Study on Non-Monotonic Hot Carrier Degradation and Predictive Model for Long Drift Region Double Field Shields LDMOS

For power devices, the hot carrier degradation is significant, and the study on long time degradation behavior and mechanism contribute to the improvement of long-term reliability substantially. Through long time stress experiments, the non-monotonic degradation behavior has been observed for long drift region double field shields lateral double diffused MOS (LDFSs-LDMOS) in this paper. The on-resistance (Rdson) displays the change of rapid increase to slight fall to slow the increase in the accumulation operation test. To reveal the physical mechanism behind the special phenomena, theoretical analyses and TCAD simulations are provided in detail. To predict the degradation of LDFS-LDMOS, a predictive model is developed finally. The proposed model can be fitted well to experimental results at various stress conditions and has been demonstrated accurately through accuracy analyses.