Silver layer instability in a SnO2/Ag/SnO2 trilayer on silicon

► Interfacial instability phenomena of SnO2/Ag/SnO2 trilayers were observed. ► At 200 °C, internal hillock, whiskers and islands of Ag were produced. ► Thermal stresses are not high enough to lead to the observed defect densities. ► Dewetting of internal Ag interfaces must be driving whisker and island formation.