AN APPARATUS AND A METHOD FOR SPECTROSCOPIC ELLIPSOMETRY, IN PARTICULAR INFRARED SPECTROSCOPIC ELLIPSOMETRY

摘要

The present invention relates to an apparatus for spectroscopic ellipsometry, preferably for infrared spectroscopic ellipsometry, and a method for spectroscopic ellipsometry employing the apparatus. The apparatus comprises a light source (12), a detector (30), a polarizer (40), an analyzer (41), and a measuring probe (10). The measuring probe comprises an ATR prism (50) having at least one first surface having at least one measuring portion (M) configured to be brought in optical contact with a measured object (72), and at least one second surface having at least one reflective portion (RX). The ATR prism (50) is configured so that at least a portion of polarized light entering the measuring probe (10) undergoes an attenuated total reflection at the least one measuring portion (M) of the first surface (M), at least a portion of the totally reflected light is reflected back towards the first surface by the at least one reflective portion (RX) of the second surface, and at least a portion of the light reflected back by the at least one reflective portion (RX) of the second surface undergoes an attenuated total reflection by the at least one measuring portion (M) of the first surface and is decoupled from the ATR prism (50). Further, the difference between the magnitude of the angle (alpha_p) between the first surface and the second surface and the magnitude of the critical total reflection angle is less than 12°.