EXCIMER-LASER-PRODUCED NANOSTRUCTURES IN POLYMERS

The ability of excimer lasers to modify the surface morphology and the electrical conductivity of polymers with spatial resolution on a nano meter scale has been demonstrated. Using holographic techniques with a KrF excimer laser, periodic line structures with periods ranging from 166 to 950 nm have been ablated into polyimide (Kapton(TM)) and polyb enzimidazole (PBI). The nonlinear nature of laser ablation allows line widths as small as 30 nm to be obtained, exceeding the resolution expe cted from linear optics. These experiments establish a new spatial res olution limit for laser ablation and illustrate the dependence of reso lution on material properties. This technique has been combined with t he ability to modify the electrical conductivity of polymers to produc e an array of permanently electrically conducting wires in polyimide w ith a 0.5-mum width and a 0.9-mum period. The electrical conductivity of these submicrometer wires was greater than 1 OMEGA-1 cm-1.