Material analysis techniques used to drive down in-situ mask contamination sources

Using SEM-EDS analysis on small (< 200 nm) particles is challenging, especially on a substrate with multiple background elements present. We will show a methodology combining three techniques to get the most information out of small particles. This method combines low energy EDS with a nontraditional approach to improve statistics in EDS and elemental mapping. This methodology is required for ASML’s EUV platform, the NXE scanner to continue system improvement for a system showing already low defect count. The poor particle statistics on particle defects lead to a limited amount of particles available for diagnostics, which implies that all information on particle characteristics should be used for diagnostics.