Improvement of Deep-Trench LDMOS With Variation Vertical Doping for Charge-Balance Super-Junction

A design concept of variation vertical doping is proposed to upgrade the deep-trench lateral double-diffused metal–oxide–semiconductor field-effect transistor. Due to the proposal, a drift region in the form of charge-balance super-junction is first gained in such a device. Hence, the relationship between the breakdown voltage and the specific on-resistance is significantly improved. Numerical simulations demonstrate that the proposal is valid to increase the theoretical limit of the figure of merit to be about 44.9 MW/cm
$^{\textsf {2}}$
, more than twice of that of the prior art. Besides, a feasible realization method is presented and studied.