An object is to provide a semiconductor device of which a manufacturing process is not complicated and by which cost can be suppressed, by forming a thin film transistor using an oxide semiconductor film typified by zinc oxide, and a manufacturing method thereof. For the semiconductor device, a gate electrode is formed over a substrate; a gate insulating film is formed covering the gate electrode; an oxide semiconductor film is formed over the gate insulating film; and a first conductive film and a second conductive film are formed over the oxide semiconductor film. The oxide semiconductor film has at least a crystallized region in a channel region.

Semiconductor device, and manufacturing method thereof

The present disclosure relates to a semiconductor light emitting device, comprising: a plurality of semiconductor layers, including a first semiconductor layer having a first conductivity, a second semiconductor layer having a second conductivity different from the first conductivity, and an active layer interposed between the first semiconductor layer and the second semiconductor layer, generating light via electron-hole recombination; a first electrode, supplying either electrons or holes to the plurality of semiconductor layers; a second electrode, supplying, to the plurality of semiconductor layers, electrons if the holes are supplied by the first electrode, or holes if the electrons are supplied by the first electrode; a non-conductive distributed bragg reflector coupled to the plurality of semiconductor layers, reflecting the light from the active layer; and a first light-transmitting film coupled to the distributed bragg reflector from a side opposite to the plurality of semiconductor layers with respect to the non-conductive distributed bragg reflector, with the first light-transmitting film having a refractive index lower than an effective refractive index of the distributed bragg reflector.

Semiconductor Light Emitting Device

The density-matrix theory of semiconductor lasers with relaxation broadening model is finally established by introducing theoretical dipole moment into previously developed treatments. The dipole moment is given theoretically by the k . p method and is calculated for various semiconductor materials. As a result, gain and gain-suppression for a variety of crystals covering wide wavelength region are calculated. It is found that the linear gain is larger for longer wavelength lasers and that the gain-suppression is much larger for longer wavelength lasers, which results in that single-mode operation is more stable in long-wavelength lasers than in shorter-wavelength lasers, in good agreement with the experiments.

Density-matrix theory of semiconductor lasers with relaxation broadening model - Gain and gain-suppression in semiconductor lasers

The present disclosure relates to a semiconductor light-emitting element, which comprises: a first light-emitting part, a second light-emitting part, and a third light-emitting part, wherein each of the light-emitting parts includes multiple semiconductor layers including a first semiconductor layer, an active layer, and a second semiconductor layer, laminated in sequence, the first semiconductor layer having a first conductivity, the active layer generating light through the recombination of an electron and a hole, and the second semiconductor layer having a second conductivity different from the first conductivity; a non-conductive reflecting film which is formed to cover the multiple semiconductor layers and reflects light generated from the active layer; a first electrode which is provided to electrically communicate with the first semiconductor layer of the first light-emitting part and which supplies one of an electron and a hole; a second electrode which is provided to electrically communicate with the second semiconductor layer of the second light-emitting part and which supplies the other of the electron and the hole; and an auxiliary pad formed on the non-conductive reflecting film which covers the third light-emitting part.

Semiconductor light emitting element

High-speed optoelectronic devices having a waveguide densely integrated with and efficiently coupled to a photodetector are fabricated utilizing methods generally compatible with CMOS processing techniques. In various implementations, the waveguide consists essentially of single-crystal silicon and the photodetector contains, or consists essentially of, epitaxially grown germanium or a silicon-germanium alloy having a germanium concentration exceeding about 90%.

Vertically-integrated waveguide photodetector apparatus and related coupling methods

A semiconductor optical device includes a semiconductor laser region for producing laser light and having a first optical waveguide mesa structure including a first active layer and a diffraction grating, and first current blocking layers adjacent to opposite sides; a light modulator region for modulating the laser light and having a second optical waveguide mesa structure continuous with the first optical waveguide mesa structure and including a second active layer, and second current blocking layers adjacent to opposite sides; and a window region for propagating the laser light modulated by the light modulator region and having a mesa-shaped window structure continuous with the second optical waveguide mesa structure, the mesa width of the window structure being larger than the mesa width of the second optical waveguide mesa structure. The light is prevented from leaking from the window and reaching the interface of the window structure and a burying layer adjacent to the window structure. The laser light is not reflected at the interface of the window structure and the buried layer. The shape of the beam of laser light emitted from the window structure is not distorted, resulting in a satisfactory connection to an optical system.

Semiconductor optical device

A 1.3-/spl mu/m AlGaInAs multiquantum well ridge waveguide distributed feedback laser diode was developed. By forming n-InGaAsP grating in the n-InP cladding layer close to the active region, accumulation of the holes in the grating layer was reduced and over 5 mW of output power was obtained at 120/spl deg/C. Clear eye opening was confirmed with no mask hits for OC-192 under 10-Gb/s direct modulation at the temperature up to 120/spl deg/C.

120/spl deg/C 10-gb/s uncooled direct Modulated 1.3-/spl mu/m AlGaInAs MQW DFB laser diodes

A semiconductor laser device includes a semiconductor laser chip containing a diode having a polarity; a heat sink on which the semiconductor laser chip is mounted at an interface of the semiconductor laser chip and the heat sink, the heat sink including a pn junction generally parallel to the interface; and a block on which the heat sink is mounted, wherein the diode of the semiconductor laser chip and the pn junction are electrically connected in parallel and in opposite polarity so that the pn junction of the heat sink functions as a reverse current blocking diode for the semiconductor laser chip.

Semiconductor laser device including heat sink with pn junction

A small-chirp 40-Gbps electroabsorption modulator (EAM) with high optical output power capability has been developed for the first time. An optimized tensile-strained asymmetric quantum-well structure is employed as the absorption layer of the EAM so that small chirp and reduction of the lifetime of the photogenerated holes for high optical output power tolerance is obtained. Deteriorations of frequency response and chirp due to carrier pileup under high optical output power conditions were prevented by enhancing carrier sweepout, which was experimentally confirmed as a hole lifetime as short as 35 ps under high optical output power conditions. As a result, good frequency response (bandwidth > 30 GHz) and small chirp (/spl alpha/<1) were obtained under the condition of the zero bias voltage and +4.5 dBm continuous-wave (CW) optical output power (P/sub out,CW/). Clear eye opening and high dynamic extinction ratio under 40-Gbps non-return-to-zero modulation persisted to a high average output power (P/sub out,ave/) condition of P/sub out,ave/=+1.0 dBm.

dBm average optical output power operation of small-chirp 40-gbps electroabsorption Modulator with tensile-strained asymmetric quantum-well absorption Layer

An integrated semiconductor laser-modulator device less affected by a fluctuating electric field due to modulating signals applied to the modulator has improved frequency characteristics The integrated semiconductor laser-modulator includes an active layer, a beam waveguide layer having a bulk structure with a bandgap energy larger than that of the active layer but smaller than that of a laser beam absorption layer having a bulk structure, wherein waveguides of the laser and modulator are connected and aligned, and a cladding layer including a diffraction grating is disposed on top of or beneath the waveguides

Kazuhisa Takagi

Papers

Semiconductor optical device

120/spl deg/C 10-gb/s uncooled direct Modulated 1.3-/spl mu/m AlGaInAs MQW DFB laser diodes

Semiconductor laser device including heat sink with pn junction

dBm average optical output power operation of small-chirp 40-gbps electroabsorption Modulator with tensile-strained asymmetric quantum-well absorption Layer

Method of manufacturing an integrated semiconductor laser-modulator device