A system and method for inspecting structures formed on the surface of an
object using ultraviolet (UV) light. The object is placed in position and
illuminated with at least one wavelength of UV light, directed at its
surface from a UV source. At the moment of illumination, an image is
captured by a UV-light sensitive camera positioned at an angle calculated
to intercept light diffracted at particular an angle of diffraction
associated with the pattern of structures formed on the surface of the
object. To avoid having to repeatedly reposition the camera, one (or more
in succession) illumination wavelength is selected to direct an intensity
peak associated with a particular order of diffraction at the camera
location. Ideally, a visible-light sensitive camera is also used to
capture images of the surface when illumination with UV light results in
the emanation of light in the visible portion of the spectrum.