基于浮动N型岛提升沟道载流子迁移率的4H-SiC横向扩散MOSFET技术

The low channel carrier mobility, primarily attributed to the poor quality of the SiC/SiO2 interface, remains a major challenge for SiC lateral diffused MOSFETs (LDMOS). This work proposes a method utilizing floating N-islands (FN) as “carrier reservoirs” in the channel region to address this issue. FNs in the channel region modulate the two-dimensional electrostatics and carrier distribution, which in turn enhances carrier emission efficiency and effective channel mobility, leading to a reduced specific on-resistance. As a result, a maximum 86.7% improvement in field-effect mobility is achieved and a maximum 46.2% specific on-resistance ( ${R}_{\textit {on},\textit {sp}}$ ) is reduced compared to conventional LDMOS. Besides, optimized vertical doping profiles of the P-well and FN induces a negligibly impacts on BV. This process-compatible and low-cost strategy provides a viable route to high-performance SiC LDMOSFETs.