Energy density window for location controlled Si grains by dual-beam excimer laser

The processing energy density window of the location controlled Si (LC Si) grains has been studied experimentally. These Si grains were fabricated by dual-beam excimer laser irradiation in an a-Si/SiO2/metal stack with an array of bumps in the oxide. The influence of the bump diameter and the bump height on the lower and upper laser energy bounds has been investigated for the entire energy density range, where LC Si grains were formed. The widest obtained processing window, where location-controlled single grains as large as 4.2-4.7 μm were observed, had a width of 6.8%. The experimental results were also found to be in a very good agreement with the numerical simulation, based on the resolution of the two-dimensional heat flow equation