X-ray Photon Correlation Spectroscopy Studies of Ion Beam Nanopatterning Kinetics and Dynamics

ORAL

Abstract

Solid surfaces can be ultra-smoothened or patterned on the nanoscale by irradiating with a broad beam of energetic ions. Different nano-patterns can be achieved by varying target-ion combination, the energy of ions, ions’ incident angle or the temperature of the solid target. There are several theories that seek to explain nanopatterning processes, but a definitive fundamental understanding has not been reached. In this study, the surface sensitive X-ray technique of Grazing-Incidence Small-Angle X-ray Scattering (GISAXS) is used to do real-time investigations of nano-pattern formation on Silicon and Germanium due to Ar+ and Kr+ bombardment. The coherent X-ray beam that is utilized in these GISAXS experiments enables us to study not only the kinetics, but also the fluctuations around the average kinetics, i.e. the dynamics of the nanopatterning process. The X-ray Photon Correlation Spectroscopy (XPCS) two-time correlation function shows a novel behavior in the early stage, with memory stretching back to the beginning of the bombardment. During the late stage, the stationary intensity auto-correlations are computed to determine the correlation times as a function of length-scale.

*This work was supported by NSF grant DMR-1709380 (BU) and DOE grant DE-SC0017802 (UVM).

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Presenters

  • Peco Myint

    • Haverford College
    • Division of Materials Science and Engineering, Boston University

Authors

  • Peco Myint

    • Haverford College
    • Division of Materials Science and Engineering, Boston University

  • Xiaozhi Zhang

    • Department of Physics and Materials Science Program, University of Vermont

  • Denise Erb

    • Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf e.V.

  • Andrei Fluerasu

    • NSLS-II, Brookhaven National Lab
    • National Synchrotron Light Source II
    • National Synchrotron Light Source II, Brookhaven National Laboratory
    • Brookhaven National Laboratory

  • Lutz Wiegart

    • NSLS-II, Brookhaven National Lab
    • National Synchrotron Light Source II
    • National Synchrotron Light Source II, Brookhaven National Laboratory
    • Brookhaven National Laboratory

  • Yugang Zhang

    • NSLS-II, Brookhaven National Lab
    • National Synchrotron Light Source II
    • National Synchrotron Light Source II, Brookhaven National Laboratory
    • Brookhaven National Laboratory

  • Stefan Facsko

    • Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf e.V.

  • Randall Headrick

    • Department of Physics and Materials Science Program, University of Vermont

  • Karl F Ludwig

    • Department of Physics & Division of Materials Science and Engineering, Boston University
    • Division of Materials Science and Engineering and Department of Physics, Boston University