Line Width Roughness mitigation in chemically amplified resist by post-litho processes

In order to reach and control the ITRS 3 sigma Line Width Roughness target for the 22 nm technological node, post-litho smoothing processes have been studied. To obtain a full knowledge of the roughness response to these techniques, a detailed methodological analysis in both spatial and frequency domain was performed to find the optimum settings. Furthermore, an on-line metrological study on CD-SEM parameters was executed to establish the repeatability of roughness evaluations: 0.2-0.3 nm 3 sigma roughness was in the end found. To validate our methodology, a complete off-line analysis of in-track Hard Bake smoothing process was performed. Up to 11% roughness mitigation in the high frequency range was found. (C) 2009 Elsevier B.V. All rights reserved.