  The effects of contact geometry and ideality on InGaAs and Si nano-scale
n-channel FinFET performance are studied using a quantum-corrected
semi-classical Monte Carlo method. Illustrative end, saddle/slot, and raised
source/drain contacts were modeled, and with ideal transmissivity and reduced
transmissivity more consistent with experimental contact resistivities.
Far-from-equilibrium degenerate statistics, quantum-confinement effects on
carrier distributions in real-space and among energy valleys, quasi-ballistic
transport inaccessible through drift-diffusion and hydrodynamic simulations,
and scattering mechanisms and contact geometries not readily accessible through
non-equilibrium Green's function simulation are addressed. Silicon $\langle
\hbox{110} \rangle$ channel devices, Si $\langle \hbox{100} \rangle$ channel
devices, multi-valley (MV) InGaAs devices with conventionally-reported energy
valley offsets, and idealized $\Gamma$-valley only $\left( \Gamma \right)$
InGaAs devices are modeled. Simulated silicon devices exhibited relatively
limited degradation in performance due to non-ideal contact transmissivities,
more limited sensitivity to contact geometry with non-ideal contact
transmissivities, and some contact-related advantage for Si $\langle \hbox{110}
\rangle$ channel devices. In contrast, simulated InGaAs devices were highly
sensitive to contact geometry and ideality and the peripheral valley's energy
offset. It is illustrative of this latter sensitivity that simulated
$\Gamma$-InGaAs device outperformed all others by a factor of two or more in
terms of peak transconductance with perfectly transmitting reference end
contacts, while silicon devices outperformed $\Gamma$-InGaAs for all contact
geometries with non-ideal transmissivities, and MV-InGaAs devices performed the
poorest under all simulation scenarios.
