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Publication Citation: Line Width Roughness and Cross Sectional Measurements of Sub-50 nm Structures with CD-SAXS and CD-SEM

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Author(s): Chengqing C. Wang; Ronald L. Jones; Kwang-Woo Choi; Christopher L. Soles; Eric K. Lin; Wen-Li Wu; James S. Clarke; John S. Villarrubia; Benjamin Bunday;
Title: Line Width Roughness and Cross Sectional Measurements of Sub-50 nm Structures with CD-SAXS and CD-SEM
Published: March 24, 2008
Abstract: Critical dimension small angle x-ray scattering (CD-SAXS) is a measurement platform which is capable of measuring the average cross section and sidewall roughness in patterns ranging from (10 to 500) nm in pitch with sub nm precision. These capabilities are obtained by measuring and modeling the scattering intensities of a collimated x-ray beam with sub-Angstrom wavelength from a periodic pattern, such as those found in optical scatterometry targets. In this work, we evaluate the capability of both a laboratory scale and synchrotron based CD-SAXS measurements for line-width roughness (LWR) characterization from measurement of periodic line-space patterns fabricated with EUV lithography with sub-50 nm line widths and designed with programmed roughness amplitude and frequency. For these patterns, CD-SAXS is capable of providing high precision data on cross section dimensions, including sidewall angle, line height, line width and pitch, as well as the LWR amplitude. We also discuss the status of ongoing efforts to compare quantitatively the CD-SAXS data with top-down scanning electron microscopy (CD-SEM) measurements.
Citation: SPIE Conference Proceedings
Volume: 6922
Pages: 6 pp.
Keywords: line edge roughness;line width roughness;small angle x-ray scattering
Research Areas: Semiconductor Materials, Nanoelectronics and Nanoscale Electronics
PDF version: PDF Document Click here to retrieve PDF version of paper (583KB)