Comprehensive nanostructure and defect analysis using a simple 3D light-scatter sensor

Abstract

Light scattering measurement and analysis is a powerful tool for the characterization of optical and nonoptical surfaces. A new 3D scatter measurement system based on a detector matrix is presented. A compact light-scatter sensor is used to characterize the scattering and nanostructures of surfaces and to identify the origins of anisotropic scattering features. The results from the scatter sensor are directly compared with white light interferometry to analyze surface defects as well as surface roughness and the corresponding scattering distributions. The scattering of surface defects is modeled based on the Kirchhoff integral equation and the approach of Beckmann for rough surfaces.

Coherent Fourier scatterometry for detection of nanometer-sized particles on a planar substrate surface

“…The experiments were performed in the most simple configuration possible which implies that higher sensitivity, if required, can be achieved by using more complex polarization control, structured illumination or with some data processing of different kind, without reducing the illumination wavelength. It may be noted that the simplicity of the method lies not only in its practical implementation but also in the analysis of the data it produces, since simple measurement like change in the amount of power through the pupil can be used for successful particle detection compared to some recent methods introduced in this field [27]. The advantage here is a compact design, employing single source-single detector configuration with normal incidence which is easily upgradable to parallel implementation of multiple scanners.…”

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.…”

“…10 -3 sr -1 . [8] A similar approach was realized in the BTDF Sensor which was designed for the investigation of the light scattering of transparent optical components and optical systems. It is also equipped with a matrix detector for fast data acquisition.…”

Light scattering techniques for the characterization of optical components

“…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 [8][9][10][11]. This includes systems for different spectral regions using various detector elements and measurement principles.…”

“…10 -3 sr -1 ), range of scattering angles covered (±10° around the specular reflection) and the operation at only one wavelength (convertible). [11] Because the light scattering measurements on space optics require highest performance, flexibility, and clean room environment, the measurement examples presented in the next section were all performed with the laboratory systems ALBATROSS and MARS.…”