Surface morphology evolution during electric field assisted dissolution of thin metal films

Electric field assisted dissolution is a process that enables micro- and nano- structuring of metal nanocomposite glasses, metal island films and compact metal layers on glass substrates, using simple equipment and technical setup. During the process, metal ions drift into a glass matrix under the influence of moderately elevated temperature and the applied electric field. The surface quality of nanostructured metal layers has great importance in many applications as it influences the device performance. In this work, a study of the surface morphology evolution during the dissolution of a compact metal layer is presented. It is found that in the course of gradual change from a compact to a completely dissolved layer, drift of metal ions from glass/layer interface is followed by the simultaneous deterioration of the surface quality already from the very beginning of the process. The surface morphology evolution could be described by the occurrence of surface roughness of the metal layer and continuous thinning of the layer. Understanding how this process takes place is important for improvement of electric field assisted dissolution application in structuring metal layers for optoelectronic devices.