Reticle and technique for multiple and single patterning

Abstract

Double patterning is achieved with a single reticle while maintaining the integrity of in-scribe patterns and without blading the reticle. In-scribe structures may or may not be double patterning. For example, elements such as electrical test structures might have features that are so closely spaced that double pattering is desired. However, elements such as optical alignment marks might not require double patterning. For those elements for which double patterning is not desired, a first sub-array of the reticle has a pattern for the element, whereas the corresponding location in a second sub-array has a blank. By the corresponding location, it is meant the location on the reticle that would be exposed to the same target region to which the element would be exposed if the reticle were used for double patterning. Thus, the blank prevents target region from being exposed more than once.