Polarization errors associated with reflective objectives in a micro-spot spectroscopic ellipsometer

Abstract

A micro-spot spectroscopic ellipsometer covering 1.5-4.8 eV is developed using two infinity-corrected reflective objectives. Only a small portion of the entrance pupil in the objective is used to obtain a similar to 50 mu m x 70 mu m spot on a sample. However, non-normal reflections inside the objectives cause experimental errors (up to 2.3 degrees in Delta) when they are arranged symmetrically about a sample. In this paper, we show how to diagnose the polarization errors associated with the reflective objectives and how to deal with them. (C) 2019 The Japan Society of Applied Physics