Sharp Kabushiki Kaisha Corporation

Kazuhiko Wada

Taiji Morimoto

Keisuke Miyazaki

Masaki Tatsumi

Yoshiaki Ueda

Ryuhichi Sogabe

An AlGaInPAs-based semiconductor laser device includes a substrate, an n-type clad layer, an n-type guide layer, an active layer, a p-type guide layer composed of AlGaInP containing Mg as a dopant, a p-type clad layer composed of AlInP containing Mg as a dopant, and a p-type cap layer composed of GaAs. Further, the semiconductor laser device has, between the p-type guide layer and the p-type clad layer, a Mg-atomic concentration peak which suppresses inflow of electrons, moving from the n-type clad layer to the active layer, into the p-type guide layer or the p-type clad layer.

AlGaInPAs-based semiconductor laser device and method for producing same

A light confinement layer constructed of a semiconductor that has a refractive index different from that of p-type second cladding layers is formed to a small film thickness of not greater than 2 &#x3bc;m (about 0.5 &#x3bc;m) on the whole surface of ridge portions of two semiconductor lasers. Thus, the light confinement layer on the ridge portions is made roughly flat so as to be easily removable by etching. As a result, the exposure of p-type second cladding layers of the ridge portions due to deep etching is prevented to allow the confinement of light into the p-type cladding layers to be stably effected. A dielectric film is formed on the light confinement layer and reinforces the current constriction function lost by the reduction in the thickness of the light confinement layer.

Semiconductor laser device and manufacturing method therefor

An AlGaAs-based semiconductor laseris formed on an n-type GaAs substrateand thereafter etching is carried out until reaching an n-type AlGaAs clad layerfrom the surface. Next, the n-type AlGaAs clad layeris removed by etching with an etchant having selectivity to GaAs. Subsequently, the surface of an n-type GaAs buffer layeris lightly etched. Thus, the n-type GaAs buffer layerof the AlGaAs-based semiconductor laseris left in a slightly abraded state on the n-type GaAs substratemaintaining the flatness of the groundwork layer during growing an AlGaInP-based semiconductor laserat the second time. Therefore, the flatness of the crystals of, in particular, an active layer grown at the second time can be improved, and the poor characteristics of the AlGaInP-based semiconductor laserattributed to the poor flatness of the groundwork can be improved.

Semiconductor laser device having a multi-layer buffer layer

There is provided a semiconductor laser device having on a single substrate a plurality of laser portions each oscillating laser light of a different wavelength, the plurality of laser portions containing different types, respectively, of dopant. There is also provided a method of fabricating a semiconductor laser device, forming on a single substrate a plurality of laser portions each oscillating laser light of a different wavelength, initially forming a laser portion in a crystal growth method and subsequently forming another laser portion in a different crystal growth method.

Semiconductor laser device and method of fabricating the same

An AlGaAs-based semiconductor laseris formed on an n-type GaAs substrate, and thereafter, a non-doped GaAs protective layeris formed. When the n-type substrateis exposed by removing by etching a partial region of the AlGaAs-based semiconductor laser, an impurity Zn is prevented from evaporating from a p-type GaAs contact layer. The deterioration of the characteristic of contact with a p-type electrode as a consequence of a reduction in the carrier density of the p-type contact layercan be prevented. Furthermore, the impurity evaporated from the p-type contact layercan be prevented from readhering onto the exposed n-type substrate. A layer where the n-type GaAs substrateand the readhering impurity are mixed with each other is not formed when an AlGaInP-based semiconductor laseris succeedingly formed, and the reliability in long-term operation can be improved.

Growing community of inventors

Yamatokooriyama, Japan

Kazuhiko Wada