Abstract
In this paper, logic device patterning of 0.16-μm trenches for the 0.13-μm node using 248-nm light and 0.13-μm trenches for the 0.10-μm node using 193-nm light is investigated. Severe proximity effect through all pitches and small depth of focus for isolated trenches bring great challenges. To produce manufacture-worthy process windows, lithographic techniques such as optical proximity correction, annular illumination, sub-resolution assist features, and attenuated phase-shift mask are considered. No prominent performance gain is achieved in the aforementioned combination if full-pitch-range performance is required. However, manufacture-worthy 0.5-μm depth of focus can be obtained through all pitches by replacing annular illumination with quadrupole illumination while retaining sub-resolution assist features and optical proximity correction, even without having to resort to attenuated phase-shifting mask. We also observe that attenuated phase-shift mask or dipole illumination improves depth of focus and photoresist profile of dense patterns only in the cases studied.