Electron transport modeling in the inversion layers of 4H and 6H-SiC MOSFETs on implanted regions

摘要

In this work, we present the characterization of electron transport in 4H and 6H-SiC inversion layers with the development of a physics-based, 2-D quantum-mechanical model to explain the I_(DS)-V_(GS),gm-V_(GS) device electrical characteristics, the field-effect and conductivity mobility behaviors. The model considers the combined effects of surface roughness and Coulomb scattering centers arising from fixed oxide charge and interface trapped charge. The experimental characteristics in 6H and 4H-SiC MOSFETs, fabricated on implanted regions, are presented and interpreted with this model. The peak field-effect mobility values for the 4H and 6H-SiC MOSFETs are 45 and 50 cm~2 V~(-1) s~(-1), respectively. The peak conductivity mobility for the 4H-SiC MOSFETs are 37 before and 220 cm~2 V~(-1)s~(-1)after correction for interface trapped charge. The I_(DS)-V_(GS), gm-V_(GS), and the field-effect mobility are modeled to an accuracy of 3% in subthreshold and strong inversion regions.