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TaO x film formation by a photo-CVD method using TaCl5 as a source material is examined. The deposition rate increases with increasing growth temperature and decreasing chamber pressure down to 1 Torr. The leakage current of the formed TaO x film decreases drastically with annealing in the presence of both UV-irradiation and an oxygen ambient after deposition (p-O2 annealing), when the underlying layer contains Si. The leakage current density is 10-8 A/cm2 at the 4 MV/cm electric field. The dielectric constant for MIS structure capacitors decreases with decreasing TaO x thickness, but does not decrease much with p-O2 annealing. In addition, the mechanisms of reduction of the leakage current with p-O2 annealing are discussed.

Here, a new type of terahertz chemical microscope (TCM) is proposed and developed, and the first demonstration of imaging the chemical concentration in fluid channels is reported. Fluid samples flow through channels possessing a semiconductor sensing plate as a bottom wall. Terahertz (THz) waves are radiated from the sensing plate as a result of femtosecond laser illumination. Because the amplitude of the THz radiation depends on the concentration of ions adsorbed on the surface of the plate, the ion distribution in the fluid channels can be visualized by scanning the laser across the plate. An image showing separated solutions with two different proton concentrations is successfully observed as the first demonstration of this instrument.

A new type of laser-terahertz emission system for noncontact investigations of chemical solutions has been developed. The system monitors terahertz emission from a sensing plate, which consists of silicon oxide and silicon thin film layers on a sapphire substrate. Sensing of chemical solutions with pH values between 1.68 and 10.01 was demonstrated. The amplitude of the terahertz emission from the sensing plate increased with increasing pH value. This change in the amplitude was caused by a change in the depletion layers of the silicon thin film when protons were adsorbed on the surface of the sensing plate. This study demonstrates that full noncontact monitoring of chemical solutions is possible using the laser-terahertz emission system.

Objectives-Double balloon enteroscopy (DBE) with retrograde contrast is useful as a monitoring tool for small intestinal lesions in Crohn's disease (CD), but these are burdensome for patients. Intestinal ultrasound (IUS) can be used with ease in daily clinical practice, but there is less evidence regarding the accuracy of detection of small intestinal stenosis in CD. This study aimed to examine the diagnostic power of IUS for small intestinal stenosis in patients with CD.Methods-The findings of DBE and IUS in 86 patients with CD with small intestinal lesions were evaluated. Using DBE as the reference standard, we examined the detection rate of IUS for small intestinal stenosis. We evaluated three parameters: luminal narrowing, prestenotic dilation, and to-and-fro movement for determining stenosis using IUS. In addition, we compared the characteristics between the stenosis-detectable and stenosis-undetectable groups by IUS.Results-Of the 86 patients, 30 had small intestinal stenosis. In IUS findings, when lesions that met two or more of the three parameters were judged as stenosis, the detection rate was 70.0% for sensitivity, 98.2% for specificity, and 88.4% for accuracy. Moreover, there were patients with a younger age at diagnosis (P < 0.05) and more ileocolonic disease location (P < 0.05) in the stenosisdetectable group by IUS. The stenoses detected by IUS were significantly longer than those undetected by IUS (14.1 mm versus 5.2 mm, P < 0.05).Conclusions-IUS delivered reliable results for clinically important small intestinal stenosis of CD with high diagnostic accuracy.