Shinshu University Distance-Learning Systern using Broadband-Internet via Microwave

In Shinshu University, the campuses are connected by a microwave network called SUNS (Shinshu University Campus Collaboration Network System), in which 7.5 GHz digital microwave with the transmission capacity of 19 Mbps is used. SUNS is mainly composed of two networks: one is a video and audio data network with bilateral communication and other is a computer data network. Distance learning system applying SUNS is widely used for intercampus- and interuniversity- lectures, extension lectures, meetings and conferences. In this paper, the network system configurations of SUNS and its application to the distance learning are introduced.Article信州大学教育システム研究開発センター紀要 6: 87-96(2000)departmental bulletin pape

Preparation and Characterization of Deposited Tetraethylorthosilicate-SiO2/SiC MIS Structure

The SiO2 layer was deposited on the 4H-SiC Si face by the thermal decomposition of tetraethylorthosilicate(TEOS) in N2 atmosphere to from MIS diodes. The post deposition annealing was effective to improve the interface properties. The interface state density of the deposited SiO2/SiC MIS structure was estimated to be the order of 1011 cm-2eV-1 by Terman method. The direct nitridation of SiC surface prior to the deposition of the SiO2 layer was effective to reduce the interface state density.ArticleMaterials Science Forum, Vols. 740-742, pp. 805-808 (2013)journal articl

Plasma Nitridation of 4H-SiC by Glow Discharge of N2/H2 Mixed Gases

The mixed gas of nitrogen and hydrogen was used for the plasma nitridation of SiC surface.A small amount of hydrogen was effective to activate the nitridation reaction and suppress the oxidationreaction. The interface properties were improved by using nitride layer as an interfacial bufferlayer of SiC MIS structure.ArticleMaterials Science Forum, Vols. 821-823, pp. 504-507 (2015)journal articl

Preparation and Characterization of Nitridation Layer on 4H SiC (0001) Surface by Direct Plasma Nitridation

A nitride layer was formed on a SiC surface by plasma nitridation using pure nitrogen as the reaction gas at the temperature from 800°C to 1400°C. The surface was characterized by XPS. The XPS measurement showed that an oxinitride layer was formed on the SiC surface by the plasma nitridation. The high process temperature seemed to be effective to activate the niridation reaction. A SiO2 film was deposited on the nitridation layer to form SiO2/nitride/SiC structure. The interface state density of the SiO2/nitride/SiC structure was lower than that of the SiO2/SiC structure. This suggested that the nitridation was effective to improve the interface property.ArticleMaterials Science Forum, Vols. 778-780, pp. 631-634 (2014)journal articl

Interface State Density between Direct Nitridation Layer and SiC Estimated from Current Voltage Characteristics of MIS Schottky Diode

Interface state density was estimated from diode factor n of SiC MIS Schottky diode. The interface state density was the order of 10(12) cm(-2)eV(-1), and was same order to the value for the sample carefully prepared by oxidation and post oxidation annealing. The interface state density determined from n was consistent to the value calculated from the capacitance voltage curve of SiO(2)/nitride/SiC MIS diode by Terman method. High temperature nitridation was effective to reduce the interface state density.ArticleIEICE TRANSACTIONS ON ELECTRONICS. E92C(12):1470-1474 (2009)journal articl

Model Calculation for the Field Enhancement Factor of Carbon Nanowall Array

To estimate the field emission current associated with an array of carbon nanowalls (CNWs), the model of the floating rods between anode and cathode plates was proposed. An approximate formula for the enhancement factor was derived, showing that the interwall distance of the CNW array critically affects the field emission. The field enhancement factor was almost one order of magnitude less than that of vertically aligned CNTs. Considering the field emission current density, the field emission can be optimized when the interwall distance is comparable with the wall height. For same separation distance, the macroscopic field strength of the CNW array is almost one order of magnitude higher than that of vertical CNT array to obtain the emission current of 1 mA from the cathode surface of 1 cm(2).ArticleIEICE TRANSACTIONS ON ELECTRONICS. E94C(12):1867-1871 (2011)journal articl

Model Calculation for the Field Enhancement Factor of Carbon Nanowall Array

To estimate the field emission current associated with an array of carbon nanowalls (CNWs), the model of the floating rods between anode and cathode plates was proposed. An approximate formula for the enhancement factor was derived, showing that the interwall distance of the CNW array critically affects the field emission. The field enhancement factor was almost one order of magnitude less than that of vertically aligned CNTs. Considering the field emission current density, the field emission can be optimized when the interwall distance is comparable with the wall height. For same separation distance, the macroscopic field strength of the CNW array is almost one order of magnitude higher than that of vertical CNT array to obtain the emission current of 1 mA from the cathode surface of 1 cm(2).ArticleIEICE TRANSACTIONS ON ELECTRONICS. E94C(12):1867-1871 (2011)journal articl