High Mobility 4H-SiC Lateral MOSFETs Using Lanthanum Silicate and Atomic Layer Deposited SiO2

We report high mobility Si-face 4H-SiC MOSFET results via a novel interface engineering technique using a gate-stack consisting of lanthanum silicate (LaSiO_x) and atomic layer deposited SiO₂. Peak field effect mobility of 132.6 cm²/V · s has been achieved while maintaining a positive threshold voltage (3.1 V). From the peak field effect mobility´s dependence on measurement temperatures, it has been found that the mobility of La containing MOSFET is limited by phonon scattering.