OPTIMUM PROCEDURES FOR LOW ABSORBING SYSTEMS, PARAMETER CORRELATION AND INTERNAL REFLECTION IN ELLIPSOMETRY

Sensitivity and precision have been and continue to be considerations which have contributed to the increasing use of ellipsometry in the last two decades. In this work we provide more specific documentation than has been available on the advantages of the polarizer, specimen, compensator and analyzer (PSCA) ellipsometer arrangement in reducing the effect of polarizer beam deviation and improving sensitivity by facilitating measurements near the principal angle in studies on low absorbing systems such as SiO(,2)-Si, which are widely used in electronic devices. A quantitative test is developed for parameter correlation and the limits on confidence in the precision of multiple-angle-of-incidence measurements, thereby putting on a firm basis the use of multiple-angle measurements which can more easily provide more data than other methods. Procedures are developed for correcting common defects in prism fabrication which have discouraged use of prism couplers in ellipsometer internal reflection measurements which would provide more data than the more generally-used intensity measurements