Growth of surface relief structures on Ag/AsS2 bilayer thin films by electron beam irradiation

Metal/chalcogenide thin films have a great potential for the application in electronics and microelectromechanical systems. Methods of creating different surface relief structures on metal/amorphous chalcogenide (Ag/AsS2) thin film bilayer surface by using focused electron beam were explored in this study. Ag/AsS2 bilayer was prepared in two steps - (1) Ag thin film was sputtered on a substrate by DC magnetron sputtering method and (2) AsS2 thin film was deposited on Ag thin film surface by thermal evaporation method. Using EB in scanning electron microscope, two types of surface relief structures were obtained on the surface of Ag/AsS2 bilayer: nanodots and micro-squares. The obtained structures were measured by atomic force microscopy. Changes in chemical composition during EB irradiation were observed by energy dispersive spectroscopy. The height of the obtained nanodots was up to 120 nm and the width at half height was up to 230 nm. The height of the middle area of micro-squares was up to 60 nm and additional structure growth was observed along the edges of micro-squares.