Passivation of oxygen vacancy states and suppression of Fermi pinning in HfO2 by La addition
- 26 January 2009
- journal article
- Published by AIP Publishing in Applied Physics Letters
- Vol. 94 (4), 042904
- https://doi.org/10.1063/1.3076119
Abstract
We show that group III elements such as La, Y, Sc, and Al can passivate adjacent oxygen vacancies in HfO 2 and ZrO 2 by shifting the vacancy gap state up into the conduction band. The shift arises from the outward relaxation of the cations around the vacancy due to its positive charge, becoming a closed shell configuration. La substitution at Hf sites in HfO 2 suppresses Fermi level pinning because its holes offer a deeper sink for electrons generated by the vacancy than transfer to the metal gate.Keywords
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