Wafer-Scale Surface-Enhanced Raman Scattering Substrates with Highly Reproducible Enhancement

Here, we report a simple colloidal templating approach for fabricating surface-enhanced Raman scattering (SERS) substrates with highly reproducible enhancement over wafer-sized areas. The substrates are produced by evaporating a thin layer of gold on highly ordered silica colloidal crystal−polymer nanocomposites created by a scalable spin-coating technology. The ordered inorganic−organic composite structure induces the formation of island-type gold films. Systematic measurements and statistical analysis show that the substrates exhibit high SERS reproducibility with less than 28% standard deviation over a 4 in. wafer surface. Finite element electromagnetic modeling has also been employed to simulate SERS enhancement from these structured substrates.