Drain-Leakage Degradation During Single-Event Burnout Experiments in N-Channel Power VDMOS Transistors
Fengkai Liu, Zhongli Liu, Lei Wu, Xiaodong Xu, Shuo Liu, Xin Jin, Jianqun Yang, Xingji Li
Abstract
This article investigates the impact of bismuth-heavy ion and high-energy proton irradiation on single-event burnout (SEB) and complete off-state drain-leakage degradation (CO-DLD) in n-channel 115-V-rated vertical-diffused (VD) metal-oxide-semiconductor field-effect transistors (MOSFETs). Initially, bismuth-heavy ion irradiation experiments are conducted to determine the SEB failure threshold voltage (VSEB). CO-DLD is observed, and it is hypothesized that increased temperatures at the source contact and silicon surface may contribute to this degradation. Subsequent experiments with high-energy proton irradiation aim to examine the role of temperature in CO-DLD, eventually discounting it as a contributing factor. Displacement damage is then identified as the principal cause of CO-DLD, with this hypothesis being corroborated by technology computer-aided design (TCAD) simulations. The comprehensive analysis of both experiments and simulations concludes that temperature-induced source-contact degradation is not the primary driver of CO-DLD. Instead, displacement damage caused by bismuth-heavy ion and high-energy proton irradiation emerges as the predominant mechanism behind CO-DLD. This finding is significant as both experiments and simulations confirm that displacement damage leads to CO-DLD in VDMOS transistors, shedding light on protecting the VDMOS from degrading.