Field-directed sputter sharpening for tailored probe materials and atomic-scale lithography.

Schmucker, S W; Kumar, N; Abelson, J R; Daly, S R; Girolami, G S; Bischof, M R; Jaeger, D L; Reidy, R F et al. · Nat Commun · 2012

basic_science · Level V

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Abstract

Fabrication of ultrasharp probes is of interest for many applications, including scanning probe microscopy and electron-stimulated patterning of surfaces. These techniques require reproducible ultrasharp metallic tips, yet the efficient and reproducible fabrication of these consumable items has remained an elusive goal. Here 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-HfB(2) 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.