HEAT-TREATMENT EFFECTS ON POROUS SILICON

High-resolution scanning electron microscoPy of porous silicon (PS) su bjected to various annealing treatments in vacuum has revealed a spher oidal particlelike structure that only become clearly apparent after t reatment at about 250-degrees-C. This is consistent with recent sugges tions that any quantum effects arise from particles. It is deduced tha t the particles have a coating that is reduced or removed on heating. The concomitant effects on the current-voltage curves of PS, caused by annealing and also by prolonged air exposure, have been measured, and are consistent with the interpretation.