High Field-Effect Mobility in n-Channel Si Face 4H-SiC MOSFETs With Gate Oxide Grown on Aluminum Ion-Implanted Material

摘要

We report investigations of Si face 4H-SiC MOSFETs with aluminum (Al) ion-implanted gate channels. High-quality SiO{sub}2-SiC interfaces are obtained both when the gate oxide is grown on p-type epitaxial material and when grown on ion-implanted regions. A peak field-effect mobility of 170 cm{sup}2/V · s is extracted from transistors with epitaxially grown channel region of doping 5×10{sup}15 cm{sup}(-3). Transistors with implanted gate channels with an Al concentration of 1 ×10{sup}17 cm{sup}(-3) exhibit peak field-effect mobility of 100 cm{sup}2/V · s, while the mobility is 51 cm{sup}2/V · s for an Al concentration of 5 ×10{sup}17 cm{sup}(-3). The mobility reduction with increasing acceptor density follows the same functional relationship as in n-channel Si MOSFETs.