Engineering metamaterials with tunable resonances from mid-infrared to near-infrared wavelengths could have far-reaching consequences for chip based optical devices, active filters, modulators, and sensors. Utilizing the metal-insulator phase transition in vanadium oxide (VO(2)), we demonstrate frequency-tunable metamaterials in the near-IR range, from 1.5 - 5 microns. Arrays of Ag split ring resonators (SRRs) are patterned with e-beam lithography onto planar VO(2) and etched via reactive ion etching to yield Ag/VO(2) hybrid SRRs. FTIR reflection data and FDTD simulation results show the resonant peak position red shifts upon heating above the phase transition temperature. We also show that, by including coupling elements in the design of these hybrid Ag/VO(2) bi-layer structures, we can achieve resonant peak position tuning of up to 110 nm.

We introduce using sputtered aluminum oxide (alumina) as a resilient etch mask for fluorinated silicon reactive ion etches. Achieving selectivity of 5000:1 for cryogenic silicon etching and 68:1 for SF(6)/C(4)F(8) silicon etching, we employ this mask for fabrication of high-aspect-ratio silicon micropillars and nanopillars. Nanopillars with diameters ranging from below 50 nm up to several hundred nanometers are etched to heights greater than 2 microm. Micropillars of 5, 10, 20, and 50 microm diameters are etched to heights of over 150 microm with aspect ratios greater than 25. Processing and characterization of the sputtered alumina is also discussed.

Visible and near-IR photoluminescence (PL) is reported from sub-10 nm silicon nanopillars. Pillars were plasma etched from single crystal Si wafers and thinned by utilizing strain-induced, self-terminating oxidation of cylindrical structures. PL, lifetime, and transmission electron microscopy were performed to measure the dimensions and emission characteristics of the pillars. The peak PL energy was found to blue shift with narrowing pillar diameter in accordance with a quantum confinement effect. The blue shift was quantified using a tight binding method simulation that incorporated the strain induced by the thermal oxidation process. These pillars show promise as possible complementary metal oxide semiconductor compatible silicon devices in the form of light-emitting diode or laser structures.

In order to expand the use of nanoscaled silicon structures we present a new etching method that allows us to shape silicon with sub-10 nm precision. This top-down, CMOS compatible etching scheme allows us to fabricate silicon devices with quantum behavior without relying on difficult lateral lithography. We utilize this novel etching process to create quantum dots, quantum wires, vertical transistors and ultra-high-aspect ratio structures. We believe that this etching technique will have broad and significant impacts and applications in nano-photonics, bio-sensing, and nano-electronics.

Fabricated silicon nanostructures demonstrate mechanical properties unlike their macroscopic counterparts. Here we use a force mediating polymer to controllably and reversibly deform silicon nanowires. This technique is demonstrated on multiple nanowire configurations, which undergo deformation without noticeable macroscopic damage after the polymer is removed. Calculations estimate a maximum of nearly 24% strain induced in 30 nm diameter pillars. The use of an electron activated polymer allows retention of the strained configuration without any external input. As a further illustration of this technique, we demonstrate nanoscale tweezing by capturing 300 nm alumina beads using circular arrays of these silicon nanowires.