Patent ID: 6965427

Claim:
A system comprising: an illumination system that produces light; a processing system that processes substrates; an exposure system using pairs of reticles to pattern the light and exposes the substrates to the patterned light; and a controller that controls a sequence of introducing pairs of the substrates into the exposure system and a sequence of positioning pairs the reticles to perform the patterning of the substrates, such that, during a first exposure period a first reticle in a first pair of reticles patterns a first pair of substrates, during a second exposure period a second reticle in the first pair of reticles patterns the first pair of substrates and a second pair of substrates, and during a third exposure period the first reticle in the first pair of reticles patterns the second pair of substrates, wherein the first, second, and third exposure periods use subsequent pairs or reticles to pattern subsequent pairs of substrates.