In:
ECS Transactions, The Electrochemical Society, Vol. 11, No. 4 ( 2007-09-28), p. 199-211
Abstract:
Ionicity has been raised as an important factor in discussing defect formation in Hf-based oxides. It has been elucidated from our first-principles calculations, that the stability of defects is dominated by Coulomb interactions between charged defects and surrounding ions. For instance, the formation energy of positively charged oxygen vacancies (VO+2) is markedly decreased when they are coupled with substitutional N atoms at O sites, as the nominal charges of N3- are negatively greater than those of the oxygen ions O2-. Our computational results have further revealed that the ionic character of Hf causes generation of a low-lying Si dangling bond level in Si doped HfSiOx. These results suggest that one must take into account the ionicity of the Hf-based compounds, which possess totally different properties from the conventional gate insulator SiO2 in terms of defect formation.
Type of Medium:
Online Resource
ISSN:
1938-5862
,
1938-6737
Language:
Unknown
Publisher:
The Electrochemical Society
Publication Date:
2007