Line-end gap measurement for OPC calibration is a challenge for metrology. Even for CD-SEM, the rounded shape of the line end makes it very difficult to measure precisely. We have presented preliminary results of the application of scatterometry to these challenging structures using an angle resolved polarized scatterometer: ASML YieldStar [1]. In this paper, the exercise was extended to several different structures combining multiple line-end gap situations. Systematic comparison with CD-SEM is performed and discussed. Lithographic behavior of the main parameters is analyzed. Strengths and limits of the technique will be shown. Once validated, the metrology is used to build an OPC model and correct our test vehicle.
[1]
Peter Vanoppen,et al.
3D features measurement using YieldStar, an angle resolved polarized scatterometer
,
2011,
Advanced Lithography.
[2]
Alek Chen,et al.
High-speed, full 3D feature metrology for litho monitoring, matching, and model calibration with scatterometry
,
2012,
Advanced Lithography.