2-D MOSFET MODELING INCLUDING SURFACE EFFECTS AND IMPACT IONIZATION BY SELF-CONSISTENT SOLUTION OF THE BOLTZMANN, POISSON, AND HOLE-CONTINUITY EQUATIONS

We present a new two-dimensional (2-D) MOSFET simulation method achiev ed by directly solving the Boltzmann Transport equation for electrons, the Hole-Current Continuity equation, and the Poisson equation self-c onsistently. The spherical harmonic method is used for the solution of the Boltzmann equation, The solution directly gives the electron dist ribution function, electrostatic potential, and the hole concentration for the entire 2-D MOSFET, Average quantities such as electron concen tration and electron temperature are obtained directly from the integr ation of the distribution function, The collision integral is formulat ed to arbitrarily high spherical harmonic order, and new collision ter ms are included that incorporate effects of surface scattering and ele ctron-hole pair recombination/generation. I-V characteristics, which a gree with experiment, are calculated directly from the distribution fu nction for an LDD submicron MOSFET, Electron-hole pair generation due to impact ionization is also included by direct application of the col lision integral, The calculations are efficient enough for day-to-day engineering design on workstation-type computers.