High-temperature post-oxidation annealing on the low-temperature oxide/4H-SiC(0001)

Abstract

A silicon–oxide layer was deposited by a low-pressure chemical vapor deposition technique at temperatures as low as 400 °C for gate dielectric material of the 4H-SiC metal–oxide–semiconductor (MOS) capacitors. Interfacial properties such as the amount of effective charge (Neff), interfacial oxide trapped density (Dit) and hot-carrier tolerance of the 4H-SiC(0001) MOS capacitors were evaluated by simultaneous C–V measurement as a dependence of a post-oxidation annealing (POA) at temperatures ranging from 1000 to 1200 °C. It was found that the POA temperature dependence of the Dit was different from that of the Neff. On the other hand, the POA dependence of hot-carrier tolerance was similar to that of the Dit. In consequence, those interfacial properties were sufficiently improved and became stable above the POA temperature of 1100 °C, which corresponds to the softening temperature of SiO2 bulk.