06611316 is referenced by 289 patents.
The present invention provides a method and system for simultaneously imaging at least two reticles onto a substrate. According to the present invention, the wafer is passed through the exposure sequence once with images from the reticles being exposed simultaneously onto the wafer. The throughput of the system is effectively maintained at the standard single pass throughput level or twice that of conventional systems. In one embodiment, the present invention produces two reticle images side-by-side in the exit pupil of the optics of a step and scan wafer exposure system. The scanning action of the exposure tool then effectively superimposes the two images during the exposure of the wafer. Each image exposes the photoresist as the wafer is scanned through the image field synchronously with the scanning of the reticles. According to one embodiment, the image scanning is synchronized so that two required images are superimposed. According to another embodiment, the two images can be independently focused and aligned.