A method is provided for improving metallic nanostructure stability. The method provides a substrate, and using a physical vapor deposition (PVD) process for example, deposits metallic nanostructures having a first diameter overlying the substrate. Some examples of metallic nanostructures include Ag, Au, and Al. The metallic nanostructures are annealed in an atmosphere including an inert gas and H2. The annealing temperature is less than the melting temperature the metal material in bulk form. In response to the annealing, stabilized metallic nanostructures are formed. If the stabilized metallic nanostructures are exposed to an ambient air environment the stabilized metallic nanostructure maintain the first diameter. Typically, the metallic nanostructures are initially formed having a rectangular shape with corners. After annealing, the stabilized metallic nanostructures have a dome shape.