Monolithic Integrations of Slanted Silicon Nanostructures on 3D Microstructures and Their Application to Surface Enhanced Raman Spectroscopy

摘要

We demonstrated fabrication of black silicon with slanted nanocone array onboth planar and 3D micro and meso scale structures produced by ahigh-throughput lithography-free oblique-angle plasma etching process.Nanocones with gradual change in height were created on the same piece ofsilicon. The relation between the slanted angle of nanocones and incident angleof directional plasma is experimentally investigated. In order to demonstratethe monolithic integration of nanostructures on micro and meso scale non-planarsurfaces, nanocone forest is fabricated on non-planar silicon surfaces invarious morphologies such as silicon atomic force microscopy (AFM) tips andpyramidal pits. By integrating nanocones on inverse silicon micro-pyramid arraydevices, we further improved the surface enhanced Raman scattering (SERS)enhancement property of this optimized commercial SERS substrate by severalfolds even when using 66% less noble metal coating. We investigated the lengthgradient dependence and asymmetric properties of SERS effects for slantednanocone with polarized excitation. This versatile and angle-controllablenanocone fabrication and monolithic 3D nano-micro-meso integration methodprovides new dimensions for production and optimization of SERS and othernanophotonic sensors.