18 March 2015 RET selection on state-of-the-art NAND flash
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We present results generated using a new gauge-based Resolution Enhancement Technique (RET) Selection flow during the technology set up phase of a 3x-node NAND Flash product. As a testcase, we consider a challenging critical level for this ash product. The RET solutions include inverse lithography technology (ILT) optimized masks with sub-resolution assist features (SRAF) and companion illumination sources developed using a new pixel based Source Mask Optimization (SMO) tool that uses measurement gauges as a primary input. The flow includes verification objectives which allow tolerancing of particular measurement gauges based on lithographic criteria. Relative importance for particular gauges may also be set, to aid in down-selection from several candidate sources. The end result is a sensitive, objective score of RET performance. Using these custom-defined importance metrics, decisions on the final RET style can be made in an objective way.
© (2015) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Neal V. Lafferty, Neal V. Lafferty, Yuan He, Yuan He, Jinhua Pei, Jinhua Pei, Feng Shao, Feng Shao, QingWei Liu, QingWei Liu, Xuelong Shi, Xuelong Shi, } "RET selection on state-of-the-art NAND flash", Proc. SPIE 9426, Optical Microlithography XXVIII, 94260L (18 March 2015); doi: 10.1117/12.2087176; https://doi.org/10.1117/12.2087176


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