A new method of patterning metallic thin films is described. Through the use of a focused laser deflected by a high‐speed, galvanometer scanning system, a variety of fine metal patterns are realized on inorganic and organic substrates. This method exploits the metastable wetting characteristics of metallic thin films as deposited by physical vapor deposition upon non‐metallic substrates. Differences in surface energy and intermolecular forces between the target and the substrate provide a driving force for retraction of the thin film, while the laser provides the energy needed to overcome the kinetic barrier to dewetting. Electronically isolated feature sizes in the range of the tens of microns are fabricated. During formation, material is displaced rather than ablated allowing controlled accumulation of the target material. This results in a user‐determined increase of the metal feature thickness. Evidence of accurate and reproducible periodic and complex structures made feasible by virtue of the scan system, are presented. This technique provides an alternative to current thin film patterning techniques and introduces a new way of building out‐of‐plane structures from metallic thin films. Application fields may include flexible sensors, electrochemical devices, and especially microfluidic devices, as the technique allows formation of conductive micro‐channels with user‐defined height.
Microelectromechanical systems (MEMS) are pervasive in modern technology due to their reliability, small foot print, and versatility of function. While many of the manufacturing techniques for MEMS devices stem from integrated circuit (IC) manufacturing, the wide range of designs necessitates more varied processing techniques. Here, new details of a scanning laser based direct-write dewetting technique are presented as an expansion of previous demonstrations. For the first time, the ability to pattern a high melting temperature and high reflectance metallic thin films of Ni and Ag, respectively, on polymer substrates is reported. Novel methods for reducing the power necessary for processing highly reflective films are demonstrated by depositing very thin films of high near-infrared absorbance.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.