Ion-beam induced structural transformations in hydrogenated microcrystalline silicon

Ion-implantation induced structural transformations are investigated in hydrogenated microcrystalline silicon (μc-Si:H). Ion-beam processing of the μc-Si:H samples was done using 160 keV Ar+ ions at different dose values, in the range of 1013–1016 ions/cm2. Ion-beam induced transformation from the microcrystalline-to-amorphous phase was examined with the help of x-ray diffraction (XRD) and laser-Raman spectroscopic techniques. The conductivity changes in the samples were also monitored as a function of ion dose. It is observed that at a specific threshold ion dose value, the conductivity decreases by more than an order of magnitude. There are concomitant changes in XRD and laser Raman features. Furthermore the results clearly indicate grain growth under ion-beam irradiation at high dose values.