Resist Patterning Characteristics using KrF Laser-ablation Process

The patterning characteristics of a variety of resist material platforms were investigated using a KrF laser ablation process. The results showed that a fullerene-based resist material with a 170-nm film thickness is capable of sub-micron resolution up to 0.8 μm 1:1 lines and spaces (L/S). Moreover, using a novolac-based resist material, the dependence of laser ablation patterning performance on the resist process conditions was determined. An increase in the total exposure energy (exposure energy per pass × total number of passes) is necessary as the film thickness increases. Moreover, using the same novolac-based resist material fixed at a 5-μm film thickness, results suggested that exposure energy has a more significant impact on the effective formation of laser ablation patterns (compared to number of exposure passes). Finally, preliminary investigations using a metal resist (at a 90-nm film thickness) resulted in resolution capabilities up to 2 μm 1:1 L/S at a relatively lower total exposure energy. This showed the potential of the metal resist material for application in laser ablation patterning.