Density functional theory molecular dynamics simulations and experimental measurements of a-HfO2/a-SiO/SiGe(001) and a-HfO2/a-SiO2/SiGe(001) interfaces

To determine the optimal interface between a-HfO
2
igh-K oxide and Si
0.5
Ge
0.5
(001), density functional theory molecular dynamics (DFTMD) simulations of several amorphous stoichiometric and sub-stoichiometric SiOxNy interlayers were performed. The stack with oxygen deficient a-SiO interlayer demonstrated superior electric properties because it avoided all dangling bond formation. Experimental studies confirmed that a nearly pure SiOx interface between a-HfO2 and SiGe(001) could be formed which correlated with a low interface state density.