Boosted high-temperature electrical characteristics of AlGaN/GaN HEMTs with rationally designed compositionally graded AlGaN back barriers  

作　　者：Haochen ZHANG Yue SUN Kunpeng HU Lei YANG Kun LIANG Zhanyong XING Hu WANG Mingshuo ZHANG Huabin YU Shi FANG Yang KANG Haiding SUN 

机构地区：[1]School of Microelectronics,University of Science and Technology of China,Hefei 230026,China

出　　处：《Science China(Information Sciences)》2023年第8期250-258,共9页中国科学（信息科学）（英文版）

基　　金：supported by National Natural Science Foundation of China(Grant Nos.52161145404,61905236,51961145110);Fundamental Research Funds for the Central Universities(Grant Nos.WK3500000009,WK2100230020);Students’Innovation and Entrepreneurship Foundation of USTC(Grant No.CY2022X04);partially carried out at the USTC Center for Micro and Nanoscale Research and Fabrication。

摘　　要：Wide bandgap GaN-based HEMTs have shown great potential as key components in various power electronic systems but still face challenges in the pursuit of devices with stable operation capability especially in harsh environments.Here,we report a high-performance double heterojunction(DH)based AlGaN/GaN HEMT by incorporating a decreasing-Al-composition(DAC)graded AlGaN back barrier(BB)beneath the GaN channel.Thanks to the improved electron confinement enabled by graded BB,the DHHEMT exhibits significantly improved on-state drain current density and off-state breakdown voltage compared with a single heterojunction(SH)based HEMT.More intriguingly,with an additional Si Nx passivation layer,the surface states of the DH-HEMTs can be effectively suppressed,leading to an almost constant offstate leakage current and negligible gate contact degradation across the temperature range from 25℃to 150℃.These results highlight the superiority and reliability of the proposed graded AlGaN BB to boost device characteristics for applications under high temperatures and harsh conditions.

关 键 词：AlGaN/GaN HEMT graded AlGaN back barrier SiNa passivation DHHEMT high temper-aturestability 

分 类 号：TN386[电子电信—物理电子学]