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.

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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

Successive reactive-ion etching and microphotoluminescence (PL) intensity mapping have been performed in order to investigate the sources of epitaxial growth-induced stacking faults (SFs) in thick 4H-SiC epilayers. Three kinds of SFs, i.e., 4SSFs, 3SSFs, and 2SSFs, have been identified in the samples. Two of these (3SSFs and 2SSFs) show similar nucleation behaviors, and their formation may be due to stress within the epitaxial layer. In contrast, 4SSFs nucleate at the epilayer–substrate interface and might be related to an unknown dislocation, which shows a rounded-shape etch pit in the substrate.

Sources of Epitaxial Growth-Induced Stacking Faults in 4H-SiC

TaC-coated graphite prepared via a wet ceramic process: Application to CVD susceptors for epitaxial growth of wide-bandgap semiconductors

Many processing steps are required to fabricate complex electronic devices, including doping by ion implantation, patterning, etching, oxidation, passivation, and metallization. The process flow in SiC device fabrication is similar to that in silicon technology but several unique processes, with particular requirements, are also needed because of the unique physical and chemical properties of SiC. This chapter introduces the fundamental aspects and technological development of ion implantation, etching, oxidation, interface passivation, and Schottky and ohmic contacts in SiC.

Device Processing of Silicon Carbide

Implantation of Al and B Acceptors into Alpha-SiC and pn Junction Diodes

Homoepitaxial growth and fundamental aspects of device processing on 4H -SiC(11 20) and (03 38) have been reviewed. Although the efficiency of nitrogen incorporation is higher on the non-standard faces than on (0001), a low background doping concentration of 2~3 x10 cm can be achieved. On these faces, boron atoms are less effectively incorpora ted, compared to the growth on off-axis (0001). 4H-SiC(11 20) epilayers are micropipe-free, as expected. More interestingl y, almost perfect micropipe closing has been realized in 4H-SiC(03 38) epitaxial growth. Owing to the superior lattice recovery during post-implantation annealing and to the superior quality of MOS interface, both 4H-SiC(1120) and (03 38) possess much potential to develop SiC power MOSFETs. Introduction Various kinds of silicon carbide (SiC) electronic devices have been de veloped using a key technology, step-controlled epitaxy, for high-quality epilayers on off-a xis (0001) substrates by CVD [1]. Among them, SiC power MOSFETs have been expected in handling high pow er with low loss at high switching speed. However, they have major obstacles of low cha nnel mobility at the SiO2/SiC interface, especially in 4H-SiC. Researches to elucidate the cause for the low channel mobility and its improvement have been carried out mainly on the (0001) sur face with an off-angle of several degrees toward the [1120] direction. Based on our demonstration of high channel mobility of MOSFETs using the (1120) face [2], the SiO2/SiC interface properties seem to have correlation with chemical bonds on different crystal orientations. In order to make the correlation clear, epitaxial growth of high-quality 4H-SiC layers on non-standar d su faces should be completed at the first step. The authors have also proposed 4H-SiC(03 38), which is tilted by 54.7° from (0001) toward [01 10] as shown in Fig.1, as a novel face with potentially superior quality of MOS interface [3]. To scale up the current handling capability of SiC power devices, micropipes (hollow cores associated with superscrew dislocations) have to be eliminated [4]. In this respect, 4H-SiC(11 20), parallel to the caxis, is expected to be micropipefree [5]. Sublimation growth of micropipe-free 4H-SiC(03 38) ingots has also been suggested [6]. However, structural defects of 4HSiC epilayers on these non-standard faces have not been investigated Fig.1 4H-SiC(11 20) and (03 38) faces illustrated with the unit cell of 4H-SiC. 4H [0001]

Tsunenobu Kimoto

Papers

Sources of Epitaxial Growth-Induced Stacking Faults in 4H-SiC

TaC-coated graphite prepared via a wet ceramic process: Application to CVD susceptors for epitaxial growth of wide-bandgap semiconductors

Device Processing of Silicon Carbide

Implantation of Al and B Acceptors into Alpha-SiC and pn Junction Diodes

SiC epitaxy on non-standard surfaces