Investigation of NBTI and Relaxation Effects in P-Channel Power VDMOS Transistors

This study investigates the effects of NBTI on p-channel Vertical Double-Diffused MOSFETs (VDMOS), focusing on threshold voltage degradation and the potential for recovery through thermal relaxation. Devices were subjected to static NBT stress followed by relaxation at various temperatures. The measured transfer characteristics revealed a shift along the voltage axis, indicating changes in threshold voltage during the early stress phases, followed by saturation over time. High-temperature relaxation induced partial recovery of the degraded parameters, while low-temperature treatments had no significant recovery effect. These findings contribute to a better understanding of degradation and recovery mechanisms in power VDMOS transistors and support the design of more reliable, high-performance electronic systems.