On the identification of the oxygen vacancy in HfO2

The single positively charge oxygen vacancy in HfO2 is found to undergo a symmetry breaking distortion to a C-2v symmetry, driven by electron localization, which is consistent with the experimentally observed electron spin resonance signal. This completes the identity of the oxygen vacancy defect in HfO2 and ZrO2 as the active defect that affects reliability and gate threshold voltage instabilities in high K metal gate stacks. (C) 2011 Elsevier B.V. All rights reserved.