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

Fast Epitaxial Growth of 4H-SiC by Chimney-Type Hot-Wall CVD

Deep Level Transient Spectroscopy (DLTS) and Double-correlated DLTS (DDLTS) measurements have been conducted on Schottky contacts fabricated on n-type 4H-SiC epilayers using different contact metals in order to separate the EH6- and EH7-centers, which usually appear as a broad double peak in DLTS spectra. The activation energy of EH6 (EC - ET(EH6) = 1.203 eV) turns out to be independent of the electric field. As a consequence, EH6 is acceptor-like according to the missing Poole-Frenkel effect. Therefore, it can be excluded that the EH6-center and the prominent acceptor-like Z1/2-center belong to different charge states of the same microscopic defect as theoretically suggested. It is proposed that EH6 is a complex containing a carbon vacancy and another component available at high concentrations. The activation energy of EH7 (EC - ET(EH7) = 1.58 eV) has been evaluated indirectly by fitting the DLTS spectra of the EH6/7 double peak taking the previously determined parameters of EH6 into account.

Z1/2- and EH6-Center in 4H-SiC: Not Identical Defects ?

250 nm thick AlN layers without a nucleation layer were grown directly on 6H-SiC(0001) with 3-bilayer-height steps by rf-plasma-assisted molecular-beam epitaxy The structure and morphology of the AlN layers have been studied using atomic force microscopy, X-ray diffraction and transmission electron microscopy Two different types of unique defect structures were observed Rows of pure-edge-type threading dislocations were observed along the pre-existing step-edges of the SiC substrate for AlN grown on as-gas-etched SiC sub- strates, while the planar defects threading through the AlN layer were observed at the step-edges of the substrate for AlN on SiC with sacrificial oxidation We concluded that these planar defects were the stacking mismatch boundaries due to the difference in stacking sequence of AlN layers on different SiC terraces

Observation of novel defect structure in 2H‐AlN grown on 6H‐SiC(0001) substrates with 3‐bilayer‐height step‐and‐terrace structures

We investigated the glide velocities of 30° Si-core partial dislocations for the expansion of double-Shockley stacking faults (DSFs) in heavily nitrogen-doped 4H-SiC crystals at high temperatures of approximately 1000 °C. The heavily doped epilayers grown by chemical vapor deposition were successively annealed. The expansion of DSFs in the heavily doped epilayers was tracked by a photoluminescence (PL) imaging technique. From the PL images obtained after each annealing treatment, the glide velocities of the 30° Si-core partial dislocations were estimated. In particular, temperature dependence and nitrogen-concentration dependence of the dislocation velocities were obtained. We also report the influence of the strain energies of the bounding dislocations on the velocities. Based on the experimental results, the quantitative expression of the dislocation glide is discussed.

Glide velocities of Si-core partial dislocations for double-Shockley stacking fault expansion in heavily nitrogen-doped SiC during high-temperature annealing

Characterization of n+-GaN/p−-SiC and n+-GaN/p+-SiC heterojunctions as well as fabrication of GaN/SiC heterojunction bipolar transistors (HBTs) using these heterojunctions is presented. The electroluminescence spectrum from n+-GaN/p+-SiC heterojunction diodes under forward bias clearly indicates electron injection from n+-GaN into p+-SiC. HBTs consisting of n+-GaN emitter /p+-SiC base/n−-SiC collector/n+-SiC substrate have been fabricated. Although clear common-base properties were obtained, the current gain was very low (10-4). SiC homojunction bipolar junction transistors (BJT) using the same base-collector junction exhibited a current gain value of 0.5, suggesting the low current gain of GaN/SiC HBTs originates from low emitter efficiency.

Tsunenobu Kimoto

Papers

Fast Epitaxial Growth of 4H-SiC by Chimney-Type Hot-Wall CVD

Z1/2- and EH6-Center in 4H-SiC: Not Identical Defects ?

Observation of novel defect structure in 2H‐AlN grown on 6H‐SiC(0001) substrates with 3‐bilayer‐height step‐and‐terrace structures

Glide velocities of Si-core partial dislocations for double-Shockley stacking fault expansion in heavily nitrogen-doped SiC during high-temperature annealing

Electron Injection from GaN to SiC and Fabrication of GaN/SiC Heterojunction Bipolar Transistors