Laser patterning captured in real-time: surface modifications of multilayer thin-films under nanosecond laser heating

Abstract

Controlled wrinkle formation has attracted intensive research interest as a means to modify surface properties. However, most of the currently explored methods rely on mechanically stretching polymer substrates with hard surface coatings, and the application of these methods to different materials is limited. Here, for the first time, we demonstrate laser-assisted periodic wrinkle formation on silicon nitride (SiN) membranes that are coated with titanium (Ti)/nickel (Ni) multilayers. Corrugated surface formation mechanism, as well as grain nucleation and growth, are studied using ultrafast transmission electron microscopy (UTEM). Periodic wrinkling and patterning of multilayers on thin SiN membranes are induced by a nanosecond pulsed laser, and the deformation of the film is captured by single-shot imaging. The investigated structures revealed periodic wrinkling of the membrane and corrugated surface formation on both sides of the film. The findings of this work could allow laser-irradiation-based fast fabrication of corrugated films with tailored properties.