'Field Balanced' SG-RSO structure showing tremendous potential for low voltage Trench MOSFETs

摘要

This paper presents a 30V range 'Field Balanced' Split-Gate RSO (Resurf Stepped Oxide) MOSFET showing extremely low Q_(gd) of 1.0 nC mm~(-2) for the first time. By introducing a low doped region on an optimised 30V Split-Gate RSO MOSFET, the Figure of Merit (FOM) improves from 8.09 mΩ nC to around 6.40 mΩ nC. From this investigation, it has been demonstrated that the 'Field Balanced' on a a Split-Gate structure can give a good R_(dsON) vs Q_(gd) trade off. The exceptionally low Q_(gd) will allow the 'Field Balanced' structure to achieve a good efficiency even in high switching frequency converter.