Photoablation and microstructuring of polyestercarbonates and their blends with a XeCl excimer laser

The growing field of microtechnology creates a need for new methods of structuring affordable materials. Excimer ablation lithography (EAL) has been introduced as a new method for producing microstructures. The ablation and microstructuring behavior of bis-phenol-polycarbonate-A, several polyestercarbonates and their blends in varying proportions, were investigated by using the radiation of a XeCl excimer laser. It was found that a minimum content of polyester, either in the co-condensate or in the blend, is necessary to obtain transparent structures in the irradiated film for irradiation at 308 nm. When recorded as a function of the molar fraction of the polyester, the etch rate passes through a local maximum and consecutively decreases with increasing content of the polyester group in the polymer bulk. Microstructures with a resolution in the sub-micron scale were obtained by EAL, and the resultant structures were made visible and analyzed using an atomic force microscope (AFM).