title: Scatterometry specialized for a highly asymmetric triangular grating on a transparent substrate.
abstract: We present a specialized scatterometry method to measure the groove profiles of highly asymmetric triangular gratings. Compared with the conventional scatterometry working in a specular way, this method utilizes diffraction spectra of the reflected ±1st orders and is good at measuring this kind of asymmetric grating with a higher sensitivity. In our work, diffraction efficiency angular spectra at a single wavelength are measured and passed on to a parameter optimization process to retrieve three profile defining parameters. Final results are compared with the ones from an atomic force microscope and discrepancies are discussed and explained.
authors.forename: Lin
authors.initials: L
authors.lastname: Yang
authors.forename: Lijiang
authors.initials: L
authors.lastname: Zeng
authors.forename: Lifeng
authors.initials: L
authors.lastname: Li