Apparatus for inspection of a sample includes a radiation source and an
array of detector elements arranged to receive radiation from the surface due to
irradiation of an area of the surface by the radiation source. The array has a
first operative configuration for resolving the received radiation along a first
axis perpendicular to the surface, and a second operative configuration for resolving
the received radiation along a second axis parallel to the surface. A signal processor
processes the signal from the detector array in the two configurations so as to
determine a reflectance of the surface as a function of elevation angle relative
to the surface and a scattering profile of the surface as a function of azimuthal
angle in a plane of the surface.
