다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

Deposits of clastic carbonate-dominated (calciclastic) sedimentary slope systems in the rock record have been identified mostly as linearly-consistent carbonate apron deposits, even though most ancient clastic carbonate slope deposits fit the submarine fan systems better. Calciclastic submarine fans are consequently rarely described and are poorly understood. Subsequently, very little is known especially in mud-dominated calciclastic submarine fan systems. Presented in this study are a sedimentological core and petrographic characterisation of samples from eleven boreholes from the Lower Carboniferous of Bowland Basin (Northwest England) that reveals a >250 m thick calciturbidite complex deposited in a calciclastic submarine fan setting. Seven facies are recognised from core and thin section characterisation and are grouped into three carbonate turbidite sequences. They include: 1) Calciturbidites, comprising mostly of highto low-density, wavy-laminated bioclast-rich facies; 2) low-density densite mudstones which are characterised by planar laminated and unlaminated muddominated facies; and 3) Calcidebrites which are muddy or hyper-concentrated debrisflow deposits occurring as poorly-sorted, chaotic, mud-supported floatstones. These

Phd by thesis

Wide bandgap semiconductors show superior material properties enabling potential power device operation at higher temperatures, voltages, and switching speeds than current Si technology. As a result, a new generation of power devices is being developed for power converter applications in which traditional Si power devices show limited operation. The use of these new power semiconductor devices will allow both an important improvement in the performance of existing power converters and the development of new power converters, accounting for an increase in the efficiency of the electric energy transformations and a more rational use of the electric energy. At present, SiC and GaN are the more promising semiconductor materials for these new power devices as a consequence of their outstanding properties, commercial availability of starting material, and maturity of their technological processes. This paper presents a review of recent progresses in the development of SiC- and GaN-based power semiconductor devices together with an overall view of the state of the art of this new device generation.

A Survey of Wide Bandgap Power Semiconductor Devices

Light-Emitting Diodes. (Monographs in Electrical and Electronic Engineering.) By A. A. Bergh and P. J. Dean. Pp. viii+591. (Clarendon: Oxford; Oxford University: London, 1976.) £22.

/pdf/light-emitting-diodes-ubzde6g9qc.pdf

Light-emitting diodes

An object is to provide a semiconductor device of which a manufacturing process is not complicated and by which cost can be suppressed, by forming a thin film transistor using an oxide semiconductor film typified by zinc oxide, and a manufacturing method thereof. For the semiconductor device, a gate electrode is formed over a substrate; a gate insulating film is formed covering the gate electrode; an oxide semiconductor film is formed over the gate insulating film; and a first conductive film and a second conductive film are formed over the oxide semiconductor film. The oxide semiconductor film has at least a crystallized region in a channel region.

Semiconductor device, and manufacturing method thereof

The temperature dependencies of hole density and hole mobility of p-type 4H-SiC obtained by Hall effect measurement were theoretically analyzed taking account of its anisotropic valence band structure. The experimental Hall factor, which was derived from the ratio of theoretical hole density to experimental Hall hole density, was reproduced by theoretical Hall factor computed using the valence band structure and relaxation times of scattering mechanisms. The product of the theoretical Hall factor and drift mobility computed by the same transport model agreed well with the experimental Hall mobility. Based on analyses of the results, it was revealed that the temperature dependence of Hall factor can be explained by considering the anisotropic valence band structure along with consideration of anisotropic relaxation times. The contribution of each scattering mechanism was also discussed, and empirical formulas for Hall and drift mobilities are presented.

Theoretical analysis of Hall factor and hole mobility in p-type 4H-SiC considering anisotropic valence band structure

Ni/4H–SiC Schottky barrier diodes have been fabricated on homoepitaxial layers grown on 4H–SiC(038) substrates. Micropipes existing in the substrates were almost completely dissociated during epitaxial growth. Schottky barrier diodes processed on the areas with closed micropipes exhibited low leakage current, at least, up to 1 kV. The difference in breakdown voltage between micropipe-free diodes and diodes with closed micropipes was less than 10%. A 2.9 kV–22 mΩcm2 diode was realized on the area with closed micropipes.

High-Voltage 4H–SiC Schottky Barrier Diodes Fabricated on (033̄8) with Closed Micropipes

300-nm-thick AlN layers without a nucleation layer were grown on 6H-SiC (0001) vicinal substrates with 3-bilayer-height steps by rf-plasma-assisted molecular-beam epitaxy. A Ga beam was supplied for 0 to 30 seconds just before growth of AlN. The Ga pre-irradiation for 7 seconds (∼1.6 ML) was found to be effective for realization of the AlN layer-by-layer growth mode at an earlier stage of the growth and reduction of threading dislocation densities (TDD) in the AlN layers. The screw-type and edge-type TDDs were ∼106 cm-2 and 6×108 cm-2, respectively. (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Enhancement of initial layer‐by‐layer growth and reduction of threading dislocation density by optimized Ga pre‐irradiation in molecular‐beam epitaxy of 2H‐AlN on 6H‐SiC(0001)

The Shockley–Read-Hall (SRH) lifetime in homoepitaxial p-GaN (N a = 1 × 1017 cm−3) is investigated by analyzing forward current–voltage (I–V) characteristics in GaN-on-GaN p–n+ junction diodes with mesa-isolation structure. The ideality factor around 2 due to recombination current was obtained in the 1.8–2.7 V window, which is different from the characteristic of a p+-n− junction involving considerable diffusion current. The recombination current was proportional to the junction area, indicating that the recombination current is a bulk component, not a mesa-surface component. Analyzing the recombination current with consideration of the SRH recombination rate in the depletion layer, we obtained an SRH lifetime of 46 ps at 298 K. The temperature dependence of the I–V characteristics was also investigated and the SRH lifetimes were extracted in the range of 223–573 K. The SRH lifetime in homoepitaxial p-GaN followed the empirical power law of = 1.2 × 10−16 × T 2.25 (s).

https://iopscience.iop.org/article/10.7567/1347-4065/ab07ad/pdf

Tsunenobu Kimoto

Papers

Theoretical analysis of Hall factor and hole mobility in p-type 4H-SiC considering anisotropic valence band structure

High-Voltage 4H–SiC Schottky Barrier Diodes Fabricated on (033̄8) with Closed Micropipes

Enhancement of initial layer‐by‐layer growth and reduction of threading dislocation density by optimized Ga pre‐irradiation in molecular‐beam epitaxy of 2H‐AlN on 6H‐SiC(0001)

Shockley-Read-Hall lifetime in homoepitaxial p-GaN extracted from recombination current in GaN p-n + junction diodes

High Voltage (>2.5kV) 4H-SiC Schottky Rectifiers Processed on Hot-Wall CVD and High-Temperature CVD Layers