MOLECULAR-DYNAMICS MONTE-CARLO SIMULATIONS OF GRAIN-BOUNDARY ELECTRON-TRANSPORT IN N-SILICON

Electron transport in Si low-angle bicrystals is analyzed by a novel M onte Carlo molecular dynamics simulation scheme. The effect of discret e charges at the grain boundaries is studied and compared to results f rom one-dimensional treatments. The average grain boundary charge dens ity strongly influences transport, and a field-dependent threshold eff ect is predicted. Details of the internal charge arrangement are shown to be quite important at low fields and/or high grain boundary charge densities. Substantial increases in current conduction are predicted at lower temperatures over the thermionic emission model. Finally, ana lyses of interacting grain boundaries indicate site-correlation effect s and a strong dependence of conductivity on the separation distance. (C) 1998 American Institute of Physics.