High field-effect mobility in n-channel Si face 4H-SiC MOSFETs with gate oxide grown on aluminum ion-implanted material

We report investigations of Si face 4H-SiC MOSFETs with aluminum (Al) ion-implanted gate channels. High-quality SiO2-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(2)/V (.) s is extracted from transistors with epitaxially grown channel region of doping 5 x 10(15) cm(-3). Transistors with implanted gate channels with an Al concentration of 1 x 10(17) cm(-1) exhibit peak field-effect mobility of 100 cm(2)/V (.) s, while the mobility is 51 cm(2)/V (.) s for an Al concentration of 5 x 10(17) cm(-3). The mobility reduction with increasing acceptor density follows the same functional relationship as in n-channel Si MOSFETs.