界面极化效应对AlGaN/4H-SiC HBT器件性能影响研究  

The impact of interface polarization effects on electrical properties of AlGaN /4H-SiC HBT

作　　者：周守利[1] 李伽[1] 梁显锋 安军社 

机构地区：[1]浙江工业大学信息学院,杭州310023 [2]中科院国家空间中心,北京100190

出　　处：《真空科学与技术学报》2014年第1期49-52,共4页Chinese Journal of Vacuum Science and Technology

基　　金：浙江省自然科学基金(批准号:LY12F04003)资助;信息功能材料国家重点实验室2009开放基金(批准号:FMI2009-08)资助;国家自然科学基金(批准号:61205121)资助

摘　　要：AlGaN/4H-SiC异质结界面存在大的自发和压电极化效应,从而使界面出现较多数量的极化电荷,这导致器件电学性能的改变。利用热场发射-扩散模型,基于数值模拟方法研究了异质结界面极化效应产生的极化电荷对AlGaN/4H-SiC HBT器件直流性能和高频性能的影响。得到了AlGaN/4H-SiC异质结界面极化效应引诱的正极性极化界面电荷削弱了异质结的内建电场,加速了载流子的扩散运动,因而能促进载流子的输运,从而使器件的直流特性和高频特性得到改善。The impact of the polarizd charge, accumulated at the AlGaN/4H-SiC hetero-iunction because of strong spontaneous polarization and piezopelectric polarization, on the characteristics of the Heterojunction Bipolar Transistor （HBT） fabricated with the AlGaN/4H-SiC hetero-junction was mathematically modeled, physically analyzed, and numeri- cally simulated. The newly-formulated thermionic-field-diffusion model combined the drift-diffustion transport in the bulk of a HBT and the thermionic emission and tunneling at the interface. The calculated results show that the accumulated positive charges at the interface, originated from the strong polarizations, signficantly weaken the buih-inelectric field in the hetero-junction, promoting the diffusion and transport of carriers and improving the performance of the AlGaN/4H-SiC HBT, its DC and high frequency characteristics in particular.

关 键 词：ALGAN 4H-SIC HBT 异质结界面极 化效应 热场发射-扩散 

分 类 号：TN385[电子电信—物理电子学]