Monte Carlo simulation of electron transport in ${\mathrm{S}\mathrm{i}/\mathrm{S}\mathrm{i}\mathrm{O}}_2$ superlattices: Vertical transport enhanced by a parallel field

Considerable effort is presently devoted to develop Si quantum structures for microelectronics and nanoelectronics. In particular, well-defined ${\mathrm{S}\mathrm{i}/\mathrm{S}\mathrm{i}\mathrm{O}}_2$ superlattices and quantum wells are under study. We investigate here the transport properties of a ${\mathrm{S}\mathrm{i}/\mathrm{S}\mathrm{i}\mathrm{O}}_2$ superlattice with a multiband one-particle Monte Carlo simulator. The band structure is obtained with an analytical model and the scattering mechanisms introduced in the simulator are confined optical phonons, both polar and nonpolar. Owing to the very flat shapes of the bands along the growth direction, very low drift velocities are obtained for vertical transport. However, the simulation shows that, for oblique fields, the transport properties along the vertical direction are strongly enhanced by the in-plane component of the electric field, consequently higher vertical drift velocities can be easily obtained.