Dual beam set-up for scatterometer

摘要: A scatterometer or parousiameter having a dual beam setup and method for use thereof is provided producing measurements of optical parameters. The includes hemispherical dome enclosure (318) sealed at the bottom with base (320). radiation source (302) produces in two beams, an illumination (304) illuminating sample surface (308) calibration (330) providing characterization information about (304). Each guided into via separate paths. An imaging device (324) positioned to acquire image scatter (314) scattered by illuminated (304), beam, simultaneously. used compensate variability output when analyzing data.