Mapping of structures and properties evolved during sono-electroplating of nickel thin films

Abstract

Nickel and its alloy films have versatile applications including metal coatings for its high strength, surface finishing and corrosion resistance, use in microelectronics, integrated optoelectronics and data storage technologies also used in decoration, electroplating industry and protection industries. Most properties of thin films are influenced by some factors such as crystalline structure, texture, or internal/residual stresses. The present research revolves around the residual stresses evolved during film synthesis. Residual stresses are stresses that remain after the original cause of the stresses (external forces) has been removed, which can have strong effects on film performance. These stresses are basically caused by interface coherency, thermal cycling and change in deposition parameters. Hence an understanding of the evolution of the same during synthesis will be a great avenue to thin film technologists. In the present study, an emerging technique sono-electroplating (electroplating plus ultrasound), has been used to synthesize Ni thin films at room temperature for four different electrolyte baths i.e. sulphate, chloride, Watts and sulphamate. And the aim of this study is to find the effect of ultrasonic vibration on evolution of residual stresses along with analysis of various parameters and properties including hardness, stress, surface finish and basic behavior of the depositing system in terms of cyclic voltammetry and chronoamperometry. The in-process analysis includes the electrochemical techniques and post-synthesis analysis followed by morphological studies includes SEM, AFM, XRD, hardness, residual stress and film thickness from surface profilometer. The same is solicited for electroplated and sonoelectroplated nickel thin films in four different aqueous solutions.