Investigation of scalability for Ge and InGaAs channel multi-gate NMOSFETs

Using a physical and predictive 2-D confinement model considering the impact of source/drain coupling on the potential well, this work investigates the scalability of Ge and InGaAs multi-gate NMOSFETs by exploring a wide design space with various aspect ratio (AR). Our study indicates that, for a given subthreshold swing, multi-gate devices with InGaAs channel are more scalable than the Ge counterpart because of the larger fin-width allowed. Since the quantum-confinement effect can improve the V
th
roll-off, Tri-gate (AR=1) with significant 2-D confinement effect exhibits better V
th
roll-off than FinFET (AR>1). In addition, the InGaAs devices exhibit better V
th
roll-off than the Ge devices.