Chemically Heterogeneous Nanowrinkling of Polymer Surfaces Induced by Low-Energy Cluster Implantation

Abstract

The properties of a thin film are, in part, governed by the nucleation or seeding of the material on a given substrate. Control over the seeding process is highly desirable, resulting in the ability to "dial up" desired film properties for the end application. In this study, we investigate the seeding process for thin films of Cr (thickness < 5 nm) sputtered onto polymeric substrates. These substrates are fabricated having Young's moduli spanning from the rubbery to the glassy state. Compliant substrates in the rubbery state display nanowrinkled structures during the early stages of film deposition (seeding). The combined chemical and morphological analysis of these films suggests implantation of Cr clusters within the polymeric substratethis implantation process is strongly influenced by substrate's mechanical properties. Understanding the seeding process, the resultant nanowrinkles, and the evolution to a continuous ultrathin film, will have an impact on the way these systems are engineered for practical applications.

Following in Situ the Deposition of Gold Electrodes on Low Band Gap Polymer Films

“…It should be noted thatin contrast to thermal evaporationsputtering creates gold particles of a comparably high energy, which can lead to diffusion of gold atoms into the first few nanometers of the soft polymer film. The implantation of metal atoms or ions within the surface-near region of polymers has been examined and described extensively for metals such as gold or chromium. ,− The nucleation process is linked to this embedding and immobilization of the gold particles within the surface-near region of the polymer film. The nucleation is followed by a further 3D growth of gold clusters, as seen in the pronounced increase of the cluster radius R .…”

Metal–Insulator Transition of Ultrathin Sputtered Metals on Phenolic Resin Thin Films: Growth Morphology and Relations to Surface Free Energy and Reactivity

“…In any event, the presence of the covalent polymer network is especially intriguing as it may prevent penetration of surface situated metal structures into the polymer or migration of fillers within the polymer even above its glass transition temperature [25,26]. On the other hand, metal implantation in compliant covalent polymer networks can be used to induce surface strain yielding tailorable buckling structures [27].…”

“…Describing and predicting the behavior of metal-polymer interfaces is aggravated by several circumstances such as the intrinsically irregular shape and composition of the polymer surface. Adatom implantation may add another layer of complexity since it can result in altered mechanical properties and morphology of the surface or the metal-enriched zone [27]. In general, however, polymeric materials possess a low-surface free energy (SFE) as a result of low cohesion energy density.…”