Selected Area Deposition of High Purity Gold for Functional 3D Architectures

John Lasseter; Philip D Rack; Steven J Randolph

doi:10.3390/nano13040757

Selected Area Deposition of High Purity Gold for Functional 3D Architectures

Nanomaterials (Basel). 2023 Feb 17;13(4):757. doi: 10.3390/nano13040757.

Authors

John Lasseter¹, Philip D Rack¹, Steven J Randolph²

Affiliations

¹ Department of Materials Science and Engineering, University of Tennessee, Knoxville, TN 37996, USA.
² Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA.

Abstract

Selected area deposition of high purity gold films onto nanoscale 3D architectures is highly desirable as gold is conductive, inert, plasmonically active, and can be functionalized with thiol chemistries, which are useful in many biological applications. Here, we show that high-purity gold coatings can be selectively grown with the Me₂Au (acac) precursor onto nanoscale 3D architectures via a pulsed laser pyrolytic chemical vapor deposition process. The selected area of deposition is achieved due to the high thermal resistance of the nanoscale geometries. Focused electron beam induced deposits (FEBID) and carbon nanofibers are functionalized with gold coatings, and we demonstrate the effects that laser irradiance, pulse width, and precursor pressure have on the growth rate. Furthermore, we demonstrate selected area deposition with a feature-targeting resolutions of ~100 and 5 µm, using diode lasers coupled to a multimode (915 nm) and single mode (785 nm) fiber optic, respectively. The experimental results are rationalized via finite element thermal modeling.

Keywords: 3-dimensional nanostructures; chemical vapor deposition; laser heating; selected area deposition.

Grants and funding

This research was supported by the Center for Nanophase Materials Sciences, which is a U.S. Department of Energy Office of Science user facility at Oak Ridge National Laboratory (ORNL). Support for S.J.R. was partially provided through Strategic Hire funding through the Laboratory Directed Research and Development Program of Oak Ridge National Laboratory, managed by UT-Battelle, LLC, for the U.S. Department of Energy.