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First‐principles simulations of the leakage current in metal–oxide–semiconductor structures caused by oxygen vacancies in HfO 2 high‐ K gate dielectric
Author(s) -
Mao L. F.,
Wang Z. O.
Publication year - 2008
Publication title -
physica status solidi (a)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.532
H-Index - 104
eISSN - 1862-6319
pISSN - 1862-6300
DOI - 10.1002/pssa.200723166
Subject(s) - quantum tunnelling , oxide , dielectric , oxygen , condensed matter physics , materials science , high κ dielectric , band gap , gate dielectric , gate oxide , time dependent gate oxide breakdown , semiconductor , metal , leakage (economics) , chemistry , optoelectronics , electrical engineering , transistor , physics , voltage , metallurgy , organic chemistry , economics , macroeconomics , engineering
HfO 2 high‐ K gate dielectric has been used as a new gate dielectric in metal–oxide–semiconductor structures. First‐principles simulations are used to study the effects of oxygen vacancies on the tunneling current through the oxide. A level which is nearly 1.25 eV from the bottom of the conduction band is introduced into the bandgap due to the oxygen vacancies. The tunneling current calculations show that the tunneling currents through the gate oxide with different defect density possess the typical characteristic of stress‐induced leakage current. Further analysis shows that the location of oxygen vacancies will have a marked effect on the tunneling current. The largest increase in the tunneling current caused by oxygen vacancies comes about at the middle oxide field when defects are located at the middle of the oxide. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)