场板结构AlGaN/GaN HEMT的电流崩塌机理  

Current collapse mechanism of field-plated AlGaN/GaN HEMTs

作　　者：魏巍[1] 林若兵[1] 冯倩[1] 郝跃[1] 

机构地区：[1]西安电子科技大学微电子学院,宽禁带半导体材料与器件教育部重点实验室,西安710071

出　　处：《物理学报》2008年第1期467-471,共5页Acta Physica Sinica

基　　金：国家重点基础研究发展计划(973)项目(批准号:51327020301;2002CB311904)资助的课题~~

摘　　要：在不同的漏偏压下,研究了钝化和不同场板尺寸AlGaN/GaNHEMT对电流崩塌的抑制能力.实验结果表明,钝化器件对电流崩塌的抑制能力随着漏偏压的升高而显著下降;在高漏偏压下,场板的尺寸对器件抑制崩塌的能力有较大影响,而合适尺寸的场板结构在各个漏偏压下都能够很好的抑制电流崩塌.深入分析发现,场板结构不仅能够抑制虚栅的充电过程,而且提供了放电途径,有利于虚栅的放电,从而抑制电流崩塌.在此基础上,通过建立场板介质对虚栅放电的模型,解释了高漏偏压下场板的尺寸对器件抑制崩塌的能力有较大影响的原因.Current collapse restrain ability of passivated AIGaN/GaN HEMTs and AIGaN/GaN HEMTs with varying field-plate（FP） length is investigated under different drain bias. The results show that, the passivated HEMTs suffer no current collapse at relatively low but not at higher drain bias, while the HEMTs with optimal field-plate suffer no current collapse for all drain bias used in our tests. Under high drain bias, the FP length plays a crucial role in the current collapse removal. After a thoroughly analysis, it can be concluded that FP structure not only restrains the trapping of virtual gate, but also discharge the virtual gate. Finally, a discharging model of dielectric under FP is presented to explain the effect of FP length on current collapse removal.

关 键 词：A1GaN GAN HEMT 场板 电流崩塌 

分 类 号：TN386[电子电信—物理电子学]