600V Integrable Dual-Trench LDMOS with Ultralow Specific On-Resistance and Enhanced Switching Performance

Novel 600V integrable dual-trench (split-gate-trench and oxide-trench) power LDMOS (DT-MOS) with a reduced specific on-resistance and enhanced switching performance is proposed. The dual-trench structure reshapes the electric field by wrapped drift-region togerther with lateral depletion effect of the MIS structure, enabling voltage support capability with reduced specific on-resistance (R
_on
,
_sp
). Breakdown voltage (BV) of 630V and R
_on
,
_sp
of 4.0ohm
_.
mm2 are obtained by simulation, and the proposed DT-MOS exhibits almost the highest power figure of merit (FOM, defined as BV
²
/Ron,sp) and better switching performance compared with the published structures. A low-cost (less mask-layers needed and no epitaxy process) and high reliability (relatively improved process tolerance) technology is exhibited, in which dual-trench is achieved using 14.0μm trench-etch process and inter-diffused process after ion-implantation.