Modeling and Experimental Aspects of Apparent Beam Width as an Edge Resolution Measure
C Archie, J R. Lowney, Michael T. Postek
The SEMATECH advanced metrology advisory group (AMAG) recently issued a critical dimension (CD) scanning electron microscope (SEM) specification. One component of this specification was the measurement of the apparent beam width (ABW). The edge width of the video profile (waveform) is critical to the measurement precision and ultimately accuracy for the CD-SEM. For the semiconductor industry, edge width of a good quality isolated structure of typical semiconductor material like photoresist on anitreflective coating (ACR) on silicon is critical and can be characterized by a measurement of the apparent beam width. The ABW measurement convolutes all the edge resolution-limiting contributors that can be present during the linewidth measurement process since it is an actual measurement from a product wafer structure, These factors include beam size, depth of field, autofocus imprecision, astigmatism and electronic filtering in a singe measurement. The choice of the ABW artifact, in itself, is also a potential contributor to the measurement and must be fully understood. Using the NIST Monte Carlo modeling program, MONSEL-II, the ABW measurement technique is examined and many contributors to measurement variation are studied. Results are compared with experiments using an existing ABW artifact. Furthermore the requirements for future ABW artifacts are determined and discussed.
Proceedings of SPIE, Metrology, Inspection, and Process Control for Microlithography XIII, Bhanwar Singh, Editor
, Lowney, J.
and Postek, M.
Modeling and Experimental Aspects of Apparent Beam Width as an Edge Resolution Measure, Proceedings of SPIE, Metrology, Inspection, and Process Control for Microlithography XIII, Bhanwar Singh, Editor, Santa Clara, CA, USA
(Accessed May 28, 2023)