Sputtering is a physical vapour deposition method that involves depositing thin films in a vacuum environment. During this process, a solid material and substrate are positioned separately within a vacuum system. A high-energy argon ion plasma stream is targeted at the material, resulting in the subject material being ejected and deposited onto the substrate, creating a thin film. As this is not an evaporative process, the temperatures required for sputtering are lower than evaporation methods. This makes it one of the most flexible deposition processes and it is particularly useful for depositing materials with a high melting point or a mixture of materials, as compounds that may evaporate at different rates, can be sputtered at the same rate. Certain processes will benefit from improved film adhesion due to higher impact energy. The sputtering process is used extensively in the semiconductor industry, screen displays, photovoltaics and magnetic data storage. Sputtering can be used to deposit a wide variety of thin films including metals, oxides, nitrides and alloys.