Interfacial oxygen and nitrogen induced dipole formation and vacancy passivation for increased effective work functions in TiN/HfO[sub 2] gate stacks
AuthorsHinkle, C. L.
Galatage, R. V.
Chapman, R. A.
Vogel, E. M.
Alshareef, Husam N.
Shaw, J. B.
Chambers, J. J.
KAUST DepartmentFunctional Nanomaterials and Devices Research Group
Material Science and Engineering Program
Physical Science and Engineering (PSE) Division
Online Publication Date2010-03-09
Print Publication Date2010-03-08
Permanent link to this recordhttp://hdl.handle.net/10754/552747
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AbstractEffective work function (EWF) changes of TiN/HfO2annealed at low temperatures in different ambient environments are correlated with the atomic concentration of oxygen in the TiN near the metal/dielectric interface. EWF increases of 550 meV are achieved with anneals that incorporate oxygen throughout the TiN with [O]=2.8×1021 cm−3 near the TiN/HfO2interface. However, further increasing the oxygen concentration via more aggressive anneals results in a relative decrease of the EWF and increase in electrical thickness. First-principles calculations indicate the exchange of O and N atoms near the TiN/HfO2interface cause the formation of dipoles that increase the EWF.
CitationInterfacial oxygen and nitrogen induced dipole formation and vacancy passivation for increased effective work functions in TiN/HfO[sub 2] gate stacks 2010, 96 (10):103502 Applied Physics Letters
JournalApplied Physics Letters