Direct observation of nanometer-scale strain field around CoSi2/Si interface using scanning moiré fringe imaging

Abstract

We report the use of scanning moiré fringe (SMF) imaging through high-angle annular dark-field scanning transmission electron microscopy (STEM) to measure the strain field around a CoSi2 contact embedded in the source and drain (S/D) region of a transistor. The atomic arrangement of the CoSi2/Si (111) interface was determined from the high-resolution (HR)-STEM images, and the strain field formed around the S/D region was revealed by nanometer-scale SMFs appearing in the STEM image. In addition, we showed that the strain field in the S/D region measured by SMF imaging agreed with results obtained via peak-pairs analysis of HR-STEM images.