High Quality Content by WIKIPEDIA articles! Thin films are thin material layers ranging from fractions of a nanometre (monolayer) to several micrometres in thickness. Electronic semiconductor devices and optical coatings are the main applications benefiting from thin film construction. A familiar application of thin films is the household mirror which typically has a thin metal coating on the back of a sheet of glass to form a reflective interface. The process of silvering was once commonly used to produce mirrors. A very thin film coating (less than a nanometre) is used to produce two-way mirrors.