127 Mater. Res. Soc. Symp. Proc. Vol. 1354 © 2011 Materials Research Society DOI: 10.1557/opl.2011. 4 Study of scalable IBS nanopatterning mechanisms for III-V semiconductors using in-situ surface characterization Jean Paul Allain 1,2 , Osman El-Atwani 1,2 , Alex Cimaroli 1 , Daniel L. Rokusek 1 , Sami Ortoleva 1 , Anastassiya Suslova 1 , 1 Purdue University, West Lafayette, IN 47907, USA 2 Birck Nanotechnology Center, West Lafayette, IN 47907, USA ABSTRACT Ion-beam sputtering (IBS) has been studied as a means for scalable, mask-less nanopatterning of surfaces. Patterning at the nanoscale has been achieved for numerous types of materials including: semiconductors, metals and insulators. Although much work has been focused on tailoring nanopatterning by systematic ion-beam parameter manipulation, limited work has addressed elucidating on the underlying mechanisms for self-organization of multi-component surfaces. In particular there has been little attention to correlate the surface chemistry variation during ion irradiation with the evolution of surface morphology and nanoscale self-organization. Moreover the role of surface impurities on patterning is not well known and characterization during the time-scale of modification remains challenging. This work summarizes an in-situ approach to characterize the evolution of surface chemistry during irradiation and its correlation to surface nanopatterning for a variety of multi-components surfaces. The work highlights the importance and role of surface impurities in nanopatterning of a surface during low-energy ion irradiation. In particular, it shows the importance of irradiation-driven mechanisms in GaSb(100) nanopatterning by low-energy ions and how the study of these systems can be impacted by oxide formation. INTRODUCTION It is well known that many shapes and sizes of nanostructures can be formed via ion beam sputtering (IBS) techniques. Numerous techniques are known that pattern surfaces including: block co-polymer self-assembly. Ion irradiation can be operated at very low energies (e.g. below the threshold energy for displacement damage) and can introduce new processing pathways not offered by traditional thermodynamic self-assembly approaches. IBS also provides the flexibility to tailor both the surface concentration and surface nanopatterning by changing the ion fluence, incident ion angle, ion energy and co-implantation of ion beams. With device features approaching characteristic lengths of the order of several monolayers (~ 1-2 nm), irradiation at low energies near the threshold regime becomes invaluable for ion-irradiation based nanopatterning. There are two primary reasons for this requirement. One, plasma-based processing of materials continues to be a reliable, efficient and versatile method to modify materials. Although very high-energy ion beams can modify the surface of materials via electronic energy losses, ion-beam accelerators cannot be cheaply integrated into existing materials processing tools. Second, the stopping power is such that to modify only the top few nm of a surface, extremely low-energy ions must be used. Thus the work presented here focuses on energies that range between 50 and 1000 eV. 1 58