Atomic-scale models of the abrupt high- k/Ge interface with a range of suboxide stoichiometries GeOx are presented and compared to their Si analogs. Molecular dynamics and geometry optimization were carried out at the density functional theory level to yield structures and energetics. Cohesion across the interface becomes stronger with increasing oxidation of the Ge suboxide. Three-coordinate Ge is identified as the main defect and is formed at low energetic cost, which accounts for the observed abundance of defects at oxide/Ge interfaces. The optimum low temperature interface is defect-free, predominantly Ge2+ with some Ge+.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)