Fabrication of SB-MOSFETs on SOI Substrate Using Ni Silicide Containing Er Interlayer

SB-MOSFETs were fabricated on SOI substrates by applying novel Schottky barrier height modulation technique of Er interlayer insertion at the interface of Ni/Si prior to Ni silicidation process. It was found that Er interlayer insertion lowered Schottky barrier height for electrons while no significant increase of the resistivity in the Er interlayer inserted films compare to pure Ni silicide films in the annealing temperature range of 500-750 o C. Effects of Er insertion to the transistor characteristics of SOI SB-MOSFETs are also discussed

Usefulness and safety of 0.4% sodium hyaluronate solution as a submucosal fluid "cushion" for endoscopic resection of colorectal mucosal neoplasms: A prospective multi-center open-label trial

<p>Abstract</p> <p>Background</p> <p>Sodium hyaluronate (SH) solution has been used for submucosal injection in endoscopic resection to create a long-lasting submucosal fluid "cushion". Recently, we proved the usefulness and safety of 0.4% SH solution in endoscopic resection for gastric mucosal tumors. To evaluate the usefulness of 0.4% SH as a submucosal injection solution for colorectal endoscopic resection, we conducted an open-label clinical trial on six referral hospitals in Japan.</p> <p>Methods</p> <p>A prospective multi-center open-label study was designed. A total of 41 patients with 5–20 mm neoplastic lesions localized in the colorectal mucosa at six referral hospitals in Japan in a single year period from December 2002 to November 2003 were enrolled and underwent endoscopic resection with SH. The usefulness of 0.4% SH was assessed by the <it>en bloc </it>complete resection and the formation and maintenance of mucosal lesion-lifting during endoscopic resection. Safety was evaluated by analyzing adverse events during the study period.</p> <p>Results</p> <p>The usefulness rate was high (82.5%; 33/40). The following secondary outcome measures were noted: 1) steepness of mucosal lesion-lifting, 75.0% (30/40); 2) intraoperative complications, 10.0% (4/40); 3) time required for mucosal resection, 6.7 min; 4) volume of submucosal injection, 6.8 mL and 5) ease of mucosal resection, 87.5% (35/40). Two adverse events of bleeding potentially related to 0.4% SH were reported.</p> <p>Conclusion</p> <p>Using 0.4% SH solution enabled sufficient lifting of a colorectal intramucosal lesion during endoscopic resection, reducing the need for additional injections and the risk of perforation. Therefore, 0.4% SH may contribute to the reduction of complications and serve as a promising submucosal injection solution due to its potentially superior safety in comparison to normal saline solution.</p

Essential pre-treatment imaging examinations in patients with endoscopically-diagnosed early gastric cancer

<p>Abstract</p> <p>Background</p> <p>There have been no reports discussing which imaging procedures are truly necessary before treatment of endoscopically-diagnosed early gastric cancer (eEGC). The aim of this pilot study was to show which imaging examinations are essential to select indicated treatment or appropriate strategy in patients with eEGC.</p> <p>Methods</p> <p>In 140 consecutive patients (95 men, 45 women; age, 66.4 +/- 11.3 years [mean +/- standard deviation], range, 33-90) with eEGC which were diagnosed during two years, the pre-treatment results of ultrasonography (US) and contrast-enhanced computed tomography (CT) of the abdomen, barium enema (BE) and chest radiography (CR) were retrospectively reviewed. Useful findings that might affect indication or strategy were evaluated.</p> <p>Results</p> <p>US demonstrated useful findings in 13 of 140 patients (9.3%): biliary tract stones (n = 11) and other malignant tumors (n = 2). Only one useful finding was demonstrated on CT (pancreatic intraductal papillary mucinous tumor) but not on US (0.7%; 95% confidential interval [CI], 2.1%). BE demonstrated colorectal carcinomas in six patients and polyps in 10 patients, altering treatment strategy (11.4%; 95%CI, 6.1-16.7%). Of these, only two colorectal carcinomas were detected on CT. CR showed three relevant findings (2.1%): pulmonary carcinoma (n = 1) and cardiomegaly (n = 2). Seventy-nine patients (56%) were treated surgically and 56 patients were treated by endoscopic intervention. The remaining five patients received no treatment due to various reasons.</p> <p>Conclusions</p> <p>US, BE and CR may be essential as pre-treatment imaging examinations because they occasionally detect findings which affect treatment indication and strategy, although abdominal contrast-enhanced CT rarely provide additional information.</p

Biotransformation of lanthanum by Aspergillus niger

Lanthanum is an important rare earth element and has many applications in modern electronics and catalyst manufacturing. However, there exist several obstacles in the recovery and cycling of this element due to a low average grade in exploitable deposits and low recovery rates by energy-intensive extraction procedures. In this work, a novel method to transform and recover La has been proposed using the geoactive properties of Aspergillus niger. La-containing crystals were formed and collected after A. niger was grown on Czapek-Dox agar medium amended with LaCl 3. Energy-dispersive X-ray analysis (EDXA) showed the crystals contained C, O, and La; scanning electron microscopy revealed that the crystals were of a tabular structure with terraced surfaces. X-ray diffraction identified the mineral phase of the sample as La 2(C 2O 4) 3·10H 2O. Thermogravimetric analysis transformed the oxalate crystals into La 2O 3 with the kinetics of thermal decomposition corresponding well with theoretical calculations. Geochemical modelling further confirmed that the crystals were lanthanum decahydrate and identified optimal conditions for their precipitation. To quantify crystal production, biomass-free fungal culture supernatants were used to precipitate La. The results showed that the precipitated lanthanum decahydrate achieved optimal yields when the concentration of La was above 15 mM and that 100% La was removed from the system at 5 mM La. Our findings provide a new aspect in the biotransformation and biorecovery of rare earth elements from solution using biomass-free fungal culture systems. </p

Rare earth oxides in microelectronics

A feasibility study of rare earth oxides for replacing SiO2 gate oxide for CMOS integrated circuits has been conducted. Rare earth oxides have relatively higher dielectric constants and are suitable as gate dielectrics. Two-dimensional device simulations reveal that the desirable dielectric constant, without affecting the short-channel performance, is less than 50. The dielectric constant values of rare earth oxides satisfy this condition. One of the issues in rare earth oxides that needs to be addressed is the hygroscopic properties of the film. These physical and electrical changes in the oxides caused by this moisture absorption, which are not suitable in electronics applications, can be suppressed by coating a metal film or by using a passivation layer. Of all the rare earth oxides, it is found that La2O3, after a proper heat treatment, has the best electrical properties for gate insulator applications in MOSFETs, because of its higher barrier height for the conduction band electrons and valence band holes as well as its higher dielectric constant. The smallest gate leakage current demonstrated through experimental results was 3 x 10(-4)/cm(3) at 1V for an EOT of 0.6 nm. The conduction mechanism through La2O3 has been modeled, and has been shown to be mainly by SCLC. With post-metallization annealing (PMA) after A1 gate electrode formation, La2O3 gated MISFET has shown high effective electron mobility of 319 cm(2)/V s. This value is lower compared to SiO2, but still one of the highest among all the high-kappa MISFETs, for a gate oxide EOT value which is slightly larger than 2.3 nm. The PMA recovers the flat band shift and improves the mobility presumably by the diffusion of Al into La2O3 which compensates the positive charges in the film. However, the growth of an interfacial A1(2)O(3) layer, which results in air increase in EOT, is still a problem. The solution could be to replace the A1 gate electrode with a less reactive metal with La2O3, and doping La2O3 films with some elements which compensate the negative charge. Interfacial layer suppression between the silicon substrate and the La2O3 film has been accomplished by Using Y2O3 as a buffer layer, which is necessary to achieve an EOT less than 1 nm. Reliability and yield of rare earth oxides still need to be investigated, but the results shown here hold promise for rare earth oxides, especially La2O3, as a suitable candidate for the post-Hf-based gate insulator in advanced CMOS integrated circuits. Interfacial layer suppression between the silicon substrate and the La2O3 film has been achieved by Using Y2O3 as a buffer layer, which is necessary to achieve an EOT less than 1 nm. Reliability and yield of rare earth oxides still need to be investigated, but the results shown above hold promise for rare earth oxides, especially La2O3, as a suitable candidate for the post-Hf-based gate insulator in advanced CMOS integrated circuits

Parasitic effects in multi-gate MOSFETs

In this paper, we have systematically investigated parasitic effects due to the gate and source-drain engineering in multi-gate transistors. The potential impact of high-K dielectrics on multi-gate MOSFETs (MuGFETs), such as FinFET, is evaluated through 2D and 3D device simulations over a wide range of proposed dielectric values. It is observed that introduction of high-K dielectrics will significantly degrade the short channel effects (SCEs), however a combination of oxide and high-K stack can effectively control this degradation. The degradation is mainly due to the increase in the internal fringe capacitance coupled with the decrease in gate-channel capacitance. From the circuit perspective, an optimum K value has been identified through mixed mode simulations. Further, as a part of this work, the importance of optimization of the shape of the spacer region is highlighted through full 3D simulations