Patent ID: 7324198

Claim:
A method of enhancing image contrast between a first material and a second material on a sample surface, said sample surface being comprised of a first portion having said first material exposed thereon and a second portion having said second material exposed thereon, said first and second materials having substantially different indices of refraction, comprising the steps of: a) providing a collimated illumination beam directed toward said sample surface at an angle of illumination, said collimated illumination beam illuminating an extended area of said sample surface, said angle of illumination being at angle θ from a normal to said sample surface, said angle θ being selected such that the ratio of reflectivity between s-polarized light and p-polarized light is substantially different for said first material as compared to said second material at an angle of illumination equal to said angle θ; b) polarizing said collimated illumination beam so as to yield a p-polarized portion of said collimated illumination beam impinging on said sample surface; c) detecting an extended-area image of reflected light from said p-polarized portion of said collimated illumination beam off of said sample surface; and f) processing said image of reflected light from said p-polarized portion of said collimated illumination beam to enhance said image contrast between said first material and said second material over said extended area.