One and two micron wide silicon fin patterns realized using standard g-line UV lithography are oxidized to accomplish nanowires. Simulation results envisage the possibility of silicon nanowire fabrication using top down fabrication approach. Experimental results show the feasibility of the process. SEM imaging was used to characterize the nanowires. Silicon nanowires up to 150 nm are demonstrated by the mentioned top down approach. Silicon consumption from three sides of the fins reduces their cross-sectional geometries. Stress developed during the oxidation of silicon leads to pinch-off in the fins, with aspect ratios >3. This pinch-off divides the fin patterns into two parts vertically; upper part detaches from the lower one and converges into silicon Nanowire, buried in silicon oxide. Simulation and process results for different process temperatures, time and fin aspect ratios are presented in the paper.