Molecular dynamics extensions of Monte Carlo simulation in semiconductor device modeling

The modeling of relaxation and transport is semiconductors is often performed using Monte Carlo techniques in which electrons follow free trajectories between discrete scattering events, the scattering events being defined to include carrier-phonon interactions and Coulomb interactions among various carrier species and the ionized impurities. We consider situations in which this approach is inappropriate, and describe corresponding implementations of a more accurate technique in which the usual Monte Carlo technique is combined with a molecular dynamics time evolution between scattering events. In these approaches, the Coulomb interaction is not approximated as screened scattering between pairs of particles, but instead is treated explicitly by allowing the carriers to follow trajectories accelerated by the electric field of the other charges in the system. In one implementation, the particle dynamics incorporates quantum corrections such as exchange interaction.