In-situ electrical probing of zones of nanoindentation-induced phases of silicon

Abstract

Phase transformed zones of silicon have been formed by nanoindentation both at the micro- and nanoscale and electrically probed using an in-situ measurement system. Zones composed of the high pressure crystalline phases (Si-III/Si-XII) have higher conductivity than those of amorphous silicon (a-Si). At the microscale probing laterally across the surface shows that the conductivity varies within the zones composed of the high pressure phases. The sensitivity to the different conductivities of the two phases allows mapping within the zones. Finally, at the nanoscale the conductivity of the high pressure phase zones can be correlated with the position of the pop-out associated with the formation of the phases. The zones have higher conductivity when the pop-out occurs earlier on unloading and we suggest that this is due to the reduction in trace volumes of a-Si formed during the early portion of the unloading cycle.