Measurement system to determine the total and angle-resolved light scattering of optical components in the deep-ultraviolet and vacuum-ultraviolet spectral regions

An instrumentation for total and angle resolved scattering at 193 nm and 157 nm has been developed at the Fraunhofer Institute in Jena to meet the severe requirements for scattering analysis of DUV/VUV optical components. Extremely low backscattering levels of 10-6 for the TS measurements and more than 9 orders of magnitude dynamic range for ARS have been accomplished. Examples of application extend from the control of at-wavelength scattering losses of superpolished substrates with rms roughness as small as 0.1 nm, to the detection of volume material scattering and the study into the scattering of multilayer coatings. In addition, software programs were developed to model the roughness induced light scattering of substrates and thin film coatings.