半绝缘GaAs电传输特性

半绝缘ＧａＡｓ是弛豫半导体，其电传输特性和通常的寿命半导体有所不同。对弛豫半导体和寿命半导体电特性的差异进行了介绍，并介绍了不同金属／半绝缘ＧａＡｓ接触结构的电传输特性。     

Electron-beam lithography in n+self-aligned GaAs MESFET fabrication

An electron-beam direct-writing technology for the fabrication of short-channel n⁺sef-aligned (SAINT) GaAs MESFET's is discussed. A four-level multiresist which includes a thin Mo layer is developed to avoid charging in the semi-insulating GaAs substrate. The alleviation of short channel effects is experimentally demonstrated by reducing the n⁺layer depth. A ring oscillator with a 0.3-µm-long gate SAINT FET shows a minimum propagation delay time of 16.7 ps with an associated power dissipation of 7.3 mW, which is one of the fastest among room-temperature semiconductor devices.     

Below 10 ps/gate operation with buried p-layer SAINT FETs

GaAs SAINT FETs with a p-layer buried under the active layer have achieved below 10 ps/gate (9.9 ps/gate) operation for the first time in semiconductor devices. The p-layer formed by Be+ implantation is completely depleted by the built-in potential. It has successfully alleviated the short channel effects without increasing parastic capacitance.     

Radiation-induced breakdown of a nonuniformly doped PN junction

A quasi-hydrodynamic model is developed for carrier transport under ionizing irradiation subject to the nonsteady-state thermal effect of the current on the semiconductor lattice. Computer simulations are run for the thermal breakdown of a nonuniformly doped pn junction caused by a pulse of ionizing radiation. The simulation model includes the temperature dependence of electron energy and momentum relaxation times and the suppression of impact ionization with increasing temperature. The simulation results are verified by comparison with previously reported experimental data.     

砷化镓类半导体材料在太赫兹波段的透射特性研究

首先给 出了利用光电导天线产生的太赫兹波的时域和频域光谱,进而,基于搭建的太赫 兹时域光谱系统, 并采用透射光谱法分别测量了砷化镓类型的三种半导体材料在太赫兹波段的透过率。结果表 明,基于光电导 天线产生的太赫兹波在0~2THz范围内,光谱比较稳定,频率带宽比 较宽;砷化镓半导体材料在0~2.0THz 范围内的透过率的变化相对较小,具有较高的透过率(>60%),并且 明显优于碲化锌以及碲化镉半导体 材料在太赫兹波段的透过率。因此,相比于碲化锌以及碲化镉半导体材料而言,砷化镓半导 体材料更适用于设计宽频带的太赫兹功能器件。     

红外GaAs液晶光阀一维等效电路模型分析

叙述了红外GaAs液晶光阀的工作原理和主要构成,并由此建立了红外GaAs液晶光阀一维等效电路模型,根据此模型着重分析光电导层GaAs的厚度对红外液晶光阀的红外调制动态范围、驱动频率和分辨率的影响,给出了部分相关曲线,得到最佳GaAs厚度范围。根据此模型计算出液晶光阀的结构参数,重新设计了液晶光阀并给出了部分实验结果。     

以Si为衬底GaAs异质外延工艺及其在半导体激光器中应用的研究进展

本文较系统地评述了 MOCVD 或 MBE 实现以 Si 为衬底 GaAs 异质外延工艺,及其在半导体激光器中应用的研究进展。叙述了以 Si 为衬底异质外延的工艺关键,使用 GaAs/Si 材料制备激光器的发展水平,降低外延层中位错密度和应力可能的方法。最后,介绍了该技术及其用于制备高性能激光器的发展动向。     

半绝缘GaAs光电导开关亚皮秒传输特性的研究

 本文应用Ensemble-Monte Carlo方法模拟了半绝缘GaAs(SI-GaAs)光电导开关基于Auston等效电路亚皮秒传输特性.从载流子在开关体内的动态特性出发,研究了光电导开关在飞秒激光脉冲触发下光电导传输特性、电介质弛豫特性、开关储能特性以及开关工作模式;分析了非线性光电导开关对光能阈值和偏置电场阈值要求的物理机制.     

Quantum mechanical simulation of charge transport in very smallsemiconductor structures

A quantum-mechanical simulation method of charge transport in very small semiconductor devices is presented that is based on the numerical solution of the time-dependent Schrodinger equation (coupled self-consistently to the Poisson equation to determine the electrostatic potential in the device). Carrier transport is considered within the effective mass approximation, while the effects of the electron-phonon interaction are included in an approximation that is consistent with the results of the perturbation theory and gives the correct two-point time correlation function. Numerical results for the transient behaviour of a planar ultrasubmicrometer three-dimensional GaAs MESFETs (gate length of 26 nm) are also presented. They indicate that extremely fast gate-step response times (switching times) characterize such short-channel GaAs devices     

Specific features of radiation-stimulated breakdown of a nonuniformly doped <Emphasis Type="Italic">p</Emphasis>-<Emphasis Type="Italic">n</Emphasis> junction

A quasi-hydrodynamic model of the transport of charge carriers under the ionizing effect of quantum radiation with the allowance made for the dynamics of heating of the semiconductor crystal by the flowing current is developed. Simulation of thermal breakdown of a nonuniformly doped p-n junction caused by a single radiation pulse is investigated. The variation in the times of relaxation of energy and pulse of electrons and suppression of the mechanism of impact ionization under the dynamic increase in the temperature of the semiconductor crystal is taken into account. The adequacy of the results of calculations is proved by comparing them with experimental data.     

Enhanced CAD model for gate leakage current in heterostructurefield effect transistors

A simple and accurate circuit model for Heterostructure Field Effect Transistors (HFETs) is proposed to simulate both the gate and the drain current characteristics accounting for hot-electron effects on gate current and the effect of the gate current on the channel current. An analytical equation that describes the effective electron temperature is developed in a simple form. This equation is suitable for implementation in circuit simulators. The model describes both the drain and gate currents at high gate bias voltages. It has been implemented in our circuit simulator AIM-Spice, and good agreement between simulated and measured results is achieved for enhancement-mode HFETs fabricated in different laboratories. The proposed equivalent circuit and model equations are applicable to other compound semiconductor FETs, i.e., GaAs MESFETs     

钝化介质层对功率GaAs MESFET的栅-漏击穿特性影响

用直接测定GaAs MESFET的栅-漏极电容-频率（C-f)和高频电容—电压（C-V）的方法,研究了钝化层—半导体界面的慢界面陷阱电荷对栅—漏反向击穿特性的影响,为解决GaAs MESFET的栅—漏反向击穿特性不良和不稳定提供了依据。     

Projected noise in submillimeter-wave mixers with InSb Schottky diodes

The reduction of the equivalent noise temperature in liquidnitrogen-cooled submillimeter-wave mixers by the use of Schottky barriers on InSb instead of GaAs is evaluated by an analytical model that assumes limited local oscillator power and matched impedances. The calculations, executed at 1.0 and 1.8 Thz, take plasma resonance and skin effect into account. For single and multiple contacts on homogeneous semiconductor materials of optimum doping, the noise of InSb diodes is smaller than that of GaAs diodes by a factor of 3 to 14. A simplified model is used to predict the performance of epitaxial structures as well as alternative materials.     

First 8*8 semiconductor optical matrix switches using GaAs/AlGaAs electro-optic guided-wave directional couplers

Monolithically integrated 8*8 semiconductor optical matrix switches have been successfully fabricated for the first time. They were constructed on GaAs from 64 GaAs/AlGaAs electro-optic directional couplers using a simplified tree architecture. The devices have a chip size of 26.5*3 mm/sup 2/ and a minimum total loss (excluding coupling loss) of 8.7 dB.<>     

Electron transit time of PIN photodiodes fabricated in two-valley semiconductors

Electron transit time was calculated for a PIN photodiode with the absorption layer realized in two-valley semiconductor (GaAs, InGaAs...). Non-stationary effects and changes of the electric field along the layer result in a dependence of the electron transit time on both the applied voltage and the thickness of the layer. This dependence shows marked maximum and minimum, which could be important when modelling the response times of PIN photodiodes fabricated in these materials.     

基于GaAs的新型稀磁半导体材料(Ga,Mn)As

介绍了一种基于 Ga As的新型稀磁半导体材料 ( Ga,Mn) As,包括 ( Ga,Mn) As的制备方法、结构特性、磁性质及磁输运性质。最后 ,展望了 ( Ga,Mn) As的应用前景     

Pulse and frequency response of a p-i-n photodiode with absorption layer fabricated in two-valley semiconductor

Starting from the transport equations of the phenomenological model for a two-valley semiconductor, we obtained the pulse response of a p-i-n photodiode with the absorption layer fabricated in a two-valley semiconductor (GaAs, InGaAs...). The pulse response was determined for the case when it was possible to linearize the transport equations. It was shown that the nonstationary effects influence significantly the intensity and speed of the response. The frequency response was obtained by applying the fast Fourier transform (FFT) to the pulse response.     

A new extraction method for noise sources and correlationcoefficient in MESFET

A new extraction method for noise sources and correlation coefficient in the noise equivalent circuit of GaAs metal semiconductor field effect transistor (MESFET) is proposed. It is based on the linear regression, which allows us to extract physically meaningful parameters from the measurement in a systematic and straightforward way. The confidence level of the measured data can also be easily examined from the linearity, y-intercept of the linear regression, and the scattering from the regression line. Furthermore, it is found that the time constant of correlation coefficient whose value is almost the same as that of the transconductance should be considered to model noise parameters accurately. The calculated values of minimum noise figure, optimum impedance, and noise resistance using above approach, show excellent agreement with measurement for a typical MESFET device studied in this paper     

Device and material properties of pseudomorphic HEMT structuressubjected to rapid thermal annealing

The device-related effects of rapid thermal annealing (RTA) on the electrical and optical properties of planar-doped AlGaAs/InGaAs/GaAs high-electron-mobility transistor structures grown by molecular beam epitaxy were investigated. Specifically, electrical and optical characterization techniques such as capacitance versus voltage, current versus voltage, Hall effect, and photoluminescence have been applied to study the effects that typical III-V compound semiconductor rapid thermal processes (RTPs) have on the properties of pseudomorphic AlGaAs/InGaAs/GaAs structures for two different values of In mole fraction content. The effect and stability of the indium mole fraction on both heterostructure and device integrity with respect to RTA schedule has been investigated in detail     

半导体量子点最低导带态的量子限制效应

采用最新计算方法和半导体体材料传统量子计算结果,系统研究了14种半导体(Si,Ge,Sn,AlSb,GaP,GaAs,GaSb,InP,InAs,InSb,ZnS,ZnSe,ZnTe,CdTe)的立方量子点,得到了最低导带态的量子限制效应结果,我们把量子点对尺寸的依赖关系分为三类并详细讨论了它们的差别。