Study for lithography techniques of hybrid mask shape of contact hole with 1.35NA polarized illumination for 28nm-node and below logic LSI

摘要

In this presentation, the advantage in the use of combination of polarized illumination and technique of optimum shape mask for contact-hole lithography will be discussed. Both simulation and experimental work were carried out to characterize performance of this technique. We confirmed that some polarized illuminations show improvement in image contrast, MEEF, and DOF for nested contact-hole than non-polarized condition. In addition, certain shape mask shows more improvement. Totally 63% DOF improvement from traditional square shape with nonpolarized condition was confirmed. In final single exposure era for contact-hole, this result with techniques of hybrid mask shape and polarized illumination is very attractive.