The influence of ambient temperature on KrF laser ablation of polyimide in air

The ablation rate of polyimide in air in the temperature range of 258C to 2008C is investigated with a 20 ns KrF excimer laser. The ablation rates for laser fluences between 60 and 2750 mJrcm2 show a decline vs. increasing temperature. Using Beer’s law of absorption, a fitting formula is found containing an empirical linear correction term which decreases with increasing substrate and ambient temperature. The optical properties of polyimide at elevated temperatures are considered also. q2000 Elsevier Science B.V. All rights reserved