Simulation Study of a Super-Junction Deep-Trench LDMOS With a Trapezoidal Trench

A super-junction (SJ) deep-trench (DT) lateral double-diffused metal-oxide-semiconductor transistor improved by tilting the DT sidewalls is proposed. The incline of sidewalls introduces some vertically varying charges into the SJ drift regions on both sides of the DT. Therefore, the adverse effect of the DT on the surface electric field distribution is withstood, and the device can approach an ideal state of charge-balance. Simulation results show compared with a conventional device, which has the same drift region concentration and the same size but the perpendicular sidewalls, the proposed device presents a better figure of merit over 2.5 times higher. Besides, a feasible fabrication process for the proposal is presented and discussed.