一种快速精确的GaAs MESFET寄生参数提取方法

提出了一种快速精确地提取GaAs MESFET寄生参数方法．这种方法以两组S参数为基础,应用解析表达式直接确定GaAs MESFET的九个寄生参数．该方法适用范围广．以一个0.3μｍ×280μｍ商用器件的一组寄生参数为基础,对该方法进行了验证．     

一种快速精确的GaAs MESFET寄生参数提取方法

提出了一种快速精确地提取GaAs MESFET寄生参数方法.这种方法以两组S参数为基础,应用解析表达式直接确定GaAs MESFET的九个寄生参数.该方法适用范围广.以一个0.3μm×280μm商用器件的一组寄生参数为基础,对该方法进行了验证.     

GaAs MESFET的背栅效应研究

本文着重研究了分立GaAc耗尽型MESFET背栅效应的光敏性和尺寸效应。本文还采用一种实验方法——器件在光照下,观察栅压的调制作用,解释了背栅效应机理。不同栅压下,背栅效应的大小不同,零栅压下的背栅效应比负栅偏压下的背栅效应更小。发现衬底峰值电流与背栅效应有密切关系。     

GaAs MESFET中的背栅效应

随着集成电路集成度的提高,器件间距不断减小,在GaAs MESFET中产生了一种被称为背栅效应的有害寄生效应。由于器件间距越来越小,某一个器件的电极可能就是另一个器件的背栅,背栅效应影响了集成电路集成度的提高,因此背栅效应在国内外引起了重视。本文介绍了背栅效应及其可能的起因。     

GaAs MESFET栅的取向效应——Ⅱ.实验

研究了(100)GaAs衬底上,离子注入自对准 WSi_x栅 GaAs MESFET的阈值电压漂移与栅长和取向的关系。当栅长小于2μm时,栅不同取向的阈值电压差别很大.本文同样将解析模型与已有的(111)GaAs衬底的实验进行了比较.结果表明解析模型与实验符合较好.     

GaAs MESFET的压力敏感特性

本文研究了ＧａＡｓ ＭＥＳＦＥＴ对应力的敏感特性，分析了敏感原理。对ＧａＡｓ ＭＥＳＦＥＴ用作力学量传感器的可能性进行了讨论。     

旁栅效应对GaAs MESFET数字IC设计的影响

研究了不同旁栅电极结构、不同旁栅电极取向对旁栅阈值特性的影响，并研究了旁栅阈值的光敏特性．结果表明：半绝缘衬底中的电子和空穴陷阱是旁栅效应及其光敏特性的主要原因，Ti/Au/Ti布线金属做旁栅电极具有最好的旁栅阈值特性，Au/Ge/Ni/Au欧姆接触和Ti/Pt/Au/Ti栅金属的旁栅阈值特性相似，三者都有明显的光敏特性．上述结果为GaAs MESFET数字集成电路版图设计规则的制定提供了可靠依据．     

旁栅效应对GaAs MESFET数字IC设计的影响

研究了不同旁栅电极结构、不同旁栅电极取向对旁栅阈值特性的影响,并研究了旁栅阈值的光敏特性.结果表明:半绝缘衬底中的电子和空穴陷阱是旁栅效应及其光敏特性的主要原因,Ti/Au/Ti布线金属做旁栅电极具有最好的旁栅阈值特性,Au/Ge/Ni/Au欧姆接触和Ti/Pt/Au/Ti栅金属的旁栅阈值特性相似,三者都有明显的光敏特性.上述结果为GaAs MESFET数字集成电路版图设计规则的制定提供了可靠依据.     

GaAs MESFET旁栅效应与旁栅距的关系研究

旁栅效应是影响GaAs器件及电路性能的有害寄生效应。本文研究了旁栅阈植电压V^thsSG与旁栅距LSG的关系,发现V^thSG的大小与LSG成正比关系,并理论探讨了产生这一现象的机制,从而验证了旁栅阈值电压电旁栅距关系的有关理论。     

a-Si∶HTFT的寄生效应

a- Si∶ H TFT的栅源几何交迭会引起几何寄生电容 ,实验研究表明它并不能完全表征 TFT的寄生效应 ,研究发现由栅极和源极形成的电场的电力线交迭也会导致物理寄生效应且这种效应始终存在 .从 L CD的结构、材料、制备工艺等普遍性出发 ,依据交迭电力线建立了物理寄生效应模型并对其进行了详细的分析和计算 ,实验结果表明该方法是有效可行的 ,从而使 L CD寄生效应有了一个较完美的理论表征和分析计算方法.     

GaAs MESFET开关模型的研究

讨论了开关 Ga As MESFET的开态模型和关态模型 ,介绍了利用高频器件建模软件 Modelling建立 Ga As MESFET开关模型的方法 ,给出了模型模拟与器件测量的曲线和模型参数。     

Feedback Effects in the GaAs MESFET Model (Letters)

GaAs MESFET models correctly predict a positive feedback conductance. The effect of common-lead inductance on Y/sub 12/ rising computer modeling techniques is examined. Experimental data are also included which indicate that the common-lead inductance of about 0.06 nH cannot be omitted from the model in order to accurately predict the feedback conductance.     

SiC MESFET技术与器件性能

介绍了SiC MESFET器件的技术和性能。用SiC材料制造的MESFET的射频功率密度达到4.6W/mm，功率增加效率（PAE）达到65.7%，击穿电压超过100V，表明SiC器件具有高功率密度和高效率，在高功率微波应用中具有巨大的潜力。     

基于物理的GaAs MESFET模型参数计算

根据材料性能和物理结构参数近似计算 Ga As MESF ET等效电路模型参数 ,并给出等效电路参数随物理参数的变化曲线。     

Parasitic MESFET in (Al, Ga) As/GaAs modulation doped FET's and MODFET characterization

A charge-control model for n-channel modulation doped FET's (MODFET's) is extended to include the drain-to-source current through the doped (Al, Ga)As layer which becomes important for large positive gate voltages. This parasitic conduction leads to decreased device transconductances at high gate voltages. A unified and complete characterization technique for deducing the parameters of our model is introduced and used for the device characterization. Parameters, e.g., the saturation velocity, two-dimensional gas concentration at equilibrium, thickness of the doped (Al, Ga)As layer, etc., deduced using the model, are in good agreement with the independent calculations and measurements. However, the deduced values of the room-temperature low field mobility of the two-dimensional electron gas are considerably smaller than those measured by Hall effect and in long-gate MODFET's. This model is in good agreement with the characteristics of high-current normally on MODFET's. The maximum measured current swing of 300 mA/mm gate is reported.     

GaAsMESFET和DHEMT的中子辐射效应研究

本文介绍了ＧａＡｓＭＥＳＦＥＴ和ＨＥＭＴ的中子辐射效应。依据中子辐射损伤机理，分析了器件参数与中子辐射剂量Φ的依从关系，其中，器件参数包括物理参数Ｎ＿Ｄ、Ｎ＿ｓ、Ｖ＿ｓ，μ和电参数Ｉ＿ＤＳ、ｇ＿ｍ、Ｖ＿ｐ、Ｇ等。     

Effect of carrier injection into MESFET substrates : comparison of MESFET on a semi-insulating buffer,MESFET on a P substrate,and substrate-less MESFET

The carrier injection from the active-layer of the submicron-gate-lengthMesfet into the buffer-layer, or substrate in general, is studied by means of a two-dimensional computer simulation in which the energy conservation equation is simultaneously solved with the carrier conservation equation and Poisson’s equation. The mobility, electron temperature and energy relaxation time are treated as energy dependent parameters. This model is capable of simulating the non-stationary conditions associated with the submicron-gate-length devices. The effect of the carrier injection on the I-V characteristics as well as on the small-signal parameters is investigated by simulating twoMesfet structures; the first is aMesfet on a perfect buffer-layer while the second is a symmetricalMesfet which has no substrate. It is found out that the drain current is increased by the carrier injection, whereas the transconductance is reduced due to the increase of the device dynamic range. TheMesfet with an interfacial potential barrier is also simulated. It exhibits characteristics intermediate between those of the other two devices.     

机载雷达探地及其特性分析

针对机载雷达探地时的不同背景噪音情况,讨论了雷达杂波对雷达接收机工作的影响,分析了常规雷达在毫米波波段,信杂比、信噪比、杂噪比和信号杂波噪声比与雷达工作频率、雷达方位角、俯仰角的关系,根据雷达分辨率和工作频率的不同,推导了具体公式.在给定有关参数的前提下,给出这些量随距离变化的关系曲线,得知不同比值随距离的增加是逐渐下降的,而且杂波和噪声对目标信号产生同样的影响.在低分辨率雷达情况下,地杂波的影响是主要的.