Breakthrough of drain current capability and on-resistance limits by gate-connected superjunction MOSFET

Abstract

This paper reports a new structure of Gate-connected Superjunction (GS) MOSFET to cope with both high drain current density and low on-resistance. The conventional superjunction (SJ) structure is attractive to reduce the specific on-resistance dramatically due to the charge compensation concept. The drain saturation current density, however, is limited by JFET depletion at the bottom region of the SJ structure even if the on-resistance can be reduced by the lateral SJ pitch narrowing. The accumulation-mode operation is effective not only for low on-resistance but also for suppressing the depletion at the SJ bottom due to the accumulation carriers. This paper reports the potential of the GS-MOSFET for high drain current density and low on-resistance based on the simulation results. Dynamic characteristics are also compared with the conventional SJ-MOSFET.