The research work is focused on a nanosecond/ sub-nanosecond pulsed laser-assisted micromachining of Cu coated on a dielectric material in environmentally-friendly solutions, such as NaCl and micron-level removal of copper from dielectric substrate materials without damaging the substrate. The influence of laser pulse duration (namely, 6 ns, 500 ps, 1 ps, and 120 fs) on micro-scribing on Cu coated on a dielectric material is studied. A thermo-temporal model is used to estimate the spatial and temporal variation of temperature in the sample and the microchannel depth. The LIBS-based elemental analysis approach is investigated for monitoring the channel depth and substrate ablation during laser-assisted micro-scribing. Further, a novel hybrid laser-processing approach is developed by combining the pulsed laser-assisted ablation technique with a selective etching technique for micro-scribing of Cu films. The hybrid laser-scribing technique is demonstrated by fabricating functional devices, such as a frequency selective surface (FSS) working in the X-band and an interdigitated electrode for an organic field-effect transistor (FET).

Keywords: Laser-assisted selective etching, Hybrid laser-assisted micro-scribing, Laser-induced breakdown spectroscopy (LIBS), Cu film micro-scribing