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Title: Computational investigation of the phase stability and the electronic properties for Gd-doped HfO{sub 2}

Rare earth doping is an important approach to improve the desired properties of high-k gate dielectric oxides. We have carried out a comprehensive theoretical investigation on the phase stability, band gap, formation of oxygen vacancies, and dielectric properties for the Gd-doped HfO{sub 2}. Our calculated results indicate that the tetragonal phase is more stable than the monoclinic phase when the Gd doping concentration is greater than 15.5%, which is in a good agreement with the experimental observations. The dopant's geometric effect is mainly responsible for the phase stability. The Gd doping enlarges the band gap of the material. The dielectric constant for the Gd-doped HfO{sub 2} is in the range of 20–30 that is suitable for high-k dielectric applications. The neutral oxygen vacancy formation energy is 3.2 eV lower in the doped material than in pure HfO{sub 2}. We explain the experimental observation on the decrease of photoluminescence intensities in the Gd-doped HfO{sub 2} according to forming the dopant-oxygen vacancy complexes.
Authors:
 [1] ;  [2] ; ; ; ; ;  [1] ;  [3] ;  [2]
  1. General Research Institute for Nonferrous Metals, Beijing 100088 (China)
  2. (United States)
  3. Brown University, Providence, Rhode Island 02912 (United States)
Publication Date:
OSTI Identifier:
22273376
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 104; Journal Issue: 20; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; DIELECTRIC MATERIALS; DOPED MATERIALS; FORMATION HEAT; HAFNIUM OXIDES; MONOCLINIC LATTICES; PERMITTIVITY; PHASE STABILITY; PHOTOLUMINESCENCE; VACANCIES