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

Various interesting phenomena related to the step-and-terrace structures of crystal surfaces have been previously observed. In this paper, we report a unique phenomenon not observed previously: the formation of a new class of step-and-terrace structure on the 4H-SiC(0001) surface after high-temperature gas etching. The structure consists of a periodic array of pairs of 1-bilayer-height "down" steps and 5-bilayer-height "up" steps, in contrast to conventional step-and-terrace structures which consist of only "up" (or only "down") steps. We show that the newly observed (5–1)-bilayer-height step-and-terrace structure originates from spiral etching at a screw dislocation. A mechanism for step-flow etching which conserves the "up"-and-"down" step pairs is also proposed.

A New Class of Step-and-Terrace Structure Observed on 4H-SiC(0001) after High-Temperature Gas Etching

This work reports on description and application of a new Photoluminescence (PL) Imaging technique for in-grown stacking fault (SF) characterization and identification on 4H-SiC epilayers. The purpose of this technique is to make a spectroscopic picture from a collection of PL imaging picture taken at different output wavelengths in order to both display the shape and an approximation of the maximum PL intensity wavelength at room temperature (RT) of the characterized SF. This is why we called this technique “PL Imaging Spectroscopy”. Five types of SFs have been observed and compared to PL spectra collected at RT and 10K.

Identification of Stacking Faults by UV Photoluminescence Imaging Spectroscopy on Thick, Lightly-Doped n-Type 4°-off 4H-SiC Epilayers

SiC Schottky Barrier Diodes with High Blocking Voltage of 1kV

We investigate the electrical characteristics of 1-kV pnp SiC bipolar junction transistors (BJTs) and compare them with those of npn SiC BJTs. The base resistance, current gain, and blocking capability are characterized. It is found that the base resistance of pnp SiC BJTs is two orders of magnitude lower than that of npn SiC BJTs. However, the obtained current gains are low below unity in pnp SiC BJTs, whereas npn SiC BJTs exhibit a current gain of 14 without surface passivation. The reason for the poor current gain of pnp SiC BJTs is discussed.

https://iopscience.iop.org/article/10.7567/JJAP.57.04FR04/pdf

A comparative study on electrical characteristics of 1-kV pnp and npn SiC bipolar junction transistors

The surface pretreatment of SiC substrate for AlN heteroepitaxial growth was investigated to realize initial two-dimensional (2D) layer-by-layer growth. AlN layers were grown on atomically flat SiC (0001) substrates by plasma-assisted molecular-beam epitaxy (PA-MBE). To achieve initial 2D growth, the control of SiC surface chemistry was very important as well as that of surface flatness. Owing to Ga deposition on the SiC surface and subsequent flash-off, an oxygen-free () R30° surface structure was achieved, and initial 2D growth with an evident RHEED intensity oscillation was demonstrated. The initial growth mode of AlN closely correlated with the crystalline quality of AlN layer. (© 2003 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Tsunenobu Kimoto

Papers

A New Class of Step-and-Terrace Structure Observed on 4H-SiC(0001) after High-Temperature Gas Etching

Identification of Stacking Faults by UV Photoluminescence Imaging Spectroscopy on Thick, Lightly-Doped n-Type 4°-off 4H-SiC Epilayers

SiC Schottky Barrier Diodes with High Blocking Voltage of 1kV

A comparative study on electrical characteristics of 1-kV pnp and npn SiC bipolar junction transistors

Impact of SiC surface control on initial growth mode and crystalline quality of AlN grown by molecular-beam epitaxy