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Density functional study of the TiN/Ge 2 Sb 2 Te 5 interface
Author(s) -
Mandelli D.,
Caravati S.,
Bernasconi M.
Publication year - 2012
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.201248290
Subject(s) - tin , epitaxy , materials science , density functional theory , atomic orbital , atom (system on chip) , phase (matter) , metal , crystallography , atomic physics , chemistry , computational chemistry , nanotechnology , layer (electronics) , metallurgy , physics , electron , organic chemistry , quantum mechanics , computer science , embedded system
We studied the epitaxial TiN(001)/Ge 2 Sb 2 Te 5 (001) (GST) interface of interest for applications in phase change non‐volatile memories by means of density functional calculations. The cubic phase of GST of interest for the memory devices was considered. From geometry optimization we found an equilibrium distance of about 3.0 Å between Ti and Te, Ge and Sb atoms located directly above along the [001] direction. The interface formation energy of a large 1440‐atom model is γ int = 50 meV/Å 2 . The surface energy of TiN(001) and GST(001) are γ S = 81 and 10 meV/Å 2 resulting in an adhesion energy of γ ad = 41 meV/Å 2 . A good adhesion between the two materials can thus be achieved in the ideal epitaxial configuration. The presence of metal induced gap states (MIGS) is revealed by the analysis of Kohn–Sham (KS) orbitals.