The transient behavior of the laser lift-off of thin molybdenum films, initiated by glass substrate side irradiation with a
660 fs laser pulse, is investigated in the picosecond range. For this purpose, a pump-probe microscopy setup is utilized to measure the transient relative reflectivity change in the center of the irradiated spot at the molybdenum/glass interface, which enables an interferometric observation of the shock wave propagation in the glass. In addition, a transient simulation of the electron and lattice temperature was performed. The results suggest that ultrafast heating initiates a shock wave in the molybdenum and the glass when the laser pulse has reached maximum intensity. At 10 ps, a confined phase explosion adds further momentum, and the Mo layer is caused to bulge.
Molybdenum films on a glass substrate are ablated from the glass side by picosecond laser pulses at fluences
below 1 J/cm2, without damage. Thin films of chromium, titanium and platinum with thicknesses between 200 nm and
1 μm were examined to investigate the underlying ablation mechanisms. For molybdenum an influence of the
intermediate buffer layer was observed. Ablation from the glass side clearly has higher ablation efficiency and a better
structural quality in contrast to metal side patterning. A model will be presented, in which the ablation characteristics are
connected with the mechanical ductility of the metal.