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An interesting hydrogen (H2) gas sensor, synthesized by an indium oxide (In2O3) layer and evaporated palladium (Pd) nanoparticles (NPs), is manufactured and studied. The utilized Pd NPs essentially enhance the surface area/volume (${S}_{A}/{V})$ ratio and catalytic reactivity of the Pd metal. Energy-dispersive X-ray spectroscopy (EDS), atomic force microscopy (AFM), high-resolution scanning electron microscopy (HRSEM), and TEM were used to investigate the relevant material behaviors of the proposed Pd NP/In2O3 sensor device. The sensing mechanism is explicated in this study. A very high-sensing response of 5243 under 1% H2/air gas with a response time of 12 s and an extremely low-detecting content of 100 ppb H2/air were obtained at the optimal operating temperature of 225 °C. In addition, excellent selectivity toward hydrogen gas is observed for the studied device. The proposed sensor also shows advantages of simple structure, low-cost, and relatively easy fabrication process. [ABSTRACT FROM AUTHOR]

In the traditional neural sensing microstructure, the limited metal line pitch and the metal layer numbers restrict the neural signal routing ability from electrodes to circuit chips. Miniature packaging and excessive noise interference bottlenecks are some of the challenges faced by the electrodes and circuit chips integration with traditional wire bonding. This paper proposes a 2.5-D heterogeneous integration neural sensing microsystem based on the silicon substrate to overcome these issues. With standard semiconductor and 3-D integration processes, high-channel-density (256 channels at 25 mm2) neural sensing microsystem is achieved. Through silicon via provides the shortest vertical interconnection and dramatically minimizes the packaging. Furthermore, the interposer can carry multiple chips to enhance the function of the biosensor. Electrical characteristics and reliability examinations reveal its high quality and great performance as compared to traditional approaches. This novel highly integrated neural sensing microsystem is expected to contribute to the biomedical field for exploring and solving unknown biological mysteries. [ABSTRACT FROM AUTHOR]

The azimuthal distribution of the ohmic loss in the coaxial waveguide with a misaligned inner rod is investigated in this paper. For axially symmetric modes with zero caustic radii, a little misalignment will bring a large change of the azimuthal ohmic loss distribution on the inner rod and the outer wall, and the change is more noticeable for a larger misalignment or a larger ratio of the inner to the outer radii in a coaxial waveguide; for asymmetric volume modes and whispering-gallery modes with nonzero caustic radii, when the inner rod radius is smaller than the caustic radius of a given mode, the azimuthal ohmic loss distribution is almost unchanged with a small misalignment, but when the inner rod radius is larger than the caustic radius, the azimuthal ohmic loss distribution changes obviously with the misalignment, and this change is larger for the coaxial waveguide with a larger ratio of the inner to the outer radii or a larger misalignment of the inner rod. This noticeable change may cause the azimuthal accumulation of heat on the inner rod and the outer wall in a coaxial waveguide or cavity. [ABSTRACT FROM AUTHOR]

Building on a previously presented compact gate capacitance (Cg-Vg) model, a computationally efficient and accurate physically based compact model of gate substrate- injected tunneling current (19-V9) is provided for both ultra- thin SiO2 and high-dielectric constant (high-κ) gate stacks of equivalent oxide thickness (EOT) down to ~ 1 nm. Direct and Fowler-Nordheim tunneling from multiple discrete subbands in the strong inversion layer are addressed. Subband energies in the presence of wave function penetration into the gate dielectric, charge distributions among the subbands subject to Fermi-Dirac statistics, and the barrier potential are provided from the compact Cg-Vg model. A modified version of the conventional Wentzel-Kramer-Brillouin approximation allows for the effects of the abrupt material interfaces and nonparabolicities in complex band structures of the individual dielectrics on the tunneling current. This compact model produces simulation results comparable to those obtained via computationally intense self- consistent Poisson-Schrodinger simulators with the same MOS devices structures and material parameters for 1-nm EOTs of SiO2 and high-κ/SiO2 gate stacks on (100) Si, respectively. Comparisons to experimental data for MOS devices with metal and polysilicon gates, ultrathin dielectrics of SiO2, Si3N4, and high-κ (e.g., HfO2) gate stacks on (100) Si with EOTs down to ~ 1-nm show excellent agreement. [ABSTRACT FROM AUTHOR]

Stacked gate dielectrics are modeled with respect to the impact on the leakage current of interfacial layers and transition regions, considering the tradeoff with the gate capacitance. A Franz 2-band dispersion model is used. Low-EOT and low-gatecurrent regimes are explored theoretically using reasonable estimates guided by experimental data. Transition layer values of each parameter are qualitatively explored for oxynitride, Si[sub 3]N[sub 4]/SiO[sub 2], and high-K stacks. Higher dielectric constant and more insulating materials are obviously desired for each layer of dielectric; however, the transition region becomes more important as such dielectrics are considered. Higher dielectric constant of interfacial layer is desirable for the low-EOT-low-gate-current requirement. [ABSTRACT FROM AUTHOR]

Reports on the development of a tunneling model to understand the gate current as a function of voltage and temperature, based on the energy-dispersion relation in each region of the gate-dielectric-silicon system. Calculation of the gate capacitance from Schrodinger and Poisson equations subject to Fermi-Dirac statistics.

Investigates the modeling of direct tunneling current through gate dielectric stacks. Gate lengths of complementary metal oxide semiconductors; Assumptions and approximations made in the investigation; Discussion of tunneling currents.