<title>MeV ion implantation for modification of electronic, optical, and magnetic materials</title>

Abstract

ABSTRACT The University of Montreal recently inaugurated a new 1 .7 MV Tandem accelerator for materials research. It is being used tostudy a wide range of topics involving optical, electronic, opto-electronic, and magnetic materials. Current research includes:threshold dose for secondary damage in Si, gettering of impurities in Si by nano-cavities, ion beam mixing of metallicmultilayers probed by giant magnetoresistance, tracks and deformations induced by multi-MeV ion beams, and high-resolution radial distribution function of pure amorphous silicon. A selection of recent results is discussed.Keywords: ion implantation, optical materials, amorphous materials, magnetic materials, electronic materials 1. INTRODUCTION Ion implantation is virtually the only technique used today to achieve electrical doping in selected areas of silicon wafersduring microelectronic device manufacturing, and as such it is a well established and well understood process'. This is inlarge part due to the excellent effective and independent control it offers over different aspects of the required doping, such asspecies, depth, and doping concentration, and in much smaller part due to the highly non-equilibrium nature of the process.From a research point of view, it is the latter aspect that offers the greatest potential, and at the same time the greatestchallenge. Because of its highly non-equilibrium character, ion beam modification with MeV ions offers unique opportunitiesfor new processing and new understanding of a range of materials much broader than only the semiconductors. With this inmind, the University of Montreal recently acquired a new MeV Tandem accelerator, capable of accelerating a wide selectionof ions over a wide range of energies. As a note of interest, this accelerator is housed under the same roof as the prototype ofall Tandems, the 6 MV HVEE EN-i Tandem accelerator that was constructed in 1957 and 1958 for Chalk River ResearchLaboratories, and is still functional today. The new machine has now been operational for a little more than one year, andsome of the subjects being studied using either the old or the new accelerator are discussed in these proceedings.