In this paper, we compare EPE (Edge Placement Error) variability among various multiple patterning techniques such as SADP and SALELE using simple restricted 2D design of “grating” (30 nm pitch) and “cut” (15 nm tip-to-tip) EUV patterns. The lithography variability contribution to CD uniformity is carried out through Tachyon® SMO generated contours by considering dose, focus, flare, mask variations. SEMulator3D is used to run a large Monte Carlo simulation to capture the following sources of variation: resist “contours” (from Tachyon®), spacer thickness, overlay for each of the lithography exposures and etch. We developed a methodology to combine lithography and other fab processes, particularly etch and deposition, involved in multi-patterning processes for EPE characterization of given layout. For the layout considered in this study, we find that Spacer Assisted Litho-Etch-Litho-Etch (SALELE) is more adaptable to multi-patterning process for extension to 2D layouts compared to Self Aligned Double Patterning (SADP). Per this study, the differences in the two multi-patterning approaches are primarily attributed to better litho performance (lower global CDU and larger process margin) and lower process variability on most process metrics.
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