High-resolution cross-sectional analysis of the interface between SiC and SiO2 in a MOSFET device via atomic resolution STEM

Transition areas in multilayer assemblies used for electronic structures are of vital importance for the characteristics of the final devices. In this study, the interfacial region between SiC and SiO2 was studied with atomic resolution scanning transmission electron microscopy and electron energy-loss spectroscopy in order to gain insight in the structural morphology and the chemical composition of the interface and the appearance of interfacial layers formed during passivation procedures. The annealing process in an N-rich atmosphere during fabrication of the multilayer stack leads to a (sub-)monolayer of nitrogen at the interface between the bulk material and the oxide that is illustrated and quantified. In addition, closer analysis of the EELS signal reveals a transition region that is 3 nm in width, extending approximately 1 nm further into the SiO2 than the N-peak.