Applied Nanophotonics, Liquid Crystals and Biomedical Optics

PROBLEM TO BE SOLVED: To provide a measuring method and device for easily performing exact measurement of an extremely fine line width and quantification about a profile of an etching structure on a pattern wafer. ;SOLUTION: Before the diffraction from a diffracting structure 12c on a semiconductor wafer, the film thickness and index of refraction of a film underneath the structure are first measured using a spectroscopic reflectometry or spectroscopic ellipsometry when required. A rigorous model is then used to calculate the intensity or the ellipsometric signature of the diffracting structure. The diffracting structure 12c is then measured using a spectroscopic scatterometer using polarized radiation and broadband radiation to obtain the intensity or an ellipsometric signature of the diffracting structure. This signature is matched with the signature in a database to determine the grating shape parameter of the structure. ;COPYRIGHT: (C)2011,JPO&INPIT