Fabrication and metrology of novel magnetic tunnel junctions in the ultra-thin barrier limit

Within a broader program of exploring methods to fabricate structures with novel electronic properties at the nanometer scale, we are using highly charged ions (HCIs) to produce ensembles of nano-features within magnetic tunnel junctions (MTJ). Technologically, MTJs are a major component of magnetic random access memory (MRAM) architectures which are expected to eventually replace hard drives and are already standard components in automotive and aviation applications. A leading technical challenge is producing MTJs whose resistance-area (RA) product (two dimensional resistivity) fall in a range that allows for both high signal-to-noise, fast write times, and long lifetimes. Contemporary approaches have focused on producing MTJ layer structures with uniform RA products, whereas our approach is to produce a layer structure that is a superposition of high and low RA product regions, whose average RA product is determined by the relative density of each.