Sputter deposition is a method of physical vapour deposition where ionised sputtering gas (typically inert argon, krypton or xenon) sputter atoms from a target of metallic material. The target atoms then condense on a substrate to form a thin film. The sputter deposition application is used to coat various materials with a thin film on such as semiconductor devices, glass and food packing materials (eg aluminised PET film for snack bags).