Characterization of line edge roughness using CD SAXS

We are developing a transmission X-ray scattering platform capable of measuring the average cross section and line edge roughness in patterns ranging from 10 nm to 500 nm in width with sub-nm precision. Critical Dimension Small Angle X-ray Scattering (CD-SAXS) measures the diffraction of a collimated X-ray beam with sub-Angstrom wavelength from a repeating pattern, such as those in light scatterometry targets, to determine the pattern periodicity, line width, line height, and sidewall angle. Here, we present results from CD-SAXS with an emphasis on line edge roughness characterization. Line edge roughness measurements from CD-SAXS are compared with top-down scanning electron microscopy values and comparative definitions are discussed.