Apparatus for observing a surface using polarized light

Abstract

An observation apparatus of the present comprises (i) a light source for generating light; (ii) a separating optical system which splits the light from the light source into two different polarized light beams; (iii) a condenser optical system which converges the two polarized light beams from the separating optical system so as to respectively form light spots on two different positions on a sample object; (iv) a polarization selecting means which has a predetermined analyzer angle and selects a specific polarized light component from composite light made of the two polarized light beams by way of the sample object; (v) light detecting means which detects the polarized light component selected by the polarization selecting means; and (vi) phase difference adjustment means which adjusts a phase difference between the two polarized light beams by way of the sample object and guides composite light composed of the two polarized light beams as circularly polarized light to the polarization selecting means, when the sample object does not modulate both phase and amplitude of the light incident thereon. Accordingly, this observation apparatus can detect a phase difference generated between the two light components respectively emitted from both side of a level difference on the sample object.