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

A silicon-oxide layer was deposited by a low-pressure chemical vapor deposition technique at temperatures as low as 400 degreesC for gate dielectric material of the 4H-SiC metal-oxide-semiconductor (MOS) capacitors. Interfacial properties such as the amount of effective charge (N-eff), interfacial oxide trapped density (D-it) 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 degreesC. It was found that the POA temperature dependence of the D-it was different from that of the N-eff. On the other hand, the POA dependence of hot-carrier tolerance was similar to that of the D-it. In consequence, those interfacial properties were sufficiently improved and became stable above the POA temperature of 1100 degreesC, which corresponds to the softening temperature of SiO2 bulk. (C) 2002 American Institute of Physics.