Healable nanoscale deterioration of gold nanothin film

• Local EC degradation and healing of Au nanofilm surface are created and analyzed. • The effect of internal band bending and crystallinity is anticipated and indicated. • Film thickness and sample storage time are found to play the determining role. • Formation and de-stabilization of anionic Au hydrides and oxides are implied. Metal deterioration in semiconductor devices increases the risk of equipment failures leading to higher operating costs, waste generation, and poor resource utilization. Although the understanding of degradation dynamics and the corresponding molecular products especially at the early stages can improve degradation prevention, the acquisition of such information from real samples is challenging. This is not only because of the ultra-small size of degradation features but also the correlation of measurable data. Herein, nanoscale electrochemical deterioration and healability of ultrathin Au films on an n -type Si substrate are investigated. Considering the possible effect of internal band bending on surface electron mobility and surface reaction, the investigation is performed with different Au thicknesses on n -type and undoped Si substrates with sample storage time varying from 24 h up to 300 h. In conjunction with the structural insight obtained from 4-point probing (4PP) data and X-ray diffraction (XRD) data, the electrochemical dynamics of surface degradation and healing induced by highly localized contact electrification (CE) are described through anionic clusters denoted by atomic force microscope (AFM) force curve mapping data. The finding can contribute to the improvement of surface protection for functional metal films in semiconductor devices and highlights the importance of nanothickness selection.