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

In this study, the authors investigate deep levels, which are induced by reactive ion etching (RIE) of n-type/p-type 4H–SiC, by deep level transient spectroscopy (DLTS). The capacitance of a Schottky contact fabricated on as-etched p-type SiC is abnormally small due to compensation or deactivation of acceptors extending to a depth of ∼14 μm, which is nearly equal to the epilayer thickness. The value of the capacitance can recover to that of a Schottky contact on as-grown samples after annealing at 1000 °C. However, various kinds of defects, IN2 (EC−0.30 eV), EN (EC−1.6 eV), IP1 (EV+0.30 eV), IP2 (EV+0.39 eV), IP4 (HK0: EV+0.72 eV), IP5 (EV+0.85 eV), IP7 (EV+1.3 eV), and EP (EV+1.4 eV), remain at a high concentration (average of total defect concentration in the region ranging from 0.3 μm to 1.0 μm:∼5×1014 cm−3) even after annealing at 1000 °C. The concentration of all these defects generated by RIE, except for the IP4 (HK0) center, remarkably decreases by thermal oxidation. In addition, the HK0 center can also be reduced significantly by a subsequent annealing at 1400 °C in Ar.

/pdf/deep-levels-induced-by-reactive-ion-etching-in-n-and-p-type-275jrz6qrn.pdf

Deep levels induced by reactive ion etching in n- and p-type 4H-SiC

The temperature dependence of barrier height in a Ni/n-GaN Schottky barrier diode fabricated on a GaN homoepitaxial layer was investigated by capacitance–voltage, current–voltage, and internal photoemission measurements in the range of 223–573 K. The barrier height obtained by these methods linearly decreased with increasing temperature. The temperature coefficient was −(1.7–2.3) × 10−4 eV/K, which is about half of the temperature coefficient of the band gap reported previously. This indicates that the decrease in the barrier height may mainly reflect the shrinkage of the band gap (lowering of the conduction band edge) in GaN with increasing temperature.

https://iopscience.iop.org/article/10.7567/APEX.10.051002/pdf

Temperature dependence of barrier height in Ni/n-GaN Schottky barrier diode

15-kV-class 4H-SiC PiN diodes with various junction termination structures have been experimentally investigated. Employment of the space-modulated junction termination extension (SM-JTE) and the two-zone JTE have realized a breakdown voltage over 15 kV, corresponding to 93% of the parallel-plane breakdown voltage. The window of the implanted JTE dose to achieve the ultrahigh voltage has been enlarged, which indicates the robustness to the deviation of effective JTE dose. From the comparison of the experimental JTE-dose dependence of breakdown voltage with the numerical device simulation, a shift toward the heavier JTE-dose region was observed. To explain the phenomenon, effects of the charges at the SiO2/SiC interface are discussed.

Breakdown Characteristics of 15-kV-Class 4H-SiC PiN Diodes With Various Junction Termination Structures

Growth of very high-quality nonpolar (112¯0) a-plane face 4H-AlN on 4H-SiC (112¯0) substrate was investigated. Nonpolar 4H-AlN (112¯0) was isopolytypically grown on 4H-SiC (112¯0) substrate by molecular-beam epitaxy. A reduction of defects such as stacking faults and threading dislocations was achieved by keeping the growing surface flat. To this end, the SiC substrate was HCl gas etched and the V/III ratio was optimized for AlN growth. A full width at half maximum of symmetrical x-ray diffraction ω scan of the 4H-AlN layer was 40arcsec. Transmission electron microscopy revealed the stacking fault density to be 2×105cm−1, and the partial and perfect threading dislocation densities to be 7×107 and 1×107cm−2, respectively.

http://repository.kulib.kyoto-u.ac.jp/dspace/bitstream/2433/39687/1/ApplPhysLett_89_112117.pdf

High-quality nonpolar 4H-AlN grown on 4H-SiC (112¯0) substrate by molecular-beam epitaxy

The interface properties of SiO2/4H-SiC(0338) were characterized using n-type metaloxide-semiconductor structures fabricated by wet oxidation. The interface states near the conduction band edge are discussed based on the capacitance and conductance measurements at a low temperature and room temperature. 4H-SiC(0338) was found to have different energy distribution of the interface state density from the (0001) face. The shallow interface state density on (0338) is lower than on (0001) by a factor of 4 to 8.

/pdf/interface-properties-in-metal-oxide-semiconductor-structures-5d95y01ezr.pdf

Tsunenobu Kimoto

Papers

Deep levels induced by reactive ion etching in n- and p-type 4H-SiC

Temperature dependence of barrier height in Ni/n-GaN Schottky barrier diode

Breakdown Characteristics of 15-kV-Class 4H-SiC PiN Diodes With Various Junction Termination Structures

High-quality nonpolar 4H-AlN grown on 4H-SiC (112¯0) substrate by molecular-beam epitaxy

Interface properties in metal-oxide-semiconductor structures on n-type 4H-SiC(033̄8)