photolithography

thumb|Silicon wafer that has undergone photolithography Photolithography (also known as optical lithography) is a process that involves using light to transfer a pattern onto a photoresist layer deposited on a sample, typically a silicon wafer. It is used in the manufacturing of integrated circuits.

The process begins with a photosensitive material, called a photoresist, being applied to the substrate. A photomask that contains the desired pattern is then placed over the photoresist. Light is shone through the photomask, exposing the photoresist in certain areas. The exposed areas undergo a chemical change, making them either soluble or insoluble in a developer solution. After development, the pattern is transferred onto the sample through etching, chemical vapor deposition, physical vapor deposition, plating, or ion implantation processes.