低光能触发的砷化镓光导开关导通机理  

Operating Mechanism of Low-Energy-Triggered Gallium Arsenide Photoconductive Semiconductor Switch

作　　者：徐守利 刘京亮 胡龙 倪涛 许春良 Xu Shouli;Liu Jingliang;Hu Long;Ni Tao;Xu Chunliang(The 13th Research Institute China Electronics Technology Group Corporation,Shijiazhuang 050050 China;School of Electronic Science and Engineering Xi’an Jiaotong University,Xi’an 710049 China)

机构地区：[1]中国电子科技集团公司第十三研究所,石家庄050050 [2]西安交通大学电子科学与工程学院,西安710049

出　　处：《电工技术学报》2023年第22期6241-6252,共12页Transactions of China Electrotechnical Society

基　　金：国家自然科学基金(52177156);强脉冲辐射环境模拟与效应国家重点实验室开放课题(SKLIPR2004)资助项目。

摘　　要：该文建立了砷化镓(GaAs)光导开关(PCSS)的一维器件仿真模型,研究了低光能触发条件下电流通道内关键物理参数的瞬态变化过程,提出了GaAs PCSS的多雪崩电离畴物理模型,能够自洽地解释低光能触发、超快速导通和电压锁定等开关特征。GaAsPCSS受12 W、905 nm脉冲激光触发后,电流通道内产生多个高场强(200~600 kV/cm)雪崩电离畴,雪崩电离畴随等离子体浓度的提高而发展、湮灭,导致开关延迟3.0 ns后在147 ps内超快速导通。开关导通后,电流通道内仍存在少量雪崩电离畴,使开关导通后电压锁定。雪崩电离畴运动导致GaAs PCSS工作时出现ps级电流振荡现象,分析了振荡信号产生的物理原因。同时,开展了低光能触发条件下GaAs PCSS雪崩导通实验研究。结果表明,当采用50?固态脉冲形成线、4 mm间距异面结构、PCSS工作电压为17.5 kV时,负载输出脉冲峰值功率达MW级,脉冲上升时间约为620ps,最高重频达到20 kHz。High repetitive ultrawide band pulse possesses wide application prospect to civil and military fields,whose key parameters are decided by prosperities of the pulsed power semiconductor device.Gallium arsenide(GaAs)photoconductive semiconductor switch(PCSS)in avalanche mode based on semi-insulating(SI)wafer possesses properties of low-energy triggering,high voltage and ultrafast switching.The ultrawide band generator based on GaAs PCSS can achieve miniaturization,modularization and array.For decades,there were several theories explaining the phenomena in the avalanche PCSS with consideration of field-dependent trapping of charge carriers,deep impurity ionization,double injection,avalanche injection,localized impact ionization,streamer formation,collective impact ionization,and photo-activated charge domain.However,the operation mechanism,especially the lock-on effect,of the GaAs PCSS in the avalanche mode is still unclear.Operating mechanism of low-energy-triggered GaAs PCSS was analyzed using a one-dimensional physics-based numerical simulation.The transient process of physical parameters in filament was discussed.The physics of multiple avalanche domains as the operating mechanism of the PCSS in avalanche mode was described,which leads to characteristics of low-energy triggering,ultrafast switching and voltage locking of the switch.When a 905-nm optical pulse with the power of 12 W triggered the PCSS from cathode,the switch reached a high conducting state in 147 ps after a delay time of 3.0 ns,and then turn-on voltage across the PCSS was locked at an electric field of about 3.9 kV/cm due to existing of residual avalanche domains in filament.The transient process can be divided into three stages containing delay,ultrafast switching and votage locking.In the delay stage,the intrinsic positive feedback causes formation of multiple avalanche domains and dense electron-hole plasma.In the ultrafast switching stage,the increase of plasma density leads to the increase of domain field and drastic domain shrinkage that re

关 键 词：脉冲功率 光导开关 雪崩电离畴 低光能触发 亚纳秒 

分 类 号：TM89[电气工程—高电压与绝缘技术]