Abstract
We compare various sputtering simulation methods to experimental results in both the low energy (<1 keV) and high energy (≥1 keV) impact regimes for argon ions impacting a pure copper substrate at normal incidence. Our results indicate that for high energy impacts, both binary collision approximation (BCA) and molecular dynamics methods can be used to generate reasonable predictions for the yield and energy distribution of the sputtered atoms. We also find reasonable agreement between the theoretical and experimental results down to impact energies of 600 eV. However, at 200 eV impact energies, significant discrepancies appear between the experimental and theoretical ejecta energy distributions in the peak position, the width of the energy distribution, and the magnitude of the high energy tail. These discrepancies appear to arise from the experimental results being only for atoms sputtered normal to the substrate surface, whereas the theoretical results are integrated over all 2π solid angles above the surface. Using the BCA code SDTrimSP and limiting the results to only atoms emitted within ±15° of the surface normal brings theory and experiment into reasonable agreement. These results suggest that for low energy impacts, the energy distribution of sputtered atoms is highly dependent on the emission angle of the ejecta.
Highlights
Sputtering due to ion irradiation is a process important to a diverse range of fields, such as surface and exosphere evolution of airless planetary bodies[1,2,3] and the production of thin films for optical coatings and electronic devices.[4,5] Advances in these fields build on our experimental and theoretical understanding of sputtering
We find that with the binary collision approximation (BCA) methods using an Eb value that is 30% lower than the surface binding energy (SBE) predicted from molecular dynamics (MD) simulations, there is still a close agreement between the two methods
We have performed new theoretical calculations for the sputtering yield and energy distribution resulting from argon impacting a pure copper substrate at normal incidence with impact energies between 200 and 3000 eV
Summary
Sputtering due to ion irradiation is a process important to a diverse range of fields, such as surface and exosphere evolution of airless planetary bodies[1,2,3] and the production of thin films for optical coatings and electronic devices.[4,5] Advances in these fields build on our experimental and theoretical understanding of sputtering. Binary collision approximation (BCA) models consider sputtering to be a result of binary collision cascades.[5] These models can be used to predict the energy distribution and yield of sputtered atoms as a function of incoming ion type, energy, and angle, with only modest computational requirements. For this reason, the majority of theoretical sputtering studies have been conducted using BCA methods.[5] it is important to benchmark these theoretical methods against more physically realistic MD simulations and experimental results
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
