Inspection and printability of programmed defects on reticles for 0.200- and 0.175-um rule devices

摘要

Abstract: Defect specifications were studied for 0.200 and 0.175 micrometer rule memory cell patterns. Furthermore, we evaluated whether current inspection systems were capable of satisfying the defect specifications. For our evaluation, test masks with programmed defects in 0.200 and 0.175 micrometer rule memory cell patterns were fabricated using a variable shaped electron beam writing system and reactive ion etching. Recently, 0.250 micrometer rule devices have entered the mass- production phase using the defect specification based on the SIA roadmap. Accordingly, we assumed that the ratio of CD variations, corresponding to the defect size based on the SIA roadmap, to nominal sizes has no influence upon action of devices for 0.250 micrometer rule devices. Then, we also assumed that the ratio of CD variations has no influence upon action of not only 0.250 micrometer rule devices but also 0.200 and 0.175 micrometer rule devices. For 0.200 and 0.175 micrometer rule memory cell patterns, defect specifications were obtained by lithography simulations and exposure experiments for the criteria of the ratio of CD variations based on the assumption. We also evaluated whether current inspection systems were capable of satisfying the defect specifications. !4