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Particle induced defects are still one of the major sources of yield loss in semiconductor manufacturing. In addition, optical distortion of shapes cannot be ignored in modern technologies and requires increasing design effort in order to avoid yield loss and minimize manufacturing costs.Although suppliers of automated routing tools are increasingly addressing these issues, we still see significant improvement potential even in layouts produced by routers attributed as DfM aware. We propose a post-routing clean-up step to address both defect and lithography related yield loss in the routing layers. In contrast to a "find and fix" approach, this methodology creates lithography friendly layout "by construction", based on the general concept of shape simplification and standardization.

In contrast to defect limited yield loss, systematic yield detractors like lithography hotspots may cause a huge yield loss per event. For 45 nm and subsequent technology nodes, those findings are for this reason classified as DRC-like errors and need to be fixed before tape-out. In this paper, we report a comparison − from the use-model point-of-view − of two different methods for removal of lithography hotspots. First, a rip-up & re-routing and second, a guided-repair approach will be presented. This includes a discussion of the impact in the routing context, mainly radius of influence and timing closure, aspects of multiple layer involvement and the layout hierarchy, and the limitations caused by the layout grid.

A comparison has been made in terms of mask CD linearity measurements between the 2 tool versions of a 248nm based optical CD metrology tool for photomasks, i.e., the high-NA M5k-SWD and the through-pellicle M5k-LWD, as well as to a reticle SEM, i.e., the KLA-T 8250-XR. The measured pattern consists of lines and dots (dark features), and spaces arid contact holes (clear features), both in equal-lines-and-spaces and as isolated feature. Two masks have been measured with the same test pattern, i.e., a binary and a 9%-attPSM for 193nm lithography. The latter was especially challenging because typically such embedded phase shift masks are much more transparent at higher wavelengths than those for which they are optimized. All measurements on the M5k were made intentionally before calibration (apart fmm pitch calibration). The resolution performance of the M5k-LWD and the measurement offsets found between M5k and SEM, as well as between the two M5k-versions is discussed. In addition, two-dimensional metrology based on feature contour extraction from optical or from SEM images has been compared. Although its resolution is inherently lower than that of the high-NA M5k-SWD and a reticle SEM, the M5k-LWD offers a possibility to extend such assessment to pelliclized reticles, which is not possible on the alternative tools.