Abstract

Scatterometry takes advantage of the sensitivity exhibited by optical diffraction from periodic structures, and hence is an efficient technique for lithographic process monitoring. Even though the potential of such technique has been known for many years, the challenge of extracting quickly and accurately the relevant constitutive parameters from diffraction data remains. To solve this problem, a linear inversion method has been developed.¹ The linearization of this intrinsically non-linear problem is accomplished by seeking the departures of the constitutive parameters from their design values.

© 2000 IEEE