Non-resolving mask tiling method for flare reduction

摘要

Photoresist on a wafer is exposed using tiles on a mask that improve flare performance. Features that are not to be exposed on the photoresist correspond to features on the mask. The various features are surrounded by other features that vary and thus affect flare differently. Selected features have tiles added nearby but also far enough away to improve uniformity in the effects of flare on the various features that are intended to be present in the photoresist. The tiles are made either very small in width or partially absorbing so that the tiles are not resolved in the photoresist. Thus the tiles reduce flare but do not alter the desired pattern in the photoresist.