Influence of dopant species on electron mobility in heavily doped semiconductors

We present a new theoretical approach to study the influence of the dopant species on the electron drift mobility in doped semiconductors under low electric fields. The charge distribution of the impurities is described by the Thomas-Fermi theory in the energy functional formulation. We have included many-particle effects, such as dispersive screening and multiple scattering, which become important in heavily doped semiconductors. Analytical expressions for the scattering cross section for various species of dopants using the Born approximation up to second order are derived. Monte Carlo simulations including all important scattering mechanism have been performed for Si, GaAs, and InP in the doping concentration range of 10(15) to 10(21) cm(-3). The dependence on donor species is significant for concentrations beyond 10(18) cm(-3), whereas the minority electron mobility is not affected by different dopants. Not only confirm the results the experimental data of the mobility enhancement of minority electrons compared to majority electrons in degenerated semiconductors but also the lower electron mobility in As-doped Si in comparison to P-doped Si.