Highly sensitive electrolyte-insulator-semiconductor (EIS) sensors were realized by the integration of Si nanowires (NWs), which were fabricated by using a simple and economic electroless wet etching technique. EIS sensors with NWs longer than 1 μm were observed to have considerably increased capacitance and high pH sensitivity. The pH sensitivity of the EIS sensor with 3.8 μm long NWs was 60.2 mV/pH, which is higher than the theoretical Nernstian of 59 mV/pH. The EIS sensors with NWs exhibited slightly worse pH hysteresis and drift properties than that of the conventional planar type EIS sensor. The increases in pH sensitivity, hysteresis and drift are attributable to the extended surface area of the EIS sensors enabled by the NWs.

We have fabricated the nano-floating gate memory with the TiSi2 and WSi2 nanocrystals embedded in the dielectrics. The TiSi2 and WSi2 nanocrystals were created by using sputtering and rapidly thermal annealing system, and then their morphologies were investigated by transmission electron microscopy. These nanocrystals have a spherical shape with an average diameter of 2-5 nm. The electrical properties of the nano-floating gate memory with TiSi2 and WSi2 nanocrystals were characterized by capacitance-voltage (C-V) hysteresis curve, memory speed and retention. The flat-band voltage shifts of the TiSi2 and WSi2 nanocrystals capacitors obtained appeared up to 4.23 V and 4.37 V, respectively. Their flat-band voltage shifts were maintained up to 1.6 V and 1 V after 1 hr.

A nonvolatile memory device with the multi-layered SiC nanocrystals embedded in the SiO2 dielectrics for long-term data storage was fabricated and its electrical properties were evaluated. The SiC nanocrystals were formed by using post thermal annealing process. The transmission electron microscope analysis showed the multi-layered SiC nanocrystals between the tunnel and the control oxide layers. The average size and density of the SiC nanocrystals were approximately 5 nm and 2×1012 cm-2, respectively. The memory window of nonvolatile memory devices with the multi-layered of SiC nanocrystals was about 2.7 V during the operations at ±10 V for 700 ms, and then it was maintained around at 1.1 V after 105 sec.

We report on the basic characteristics and gas sensing operation of density controlled single-walled carbon nanotube (SWCNT) thin films on poly(dimethyl siloxane) (PDMS) substrates The vacuum filteration and PDMS mold transfer method allowed the density of SWCNT distributed to have non-local uniformity. The optical transparency of the SWCNT thin films was inversely proportional to SWCNT density and conductivity. The flexible SWCNT thin film showed high mechanical stability with negligible change in conductance after being bent by 180o. We evaluated its gas sensing operation depending on SWCNT density and bias voltage. It was shown that lower SWCNT density thin films had higher sensitivity to NH3 gas, which may be due to higher exposed surface area for lower density SWCNT thin films. Also, we found that lower bias voltage devices showed faster recovery times. The results show that vacuum filteration and mold transfer method produced flexible SWCNT thin films that have stable mechanical and electrical characteristics and also stable gas sensing capabilities making them applicable to future flexible integrated sensors.

The aim of this study was to investigate the usefulness of a three-dimensional (3D) reconstruction of computed tomography (CT) images in determining the anatomy and topographic relationship between various important structures. Using 40 ears from 20 patients with various otological diseases, a 3D reconstruction based on the image data from spiral high-resolution CT was performed by segmentation, volume-rendering and surface-rendering algorithms on a personal computer. The 3D display of the middle and inner ear structures was demonstrated in detail. Computer-assisted measurements, many of which could not be easily measured in vivo, of the reconstructed structures provided accurate anatomic details that improved the surgeon’s understanding of spatial relationships. A 3D reconstruction of temporal bone CT might be useful for education and increasing understanding of the anatomical structures of the temporal bone. However, it will be necessary to confirm the correlation between the 3D reconstructed images and histological sections through a validation study.

We fabricated narrow fins structures and non-planar MOSFETs like FinFETs and triple-gate MOSFETs using plasma doping with substrate heating under 350··, and measured their I-V characteristics. Fins and MOSFETs using low-temperature doping process show good current drivability and low subthreshold slope. However, without post high-temperature thermal annealing, this process could not avoid generating defects and traps as well as mobile protons on the gate and gate oxide interface and junctions, and therefore degraded device reliability. The results of ultra-small MOSFET research show possibility of new memory devices with these traps and ions in devices.

Sources for low frequency noise in polycrystalline silicon thin-film transistors are analytically investigated. The grain boundary is modeled as symmetric Schottky barrier and a new device equation for current conduction in thin-film transistors is presented. At lower currents where barrier height is large enough to provide necessary distribution of time constants for 1/f noise, the number fluctuation via barrier height modulation at the grain boundary is found to be the main noise generation mechanism. At higher currents, mobility and diffusivity fluctuation are found to be dominant

Ferroelectric Bi4Ti3O12 thin films have been deposited using second harmonics of a Q-switched Nd:YAG laser. Various single crystal substrates, including SrTiO3(100), SrTiO3(110). MgO(100), and MgO(110), were used. Structural and electro-optic properties of the films were investigated using XRD, x-ray pole figure, and linear birefringence measurements. It is found that substrate kinds and their surface orientations are important growth parameters which determine crystal axis orientation and electro-optic properties of the Bi4Ti3O12 thin films.