We present a systematic investigation of the oxidation properties of Si dots fabricated on a silicon-on-insulator ͑SOI͒ wafer. Dots with diameters varying from 9 to 81 nm were structured on a SOI wafer. These dots were oxidized in a dry oxygen atmosphere at 700, 850, and 1000°C. The resulting structures were investigated using a side view transmission electron microscopy ͑TEM͒ technique in combination with energy filtered TEM. The dimensions of the residual Si and the grown SiO 2 were then extracted from the micrographs and analyzed. The oxidation appears to be retarded as compared to the well-known planar oxidation. At 700 and 850°C a self-limiting effect is observed as well as a clear pattern dependent oxidation at 850 and 1000°C. We attribute these effects to stress buildup in the oxide. The critical stress, causing the self-limiting effect, is calculated using a model that considers the decrease of the reaction rate with increasing stress perpendicular to the Si surface.

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Plasmon-induced transparency (PIT) is a result of destructive interference of different plasmonic resonators. Due to the extreme dispersion within the narrow transparency window, PIT metamaterials are utilized to realize slow light and nonlinear effect. However, other applications such as broadband filtering more desire a broad transmission frequency band at the PIT resonance. In this paper, a broadband PIT effect is demonstrated theoretically in a planar terahertz metamaterial, consisting of a U-shaped ring (USR) supporting electric and magnetic dipole modes as the bright resonator and a cut wire pair (CWP) possessing planar electric quadrupole and magnetic dipole modes as the dark resonator. The dark resonant modes of the CWP can be excited simultaneously via near-field by both the electric and magnetic dipole modes of the USR. When the electric as well as magnetic excitation pathways constructively interact with each other, the enhanced near-field coupling between bright and dark resonators gives rise to an ultra-broad transparency window across a frequency range greater than 0.61 THz in the transmittance spectrum.