非钳位感性开关测试下双沟槽4H-SiC功率MOSFET失效机理研究  

Failure mechanism of double-trench(DT)4H-SiC power MOSFET under unclamped inductive switch test

作　　者：郭建飞 李浩 王梓名 钟鸣浩 常帅军 欧树基 马海伦 刘莉 Guo Jian-Fei;Li Hao;Wang Zi-Ming;Zhong Ming-Hao;Chang Shuai-Jun;Ou Shu-Ji;Ma Hai-Lun;Liu Li(Guangzhou Institute of Technology,Xidian University,Guangzhou 510555,China;School of Microelectronics,Xidian University,The National Key Discipline Laboratory of Wide Band-gap Semiconductor,Xi’an 710071,China)

机构地区：[1]西安电子科技大学广州研究院,广州510555 [2]西安电子科技大学微电子学院,宽禁带半导体国家重点实验室,西安710071

出　　处：《物理学报》2022年第13期347-353,共7页Acta Physica Sinica

基　　金：陕西省重点研发一般项目(批准号:2020GY-053)资助的课题.

摘　　要：本文对非钳位感性开关(unclamped inductive switching,UIS)下4H-SiC双沟槽功率MOSFET失效机理进行实验和理论研究.结果表明,不同于平面功率MOSFET器件失效机理,在单脉冲UIS测试下双沟槽功率MOSFET器件的栅极沟槽底角处的氧化层会发生损坏,导致了器件失效.测量失效器件的栅泄漏电流和电阻,发现栅泄漏电流急剧增大,电阻仅为25Ω;失效器件的阈值电压稳定不变.使用TCAD软件对雪崩状态下的器件电场分布进行仿真计算发现,最大电场位于栅极沟槽底拐角处,器件内部最大结温未超过电极金属熔点,同时也达到了理论与仿真的吻合.In this paper,failure mechanism of DT 4H-SiC power MOSFET under unclamped inductive switch (UIS)test is evaluated by combination of experiment and theoretical research.The results show that unlike planar4H-SiC power MOSFET,the gate oxide at the corner of of gate trench is destroyed under the UIS test,therefore,the device under test failed.And then,measurement results of the gate leakage and resistance between gate and source (Rgs) of the failed device indicate that gate leakage increases sharply and Rgs is only25Ω,however,the threshold voltage of failure device is unchanged.The analysis of the inner electrical field under avalanche state by using the TCAD software shows that the maximum electrical field exists at the corner of gate trench and the maximum junction temperature does not exceed the melt point of metal.These results are consistent with the experimental results.

关 键 词：4H-SIC 双沟槽 MOSFET 单脉冲雪崩击穿能量 失效机理 栅极沟槽拐角氧化层断裂 

分 类 号：TN386[电子电信—物理电子学]