Effect of silicon resistivity on its porosification using metal induced chemical etching: Morphology and photoluminescence studies

Abstract

The structure and light-emitting properties of porous Si nanowires (Si NWs) fabricated by metal induced chemical etching (MIE) process on two different Si substrates of different resistivities have been investigated here. The surface morphological studies have been carried out using scanning electron microscopy. It is observed that porous Si containing well aligned SiNWsis formed from high resistivity (1-20Ωcm) Si wafer, whereas interconnected pores or cheese-like structures are formed from low resistivity (0.2Ωcm) Si wafers after MIE. An explanation for the different porosification processes has been proposed based on the initial doping level, where number of dopants seems to be playing an important role in the etching process. Visible photoluminescence (PL) has been observed from all the porous Si samples, that are attributed due to quantum confinement effect. © 2015 IOP Publishing Ltd.