Laser induced damage/ablation morphology on the 8(Al/Ti)/Si system in different ambient conditions

A study of morphological and composition changes of the (8(Al/Ti)/Si) system induced by laser pulses in different ambient conditions is presented. The effects of an Er, Yb, Cr-Glass laser, operating at 1540 nm wavelength with pulse duration of 44 ns, on a complex target were investigated. Irradiation of 8(Al/Ti)/Si was carried out at intensities of 5.9 and 9.5×1011 W m−2 in air, water and ethanol. The laser-induced morphological and composition modifications have shown dependence on applied intensities, number of laser pulses and ambient conditions. The following morphological changes were observed: (i) intense surface melting of the thin film and Si-substrate; (ii) ablation/exfoliation of the 8(Al/Ti) multilayer thin film from Si, (iii) appearance of hydrodynamic features such as resolidified material, and (iv) formation of crater at multi-pulse action. The formation of parallel periodic surface structure was only occurring in single pulse air-assisted modification. Analysis of the composition revealed that laser modification induced intermixing between the components of individual Al and Ti layers with potential formation of AlTi intermetallic compounds.