• 文献标题:   Near surface structure of ultrathin epitaxial Ru films on graphene/amorphous SiO2 revealed by azimuthal RHEED
  • 文献类型:   Article
  • 作  者:   LU ZH, DHULL N, CHEN XG, ZHANG LH, KISSLINGER K, KUAN TS, WASHINGTON MA, LU TM, WANG GC
  • 作者关键词:   single crystalline graphene, quasivan der waals epitaxy, ultrathin ruthenium film, azimuthal rheed, tem, xps
  • 出版物名称:   JOURNAL OF MATERIALS RESEARCH
  • ISSN:   0884-2914 EI 2044-5326
  • 通讯作者地址:  
  • 被引频次:   0
  • DOI:   10.1557/s43578-022-00878-7 EA JAN 2023
  • 出版年:   2023

▎ 摘  要

Ru has been considered as an alternative metallic candidate for future local interconnects. The 2D reciprocal space map constructed from the azimuthal reflection high-energy electron diffraction patterns reveals that ultrathin Ru(0001) is epitaxially grown on transferred graphene on amorphous SiO2 through quasi-van der Waals interaction. The in-plane and out-of-plane lattice constants are measured from streaks' separation and intensity modulations along streaks, respectively. Weak and broad rings indicate that a low density of nanoscale polycrystals exist on the surface. The intensities of 00 and non-00 diffraction spots vs. azimuthal angles in the 2D map show a few degrees out-of-plane and in-plane angular misorientations among grains, respectively. As the film thickness decreases these angular misorientations increase. Transmission electron microscopy carried out in this study also provides precise values of lattice constant and sub-grain sizes in the films. These findings show that ultrathin Ru film is epitaxial but not exactly single crystalline.