Nitrogen passivation of deposited oxides on n 4H-SiC

Results for measurements of interface state density and breakdown field strength are reported for deposited oxides on n 4H-SiC following passivation with nitric oxide. Low-temperature oxides deposited by plasma-enhanced chemical vapor deposition and high-temperature oxides deposited at 950 degreesC were investigated. Nitrogen passivation of deposited oxides on n 4H-SiC is found to produce interface state densities of 1-2x10(12) cm(-2) eV(-1) at E-c-E=0.1 eV, regardless of variations in oxide deposition procedures that affect the residual interfacial carbon concentration. Breakdown field strengths were higher for passivated high-temperature oxides compared to passivated low-temperature oxides at room temperature and 290 degreesC. We suggest that additional oxide growth during the NO passivation is the reason for the observed interface state densities. (C) 2002 American Institute of Physics.