TITLE: COHERENT X-RAY SCATTERING STUDIES OF ION BEAM NANO-PATTERNING KINETICS AND
ABSTRACT: Spontaneous formation of nanoscale morphologies or ultrasmoothening is observed
when 0.1-10 keV energetic ions bombard a surface. Since the length scales of the nanopatterns are in tens of nanometers, X-rays can be utilized not only to characterize them, but also to study kinetics and dynamics happening on the surface in real time. We use the surface sensitive X-ray technique of Grazing-Incidence Small-Angle X-ray Scattering (GISAXS), and the resulting measurements are compared with theoretical models that attempt to explain the ion beam nano-patterning processes. By using non-coherent and coherent X-rays, in-situ studies of Si, Ge, and SiO2 surfaces, bombarded by ions, have been conducted. Non-coherent X-rays can be used to discern the averaged kinetics on a surface, but coherent X-rays further enable us to differentiate fluctuations around the average kinetics. As a complementary measurement, Multi Beam Optical Stress Sensor (MOSS) is also used to do real-time measurements of the stress evolution during nanoscale pattern formations. Python analysis pipelines that have been independently developed to analyze GISAXS and MOSS data will be discussed.
Professor Karl Ludwig, MSE/Physics; Professor Kevin Smith, MSE/Physics; Professor Soumendra N. Basu, MSE/ME; Professor William Klein, Physics