title: Amplitude and phase beam shaping for highest sensitivity in sidewall angle detection.
abstract: In integrated circuits manufacturing, specific structures are used as tools to evaluate the quality of the lithographic process, and the shape of these structures is often described by a few parameters, of which in particular the sidewall angle suffers from considerable inaccuracies. Using scalar diffraction theory, we investigate whether a properly shaped cylindrically focused probing beam could increase the ability to detect tiny changes in this angle in the case of a cliff-like structure, modeled as a phase object. This paper describes the theoretical formulation used to calculate the optimized beam and compares its performance with the case of a focused plane wave.
authors.forename: Luca
authors.initials: L
authors.lastname: Cisotto
authors.forename: H
authors.initials: H
authors.lastname: Paul Urbach