Production of two-dimensional periodical structures by laser interference irradiation on bi-layered metallic thin films

The production of one- and two-dimensional periodical structures produced by Laser Interference Metallurgy (LIMET) on bi-layered metallic films by using nanosecond pulsed laser is reported. The systems investigated are Fe/Al and Cu/Al and represent model systems where the melting point of the upper layer is higher tan the lower one. Aspect ratio, height and width of the structures are discussed as a function of laser fluence, partial energies and arrangement of the laser beams. Cross sectional analysis of the structured samples demonstrates the flux of molten metal parallel to the thermal gradient generated by the laser heating.