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Title: Assessing hafnium on hafnia as an oxygen getter

Hafnium dioxide or hafnia is a wide band gap dielectric used in a range of electronic applications from field effect transistors to resistive memory. In many of these applications, it is important to maintain control over oxygen stoichiometry, which can be realized in practice by using a metal layer, specifically hafnium, to getter oxygen from the adjacent dielectric. In this paper, we employ density functional theory to study the thermodynamic stability of an interface between (100)-oriented monoclinic hafnia and hafnium metal. The nudged elastic band method is used to calculate the energy barrier for migration of oxygen from the oxide to the metal. Our investigation shows that the presence of hafnium lowers the formation energy of oxygen vacancies in hafnia, but more importantly the oxidation of hafnium through the migration of oxygen from hafnia is favored energetically.
Authors:
;  [1] ;  [2]
  1. Department of Physics, The University of Texas at Austin, Austin, Texas 78712 (United States)
  2. SEMATECH, Albany, New York 12203 (United States)
Publication Date:
OSTI Identifier:
22275564
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 115; Journal Issue: 18; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; DENSITY FUNCTIONAL METHOD; DIELECTRIC MATERIALS; ENERGY GAP; FIELD EFFECT TRANSISTORS; FORMATION HEAT; HAFNIUM; HAFNIUM OXIDES; INTERFACES; LAYERS; MONOCLINIC LATTICES; OXIDATION; OXYGEN; PHASE STABILITY; VACANCIES