Designing a standard for strain mapping: HR-EBSD analysis of SiGe thin film structures on Si

Published: January 01, 2015


Mark D. Vaudin, William A. Osborn, Lawrence H. Friedman, Justin M. Gorham, Robert F. Cook, Victor Vartanian


Patterned SiGe thin film structures, heteroepitaxially deposited on Si substrates, are investigated as potential reference standards to establish the accuracy of high resolution electron backscattered diffraction (HR-EBSD) strain measurement methods. The proposed standards incorporate thin films of tetragonally distorted epitaxial Si1xGex adjacent to strain-free Si. Six films of three different nominal compositions (x = 0.2, 0.3, and 0.4) and various thicknesses were studied. Film composition and out-of-plane lattice spacing measurements, by x-ray photoelectron spectroscopy and x-ray diffraction, respectively, provided independent determinations of film epitaxy and predictions of tetragonal strain for direct comparison with HR-EBSD strain measurements. Films assessed to be coherent with the substrate exhibited tetragonal strain values measured by HR-EBSD identical to those predicted from the composition and x-ray diffraction measurements, within experimental relative uncertainties of order 2 %. Such films thus provide the best prototypes for designing a strain standard.
Citation: Ultramicroscopy
Volume: 148
Pub Type: Journals


high resolution electron backscattered diffraction, epitaxial SiGe-on-Si films, x-ray diffraction, x-ray photoelectron spectroscopy
Created January 01, 2015, Updated November 10, 2018