Low-temperature formation of silicon nitride gate dielectrics by atomic-layer deposition

Thin (equivalent oxide thickness Teq of 2.4 nm) silicon nitride layers were deposited on Si substrates by an atomic-layer-deposition (ALD) technique at low temperatures (<550°C). The interface state density at the ALD silicon nitride/Si-substrate interface was almost the same as that of the gate SiO2. No hysteresis was observed in the gate capacitance-gate voltage characteristics. The gate leakage current was the level comparable with that through SiO2 of the same Teq. The conduction mechanism of the leakage current was investigated and was found to be the direct tunneling. The ALD technique allows us to fabricate an extremely thin, very uniform silicon nitride layer with atomic-scale control for the near-future gate dielectrics

NH3-annealed atomic-layer-deposited silicon nitride as a high-k gate dielectric with high reliability

Extremely thin (equivalent oxide thickness, Teq = 1.2 nm) silicon-nitride high-k (er = 7.2) gate dielectrics have been formed at low temperatures (<550 °C) by an atomic-layer-deposition (ALD) technique with subsequent NH3 annealing at 550 °C. A remarkable reduction in leakage current, especially in the low dielectric voltage region, which will be the operating voltage for future technologies, has made it a highly potential gate dielectric for future ultralarge-scale integrated devices. Suppressed soft breakdown events are observed in ramped voltage stressing. This suppression is thought to be due to a strengthened structure of Si–N bonds and the smoothness and uniformity at the poly-Si/ALD-silicon-nitride interface

Mantle Cell Lymphoma Mainly Involving Thoracic Lesions: Two Case Reports

Most mantle cell lymphoma patients show remarkable disseminated disease at the initial diagnosis. We describe two cases of mantle cell lymphoma mainly involving thoracic lesions at the initial presentation of the disease. The clinical presentations were right hilar lymphadenopathy in one case and right pleural thickness in the other. The diagnosis of mantle cell lymphoma was confirmed by immunohistochemistry, including CD5, CD 20, and cyclin D1, and the presence of t(11; 14)(q13; q32) by fluorescence in situ hybridization. These thoracic manifestations at the initial diagnosis should be taken into consideration for the clinical spectrum of mantle cell lymphoma.ArticleINTERNAL MEDICINE. 50(14):1477-1481 (2011)journal articl

Antineutrophil Cytoplasmic Antibody-associated Vasculitis Complicating Graves\u27 Disease: Report of Two Adult Cases

Two adult female patients with established Graves\u27 disease were treated with propylthiouracil (PTU). One patient developed agranulocytosis, high fever of unknown origin and bilateral episcleritis. Another patient reported repeated attacks of common cold-like symptoms, polyarthralgia and skin purpura. There was no hematuria or proteinuria. Administration of PTU was withdrawn following identification of high myeloperoxidase-antineutrophil cytoplasmic antibody (MPO-ANCA) titer in the serum. Without steroids or immunosuppressive therapy, symptoms improved gradually in association with a fall in serum MPO-ANCA titer. We speculated that the symptoms of our two cases were due to MPO-ANCA associated vasculitis. MPO-ANCA positive vasculitis and glomerulonephritis are rare complications of PTU therapy, however, when these occur, the condition may become serious. Patients with Graves\u27 disease treated with PTU should be carefully observed during therapy