Doping engineering for improved immunity against BV softness and BV shift in trench power MOSFET

In this paper, we report typical soft breakdown and BV
_DSS
walk-in/walk-out phenomena observed in the development of ON semiconductor's T8 60V trench power MOSFET. These breakdown behaviors show strong correlation with doping profile. We propose two 1D location-dependent variables, Q
_int
(y) and C
_ave
(y), to assist the study, and demonstrate the effectiveness of them in revealing hidden information behind regular SIMS data. Our study details the methodology of engineering doping profiles for improved breakdown stability.