Nature of Transition Layers at the SiO2/SiC Interface
T Zheleva, Aivars Lelis, G Duscher, F Liu, Igor Levin, M Das
Electrical performance of SiC-based microelectronic devices is strongly affected by the densities of interfacial traps introduced by the chemical and structural changes at the SiO2/SiC interfaces during processing. We analyzed the structure and chemistry of these interfaces in the thermally grown SiO2/4H-SiC heterostructures using high-resolution transmission electron microscopy (TEM), Z-contrast scanning TEM, and spatially-resolved electron energy loss spectroscopy. The analyses revealed presence of distinct layers, several nanometers thick, on each side of the interface; additionally, partial amorphization of the top SiC surface was observed. These interfacial layers were attributed to a formation the ternary Si-C-O phase during thermal annealing.
Applied Physics Letters
electron energy loss spectroscopy, interfaces, silicon carbide, silicon oxide, transmission electron microscopy