Analysis of error and development of calibration's method to design precision rotating analyzer ellipsometer

摘要

In manufacturing a rotating-analyzer ellipsometer, error sources and calibration methods are discussed. It is important to get rid of external noise for measurement of high thickness resolution and accurate optical constant and this means that the precision of system above all is important to develop the ellipsometer. Therefore the precision design and error calibration of the optical components in ellipsometer are inevitable. We proposes a PSA (polarizer-specimen-analyzer) system to manufacture a rotating-analyzer ellipsometer. Jones matrices are used for a numerical method for the ellipsometer consisting of a polarizer, specimen and analyzer. we are modeling errors introduced by light source and detector's PDS (polarization dependence-sensitivity) and polarizer and analyzer's azimuth-angle and imperfection errors caused by noise, and determining error-coupling coefficients. Also the modeling system is simulated to make a quantization of error sensitivity so as to analysis the error-sensitivity of each component. At the systematic error (difference between ideal and including error case) cos's coefficient of Fourier function is more sensitive than sin's result from the simulation. It is shown that noneffective light source's PDS and the analyzer is more effective than polarizer's imperfection in the systematic errors. We present a new calibration method, numerical calibration, which is complementary to residue calibration using second-order approximation. This will help the design and manufacture of the rotating-analyzer ellipsometer and contribute to find correctly optical data.