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 spectrum of an intensity modulated (IM) and a combined intensity-frequency modulated (IM-FM) monochromatic light source has been generated. The amplitudes of the modulated carrier and the first three pairs of sidebands are plotted showing the influence of IM on an FM signal. The effects of first order chromatic dispersion on the baseband amplitude response and harmonic distortion are determined. The manner in which modulation type and depth, modulating frequency, wavelength, and fiber length alter harmonic distortion is presented. Numerical examples giving the amplitude response of a single-mode fiber system as well as the magnitude of the second- and third-harmonic distortion caused by chromatic dispersion are presented. Based on this material, the limits placed on analog transmission due to chromatic dispersion may be assessed.

Chromatic dispersion induced distortion of modulated monochromatic light employing direct detection

A power system having a power converter with an adaptive controller. The power system is coupled to a load and includes a power system controller that receives a signal indicating a system operational state of the load and selects a power converter operational state as a function thereof. The power system also includes a power converter with a power switch that conducts for a duty cycle to provide a regulated output characteristic at an output thereof. The power converter also includes a controller that receives a command from the power system controller to enter the power converter operational state and provides a signal to control the duty cycle of the power switch as a function of the output characteristic and in accordance with the command, thereby regulating an internal operating characteristic of the power converter to improve an operating efficiency thereof as a function of the system operational state.

Power system with power converters having an adaptive controller

Results on crystal orientation dependence of n‐ and p‐type Si doping in molecular beam epitaxial GaAs are presented. High electron and hole mobilities in AlGaAs/GaAs heterostructures on high index planes are demonstrated for the first time. The doping results should prove useful for various transistor structures and complementary circuits. Also, due to the differences in the band structure for different orientations, quantum well heterostructures are likely to exhibit many interesting phenomena which are strongly orientation dependent.

Crystal orientation dependence of silicon doping in molecular beam epitaxial AlGaAs/GaAs heterostructures

Some embodiments of a task responsibility system may be implemented as an application to support people, machines, or both functioning in a manufacturing or production environment, warehouse environment, or other work environment. The focus is on a plant-local solution. In such circumstances, the task responsibility system may identify and direct one or more tasks to a computer-implemented folder independent of the worker(s), machine(s), or a combination thereof assigned to the folder. Thus, the system (or a user of the system) is permitted to dynamically assign a worker or machine to the computer-implemented folder subsequent to the tasks being directed thereto, in which case the worker or machine may be responsible for the tasks that are directed to the folder.

Task responsibility system

High transconductance vertical FETs are produced in III-V epitaxially grown layers doped n, p and n, with the in-between submicron (0.15 μm) layer serving as the FET channel. The layer on the drain side of the channel may be thicker (3 μm) than on the source side (1.5 μm). The structure is V-grooved to expose a nearly vertical surface that is Si implanted or regrown with graded n-type GaAs/GaAlAs before a gate contact is deposited on the vertical structure. An alternative to employ a heterostructure with GaAlAs layers for the source and drain, and GaAs for the channel layer. Graded GaAs/GaAlAs is then selectively regrown in the channel layer.

Vertical Schottky barrier gate field-effect transistor in GaAs/GaAlAs

An eight‐element phase‐locked array of index‐guided separate confinement ridge AlGaAs diode lasers is fabricated. In this array the absorption of light in the region between lasers is negligible and the gain profile across the array is nearly uniform. Unlike most other arrays, this array oscillates in its fundamental mode. Stable radiation patterns of near diffraction‐limited single narrow beam with 1.6° width are obtained. The beam width approaches the theoretical limit for the present array structure.

Fundamental mode oscillation of a buried ridge waveguide laser array

The phase‐locking characteristics of two coupled, ridge waveguide InP/InGaAsP diode lasers emitting at 1.2 μm were investigated experimentally. The phase locking of the lasers was verified by the observation of phase‐locked modes (supermodes) in the spectrally resolved near fields and distinct diffraction patterns in the far field. By independent control of the laser currents it was possible to vary continuously the mutual phase shift between the two phase‐locked lasers and thus steer the far‐field diffraction lobes. In addition, the separate current control could be utilized to obtain single longitudinal mode oscillation of the phase‐locked lasers. Variation in one of the laser currents resulted then in tuning of the wavelength of this single mode over a range of 90 A.

/pdf/phase-locking-characteristics-of-coupled-ridge-waveguide-inp-2cuw7tzo32.pdf

Phase-locking characteristics of coupled ridge-waveguide InP/InGaAsP diode lasers

Phase‐locked arrays of buried‐ridge InP/InGaAsP lasers, emitting at 1.3 μm, were grown by liquid phase epitaxy. The arrays consist of index‐guided, buried‐ridge lasers which are coupled via their evanescent optical fields. This index‐guided structure makes it possible to avoid the occurrence of lower gain in the interchannel regions. As a result, the buried‐ridge arrays oscillate mainly in the fundamental supermode, which yields single lobed, narrow far‐field patterns. Single lobed beams less than 4° in width were obtained from buried‐ridge InP/InGaAsP phased arrays up to more than twice the threshold current.

/pdf/phased-arrays-of-buried-ridge-inp-ingaasp-diode-lasers-1ico47ek6p.pdf

Phased arrays of buried‐ridge InP/InGaAsP diode lasers

Phased-locked arrays of buried-ridge InP/InGaAsP diode lasers, emitting at 1.3 μm, were investigated both theoretically and experimentally. These arrays consist of index-guided buried-ridge lasers which are coupled via their evanescent optical fields. The field patterns and the modal gains of the array supermodes were calculated by using a simple waveguide model. The theoretical results show that buried-ridge arrays can be designed such that only the fundamental supermode is excited. In that case, the array lasers are coupled in-phase, which yields single-lobed, diffraction limited far-field patterns. The buried-ridge InP/InGaAsP arrays were grown by liquid phase epitaxy. These arrays exhibited single-lobed beams less than 4° in width up to more than twice the threshold current. Comparison of the measured field patterns and the calculated ones indicated that these arrays oscillated mainly in the fundamental supermode.

Z. Rav-Noy

Papers

Vertical Schottky barrier gate field-effect transistor in GaAs/GaAlAs

Fundamental mode oscillation of a buried ridge waveguide laser array

Phase-locking characteristics of coupled ridge-waveguide InP/InGaAsP diode lasers

Phased arrays of buried‐ridge InP/InGaAsP diode lasers

Phase-locked arrays of buried-ridge InP/InGaAsP diode lasers