Extended defect printability study for 100nm design rule. using 193nm lithography

This paper reports on reticle defect printability for the 100nm design rule using 193nm lithography, off-axis illumination and a binary reticle with optical proximity correction (OPC). It is part of a systematic assessment of the impact of reticle defects on the printed image. In previous work [1, 2] we concentrated on the printability of both hard and soft defects additive to the Cr pattern. Here we widen the scope to missing Cr defects, such as a divot in the main line. The printing experiments are performed on 193mn-exposure tools using a numerical aperture (NA) of 0.63 and 0.75. In a simulation study based on aerial image assessment, the printability of defects of various area, phase, transmission and shape is evaluated for the two different NA-settings. A quantitative comparison between predicted (by aerial image simulations) and printed linewidths is made. It is shown that the correlation can be further improved by implementing the actual reticle feature contours in the simulation analysis instead of the design. Furthermore, we present a comprehensive table classifying the various defects based on their printability impact.