AbstractsPhysics

In this thesis, Metal-Assisted Chemical Etching (MacEtch) as a wet anisotropic etching technique which is very promising in fabricating high aspect ratio semiconductor nanostructures with less surface damage is introduced in terms of etching mechanism, effect of different etching parameters as well as detailed fabrication process. GaAs nanopillar LED fabricated by MacEtch exhibits better light extraction due to the large surface area of nanopillars and multiple scattering interactions. A novel structure is fabricated via a MacEtch process by which it is feasible to effectively “bury” patterned metal film into the semiconductor material. The resulting structures can be fabricated with subwavelength, nanoscale pitch and feature size, and with etch depths equal to or greater than the grating pitch. The buried extraordinary optical transmission (B-EOT) gratings are modeled using three-dimensional (3D) rigorous coupled wave analysis (RCWA) and characterized experimentally by angle-dependent Fourier transform infrared (FTIR) transmission spectroscopy with good agreement between the theoretical predictions and experimental results. B-EOT structures not only show significantly enhanced peak transmission when normalized to the open area of the metal film, but more importantly, peak transmission greater than that observed from the bare semiconductor surface. In a sense, the B-EOT structure combines the benefits of both moth-eye anti-reflection coatings and EOT-inspired spectral selectivity. Advisors/Committee Members: Li, Xiuling (advisor).