Despite surface-enhanced Raman scattering (SERS) being first observed in the late 1970s, efforts to provide reproducible SERS-based chemical sensors have been hindered by the inability to make large-area devices with a uniform SERS response. Furthermore, variations in the observed spectra occur due to the variable interactions and orientations of the analyte with the textured SERS surfaces. Here we report on periodic arrays of Ag- and Au-coated vertical silicon nanopillars fabricated by e-beam lithography and reactive ion etching for use as SERS sensor templates that provide both large and uniform enhancement factors (up to 1×108) over the structure surface area. We discuss the impact of the overall geometry of the structures, by varying both the diameter and the edge-to-edge spacing in an effort to optimize the SERS response for a given excitation laser wavelength. Calculations of the electromagnetic field distributions within such structures were also performed and support the behavior observed experimentally.© (2010) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.