Patterning of aluminum thin films by 157nm F2 laser

A 157 nm F2 laser was used for the surface and interface modifications of Al thin films on silica glass substrate for fabricating a pattern of Al thin films. The F2-laser irradiated surface swelled remarkably by inducing the strong oxidation reaction of Al thin films to form Al2O3 protective layer. High adhesion strength of 663 kgf/cm2 between Al and silica glass was also obtained for the F2-laser-irradiated sample, compared with the cases in the ArF-laser irradiated, fourth harmonic of Nd:YAG-laser irradiated and nonirradiated samples of 326, 19 and 16 kgf/cm2, respectively. Thus, the F2- laser irradiated sample showed high abrasion resistance for embossing a fine pattern of Al thin films on silica glass. Mechanism of the F2-laser-induced surface and interface modifications was discussed, comparing with the cases in the ArF laser and fourth harmonic of Nd:YAG laser.