface of the n-type contact layer.

First of all, a semiconductor substrate which consists of SiC is soaked for ten minutes in a buffered hydrofluoric acid, thereby the oxidized film formed on the surface of the semiconductor substrate being etched. Then, TMA, NH,, TMG, and hydrogen for carrier are supplied at the rates of 10 &mgr;mol/min., 2.5 L/min., and 2 L/min., respectively to the semiconductor substrate at a temperature of 1090&deg; C. by using MOVPE, thereby a buffer layer which consists of single crystal AlN and has a thickness of 15 nm being grown on the main surface of the semiconductor substrate. After lowering the temperature to 800&deg; C., TMA, TMG, TMI, and NH,are supplied at the rates of 0.2 &mgr;mol/min., 2 &mgr;mol/min., 20 &mgr;mol/min., and 5 L/min., respectively, thereby a single crystal layer which consists of AlGaInN being grown on the buffer layer.

Method of manufacturing a semiconductor and a semiconductor light-emitting device

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Shiga, Japan

Masahiro Kume