Internal dielectric interface: SiO$_{2}$/HfO$_{2}$.

ORAL

Abstract

We investigate theoretically the atomic structure of the SiO$_{2}$-HfO$_{2}$ interface, its energretics, and thermodynamic stability with respect to oxygen exchange across the interface. We have examined the electronic properties of the interface including the band discontinuity. All calculations are performed using density functional theory. We employ ultra-soft pseudopotentials, and a plane wave basis set. To model the interface we build a supercell structure by connecting $\beta $-crystobalite (crystalline silica polymorph) and cubic hafnia. This model, while being obviously rather simplistic allows for systematic study of the dielectric thickness effects, and consistent placement of defects with respect to the interface. We use the idealized C9 structure of crystobalite (silica is assumed to be relaxed). The hafnia cell is matched to crystobalite \textit{via} a 45\r{ } rotation and is assumed to be under the 4{\%} tensile strain. Wee allow for the elongation of the c axis in response to strain. The striking atomic feature of the calculated interface structure is three-fold coordinated interfacial oxygen atoms connected to one Si and two Hf neighbors. The Si-O and Hf-O bond lengths are 1.62 and 2.1 {\AA}, respectively. The energy of the interface is estimated to be in the range of 900-4000 erg/cm$^{2}$ depending on the oxygen chemical potential. The structure has no states in the gap. We then consider the relative energies of oxygen vacancies on both sides of the interface. We investigate different positions and different charge states of the vacancy.

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Authors

  • Nilanjan Das

    Dept. of Physics, ESFM-IPN, Mexico City, Dept. of Physics, The University of Texas at El Paso, Texas A\&M University, Southeast Missouri State University, Departamento de Fisica, FCEN, Universidad de Buenos Aires, Nunez, Argentina, Cyclotron Institute, Texas A\&M University, University of Houston, Denison U., Advanced Space Propulsion Laboratory, AdAstra Rocket Company, Texas Tech University, Department of Chemistry and Biochemistry, Texas State Unv. - San Marcos, Department of Physics, Texas State Unv. - San Marcos, Rice U., Texas State University - San Marcos, Freescale Semiconductor, Inc., Varian Semiconductor Equipment Associates, Gloucester, MA, University of North Texas, Denton, TX, National Insitute of Standards \& Technology, Gaithersburg, MD, James Madison University, Harrisonburg, VA, Texas A\&M University, College Station, TX, Hong Kong University of Science and Technology; Texas Center for Superconductivity and Advanced Materials, University of Houston, Texas Center for Superconductivity at the University of Houston, University of Houston, University of Idaho, Department of Physics, Istanbul Technical University, University of California at Davis, Physics Department, University of South Florida, FL 33620, Physics Department, Texas A\&M University, TX 77843, Center for Studies in Statistical Mechanics and Complex Systems, The University of Texas at Austin, Rice University, TcSUH, University of Houston, Lawrence Berkeley National Laboratory, Hong Kong University of Science and Technology, Institute of Solid State Physics, Bulgarian Academy of Sciences, Hong Kong University of Science and Technology; Texas Center for Superconductivity, University of Houston; Lawrence Berkeley National Laboratory, Texas Center for Superconductivity, University of Houston

  • Nilanjan Das

    Dept. of Physics, ESFM-IPN, Mexico City, Dept. of Physics, The University of Texas at El Paso, Texas A\&M University, Southeast Missouri State University, Departamento de Fisica, FCEN, Universidad de Buenos Aires, Nunez, Argentina, Cyclotron Institute, Texas A\&M University, University of Houston, Denison U., Advanced Space Propulsion Laboratory, AdAstra Rocket Company, Texas Tech University, Department of Chemistry and Biochemistry, Texas State Unv. - San Marcos, Department of Physics, Texas State Unv. - San Marcos, Rice U., Texas State University - San Marcos, Freescale Semiconductor, Inc., Varian Semiconductor Equipment Associates, Gloucester, MA, University of North Texas, Denton, TX, National Insitute of Standards \& Technology, Gaithersburg, MD, James Madison University, Harrisonburg, VA, Texas A\&M University, College Station, TX, Hong Kong University of Science and Technology; Texas Center for Superconductivity and Advanced Materials, University of Houston, Texas Center for Superconductivity at the University of Houston, University of Houston, University of Idaho, Department of Physics, Istanbul Technical University, University of California at Davis, Physics Department, University of South Florida, FL 33620, Physics Department, Texas A\&M University, TX 77843, Center for Studies in Statistical Mechanics and Complex Systems, The University of Texas at Austin, Rice University, TcSUH, University of Houston, Lawrence Berkeley National Laboratory, Hong Kong University of Science and Technology, Institute of Solid State Physics, Bulgarian Academy of Sciences, Hong Kong University of Science and Technology; Texas Center for Superconductivity, University of Houston; Lawrence Berkeley National Laboratory, Texas Center for Superconductivity, University of Houston

  • Nilanjan Das

    Dept. of Physics, ESFM-IPN, Mexico City, Dept. of Physics, The University of Texas at El Paso, Texas A\&M University, Southeast Missouri State University, Departamento de Fisica, FCEN, Universidad de Buenos Aires, Nunez, Argentina, Cyclotron Institute, Texas A\&M University, University of Houston, Denison U., Advanced Space Propulsion Laboratory, AdAstra Rocket Company, Texas Tech University, Department of Chemistry and Biochemistry, Texas State Unv. - San Marcos, Department of Physics, Texas State Unv. - San Marcos, Rice U., Texas State University - San Marcos, Freescale Semiconductor, Inc., Varian Semiconductor Equipment Associates, Gloucester, MA, University of North Texas, Denton, TX, National Insitute of Standards \& Technology, Gaithersburg, MD, James Madison University, Harrisonburg, VA, Texas A\&M University, College Station, TX, Hong Kong University of Science and Technology; Texas Center for Superconductivity and Advanced Materials, University of Houston, Texas Center for Superconductivity at the University of Houston, University of Houston, University of Idaho, Department of Physics, Istanbul Technical University, University of California at Davis, Physics Department, University of South Florida, FL 33620, Physics Department, Texas A\&M University, TX 77843, Center for Studies in Statistical Mechanics and Complex Systems, The University of Texas at Austin, Rice University, TcSUH, University of Houston, Lawrence Berkeley National Laboratory, Hong Kong University of Science and Technology, Institute of Solid State Physics, Bulgarian Academy of Sciences, Hong Kong University of Science and Technology; Texas Center for Superconductivity, University of Houston; Lawrence Berkeley National Laboratory, Texas Center for Superconductivity, University of Houston

  • Nilanjan Das

    Dept. of Physics, ESFM-IPN, Mexico City, Dept. of Physics, The University of Texas at El Paso, Texas A\&M University, Southeast Missouri State University, Departamento de Fisica, FCEN, Universidad de Buenos Aires, Nunez, Argentina, Cyclotron Institute, Texas A\&M University, University of Houston, Denison U., Advanced Space Propulsion Laboratory, AdAstra Rocket Company, Texas Tech University, Department of Chemistry and Biochemistry, Texas State Unv. - San Marcos, Department of Physics, Texas State Unv. - San Marcos, Rice U., Texas State University - San Marcos, Freescale Semiconductor, Inc., Varian Semiconductor Equipment Associates, Gloucester, MA, University of North Texas, Denton, TX, National Insitute of Standards \& Technology, Gaithersburg, MD, James Madison University, Harrisonburg, VA, Texas A\&M University, College Station, TX, Hong Kong University of Science and Technology; Texas Center for Superconductivity and Advanced Materials, University of Houston, Texas Center for Superconductivity at the University of Houston, University of Houston, University of Idaho, Department of Physics, Istanbul Technical University, University of California at Davis, Physics Department, University of South Florida, FL 33620, Physics Department, Texas A\&M University, TX 77843, Center for Studies in Statistical Mechanics and Complex Systems, The University of Texas at Austin, Rice University, TcSUH, University of Houston, Lawrence Berkeley National Laboratory, Hong Kong University of Science and Technology, Institute of Solid State Physics, Bulgarian Academy of Sciences, Hong Kong University of Science and Technology; Texas Center for Superconductivity, University of Houston; Lawrence Berkeley National Laboratory, Texas Center for Superconductivity, University of Houston