Driving force of oxygen-ion migration across high-k/SiO2 interface

作者:Kunugi Ryota*; Nakagawa Nobuhiro; Watanabe Takanobu
来源:Applied Physics Express, 2017, 10(3): 031501.
DOI:10.7567/APEX.10.031501

摘要

We clarified the mechanism of oxygen (O-)-ion migration at a high-k/SiO2 interface, which is a possible origin of the flat-band voltage shift in metal/high-k gate stacks. The oxygen density difference accommodation model was reproduced by a molecular dynamics simulation of an Al2O3/SiO2 structure, in which O- ions migrate from the higher oxygen density side to the lower one. We determined that the driving force of the O--ion migration is the short-range repulsion between ionic cores. The repulsive force is greater in materials with a higher oxygen density, pushing O- ions to the lower oxygen density side.

  • 出版日期2017-3