Accurate investigation of the high-k soft phonon scattering mechanism in metal gate MOSFETs

Author

Weber, O. ; Cassé, M. ; Thevenod, L. ; Ducroquet, F. ; Ernst, T. ; Guillaumot, B. ; Deleonibus, S.

Author_Institution

CEA-LETI, Grenoble, France

fYear

2005

fDate

12-16 Sept. 2005

Firstpage

379

Lastpage

382

Abstract

We report an experimental study of the mobility in TiN/HfO₂ gate stacks focused on the accurate determination of the HfO₂ remote soft phonon scattering mechanism. The high-K intrinsic mechanism is clearly dissociated from Coulomb scattering which generally dominates the mobility degradation in high-K/metal gate stacks. The temperature dependence of this additional phonon scattering mechanism is nearly linear. This scattering mechanism is shown to be negligible with a metal gate for a SiO_x interfacial layer (IL) thicker than 9-10Å. For a IL thickness of 7˚A, this mechanism degrades the electron mobility at high effective fields by ∼16% at 300K and ∼13%at 400K.

Keywords

MOSFET; dielectric materials; electron mobility; hafnium compounds; high-k dielectric thin films; interface phonons; titanium compounds; 300 K; 400 K; Coulomb scattering; MOSFET; SiO_x; TiN-HfO₂; electron mobility; high-K gate stacks; metal gate stacks; mobility degradation; soft phonon scattering mechanism; Degradation; Electron mobility; Hafnium oxide; High K dielectric materials; High-K gate dielectrics; MOSFETs; Phonons; Scattering; Temperature dependence; Tin;

fLanguage

English

Publisher

ieee

Conference_Titel

Solid-State Device Research Conference, 2005. ESSDERC 2005. Proceedings of 35th European

Print_ISBN

0-7803-9203-5

Type

conf

DOI

10.1109/ESSDER.2005.1546664

Filename

1546664