Patent ID: 6693711
Filing Date: 2004-02-17
Classification: G01J,G01N

Abstract:
An ellipsometry method comprising:providing radially symmetric polarized light incident normal to a sample plane of a sample material; focusing the radially symmetric polarized light to a spot, wherein the sample material reflects at least a portion of the focused radially symmetric polarized light as radially symmetric elliptically polarized light; operating on the radially symmetric elliptically polarized light to generate a radially symmetric ellipsometric signal, wherein operating on the radially symmetric elliptically polarized light comprises modifying polarization of the radially symmetric elliptically polarized light to generate a radially symmetric ellipsometric signal, wherein such modification maintains radial symmetry of the radially symmetric elliptically polarized light; and detecting the radially symmetric ellipsometric signal for use in determining at least one characteristic of the sample material.