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 ( SiO _2 ) 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 Al _2 O _3 , Si _3 N _4 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.

Keywords

• single event burnout (SEB)
• high-κ dielectric
• P+ shielding region
• SEB hardening
• U-shaped trench-gate MOSFET (UMOSFET)
• silvaco TCAD simulation