Development of SiC Power MOSFETs with Low On-Resistance for Military and Commercial Applications

摘要

A large number of applications for power switching devices lie in the voltage range from 600-1800 V. In this regime, the specific on-resistance of SiC power MOSFETs is limited by their MOS channel resistance, due to the low inversion layer electron mobility at the SiO2/SiC MOS interface. Although significant progress has been made in increasing the electron mobility, it is still about an order-of-magnitude lower than in silicon devices. Our approach to this problem is to implement structural changes, namely short channel lengths, that will directly reduce channel resistance independent of and in addition to any improvements in channel mobility. The short-channel DMOSFETs utilize a novel self-aligned implantation process that easily and reliably produces sub-half- micron channel lengths.