Large Format Surface-Enhanced Raman Spectroscopy Substrate Optimized for Enhancement and Uniformity.

Area of Science:

• Nanophotonics
• Spectroscopy
• Materials Science

Background:

• Gratings are investigated as surface-enhanced Raman spectroscopy (SERS) substrates.
• Gratings can enhance far-field extinctions and near-field intensities compared to isolated particles.
• Resonance peaks in extinction spectra are observed when grating orders transition from evanescent to radiative.

Purpose of the Study:

• To apply grating fabrication principles to create high-performance SERS substrates.
• To achieve uniform SERS enhancements over large areas using a square two-dimensional array of gold-coated nanostructures.
• To utilize scalable foundry-based techniques for substrate fabrication.

Main Methods:

• Fabrication of square two-dimensional arrays of gold-coated nanostructures.
• Utilizing commonly available foundry-based techniques for large-scale wafer processing.
• Controlling grating geometric parameters to manipulate resonance peak properties.

Main Results:

• Achieved SERS enhancements of 10^7 uniformly over square centimeter areas.
• Demonstrated the applicability of foundry-based techniques for SERS substrate fabrication.
• Identified a parametric regime for repeatable and reproducible SERS performance optimization.

Conclusions:

• Developed a scalable method for fabricating high-performance SERS substrates.
• The fabricated grating substrates offer significant enhancement for SERS applications.
• The chosen fabrication techniques are suitable for large-scale manufacturing of SERS devices.