Impact of a Nonideal Metal Gate on Surface Optical Phonon-Limited Mobility in High- κ Gated MOSFETs

Author

Shah, Raheel ; De Souza, Maria Merlyne

Author_Institution

De Montfort Univ., Leicester

Volume

54

Issue

11

fYear

2007

Firstpage

2991

Lastpage

2997

Abstract

The effects of surface phonon scattering in an nMOSFET with a high-k gate insulator and a nonideal metal gate are examined. The nonideal metal gate model depends on three parameters: (1) the density of electrons in the gate; (2) the electron effective mass; and (3) the high-frequency dielectric constant associated with the choice of gate metal. The impact of these parameters on surface optical (SO) mobility is demonstrated using TiN as an example. For the selected choice of parameters and Landau damping limits, the results indicate that SO phonon scattering does not seem to play a significant role in the mobility degradation of TiN/HfO₂ MOSFETs for the entire range of sheet concentration.

Keywords

Landau levels; MOSFET; electron density; electron mobility; electron-phonon interactions; hafnium compounds; high-k dielectric thin films; oxygen compounds; permittivity; semiconductor device models; surface phonons; titanium compounds; Landau damping limits; TiN-HfO₂; electron effective mass; electrons density; high-frequency dielectric constant; high-k gate insulator; high-k gated MOSFET; mobility degradation; nMOSFET; nonideal metal gate model; sheet concentration; surface optical phonon-limited mobility; surface phonon scattering; Dielectrics and electrical insulation; Effective mass; Electron optics; High K dielectric materials; High-K gate dielectrics; MOSFET circuits; Metal-insulator structures; Optical scattering; Phonons; Tin; MOSFET; Metal gate; mobility; surface optical (SO) phonons;

fLanguage

English

Journal_Title

Electron Devices, IEEE Transactions on

Publisher

ieee

ISSN

0018-9383

Type

jour

DOI

10.1109/TED.2007.907135

Filename

4367614