微波器件失效率快速试验方法研究

介绍了微波低噪声GaAs FET恒定应力加速寿命试验结果,沟道温度T_(ch)为145℃时,平均寿命MTTF为9.64×10~6h,最主要的失效模式是源漏饱和电流I_(DSS)退化降低。建立了表征GaAs FET稳定性的敏感参数I_(DSS)的退化模型InP=a+blnt,分析了I_(DSS)退化与温度应力的加速关系。提出了快速推断器件可靠性的建议。     

Evaluation of Qbd for electrons tunneling fromthe Si/SiO2 interface compared to electron tunneling from thepoly-Si/SiO2 interface

Electrical time-to-breakdown (TTB) measurements have shown the charge to breakdown Q_bd of gate oxide capacitors fabricated on n-type well (n-well) substrates always to be higher than that of capacitors on p-type well (p-well) substrates on the same wafer when both are biased into accumulation under normal test conditions. Here the authors correlate the higher n-well Q_bd to smooth capacitor oxide/substrate interfaces and minimized grain boundary cusps at the poly-Si gate/oxide interfaces, confirming that Fowler-Nordheim tunneling is the dominant current conduction mechanisms through the oxide. They correlate higher Q_bd to higher barrier height for a given substrate type and observe that the slope of the barrier height versus temperature plot is lower for both p-well and n-well cases with electrons tunneling from the silicon substrate. This is attributed to surface roughness at the poly-Si gate/SiO₂ interface. A poly-Si gate deposition and annealing process with clean, smooth oxide/substrate interfaces will improve the p-well breakdown characteristics and allow higher Q_bd to be achieved     

色噪声背景下正弦参量估计的互谱矩和SVD方法

互谱估计方法是用于色噪声背景下正弦信号参量估计的一个十分有效的方法。但以往互谱估计都是采用FFT方法和互周期图法。本文首次将现代谱估计方法引入到互谱估计中,从理论上建立了互相关函数的Yule-Walker方程,并在此基础上进而提出了互谱估计的矩估计法和SVD方法。给出了仿真实例结果。     

The base current degradation of poly-emitter BJTs under AC stress

A simple model for the analysis of the ac stress effect in poly-emitter bipolar transistors is presented. Apart from the reverse-bias induced hot-carrier effects, the forward-bias recovery effect is a key factor under ac stress, it obviously suppresses the base current degradation of the device which is caused during the reverse-bias periods. In this work, we derived the relationship between the excess base current and the stress time for different ac stress conditions. This model is verified with experimental results.<>     

提高砷化镓功率MMIC中电容成品率的研究

金属－绝缘体－金属（ＭＩＭ）电容量影响ＧａＡｓ微波单元集成电路（ＭＭＩＣ）成品率的主要原因之一，ＰＥＣＶＤ氮化硅膜又是影响ＭＩＭ电容质量和成品率的主要因素。本文通过实验和分析，提出了提高氮化硅膜质量和减少薄膜针孔的方法，结果大大提高了ＭＩＭ电容ＧａＡｓＭＭＩＣ的成品率，降低了ＧａＡｓ ＭＭＩＣ的成本。     

PBX技术.市态.营销.选购

本文介绍了ＰＢＸ交换机的技术及市场需求态势。并提出ＰＢＸ产品的营销要素及其用户在选购时应遵循的原则。     

二极管泵浦的微型绿光激光器

本文介绍一种二极管泵浦的Nd:YAG+KTP微型绿光激光器,单纵模532μm的绿色激光输出5.6mW,无“绿色噪声”,器件体积为36mm×32mm×26mm.     

散射物体全息照片的显微结构与拍摄参数的选择

文章披露了全息光栅，散射物体的离轴全息和彩虹全息图片，在５０００倍电子显微镜下的照片，并从理论上解释了它们的显微结构。指出它们是散射物体在干板上的菲涅尔变换频谱与以考光相干涉的结果。指出这种显微结构是散射物体全息照片衍射效率低于全息光栅的根本原因，并提出了改进拍摄办法。以增加衍射效率和提高信噪比。     

STATE VERIFICATION FOR SYNCHRONOUS CIRCUITS

This paper presents the techniques of implicit traversing and state verification for sequential finite state machines(FSMs) based of on the state collapsing of state transition graph(STG). The problems of state designing are described. In order to achieve high state enumeration coverage, heuristic knowledge is proposed.     

真空微二极管发射特性的解析解

通过保角变换方法，对具有椭圆锥形发射体的真空微电子二极管进行了研究，求得了二极管区域内电位分布和电场分布的解析表达式，进而得到了电场强度和场致发射电流密度与尖端曲率之间的关系．