As the industry embarks on sub 50nm half pitch design nodes, higher resolution and advanced inspection algorithm are needed to resolve shrinking features and find critical yield limited defects. In this paper, we evaluate the detection capability of STARlight2+ 72nm pixel on DRAM masks. The mask sets targeted for this evaluation were focused on critical layers. Although memory mask sets are dominated by multi-die layout, single die layout masks were also inspected because of their significance during research and development. Inspection results demonstrated the performance of STARlight2+ based on its sensitivity to contamination defects, inspectability, first time success rate and throughput. STARlight2+ has single die inspection capability, which is also needed in order to inspect scribe-lines and frame areas. The primary defects of interest are photo induced defects or contamination, causing mask degradation. Contamination continues to be the primary reason for mask returns at 193nm exposure across the industry. The objective of this paper is to demonstrate STARlight2+ 72nm capability to support memory wafer fab mask qualification requirements.

Date Published: 19 May 2008
PDF: 6 pages
Proc. SPIE 7028, Photomask and Next-Generation Lithography Mask Technology XV, 70282N (19 May 2008); doi: 10.1117/12.793093

Published in SPIE Proceedings Vol. 7028:
Photomask and Next-Generation Lithography Mask Technology XV
Toshiyuki Horiuchi, Editor(s)