Patent ID: 8848185
Filing Date: 2014-09-30
Classification: G01B,G01N,H01L,H04L

Abstract:
1. A method for use in optical measurements in patterned structures having vias the method comprising: applying a dark-field detection mode to the patterned structure under measurements by carrying out the following: illuminating the structure with light of a broad spectrum of wavelengths such that the patterned structure is larger than the largest wavelength of the illuminating light, said light having a predetermined polarization state and propagating onto the structure with normal incidence; detecting light returned from the illuminated structure, while providing mutually perpendicular polarizations for the incident and the returned light; processing measured spectral data indicative of the detected light, said processing comprising applying a model and determining one or more of the following parameters of side walls of the via: a sidewall angle, side wall ripples, and characteristics of a thin insulating layer created on the via walls.