Interfacial properties and reliability of SiO 2 grown on 6H-SiC in dry O 2 plus trichloroethylene

Abstract

A new process of growing SiO 2 on n- and p-type 6H-SiC wafers in dry O 2+trichloroethylene (TCE) was investigated. The interface quality and reliability of 6H-SiC metal-oxide-semiconductor (MOS) capacitors with gate dielectrics prepared by the process were examined. As compared to conventional dry O 2 oxidation, the O 2 + TCE oxidation resulted in lower interface-state, border-trap and oxide-charge densities, and enhanced reliability. This could be attributed to the passivation effect of Cl 2 or HCl on structural defects at/near the SiC/SiO 2 interface, and the gettering effect of Cl 2 or HCl on ion contamination. In addition, increased oxidation rate was observed in the O 2 + TCE ambient, and can be used to reduce the normally-high thermal budget for oxide growth. All these are very attractive for fabricating SiC MOS field-effect transistors (MOSFETs) with high inversion-channel mobility and high hot-carrier reliability. © 2004 Elsevier Ltd. All rights reserved.