不同老化试验方法下SiC MOSFET失效机理分析  

Failure Mechanism Analysis of SiC MOSFET under Different Aging Test Methods

作　　者：陈杰 邓二平 赵子轩 吴宇轩 黄永章 Chen Jie;Deng Erping;Zhao Zixuan;Wu Yuxuan;Huang Yongzhang(State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources North China Electrical Power University,Beijing 102206 China;NCEPU(Yantai)Power Semiconductor Technology Research Institute Co.Ltd,Yantai 264006 China)

机构地区：[1]新能源电力系统国家重点实验室(华北电力大学),北京102206 [2]华电(烟台)功率半导体技术研究院有限公司,烟台264006

出　　处：《电工技术学报》2020年第24期5105-5114,共10页Transactions of China Electrotechnical Society

基　　金：国家自然科学基金资助项目(52007061)。

摘　　要：SiC MOSFET凭借其优异的电热特性,正逐渐投入市场,长期运行其可靠性成为关注的重点,功率循环试验是考核器件可靠性最重要的老化试验。MOSFET具有三种导通模式,分别对应三种不同的功率循环测试方法。为探究和对比SiC MOSFET在不同老化试验方法下的失效机理和失效表征参数的变化规律,对其在不同导通模式下进行功率循环试验,基于不同导通模式下的特性分析,重点对比正向MOSFET模式和体二极管模式。SiC MOSFET中的界面陷阱会造成阈值电压漂移,为此提出一种判断准则以及相应的功率循环试验方法,可以将阈值电压漂移对试验结果的影响最小化,并在老化试验过程中实现结温、通态压降和热阻的在线测量。结果表明,在两种模式下失效方式均为键合线老化,但是老化后的电热反馈机制不同,造成其退化规律和寿命不同,相同热力条件下体二极管模式下的寿命约为正向MOSFET模式下的两倍。SiC MOSFETs are gradually entering the market due to their excellent electrothermal characteristics,and their long-term reliability has become the focus of attention.The power cycling test is the most important aging test for device reliability assessment.MOSFET has three conduction modes corresponding to three different power cycling test methods.To study and compare the failure mechanism and failure parameters evolution of SiC MOSFET under different aging test methods,the power cycling tests were carried out under different modes,focusing on forward MOSFET mode and body diode mode.Since the interface trap in the SiC MOSFET can cause the threshold voltage drift,a judgment criterion and a corresponding power cycling test method were proposed to minimize the influence of the threshold voltage drift on the test result.The on-line measurement of junction temperature,on-state voltage drop and thermal resistance during the test were achieved.The results show that the main failure mode in both modes is bond wire fatigue,but the electrothermal feedback mechanism after bonding wire fatigue is different,resulting in different degradation laws and lifespan.The life in diode mode is about twice that in the forward MOSFET mode under the same thermal conditions.

关 键 词：SiC MOSFET 功率循环试验 导通模式 阈值电压漂移 结温测量 失效机理 

分 类 号：TM46[电气工程—电器]