基于参数退化法评价功率肖特基二极管寿命

Life Prediction of Power Schottky Barrier Diode Based on the Method of Parameter Degeneration

对功率肖特基二极管(SBD)施加恒定电应力、序进温度应力进行退化实验,考察了反向漏电流IR、理想因子n、势垒高度ΦB以及串联电阻RS等参数的退化情况。可以看出,在退化的过程中,SBD的IR增加较快,n逐渐减小,ΦB逐渐增大,而RS则缓慢增加。综合考察这些退化曲线,采用退化最为明显的IR作为失效判据。基于IR参数退化曲线,使用恒定电应力温度斜坡法(CETRM)模型,推导出该功率肖特基二极管的寿命约为4.3×107h,测试结果与实际预测相符。

The degenerate experiments of Schottky barrier diodes （SBD） which was applied constant electrical and progressive thermal stress were discussed. The degradation situation of parameters such as reverse leakage current （IR）, ideal factor （n）, barrier height （ФB） and series resistance （RS） were examined. During the degenerate test, barrier height increased by degrees, the series resistance increased slowly, ideal factor decreased gradually, but reverse leakage current increased significantly. With reviewing of these degradation curves comprehensively, reverse leakage current was selected as the failure criterion which degenerated significantly. Based on the degradation curves of reverse leakage current, it is predicted that the power SBD life is 4.3×10^7 h with the method of CETRM. The calculation result basically corresponds to the actual condition and requirement.