简介:针对抗辐照SOIPMOS器件的直流特性与低频噪声特性展开试验与理论研究,分析离子注入工艺对PMOS器件电学性能的影响,并预测其稳定性的变化。首先,对离子注入前后PMOS器件的阈值电压、迁移率和亚阈摆幅进行提取。测量结果表明:埋氧化层离子注入后,器件背栅阈值电压由-43.39V变为-39.2V,空穴有效迁移率由127.37cm2/Vs降低为80.45cm2/Vs,亚阈摆幅由1.35V/dec增长为1.69V/dec;结合背栅阈值电压与亚阈摆幅的变化,提取得到埋氧化层内电子陷阱与背栅界面态数量的变化。随后,分析器件沟道电流噪声功率谱密度随频率、沟道电流的变化,提取γ因子与平带电压噪声功率谱密度,由此计算得到背栅界面附近的缺陷态密度。基于电荷隧穿机制,提取离子注入前后埋氧化层内陷阱态随空间分布的变化。最后,基于迁移率随机涨落机制,提取得到离子注入前后PMOS器件的平均霍格因子由6.19×10-5增长为2.07×10-2,这表明离子注入后器件背栅界面本征电性能与应力稳定性将变差。
简介:提出了一种积累型槽栅超势垒二极管,该二极管采用N型积累型MOSFET,通过MOSFET的体效应作用降低二极管势垒。当外加很小的正向电压时,在N+区下方以及栅氧化层和N-区界面处形成电子积累的薄层,形成电子电流,进一步降低二极管正向压降;随着外加电压增大,P+区、N-外延区和N+衬底构成的PIN二极管开启,提供大电流。反向阻断时,MOSFET截止,PN结快速耗尽,利用反偏PN结来承担反向耐压。N型积累型MOSFET沟道长度由N+区和N外延区间的N-区长度决定。仿真结果表明,在相同外延层厚度和浓度下,该结构器件的开启电压约为0.23V,远低于普通PIN二极管的开启电压,较肖特基二极管的开启电压降低约30%,泄漏电流比肖特基二极管小近50倍。
简介:Acompactammoniagassensorwithtwogaschambersisproposedinthispaper,whosecoresensingdeviceisaU-bendingmicroringresonator.Thewaveguidesofringpartandfeedbackpartinthisresonatoraremadeofsilicononinsulator(SOI)ridgewaveguidecoveredwithZnOnanocrystalswhicharesensitivetoammoniagas.Thesensorcanmeasuretwogroupsofgassamplessimultaneously.Bycomputersimulation,weobtaintheclearsensitivitycurvesoftwogaschambersinammoniasensorwhenthegasconcentrationincreasesfrom0to4‰.Thegasconcentrationsintwochamberscanbeobtainedfromoneoutputspectrum,whichsignificantlyreducesthematerialandtimeconsumption.
简介:AnovelopticalfibersensorwithaU-shapedmicro-groovestructureablatedbyfemtosecondlaseronsingle-modefi-berformeasuringairrelativehumidity(RH)isreportedinthispaper.Inordertoimprovetheaccuracyofsensor,agrapheneoxide(GO)/polyvinylalcohol(PVA)compositefilmiscoatedonthesurfaceofmicro-groovestructure.IntheU-shapedmicro-groovestructure,theremainingcoreandmicro-cavityinthemicro-groovemakeuptwomajorop-ticalpropagationpaths,formingaMach-Zehnderinterferometer(MZI).ThesensorhasagoodlinearresponsewithintheRHrangeof30%--85%,andthemaximumsensitivitycanreach0.6381mrd%RH.Theeffectoftemperatureontheoverallperformanceofthehumiditysensorisalsoinvestigated.Asanewtypeofall-fiberdevice,thesensorshowsexcellentsensitivityandstability.
简介:发光二极管(LED)具有非常广泛的用途,光子晶体(PC)是一种新概念和新材料,采用PC的LED则大大提高了光输出效率,是一种很有发展前途的LED器件,已成为目前国内外研究的热点.本文介绍了PCLED的基本原理、结构、重要特性参数及其典型器件.