title: Detection of overlay error in double patterning gratings using phase-structured illumination.
abstract: With the help of simulations we study the benefits of using coherent, phase-structured illumination to detect the overlay error in resist gratings fabricated by double patterning. Evaluating the intensity and phase distribution along the focused spot of a high numerical aperture microscope, the capability of detecting magnitude and direction of overlay errors in the range of a few nanometers is investigated for a wide range of gratings. Furthermore, two measurement approaches are presented and tested for their reliability in the presence of white Gaussian noise.
authors.forename: Sandy
authors.initials: S
authors.lastname: Peterhänsel
authors.forename: Maria Laura
authors.initials: ML
authors.lastname: Gödecke
authors.forename: Valeriano Ferreras
authors.initials: VF
authors.lastname: Paz
authors.forename: Karsten
authors.initials: K
authors.lastname: Frenner
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Osten