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Field-Directed Sputter Sharpening for Tailored Probe Materials and Atomic-Scale Lithography

Fabrication of ultra-sharp probes is of interest for many applications, including scanned probe microscopy and electron-stimulated patterning of surfaces. These techniques require reproducible ultra-sharp metallic tips, yet the efficient and reproducible fabrication of these consumable items has remained an elusive goal. We describe a novel biased-probe field-directed sputter sharpening technique, applicable to conductive materials, which produces nanometer and sub-nanometer sharp W, Pt-Ir, and W-HfB2 tips able to perform atomic-scale lithography on Si. Compared with traditional probes fabricated by etching or conventional sputter erosion, field-directed sputter sharpened probes have smaller radii and produce lithographic patterns 18 – 26% sharper with atomic-scale lithographic fidelity.Office of Naval Research Grant N00014-06-10120Defense Advanced Research Project Agency and Space and Naval Warfare Center, San Diego contract N66001-08-C-2040National Science Foundation grant CHE 10-38015National Science Foundation grant DMR 10-05715National Science Foundation grant CHE 07-50422published or submitted for publicationis peer reviewe