A method at the core of today’s semiconductor and optical device production, sputtering is used to put down extremely thin films of a material onto a surface, typically referred to as a substrate.
Spluttering systems start with the substrate and coating source material being placed into a vacuum chamber that is then filled with an inert gas. The source material is then given a negative charge, and free electrons from the negatively-charged source material flow into the inert gas, turning the gas atoms into positively-charged ions. These ions are drawn to the negatively-charged source material at high speed and this causes atomic-sized particles from the source material to "sputter off" as a result of high-speed collisions. Coating material particles then cross the vacuum chamber and are deposited as a thin on the exterior of the substrate.