Paper
2 June 2000 Lithographic process monitoring using diffraction measurements
Emmanuel M. Drege, Dale M. Byrne
Author Affiliations +
Abstract
Optical diffraction is an attractive process with which to non-invasively examine materials and structures. Waves diffracted by a periodic structure carry information about geometrical characteristics of the diffracting structure as well as intrinsic properties of the material comprising the structure. These features make optical diffraction from surface relief gratings appealing as a monitor for lithographic processes. Considering that lithographic processes are usually quite stringently controlled, a search for 'departures' from a set of expected design values can linearize the highly non-linear relationship between parameter values and diffraction measurements, and hence permits analyses using classical linear methods. We therefore propose a linear inversion technique to determine key parameters of a periodic structure from an analysis of diffraction data that seeks to determine the departures from a set of expected design values. The approach is validated for the retrieval of three geometrical parameters (groove depth, line width, and sidewall angle) based on simulations performed using the rigorous coupled-wave theory (RCWT). The results obtained are very encouraging and highlight the potential of a linear inversion technique in scatterometry.
© (2000) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Emmanuel M. Drege and Dale M. Byrne "Lithographic process monitoring using diffraction measurements", Proc. SPIE 3998, Metrology, Inspection, and Process Control for Microlithography XIV, (2 June 2000); https://doi.org/10.1117/12.386467
Lens.org Logo
CITATIONS
Cited by 6 scholarly publications and 7 patents.
Advertisement
Advertisement
RIGHTS & PERMISSIONS
Get copyright permission  Get copyright permission on Copyright Marketplace
KEYWORDS
Diffraction

Reflectivity

Lithography

Scatterometry

Structural design

Diffraction gratings

Computer simulations

Back to Top