UV-laser-induced etching and metal seeding on polymers;: a surface characterization

Results of UV (308 nm) laser pulse induced dry etching with subsequent Pd deposition from a PdCl(2) solution (acid base with pH =1) on polyimide surface are reported. The surface roughness has been determined before and after illumination. The fractal-based examination techniques based on the area-perimeter and the structure function methods. It could be concluded that the preetching of the polyimide surface significantly enhances the flux of Pd atoms deposited onto the surface, which is a power function of the number of shots (30 mJ/cm(2) at 20 ns pulse duration) with a power coefficient close to 0.5. It has been observed that the seeding process started simultaneously at a number of places resulting in island-like deposits. Fractal characterisation of surfaces resulted in a fractal dimension changing between 2.28 and 2.71 carried out with the methods outlined earlier. It might be concluded that the seeding process occurs at atomic scale, but it exhibits a very strong trend towards the formation of aggregates and/or cluster-type structures. (C) 1999 Elsevier Science B.V. All rights reserved.