Nitrogen passivation of deposited oxides on n 4H–SiC

Abstract

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 °C were investigated. Nitrogen passivation of deposited oxides on n 4H–SiC is found to produce interface state densities of 1–2×1012 cm−2 eV−1 at Ec−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 °C. We suggest that additional oxide growth during the NO passivation is the reason for the observed interface state densities.