Patent · US Active

Methods and apparatus for calculating electromagnetic scattering properties of a structure and for estimation of geometrical and material parameters thereof

US9939250B2 · kind B2 · utility

4Cited by
2References
14Claims
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Key dates

Filing dateNov 4, 2014
Grant dateApr 10, 2018
Priority date
Expiry dateNov 4, 2034

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG03F7/70633
  • WIPO fieldOptics
  • WIPO sectorInstruments

Abstract

In scatterometry, a merit function including a regularization parameter is used in an iterative process to find values for the scattering properties of the measured target. An optimal value for the regularization parameter is obtained for each measurement target and in each iteration of the iterative process. Various methods can be used to find the value for the regularization parameter, including the Discrepancy Principle, the chi-squared method and novel modifications of the Discrepancy Principle and the chi-squared method including a merit function.

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