AFM STUDY OF EXCIMER-LASER ABLATION OF POLYTHIOPHENE FILMS

Atomic force microscopy (AFM) was used to estimate the etching form on excimer laser ablation of polythiophene films. Electrochemically prep ared polythiophene films were irradiated with ArF (193 nm) and KrF (24 8 nm) excimer lasers through a mask attached to the film. Single pulse irradiation of these lasers created a well-defined periodic structure on the irradiated region. The periodic structure was ascribed to Fres nel diffraction of the incident beam with the edge of the mask and was characteristic of non-fusible polythiophene films. The threshold flue nces above which the etching occurs were determined to be approximatel y 30 and 50 mJ cm(-2) for the 193 nm and 248 nm lasers respectively. T he emission spectra from the plume suggested that the degree of fragme ntation was higher for 193 nm irradiation than for 248 nm irradiation at the same fluence. (C) 1997 Elsevier Science S.A.