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

Phosphorus or aluminum ions were directly implanted into semi-insulating 4H-SiC substrates with no epitaxial layers to form n- or p-type layers, respectively, with doping densities in the range from 1017 to 1019 cm−3. The electrical properties of these implanted layers annealed at 1650 °C were characterized by Hall effect measurements in the temperature range of 160–900 K. The electrical activation ratios of implanted dopants were 88–98%. The density of compensating defects was higher in Al+-implanted layers than in P+-implanted ones. The mobilities of the implanted layers were mostly comparable to those of epitaxial layers in the doping range investigated.

https://iopscience.iop.org/article/10.7567/JJAP.56.070306/pdf

Electrical properties of n- and p-type 4H-SiC formed by ion implantation into high-purity semi-insulating substrates

The effect of the Schottky barrier height on the detection of the concentration of midgap defects using deep level transient spectroscopy (DLTS) is experimentally and theoretically studied for EH6 and EH7 defects in 4H-SiC. In this special case, the DLTS signal height for EH6 and EH7 increases with increasing barrier height and saturates at values above 1.5 and 1.7eV, respectively. Below 1.1eV, the DLTS peak completely disappears for both defects. The experimental data are explained by a theoretical model. The course of the quasi-Fermi level in the space charge region is calculated as a function of the reverse current through it, which is determined by the barrier height, and the reverse bias applied.

/pdf/effect-of-the-schottky-barrier-height-on-the-detection-of-2zdr9n3fix.pdf

Effect of the Schottky barrier height on the detection of midgap levels in 4H-SiC by deep level transient spectroscopy

Bulk 3C-SiC growth by a sublimation method was carried out. The grown layer was used as a substrate for chemical vapor deposition, that is, homoepitaxial growth of 3C-SiC was carried out for the first time. The substrate exhibited some impurity-related photoluminescence peaks and no exciton-related peak was observed. The epilayer had some sharp exciton-related peaks near the band edge, which showed high crystallinity of the epilayer. Au Schottky barrier diodes were fabricated on the epilayer, and the diode showed good characteristics. The quality of 3C-SiC was improved by homoepitaxial growth.

Photoluminescence of homoepitaxial 3C-SiC on sublimation-grown 3C-SiC substrates

Carrier lifetimes in a highly Al-doped p-type epilayer (NA = 1×1018 cm-3) are investigated by differential microwave photoconductance decay (µ-PCD) measurements. A carrier lifetime of 310 ns in the as-grown p-type epilayer decreases to 90 ns by thermal treatment in Ar, O2, or N2 atmospheres (>700 °C), and recovers to 300 ns by H2 annealing (>750 °C). Hydrogen is detected at a concentration of (2–3)×1015 cm-3 in the H2-annealed epilayer. These results suggest that a lifetime killer exists in the p-type epilayer, limiting the carrier lifetime to 90 ns and is passivated by hydrogen annealing, resulting in the improved carrier lifetime of 300 ns.

https://iopscience.iop.org/article/10.7567/APEX.6.121301/pdf

Improvement of Carrier Lifetimes in Highly Al-Doped p-Type 4H-SiC Epitaxial Layers by Hydrogen Passivation

Novel 3-kV 4H-SiC reverse blocking (RB) metal–oxide–semiconductor field-effect transistors (MOSFETs) have been demonstrated for high-voltage bidirectional switching applications. To achieve RB capability, a series Schottky barrier diode structure was introduced onto the backside of the 4H-SiC MOSFET. The developed SiC RB MOSFET exhibits bidirectional blocking voltage over 3 kV and a differential specific on-resistance of 20 $\text{m}\Omega ~\cdot $ cm2 at room temperature. In an inductive-load switching measurement, the RB MOSFET showed good turn-ON/-OFF characteristics at 1 kV. The bidirectional switch configured by the developed RB MOSFETs exhibited lower ON-state power loss than the series connection of the standard SiC MOSFETs at wide range of temperature and operation current, demonstrating the advantage of the SiC RB MOSFET as a high-performance bidirectional switch.

Tsunenobu Kimoto

Papers

Electrical properties of n- and p-type 4H-SiC formed by ion implantation into high-purity semi-insulating substrates

Effect of the Schottky barrier height on the detection of midgap levels in 4H-SiC by deep level transient spectroscopy

Photoluminescence of homoepitaxial 3C-SiC on sublimation-grown 3C-SiC substrates

Improvement of Carrier Lifetimes in Highly Al-Doped p-Type 4H-SiC Epitaxial Layers by Hydrogen Passivation

High-Temperature Characteristics of 3-kV 4H-SiC Reverse Blocking MOSFET for High-Performance Bidirectional Switch