Numerical study of carrier velocity for p-type strained silicon MOSFET

Abstract

Strained induced in the silicon channel layer provides lower effective mass and suppresses intervalley scattering. In this paper, a numerical study of carrier concentration for P-type strained Silicon MOS is presented. Density of state proportion of Fermi-Dirac integral that covers the carrier statistics to all degenerate level is studied and its limits are obtained. In the nondegenerate regime the results replicate Boltzmann statistic and its result is vary in degenerate regime. The Fermi energy with respect to the transformed band edge is a function of carrier concentration for quasi two dimensional strained Silicon PMOS. Based on the Fermi - Dirac statistic, density of state the carrier concentration is obtained. Fermi energy is a function of temperature that independent of the carrier concentration in the nondegenrate regime. In the other strongly degenerate, the Fermi energy is a function of carrier concentration appropriate for given dimensionality, but is independent of temperature. The limitations on carrier drift due to high-field streamlining of otherwise randomly velocity vector in equilibrium is reported. The results are based on asymmetrical distribution function that converts randomness in zero-field to streamlined one in a very high electric field. The ultimate drift velocity is found to be appropriate thermal velocity for a given dimensionality for non- degenerately doped nanostructure. However, the ultimate drift velocity is the Fermi velocity for degenerately doped nanostructures.