Surface Analysis of Stressed and Control Tin Oxide Thin Films on Soda Lime Glass

Surface analysis techniques have been used to investigate tin oxide-coated soda lime glass specimens prior and subsequent to their exposure to DC bias, heat, and humidity. All specimens reported here comprise the following layered structure: tin oxide/silicon oxycarbide/glass. Depth profiling using X-ray photoelectron spectroscopy (XPS) clearly shows the interfacial regions in both control samples and samples exposed to the above-mentioned conditions (stressed). Control samples show distinct and relatively compact interfacial regions as well as an intact silicon oxycarbide diffusion barrier. Stressed films, however, show more diffuse interfacial regions and a physically and chemically altered silicon oxycarbide diffusion barrier. This deterioration of the diffusion barrier is proposed to be a prerequisite event to enable tin oxide delamination.