Laser-guided pattern writing through Thiobacillus ferrooxidans metabolite

Most microstructures are fabricated by photolithography, which needs masks to define the specific patterns, and the successive exposure, developing and etching steps. A maskless fabrication process has been developed on the other hand. The designed micro patterns are written on the specimen by laser guiding to build or repair micro structure rapidly rather than using the time-consuming mask fabrication process. The current study investigates the feasibility of laser-assisted deposited copper patterns on copper substrate using Thiobacillus ferrooxidans (T.f.) metabolite as working medium is a new approach instead of chemical deposits. An optical platform with a long working distance objective is used to focus a 1064 nm Nd:YAG laser and to form the desired patterns. This laser-assisted deposited copper patterns process is a photothermal reaction in which the copper ions (Cu(2+)) oxidized from the substrate surface by T.f. metabolite are reduced and deposited along the laser scanning trajectory on substrate. In the experiment, there is a positive correlation between the deposition amount and the laser power, scanning speed and scan repetitions, respectively. Combining the etching and the laser-guided writing through T.f. metabolite reveals an innovative way of producing metallic microstructures. (C) 2008 Elsevier B.V. All rights reserved.