Laser induced forward transfer aluminum layers: Process investigation by time resolved imaging

Laser induced forward transfer of an aluminum thin film on a triazene polymer as a sacrificial layer has been studied with time resolved imaging. Both side- and front-on imaging of the process give a more detailed understanding of the stability of the ejected material during flight. For high fluence ablation (800 mJ/cm(2)) the flyer is stable for 400 ns and gets decomposed completely when interacting with the shockwave after 1 mu s. Material detachments on the edges of the flyer are observed at an early stage of the ablation process (<200 ns) which leads to a pixel smaller than its ablation cross section. For low laser fluence (200 mJ/cm(2)) the flyer has the size of the ablation spot and keeps its shape for nearly 1 mu s. The back pressure of the decomposed triazene polymer bends the flyer towards the direction of flight and indications for folding are observed. (c) 2011 Elsevier B.V. All rights reserved.