Monte Carlo study of Germanium n- and pMOSFETs

In this paper, we perform fullband Monte Carlo simulations of Ge bulk nand pMOSFETs and compare them with their Si counterparts. We consider transport in the presence of phonon, ionized impurity, surface roughness scattering, and impact ionization. Quantum confinement in the inversion layer is taken into account in the form of a modified potential. Germanium devices gave higher drive current when compared with Si devices for the device structures studied. Consistent with the arguments of Lundstrom, the performance enhancement of Ge MOSFETs lies between that which would be expected based on the higher mobility alone, and the much smaller advantage, if any, offered in the ballistic limit where transport is governed by thermal injection velocities from the source.