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Title: Direct tunneling through high-κ amorphous HfO{sub 2}: Effects of chemical modification

We report first principles modeling of quantum tunneling through amorphous HfO{sub 2} dielectric layer of metal-oxide-semiconductor (MOS) nanostructures in the form of n-Si/HfO{sub 2}/Al. In particular, we predict that chemically modifying the amorphous HfO{sub 2} barrier by doping N and Al atoms in the middle region—far from the two interfaces of the MOS structure—can reduce the gate-to-channel tunnel leakage by more than one order of magnitude. Several other types of modification are found to enhance tunneling or induce substantial band bending in the Si, both are not desired from leakage point of view. By analyzing transmission coefficients and projected density of states, the microscopic physics of electron traversing the tunnel barrier with or without impurity atoms in the high-κ dielectric is revealed.
Authors:
; ; ;  [1] ; ;  [2] ;  [3] ;  [4]
  1. Department of Physics and the Center of Theoretical and Computational Physics, The University of Hong Kong, Pokfulam Road, Hong Kong (China)
  2. Nanoacademic Technologies Inc., 7005 Blvd. Tachereau, Brossard, Quebec J4Z 1A7 (Canada)
  3. Center for the Physics of Materials and Department of Physics, McGill University, Monstreal, Quebec H3A 2T8 (Canada)
  4. (China)
Publication Date:
OSTI Identifier:
22308723
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 116; Journal Issue: 2; 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; ALUMINIUM; ALUMINIUM ADDITIONS; AMORPHOUS STATE; ATOMS; COMPUTERIZED SIMULATION; DIELECTRIC MATERIALS; ELECTRONS; HAFNIUM OXIDES; IMPURITIES; INTERFACES; LAYERS; METALS; MODIFICATIONS; NANOSTRUCTURES; NITROGEN ADDITIONS; SEMICONDUCTOR MATERIALS; SILICON; SILICON OXIDES; TRANSMISSION; TUNNEL EFFECT