Failure analysis of the VDMOS device with Vsd and Rds (on) exceeded limit based on reliability physics

摘要

Failure analysis is carried out in an irregular way because failure occurred in different situations with different phenomena. Experiences are usually needed to do failure analysis. When a new failure case occurs, it is difficult to make an effective scheme to implement the failure analysis without experiences. To solve this problem, an analysis method based on reliability physics is proposed in this article. In this paper, a power VDMOS device failed with both parameters VSD and RDS (on) degraded after 500 cycles of temperature cycle test. The failure analysis based on reliability physics is carried out to guide the implement of experiments, such as a c-mode scanning acoustic microscope test and a thermal resistance test. At last the root cause of the device failure is found.