Translator Disclaimer
3 April 2012 Evaluation of a novel ultra small target technology supporting on-product overlay measurements
Author Affiliations +
Reducing the size of metrology targets is essential for in-die overlay metrology in advanced semiconductor manufacturing. In this paper, μ-diffraction-based overlay (μDBO) measurements with a YieldStar metrology tool are presented for target-sizes down to 10 × 10 μm2. The μDBO technology enables selection of only the diffraction efficiency information from the grating by efficiently separating it from product structure reflections. Therefore, μDBO targets -even when located adjacent to product environment- give excellent correlation with 40 × 160 μm2 reference targets. Although significantly smaller than standard scribe-line targets, they can achieve total-measurement-uncertainty values of below 0.5 nm on a wide range of product layers. This shows that the new μDBO technique allows for accurate metrology on ultra small in-die targets, while retaining the excellent TMU performance of diffraction-based overlay metrology.
© (2012) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Henk-Jan H. Smilde, Arie den Boef, Michael Kubis, Martin Jak, Mark van Schijndel, Andreas Fuchs, Maurits van der Schaar, Steffen Meyer, Stephen Morgan, Jon Wu, Vincent Tsai, Cathy Wang, Kaustuve Bhattacharyya, Kai-Hsiung Chen, Guo-Tsai Huang, Chih-Ming Ke, and Jacky Huang "Evaluation of a novel ultra small target technology supporting on-product overlay measurements", Proc. SPIE 8324, Metrology, Inspection, and Process Control for Microlithography XXVI, 83241A (3 April 2012);


Back to Top