SYSTEMATIC-ERRORS IN ROTATING-COMPENSATOR ELLIPSOMETRY

Systematic error sources for the rotating-compensator ellipsometer are discussed. Starting from a general formalism, we derive explicit firs t-order expressions for the errors deltaPSI and deltaDELTA caused by a zimuthal errors and residual ellipticity introduced by imperfect polar izers or compensators and windows. Comparison is made with measurement results. It is shown that all azimuthal-angle errors can be eliminate d by a two-zone measurement and that the natural optical rotation of t he rotating quartz compensator has no effect on the measurements.