A novel MOSFET with lateral-vertical charge coupling for extremely low C gd

A novel MOSFET with lateral-vertical charge coupling (LVCC-MOSFET) is proposed in this paper. Lateral charge coupling is enabled by metal field plate, lightly doped drain (LDD) and P-Epi layer to reduce Cgd. Vertical charge coupling is enabled by shield gate, sinker and P-Epi layer to support high breakdown voltage (BV) and further reduce Cgd. By combining both lateral charge coupling and vertical charge coupling, which is first proposed in low-voltage power MOSFETs, tradeoff relationship between BV, Ron and Cgd can be significantly improved. It is verified by both small-signal analysis and transient capacitance simulation that gate-to-drain capacitance of the proposed LVCC-MOSFET can be reduced by more than 99% without deterioration of BV and Ron. LVCC-MOSFET achieves 93.7% reduction in Qgd and Ron×Qgd is only 0.81 mΩꞏnC, which is reduced by 93.9%. Furthermore, Eon and Eoff can be reduced by 73.6% and 53.8%, respectively. Hot carrier injection (HCI) reliability can be enhanced by reducing electric field and impact ionization generation rate near drain-side gate oxide. Besides, the LVCC-MOSFET can be feasibly manufactured with compatible fabrication process flow and only three extra steps are needed.