Characterization of Packaging, Electronic, and Photonic Materials at Cryogenic Temperatures Using a Multi-Angle Backscattering Mueller-Matrix Ellipsometer

A custom instrument for performing multi-angle, Return-Path Ellipsometry (RPE) utilizing commercial-off-the-shelf (COTS) retroreflective tape is proposed to overcome common cryogenic limitations to measure a variety of materials (Au and thin films of Al
2
O
3
and SiO
x
) for characterization as low as 20 K. Characterization of these materials at cryogenic temperatures are demonstrated for backscattering and multi-angle configurations.