Reflectivity measurements of the backsurface of thin polyimide films indicate a transient decrease in reflectivity during ArF (193 nm) excimer laser ablation. The posterior surface reflectivity is decreased by 20%-40% over the range of incident laser fluences from 75 to 175 mJ/cm2, respectively. The results are discussed within the framework of a theoretical model of saturable absorption, and calculations are presented which are in good agreement with the experimental results. It is concluded that the observed decrease in reflectivity is the result of transient changes in the optical properties within the solid polymer material which occur during ultraviolet laser ablation.
|Original language||English (US)|
|Number of pages||3|
|Journal||Journal of Applied Physics|
|State||Published - 1994|
ASJC Scopus subject areas
- Physics and Astronomy(all)