Time-resolved ultrafast laser ablation dynamics of thin film indium tin oxide

Opt Express. 2021 Sep 13;29(19):30062-30076. doi: 10.1364/OE.434515.

Abstract

The interaction of ultrashort laser pulses above the ablation threshold of thin-film indium tin oxide (ITO) is examined with pump-probe microscopy. We are able to observe photomechanical spallation at delay times of hundreds of picoseconds, which plays a stronger role near the ablation threshold of 0.17 J/cm2. A phase explosion may also be observed at tens of picoseconds, playing a stronger role for increasing peak fluences. As one exceeds the material removal efficiency maximum near 0.6 J/cm2, a second spallation is observable in the center of the irradiated spot at a delay time of one nanosecond and corresponds to a crater depth of 50 nanometers. No discernable ridge formation has been observed. We recommend an industrial processing window of at least two pulses per position with a peak fluence between 0.6-1.0 J/cm2.