Abstract
Abstract
A novel MOSFET with lateral–vertical charge coupling (LVCC-MOSFET) is proposed in this paper. Lateral charge coupling is enabled by a metal field plate, lightly doped drain and P-Epi layer to reduce the C
gd. Vertical charge coupling is enabled by a shield gate, sinker and P-Epi layer to support a high breakdown voltage (BV) and further reduce the C
gd. By combining both lateral charge coupling and vertical charge coupling, which is first proposed in low-voltage power MOSFETs, the trade-off relationship between BV, R
on and C
gd can be significantly improved. It is verified by both small-signal analysis and transient capacitance simulation that the gate-to-drain capacitance of the proposed LVCC-MOSFET can be reduced by more than 99% without deterioration of BV and R
on. The LVCC-MOSFET achieves 93.7% reduction in Q
gd, and R
on × Q
gd is only 0.81 mΩ·nC, which is reduced by 93.9%. Furthermore, E
on and E
off can be reduced by 73.6% and 53.8%, respectively. The hot carrier injection reliability can be enhanced by reducing the electric field and the impact ionization generation rate near the drain-side gate oxide. Moreover, the LVCC-MOSFET can be feasibly manufactured with compatible fabrication process flow, and only three extra steps are needed.