In the publication of Brian Q, et al., Optics and Laser Technology (2012), the authors reported a laser ablation method to pattern ITO film on a glass substate for the solar cell fabrication.
Experiment Setup. Ti: Sapphire Femtosecond laser is used with wavelength of 800nm, maximum pulse energy of 5mJ, repetition 0f 1 KHz, pulse duration tunable (60fs to 600fs).
Results. A groove can be cut out by the laser through tuning the pulse duration, pulse fluency, and scanning speed. The formed grooves have the following properties:
1) groove width between 2um to 20um
2) ridge height of 5nm to 30nm
Some important conclusions:
1) the damage threshold energy of 60fs pulse is 0.21 J/cm2.
2) the damage threshold energy slightly increase with longer pulse
3) at same energy, shorter pulse has stronger multi-photon ionization at higher peak intensities and increases laser ablation effects, e.g. deeper and wider grooves.
4) ridges and formed due to materials melting and surface tension as a driving force.
Source: http://dx.doi.org/10.1016/j.optlastec.2012.06.018