Defect formation of Au thin films on SiO₂/Si upon annealing

We have studied structural changes of Au film surfaces grown on Si with native oxide layers. Using X-ray photoelectron spectroscopy (XPS), we found that annealing above 200°C can cause formation of defects (or cracks), which is most likely driven by interdiffusion of Au and Si accompanying strong Au-Si interactions at the interface regime. Scanning tunneling microscopy (STM) study is also in line with defect formation upon annealing. Interaction of O ₂ with rough Au surfaces is discussed in connection with catalytic activities of Au surfaces.