CHANNELING EXPERIMENTS ON POROUS SILICON BEFORE AND AFTER IMPLANTATION

Porous silicon films with sponge like structure were implanted with ph osphorus ions in order to lower their resistivity. The effects of ion implantation and various heat treatments were investigated using ion b eam analytical methods. Depending on the layer thickness as well as th e energy and dose of the bombarding ions a highly damaged layer could be formed inside or underneath the porous layer. We found that there a re two main effects of ion implantation, the amounts of the contaminan ts can be decreased and the porous layer may be densified. If the dose was high enough to deplete almost all of the contaminants, the resist ivity decreased by three orders of magnitude after the subsequent heat treatment.