Institute Silicon Photovoltaics

Third-party funded project: OptiRefs

Project for the development of optical materials approved

A joint research proposal between the SENTECH Instruments GmbH, the Technische Universität Berlin, the Helmholtz-Zentrum Berlin für Materialien und Energie GmbH and the PTB has been approved for the ProFIT program of the Investitionsbank Berlin IBB (program for boost of research, innovation and technology). In the three-year duration of the OptiRefS project (Optical Reference data for technological layer Systems) novel reference materials for ellipsometric measurements of thin film layers in the wavelength range below 200 nm will be developed, e.g., especially textured silicon surfaces and 2D-graphen layers. By use of the vacuum-ultraviolet (VUV‑) ellipsometer at PTB’s Metrology Light Source MLS the respective optical constants will be determined with reliable uncertainties. Because of the extreme surface sensitivity of measurements in the VUV spectral range, the quality of the measurements is limited by surface effects like molecular contamination, leading to a lack of valid data for these range. By using complementary measurement techniques and numerical modeling in a hybrid metrology approach, these drawbacks should be resolved by quantitative recognition and correction of the disturbing effects, thus reliably providing optical material parameters.

VUV Ellipsometer at MLS at Bessy II,  © Prof. Esser / TU B, ISAS