Evidence for an Abrupt Transition between SiO2 and SiC from EELS and Ab Initio Modelling

Electron energy loss spectroscopy (EELS) and ab initio simulations are combined in this study to produce an atomistic interpretation of the interface morphology in lateral 4H-SiC / SiO2 MOSFETs with deposited gate oxides. This allows the question of interface abruptness, and the presence the postulated SiOxCy interlayer to be explored for a subset of devices with deposited oxides. From comparison between EELS and ab initio calculation the interfaces considered are best described as abrupt, but stepped, transitioning without any of the carbon excess or SiOxCy interlayer that have been described for other devices observed.