Laser ablation and microstructuring of Si-containing polycarbonates and polyestercarbonates

摘要

Abstract: Si-containing polymers, which act as RIE-resists by generating a passivating SiO$-2$/ film on the polymer surfaces, are applied in microlithographic processes. New Si-containing polymers, i.e., Si-containing polycarbonates and polyestercarbonates have been synthesized. Various contents of Si (up to 30 wt%) were incorporated into the polymers. Thin films (about 100 $mu@m thick) of the polymers were prepared for ablation and microstructuring at 308 nm. With a pinhole mask and a lens, a 10 $MUL 10 matrix of circular craters was created on the polymer films. The fluence and number of pulses were varied for each crater. Ablation parameters $alpha$-eff$/ (effective absorption coefficient) and F$-th$/ (threshold fluence) were determined for each polymer. Using a reflecting objective (Schwarzschild type), microstructures with a sub-micron resolution can be produced on the polymer films. The quality of the ablated structures was evaluated by scanning electron microscopy. The incorporation of Si into polymers does not affect the ablation behavior of the polymers. Si-containing polyestercarbonates exhibited good ablation behavior, while surface swelling (incubation) was observed for polycarbonates films. The results from this work includes that Si-containing polyestercarbonates are suitable for laser ablation and microstructuring.!19