GaAs PHEMT器件的退化特性及可靠性表征方法  

Device Degradation and Reliability Characterization in GaAs PHEMT's

作　　者：刘红侠[1] 郑雪峰[1] 郝跃[1] 韩晓亮[1] 李培咸[1] 张绵[2] 

机构地区：[1]西安电子科技大学微电子研究所,西安710071 [2]中国电子科技集团公司第十三研究所,石家庄050002

出　　处：《Journal of Semiconductors》2004年第1期77-81,共5页半导体学报（英文版）

基　　金：国家自然科学基金 (批准号 :60 2 0 60 0 6);国防预研基金 (批准号 :0 0 J8.4.3 DZ0 1)资助项目~~

摘　　要：测量了应力前后 Ga As PHEMT器件电特性的退化 ,指出了 Ga As PHEMT阈值电压的退化由两个原因引起 .栅极下 Al Ga As层深能级的空穴积累可以解释阈值电压漂移中暂时性的、可恢复的那部分 ,积累在栅金属与半导体之间界面层的空穴可以解释阈值电压漂移中永久性的漂移 .空穴积累来源于场助作用下电子的退陷和沟道中碰撞电离产生的空穴向栅极流动时被俘获 .对高场下碰撞电离率的实验曲线进行拟合 ,得到碰撞电离率与器件沟道电场峰值的量化关系 ,可以对 Ga AsThe electric characteristics in GaAs PHEMT's are measured before and after stress.The shift of threshold voltage in GaAs PHEMT's is caused by two reasons.The temporary shift of threshold voltage is due to the accumulated holes on deep level in AlGaAs.The permanent shift of threshold voltage is caused by the accumulated holes at the interface between gate and semiconductor.The holes originate from field-aided tunneling of electrons out of the traps and capture of some of the holes that are generated by impact ionization in the channel and flow toward the gate.The accumulated holes result from detrapped electrons under high electric field and trapped holes by impact ionization.An analytical expression of impact ionization rate versus maximum channel electric field is educed by fitting the impact ionization rate.The electric characteristic and reliability in GaAs PHEMT's can be evaluated using the analytical expression.

关 键 词：高电子迁移率晶体管 阈值电压 碰撞电离 可靠性表征 

分 类 号：TN386.3[电子电信—物理电子学]