Improvement of mask-limited yield with a vote-taking lithographic scheme

Abstract

A lithographic technique which can significantly reduce the effect of photomask defects is investigated. It is based on exposures of multiple reticle fields containing identical patterns, and is especially suitable for 1 X wafer steppers. The principle, requirements, and initial experimental results of this method are presented.

Elimination Of Mask-Induced Defects With Vote-Taking Lithography

“…Referring to Table 1, this resist contrast would be suitable for N > 4, but still falls substantially short of the level required for the best performance in a three-field voting scheme. Better results can be expected if more fields were used, and this was indeed demonstrated in a work reported earlier 9 .…”

A standardized method for CMOS unit process development

“…3) Fourfold repetition of identical structures on one reticle simplifies the detection of systematic and random reticle defects [8] and measures the effect of intra-chip parameter variations on defect density [9]. Fig.…”