Robustness enhancement of dynamic spectroscopic ellipsometry by compensating temperature dependency of the monolithic polarizing interferometer.

This paper describes a robust dynamic spectroscopic ellipsometer that can provide a highly accurate and reliable real-time spectroscopic polarization measurement capability for various in-line nanoscale measurement applications. The robustness of dynamic spectroscopic ellipsometry is enhanced significantly by employing a compensation channel that removes the temperature dependency of the monolithic polarizing interferometric module, and it results in highly accurate dynamic spectral ellipsometric measurements. We present how the monolithic interferometer is affected by external disturbances and show experimentally that the proposed scheme can provide a few hundreds of times long-term stability enhancement compared with a single-channel-based dynamic spectroscopic ellipsometer scheme.