Analysis of carbon content in direct-write plasmonic Au structures by nanomechanical scanning absorption microscopy

TL;DR

This paper introduces a novel optical method using nanomechanical resonators to measure carbon content in tiny gold nanostructures, overcoming limitations of traditional techniques for small volumes.

Contribution

It presents an alternative optical absorption technique combined with analytical modeling for chemical analysis of nanostructures with limited volume.

Findings

Successful measurement of carbon content in FEBID gold nanostructures.

Demonstration of resonance frequency detuning as a chemical signature.

Potential for non-destructive, high-precision chemical analysis at the nanoscale.

Abstract

The determination of the chemical content is crucial for the quality control in high-precision device fabrication and advanced process development. For reliable chemical composition characterization, certain interaction volume of the target material is necessary for conventional techniques such as energy-dispersive X-ray spectroscopy (EDX) and electron energy loss spectroscopy (EELS). This remains however a challenge for nanostructures. We hereby propose an alternative technique for measuring chemical composition of nanostructures with limited volume. By measuring the differences in the optical absorption of the nanostructure due to the differences in the chemical composition with the resonance frequency detuning of a nanomechanical resonator as well as the assistance of the analytical optical modelling, we demonstrate the possibility of characterizing the carbon content in the direct-write focused electron beam induced deposition (FEBID) gold nanostructures.