  Different techniques of event biasing have been implemented in the
particle-based Monte Carlo simulations of a 15nm n-channel MOSFET. The primary
goal is to achieve enhancement in the channel statistics and faster convergence
in the calculation of terminal current. Enhancement algorithms are especially
useful when the device behavior is governed by rare events in the carrier
transport process. After presenting a brief overview on the Monte Carlo
technique for solving the Boltzmann transport equation, the basic steps of
deriving the approach in presence of both the initial and the boundary
conditions have been discussed. In the derivation, the linearity of the
transport problem has been utilized first, where Coulomb forces between the
carriers are initially neglected. The generalization of the approach for
Hartree carriers has been established in the iterative procedure of coupling
with the Poisson equation. It is shown that the weight of the particles, as
obtained by biasing of the Boltzmann equation, survives between the successive
steps of solving the Poisson equation.
