MULTIWAVELENGTH (0.45-10.6-MU-M) ANGLE-RESOLVED SCATTEROMETER OR HOW TO EXTEND THE OPTICAL WINDOW

An apparatus to record scattered light in whole space over a large ran ge of visible and infrared wavelengths (0.45-10.6 mum) is described. P arasitic light, calibration, and dynamic range are discussed to point out performances and limits of the experimental setup. Angular measure ments at several wavelengths give access to bidimensional roughness sp ectra of polished samples in different frequency bandwidths. The resul ts show overlap of the spectra at the intersection of the bandwidths, which provides an extended view,of surface microroughness. In the midi nfrared, measurements are more difficult, and specific problems such a s thermal emission are analyzed.