Scattering reduction through oblique multilayer deposition

Abstract

Scattering from multilayer coatings depends on the roughness of each interface as well as their cross-correlation properties. By depositing thin film coatings under oblique incidence, the cross-correlation properties can be specifically adapted and consequently also the scattering characteristics. This will be illustrated for Mo/Si multilayers, for which a scattering reduction of more than 30% can be achieved. The characterization techniques used comprise of cross-sectional transmission electron microscopy, atomic force microscopy, and angle-resolved light scattering measurements at a wavelength of 13.5 nm.

Light scattering characterization of optical components for space applications

“…Various instruments for angle resolved scatter measurements were developed at Fraunhofer IOF together with analysis techniques to link the measured light scattering distributions to the corresponding surface or thin film properties [4][5][6][7][8][9]. This includes systems for different spectral regions, such as extreme ultraviolet, ultraviolet, visible, near-infrared, and infrared, applying different measurement principles.…”

Origins of light scattering from thin film coatings

“…One promising approach could be to extract the cross-correlation PSDs directly from cross-sectional electron microscopy images as done, for example in ref. [37].…”

Characterization of randomly rough surfaces using angle-resolved scattering of light and atomic force microscopy

“…For this purpose, the modified theories presented above must be employed. For example, the modified RRT is utilized in [26,28,[57][58][59][60][61][62][63] and the modified SDT is presented in [64][65][66][67][68][69][70][71].…”