Researched
Wafer Stepper
A stepper (GCA, about 1978) shrinks the mask image through a reduction lens and exposes the wafer field by field, reaching about one micron.
Open in the interactive tree →The step-and-repeat principle came from mask-making cameras; Philips began work on stepping in the early 1970s, and ASML was founded in 1984 to sell Philips's PAS 2000 stepper. Precise lenses and stage positioning became the core of the lithography industry.