COMPUTER-SIMULATIONS OF PORE GROWTH IN SILICON

The dynamics of pore formation in silicon was studied by computer simu lation. Porous structures were generated by a Monte Carlo algorithm th at controlled the motion of an ensemble of electronic holes on a two-d imensional square lattice. Hole motion was biased to the nearest pore tip in order to simulate local electric-field effects corresponding to the depletion layer setup in n-type silicon. Several morphological ch aracteristics seen in porous silicon were seen in the simulation: high ly directional pores, steady-state pore spacing, and a smooth pore fro nt. The pore spacing and the degree of sidebranching depended on the c oncentration of holes and the magnitude of the bias. The simulation tr ends are analogous to the pore morphologies seen in n-type silicon.