Sidewall mobility and series resistance in a multichannel tri-gate MOSFET

The sidewall mobility and the series resistance in a multichannel tri-gate MOSFET were examined with low-temperature measurement and 2D numerical simulation. With sidewall mobility separated from total transfer characteristics, it was shown that the sidewall conduction is mainly affected by the surface roughness scattering. The effect of surface roughness scattering on sidewall mobility was evaluated with the mobility degradation factor normalized by the low field mobility, which exhibited an almost six times higher value than that of top surface mobility. The series resistance of the multichannel tri-gate MOSFET was studied by comparing with that of the planar MOSFET. Through 2D numerical simulation, it was revealed that relatively high series resistance of the multichannel tri-gate MOSFET is attributed to the variation of doping concentration in the source/drain extension region in the device.