直流和脉冲工作的VDMOS可靠性试验

Reliability Testing of Power VDMOS Transistors in Switching State and Direct Current State

基于恒定电应力温度斜坡法（CETRM），对工作于直流状态和脉冲状态下的VDMOS功率器件进行可靠性研究，考察了器件阈值电压、跨导以及导通电阻的退化情况，得出在两种工作状态下均是跨导为失效敏感参数。在直流工作状态下，VDMOS失效激活能为0．57～0．68ev，寿命为7．97×10^5—1．15×10^7h；在脉冲工作状态下，VDMOS失效激活能为0．66～0．7eV，寿命为4．3×10^5-4．6×10×10^6h。对跨导的退化机理进行了分析。

The reliability and failure mechanism of power device VDMOSFET in switching state and direct current state was evaluated based on the method of CETRM （constant electrical stress and temperature ramp stress method）. The degradation situation of parameters such as VTH, gin, Ronwas studied. It shows that the gz is the failure sensitive parameter in both of the different states. The results show that the activation energy range of the VDMOS in direct current state is 0.57 to 0.68 eV and the expectation of life range is 7.97 ×10^5 - 1.15×10^7 h; the activation energy range of the VDMOS in switching state is 0.66 to 0.7 eV and the expectation of life range is 4.3 ×10^5 - 4.6 ×10^6 h. And the degradation mechanism of gm is analyzed.