Effect of Oxidant in MOCVD-Growth of Al2O3 Gate Insulator on 4H-SiC MOSFET Properties
We have examined the effect of oxidant in metalorganic chemical vapor deposition (MOCVD) of Al2O3 gate insulator on MOSFET electrical properties. High channel mobility of 311 cm2/Vs for Al2O3/SiC MOSFET is demonstrated when the Al2O3 gate insulator is deposited on HF-treated substrate at 190oC using triethyl-aluminum (TEA) and O2 as Al source and oxidant gas, respectively. This is much higher than that of Al2O3/SiC MOSFET when Al2O3 gate insulator was deposited with TEA and H2O at the same temperature. In addition, channel mobility at high gate electric field can be improved by using O2 as oxidant gas and effective mobility of 207 cm2/Vs is obtained at SiO2 equivalent gate electric field of 1.5 MV/cm.
Amador Pérez-Tomás, Philippe Godignon, Miquel Vellvehí and Pierre Brosselard
H. Moriya et al., "Effect of Oxidant in MOCVD-Growth of Al2O3 Gate Insulator on 4H-SiC MOSFET Properties", Materials Science Forum, Vols. 615-617, pp. 777-780, 2009