H. M. H. Chong

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—We present the design, fabrication, and characterization of a microcavity that exhibits simultaneously high transmission and large resonance quality-factor (Q-factor). This microcavity is formed by a single-row photonic crystal (PhC) embedded in a 500-nm-wide photonic wire waveguide—and is based on silicon-on-insulator. A normalized transmission of 85%,(More)
This paper reports on large area, metal-free deposition of nanocrystalline gra-phene (NCG) directly onto wet thermally oxidized 150 mm silicon substrates using parallel-plate plasma-enhanced chemical vapor deposition. Thickness non-uniformities as low as 13% are achieved over the whole substrate. The cluster size L a of the as-obtained films is determined(More)
In this work, we investigate sensor design approaches for eliminating the effects of parasitic resistance in nanowire and nanoribbon biosensors. Measurements of pH with polysilicon nanoribbon biosensors are used to demonstrate a reduction in sensitivity as the sensor length is reduced. The sensitivity (normalised conductance change) is reduced from 11% to(More)
This paper studies the effect of atomic layer deposition (ALD) temperature on the performance of top-down ZnO nanowire transistors. Electrical characteristics are presented for 10-μm ZnO nanowire field-effect transistors (FETs) and for deposition temperatures in the range 120°C to 210°C. Well-behaved transistor output characteristics are obtained for all(More)
We report low-loss silicon waveguides and efficient grating coupler to couple light into them. By using anisotropic wet etching technique, we reduced the side wall roughness down to 1.2 nm. The waveguides were patterned along the [112] direction on a [110] silicon-on-insulator substrate. The waveguide boundaries are decided by the [111] planes, which are(More)
We demonstrate the advantages of dual-gate polysilicon nanoribbon biosensors with a comprehensive evaluation of different measurement schemes for pH and protein sensing. In particular, we compare the detection of voltage and current changes when top- and bottom-gate bias is applied. Measurements of pH show that a large voltage shift of 491 mV pH(-1) is(More)
This paper reports on a novel MEMS resonant sensing device consisting of three weakly coupled resonators that can achieve an order of magnitude improvement in sensitivity to stiffness change, compared to current state-of-the-art resonator sensors with similar size and resonant frequency. In a 3 degree-of-freedom (DoF) system, if an external stimulus causes(More)
— Top-down ZnO nanowire FETs have been fabricated using mature photolithography, ZnO atomic layer deposition (ALD) and plasma etching. This paper investigates the effects of oxygen adsorption by measuring FET characteristics at different gate bias sweep rates and by characterizing hysteresis effects. Unpassivated devices exhibit a low threshold voltage(More)