AlGaN表面坑状缺陷及GaN缓冲层位错缺陷对AlGaN/GaN HEMT电流崩塌效应的影响  

Influence of pit defects on AlGaN surface and dislocation defects in GaN buffer layer on current collapse of AlGaN/GaN HEMTs

作　　者：席光义[1] 任凡[1] 郝智彪[1] 汪莱[1] 李洪涛[1] 江洋[1] 赵维[1] 韩彦军[1] 罗毅[1] 

机构地区：[1]清华大学电子工程系集成光电子学国家重点实验室,清华大学信息科学与技术国家实验室,北京100084

出　　处：《物理学报》2008年第11期7238-7243,共6页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:60536020,60723002);国家重点基础研究发展计划“973”(批准号:2006CB302801,2006CB302804,2006CB302806,2006CB921106);国家高技术研究发展计划“863”(批准号:2006AA03A105);北京市科委重大计划(批准号:D0404003040321)资助的课题~~

摘　　要：利用金属有机气相外延(MOVPE)技术生长了具有不同AlGaN表面坑状缺陷和GaN缓冲层位错缺陷密度的AlGaN/GaN高电子迁移率晶体管(HEMT)样品,并对比研究了两种缺陷对器件栅、漏延迟电流崩塌效应的影响.栅延迟测试表明,AlGaN表面坑状缺陷会引起栅延迟电流崩塌效应和源漏电阻的增加,而且表面坑状缺陷越多,栅延迟电流崩塌程度和源漏电阻的增加越明显.漏延迟测试显示,AlGaN表面坑状缺陷对漏延迟电流崩塌影响不大,而GaN缓冲层位错缺陷主要影响漏延迟电流崩塌.研究结果表明,AlGaN表面坑状缺陷和GaN缓冲层位错缺陷分别是引起AlGaN/GaN HEMT栅、漏延迟电流崩塌的电子陷阱来源之一.The influence of pit defects on AlGaN surface and dislocation defects in GaN buffer layer on the current collapse of MOVPE- grown AlGaN/GaN high electron mobility transistors （HEMTs） is studied in this paper. Pulsed gate voltage measurements show that the surface pit defects result in gate lag current collapse and increased of source/drain resistance. And the more pit defects exist, the more obvious current collapse and increased source/drain resistance are observed. Pulsed drain voltage measurements show that the drain lag current collapse, which is almost unaffected by the surface pit defects, can be associated with the dislocation defects in GaN buffer layer. Our experimental results indicate that pit defects on AlGaN surface and dislocation defects in GaN buffer layer can be one of the origins of gate lag and drain lag current collapse, respectively.

关 键 词：ALGAN/GAN HEMT 电流崩塌 坑状缺陷 位错缺陷 

分 类 号：TN323.2[电子电信—物理电子学]