Single event burnout hardening of trench shielded power UMOSFET using High-κ dielectrics

Abstract

This study proposes the High-κ dielectric Trench Shielded power UMOSFET (HK TS-UMOSFET) to be assessed using the two-dimensional numerical simulations. The simulations are employed to evaluate HK TS-UMOSFETs susceptibility to single-event burnout (SEB) mechanism. Based on the findings, the influence of alternative high permittivity gate dielectrics to silicon dioxide (SiO2) in TS-UMOSFET was discussed. Furthermore, in order to improve the performance of the device, its electrical behaviour was simulated with several high-κ dielectrics including Al2O3, Si3N4 and Aluminium Nitride (AlN). When heavy ions strike the sensitive areas of the device, the electric field distribution and SEB threshold values were extracted. Based on the values yielded, (AlN) was identified as a promising high-κ material to achieve SEB-hardened TS-UMOSFET compared to the other high-κ dielectrics. In conclusion, with (AlN), the HK TS-UMOSFET offers a high SEB tolerance and improved electrical characteristics.