Electron-beam induced deposition of high-purity copper nanostructures is desirable for nanoscale rapid prototyping, interconnection of chemically synthesized structures, and integrated circuit editing. However, metalorganic, gas-phase precursors for copper introduce high levels of carbon contamination. Here we demonstrate electron beam induced deposition of high-purity copper nanostructures from aqueous solutions of copper sulfate. The addition of sulfuric acid eliminates oxygen contamination from the deposit and produces a deposit with ∼95 at% copper. The addition of sodium dodecyl sulfate (SDS), Triton X-100, or polyethylene glycole (PEG) improves pattern resolution and controls deposit morphology but leads to slightly reduced purity. High resolution nested lines with a 100 nm pitch are obtained from CuSO4-H2SO4-SDS-H2O. Higher aspect ratios (∼1:1) with reduced line edge roughness and unintended deposition are obtained from CuSO4-H2SO4-PEG-H2O. Evidence for radiation-chemical deposition mechanisms was observed, including deposition efficiency as high as 1.4 primary electrons/Cu atom.
|State||Published - Feb 21 2017|
Bibliographical noteFunding Information:
This material is based upon work supported by the National Science Foundation under Grant Numbers CMMI-1125998, CMMI-1538650, and ECCS-1542164. The authors thank Professor Kathleen Dunn, SUNY Polytechnic Institute, for providing the electrodeposited copper samples.
© 2017 IOP Publishing Ltd.
- copper deposition
- direct write nanofabrication
- electron beam induced process
- liquid phase
ASJC Scopus subject areas
- Chemistry (all)
- Materials Science (all)
- Mechanics of Materials
- Mechanical Engineering
- Electrical and Electronic Engineering