Matsushita Electric Industrial Co., Ltd.

Matsushita Electronics Corporation

Kunio Itoh

Hirokazu Shimizu

Takashi Sugino

Masaru Wada

Morio Inoue

Masahiro Kume

Ken Hamada

Masahiro Ishida

Iwao Teramoto

Masaaki Yuri

Toru Takayama

Hiroki Naito

Kazuo Fujimoto

Issei Ohta

Hideyuki Sugiura

Takako Okabe

Takao Shibutani

Kunihiko Asahi

Nobuyuki Uemura

Kiyotsugu Ishikawa

Tadao Hashimoto

Hiroyuki Mizuno

Masuru Wada

Fumiko Tajiri

A semiconductor device having a plurality of semiconductor laser elements is provided, which is capable of reducing an interval of emission points between the semiconductor laser elements and also capable of preventing heat generated by a semiconductor laser element from affecting other semiconductor elements. A concave portion is formed on a silicon substrate, and a protrusion of a quadrangular truncated pyramidal shape consisting of slanted faces of a (1 1 1) plane, a (1 {overscore (1)} 1) plane, a ({overscore (1)} {overscore (1)} 1) plane and a ({overscore (1)} 1 1) plane is formed near the center of the concave portion by using the silicon process. Among these slanted faces, a (1 1 1) outer face and a (1 1 1) inner face are determined to be reflecting mirror surfaces. The semiconductor laser elements respectively are fixed on small protrusions formed on the concave portion, and a photodetector for receiving light beams L &prime; and L &prime; returning from an optical disc is disposed on a top face of the protrusion.

Semiconductor device and optical pickup device

A method for growing nitride semiconductor crystals according to the present invention includes the steps of: a) forming a first metal single crystal layer on a substrate; b) forming a metal nitride single crystal layer by nitrifying the first metal single crystal layer; and c) epitaxially growing a first nitride semiconductor layer on the metal nitride single crystal layer.

Method for growing nitride semiconductor crystals, nitride semiconductor device, and method for fabricating the same

The nitride semiconductor laser device of the present invention includes: a nitride semiconductor laser diode; and a protective layer formed on at least one facet of the nitride semiconductor laser diode. The protective layer is made of Al,Ga,In,B,N (where 0&lE;x, y, z&lE;1 and 0&lE;x&plus;y&plus;z&lE;1), which is transparent to light emitted from the laser diode.

Nitride semiconductor laser device

A semiconductor laser device of low operating current and low noise for the 780 nm band to be used as the light source for an optical disc and its fabrication method. The device comprises: a certain conduction type Ga.sub.1-Y1 Al.sub.Y1 As first light guide layer, a Ga.sub.1-Y2 Al.sub.Y2 As second light guide layer of said certain conduction type, or an In.sub.0.5 Ga.sub.0.5 P or an In.sub.0.5 (GaAl).sub.0.5 P or an InGaAsP second light guide layer, successively formed one upon another at least in one side of the principal plane of an active layer; an opposite conduction type Ga.sub.1-Z Al.sub.Z As current blocking layer formed on the second light guide layer and provided with a stripe-like window; and a Ga.sub.1-Y3 Al.sub.Y3 As cladding layer of the same conduction type a said light guide layers formed on said stripe-like window, wherein relations of Z&gt;Y3&gt;Y2 and Y1&gt;Y2 are established among Y1, Y2 Y3 and Z that define the AlAs mole-fractions.

Semiconductor laser device fabrication method

A semiconductor laser device suitable as a light source for an optical disk may be operated at a low operating current with low noise for the 780 nm band. The device comprises: a certain conduction type Ga.sub.1-Y1 Al.sub.Y1 As first light guide layer, a Ga.sub.1-Y2 Al.sub.Y2 As second light guide layer of said certain conduction type, or an In.sub.0.5 Ga.sub.0.5 P or an In.sub.0.5 (GaAl).sub.0.5 P or an InGaAsP second light guide layer, successively formed one upon another at least in one side of the principal plane of an active layer; an opposite conduction type Ga.sub.1-Z Al.sub.Z As current blocking layer formed on the second light guide layer and provided with a stripe-like window; and a Ga.sub.1-Y3 Al.sub.Y3 As cladding layer of the same conduction type as the light guide layers formed on the stripe-like window. The relations of Z&gt;Y3&gt;Y2 and Y1&gt;Y2 define the AlAs mole fractions.

Low operating current and low noise semiconductor laser device for

A laser chip is directly disposed on a support member through a mounting arrangement and a support member, the laser chip, and peripheral parts thereof are integrally sealed within a transparent plastic resin. In this structure, without requiring expensive materials and parts, a semiconductor laser apparatus may be manufactured by using the same materials and process as in the ordinary plastic-sealed LED, so that the cost may be reduced significantly.

Semiconductor laser apparatus

A BTRS (buried Twin-Ridge Substrate) structure laser, wherein an oblong protrusion (10) is provided on a substrate (1) of a first conductivity type and two ridges (9, 9) divided by a groove (31) therebetween are provided on a second layer (2) of a second conductivity type, and thereon plural layers (3, 4, 5, 6) including an active layer (4) are provided is improved to have longer service life such that: the protrusion (10) is shortened so as to have its both ends apart inside cavity facet of the substrate (1), or further by width of each ridge (9, 9) is narrowed at both ends thereof thereby forming narrowed end parts (9', 9'), so that excessive current injection to the active layer near the cavity facet is eliminated.

Buried twin ridge substrate laser

In a TRS (twin ridge substrate) type semiconductor laser, reflectivity at both facets of the resonator at the oscillation wavelength is selected to be higher than the reflectivity of the semiconductor crystal of the laser device, but smaller than 1, thereby stabilizing the light oscillation with a low S/N ratio.

Semiconductor laser device with decreased light intensity noise

A semiconductor substrate having a groove with a dove-tail-shaped cross section is used as a substrate and thereon, several epitaxial layers including an active layer are formed and a current injection region is formed immediately above the groove; the semiconductor laser attains a high power lasing with the fundamental transverse mode.

A high-output semiconductor laser of dove tail groove type

The invention provides a chemical etching method for a semiconductor device, which comprises a step of forming a first layer of Ga.sub.1-x Al.sub.x As (0.ltoreq.x&lt;1) having a surface (100), a step of forming on the first layer a second layer of Ga.sub.1-y Al.sub.y As (0.ltoreq.y&lt;1) having a surface (100), and a step of chemically etching the layers from a level above the second layer and along the direction of &lt;011&gt;. The slope angle of etch face of the second layer depends on the mol fraction y of the second layer, and the slope angle of etch face of the first layer depends on the mol fraction y of the second layer and the mol fraction x of the first layer. These facts are best utilized in the invention so that the etch profile of the first layer may have a desired slope angle. By utilizing this chemical etching method it is possible to produce by chemical etching a semiconductor laser having a flat cavity facet perpendicular to a junction; it is also possible to provide an inner stripe type semiconductor laser having grooves whose side walls are perpendicular.

Method of manufacturing semiconductor device

In a laser of such type that the distribution of the effective refractive index varies in a direction which is along the face of its active layer and perpendicular to the direction of the laser light transmission, thereby defining the active region to be between a pair of refractive index changing zones, the refractive indexes of a pair of end surfaces of a laser resonator (i.e. the active region) is made smaller than the intrinsic refractive indexes of the cleavage face of the active layer.

Semiconductor laser

A mounting of semiconductor laser chip on a heat sink or metal mount is improved so as to enable high accuracy of position and direction. A heat sink or metal mount, on which a semiconductor laser chip is mounted, comprises two parts, namely a main mount or larger portion and a sub-mount or smaller portion. The semiconductor laser chip is soldered by a solder layer on the sub-mount utilizing a microscope so as to assure an accurate position and an accurate direction with respect to the sub-mount. Then, the sub-mount is soldered on the main mount by a solder layer with an accurate relation both in position and direction by engaging a linear ridge as a first engaging means provided on the upper face of the main mount with a straight groove and a rear end face as a second engaging means. As a result of the above-mentioned structure, accurate position and direction of the semiconductor laser chip with respect to the mount is easily obtainable with a high yield.

Semiconductor laser structure including dual mounts having ridge and

A mounting of semiconductor laser chip on a heat sink or metal mount is improved so as to enable high accuracy of position and direction. A heat sink or metal mount, on which a semiconductor laser chip is mounted, comprises two parts, namely a main mount or larger portion and a sub-mount or smaller portion. The semiconductor laser chip is soldered by a solder layer on the sub-mount utilizing a microscope so as to assure an accurate position and an accurate direction with respect to the sub-mount. Then, the sub-mount is soldered on the main mount by a solder layer with an accurate relation both in position and direction by engaging a linear ridge as a first engaging means provided on the upper face of the main mount with a straight groove and a rear end face as a second engaging means, or by engaging a square recess as a first engaging means and the square bottom of the sub-mount as a second engaging means with each other. As a result of the above-mentioned structure, accurate position and direction of the semiconductor laser chip with respect to the mount is easily obtainable with a high yield.

On a semiconductor laser substrate, a groove of tapered width is formed, and at least one crystal layer is formed on the substrate. The crystal layer is usable as a waveguide with two light input ends l.sub.1 and l.sub.2 and one light output end l.sub.3 as shown in FIG. 4(C).

Growing community of inventors

Uji, Japan

Kunio Itoh