Low Energy Ion Interactions with Transition Metal Films: ballistic and Diffusive Transport Processes

Activity: Talk or presentationOral presentation

Description

Interactions of low energy ions (< 1000eV) with surfaces is of increasing importance to industries of semiconductor manufacturing, ion metrology and fusion. The nature of the interactions of ion species at high energies (>1000eV) can generally be classified as ballistic. As the energy decreases, approaching the so-called sputter threshold, the ion interactions are no longer purely ballistic. Adding to the complexity is the reactivity of certain ion-target combinations leading to dynamic changes in material surface properties. Here, we discuss the various processes of interactions between reactive ions of N2 and O2 with transition metal surfaces of industrial interest: Mo, Ru, Pd and W. Experimental studies by Angle Resolved X-Ray photoelectron spectroscopy (AR-XPS) shed light on the incorporation of implanted species and their distribution in depth. Corroborating with ballistic Monte-Carlo simulations we separate effects of ballistics from diffusion (bulk and radiation enhanced) and find that O2 ions show an enhanced depth of implantation than predicted by ballistics near threshold. Further, while N2 behaves as per ballistic mechanisms, the incorporation is unaffected by the ion energy. The interactions for similar mass species are widely different indicating a strong chemical effect near sputter thresholds and require more concerted efforts for understanding.
Period11 Jul 2022
Event title22nd International Conference on Ion Beam Modification of Materials, IBMM 2022
Event typeConference
Conference number22
LocationLisbon, Portugal
Degree of RecognitionInternational