Layer-selective lift-off processing in a TCO/Si thin film system by ultra-short (ps, fs) laser pulses

Narrow craters and trenches have been scribed into Si/TCO thin film systems on glass by selective laser lift-off using nano-, pico- and femtosecond pulses of ~ 0,5 μm wavelength. A high-resolution microstructural material investigation shows a significant reduction of HAZ (heat affected zone) by changing from ns to ps and fs pulse durations. Thus, ablation efficiency and selectivity of ps- and fs-lift-off thin film processing in comparison to thermal ablation by ns pulses is strongly increased. This allows reducing the total scribe region (optically inactive zone) to widths below 50 μm and minimized structural modifications on TCO/glass substrate regarding to laser interaction processes.