The verb to sputter is derived from the Latin word SPUTARE which means to secrete saliva with noise. Sputtering is the collisions of atoms on a surface that results in the discharge of atoms from the surface as a result of bombardments and energy transfer from the incoming particles. This process is most commonly used for thin-film deposition of various materials including metals and ceramics. The occurrence was first explained more than 150 years ago in 1852 by William Robert Grove who described vaporization and film formation of metal films by sputtering. Grove discovered “sputtering” while studying glow discharges. Grove utilized a tip of wire as the coating foundation and sputtered a deposit onto a silver surface that was close to the wire at a pressure around 0.5 Torr (1). He made a note of a coating on the silver surface when the silver surface was the cathode and the wire was the anode in an electrical circuit. . M. Faraday likewise described film deposition by sputtering in 1854. At this time sputtering was an unwanted phenomenon because it destroyed the cathode and grid in the gas discharge tube.
As early as 1585 sputtering was used to create gorgeous metallic mirror. This incident first occurred when Julius Plucker reported platinum film inside of a gas discharge tube creating the first metallic mirror via sputtering(2). Sputtering also found many other applications such as coating fabrics and phonograph wax masters. In Thomas Edison’s 1902 paten on the subject of seed coating his wax cylinder phonograph he used sputtering to deposit gold to create the gold moulded cylinder records to subsequent electroplating(3). Before 1908 it was believed that the deposits were a direct result of evaporation at hot spots on the cathode. But numerous experiments between 1908 and 1960 with ions and sputtering of singe crystals via ion beams supports momentum transfer as a result of deposition over evaporation(4).
Many applications of sputtering were replaced by thermal evaporation in the late 1930’s. But the significant process advancements of radio frequency sputtering which allows for direct deposition of alloys and insulators and magnetron sputtering which permits higher deposition rates with smaller amounts of substrate damage have evolved since that time. Advancements like these have allowed sputtering to compete with PVD techniques such as thermal evaporation and to declare it spot as one of the more important thin film deposition techniques (4). Around the same time the thermal evaporation process was replacing sputtering in the late 1930’s Penning developed...
