Annealing effects in samples of silicon implanted with helium by plasma immersion ion implantation

Silicon samples were implanted with helium using plasma immersion ion implantation (PIII). The effects of implantation were analyzed by Raman spectroscopy, scanning electron microscopy (SEM), atomic force microscopy (AFM) and reflectance measurements before and after PIII, and after annealing (325 °C, for 30, 60 and 90 min and 450 °C for 30 min, in nitrogen atmosphere). After annealing, large bubbles were observed from SEM images and a connection between surface microstructure and materials properties was analyzed through AFM measurements. It was observed a reduction of the reflectance and an increase of the peak intensity of the photoluminescence (PL) with the increasing of the annealing time.