A thin film is a layer of material ranging from fractions of a nanometer (monolayer) to several micrometers in thickness. The main applications are electronic semiconductor devices and optical coatings. Another application can be found in computer memory, where ferromagnetic films are used. Further areas of use are pharmaceuticals, solar cells and biocompatible medical parts.
The relatively high hardness and inertness of ceramic materials make this type of thin coating interesting for protecting substrate materials against corrosion, oxidation and wear. The use of such coatings on cutting tools can extend their service life considerably.