Physically Based Evaluation of Effect of Buried Oxide on Surface Roughness Scattering Limited Hole Mobility in Ultrathin GeOI MOSFETs

• This paper presents a numerical simulation study investigating the effect of buried oxide on surface roughness scattering limited hole mobility (mu(SR)) in ultrathin germanium-on-insulator (GeOI) MOSFETs, for the first time. The simulation considers wave function penetration at channel/oxide interface and nonlinear dependence of scattering matrix element on surface fluctuation. Three types of buried oxide materials are compared (GeO2, SiO2, and Si3N4). The mu(SR) increases in the order of SiO2 < GeO2 < Si3N4. This dependence of mu(SR) on buried oxide material is due to surface fluctuation scattering from backside Ge/buried oxide interface. Our simulation results show that Si3N4 and GeO2 are beneficial as buried oxide for mobility enhancement in GeOI MOSFETs, compared with conventional SiO2 as buried oxide. Our findings provide an insight into further improving mobility characteristic.

Ämnesord

TEKNIK OCH TEKNOLOGIER  -- Materialteknik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Materials Engineering (hsv//eng)

Nyckelord

Buried oxide

germanium-on-insulator (GeOI) MOSFET

mobility

surface roughness scattering

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