Scatterometer – Measurement of surface roughness by laser beam scattering characteristics

The CASI or „Complete Angle Scatter Instrument“ utilizes laser light as a nondestructive probe to measure the quality of the surface, roughness, defects, and contamination of various materials. CASI was developed to measure the scattering from reflective and transmissive samples in the plane of incidence close to the mirrored ray as well as at large scattering angles and it can o±er a dynamic range up to 14 orders.