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

In this chapter we discuss two unipolar switching devices, junction field-effect transistors (JFETs) and metal-oxide-semiconductor field effect transistors (MOSFETs), describing the basic physical processes and practical power device implementations. JFETs are presented in both single- and double-gated topologies. We begin the study of MOSFETs by reviewing basic metal-oxide-semiconductor (MOS) electrostatics. We then derive operating equations and discuss practical implementations, including both double-diffused metal-oxide-semiconductor field effect transistors (DMOSFETs) and trench-based UMOSFETs. Finally, we discuss practical issues such as threshold voltage control, inversion layer mobility, oxide reliability, and switching performance.

Unipolar Power Switching Devices

Bulk crystal growth is essential for producing single-crystal wafers, the base material for device fabrication. Continued progress in SiC device development relies on the availability of large SiC wafers with high crystal quality. At present, the standard technique for SiC bulk growth is the seeded sublimation (or modified Lely) method, but a few alternative growth techniques have also been studied. This chapter describes the fundamental aspects of SiC bulk growth and the associated technology development.

Bulk Growth of Silicon Carbide

Surface structure transitions during SiC growth on α-SiC (0001) in a high vacuum were studied based on an in-situ RHEED observation. An α-SiC (3×3) structure formed by adsorbed Si atoms changed to a (1×1) structure above 1150°C, and the reversible transition from the (1×1) to (3×3) at the temperature was newly observed. Step-flow growth was observed on the (1×1) structure leading to α-SiC homoepitaxy and two-dimensional growth on the (3×3) structure leading to β-SiC growth. Activation energies of about 6.9 and 29 kcal mol −1 were obtained in the step-flow growth region of α-SiC and two-dimensional growth region of β-SiC, respectively. Based on these results, growth mechanisms on the α-SiC (0001) are discussed.

High-temperature surface structure transitions and growth of α-SiC (0001) in ultrahigh vacuum

In this paper we revisit sharp low temperature luminescence lines (LTPL) previously generated by high dose 1018 to 1020 cm-2 electron beams in an electron microscope and now produced by low dose 1015 cm-2 electron, 5x1010 cm-2 proton and helium ion irradiation. New no phonon lines E0, F0, θ0, Φ0, K0, G0, J0, M0 and phonon replicas are found. Phonon replicas up to the fifth harmonic are well accounted for by theory giving convincing new evidence that the di-carbon antisite is responsible for these deep defect lines.

New Lines and Issues Associated with Deep Defect Spectra in Electron, Proton and 4He Ion Irradiated 4H SiC

Designing and fabrication of 4H-SiC (0001) lateral MOSFETs with a double reduced surface field (RESURF) structure have been investigated to reduce a drift resistance. In order to achieve high breakdown voltage, a two-zone RESURF structure was also employed in addition to the double RESURF structure. After device simulation for dose optimization, 4H-SiC two-zone double RESURF MOSFETs have been fabricated by using an original self-aligned process proposed in this paper. The fabricated MOSFETs with optimum doses exhibit a high breakdown voltage of 1380 V and a low on-resistance of 66 mOmegam2 (including a drift resistance of 13 mOmegacm2). The drift resistance in the fabricated MOSFETs with double RESURF structure is only 50 % or even lower than that in the MOSFETs with a normal RESURF structure. The figure-of-merit (VB2/RON) of the present device reaches 29 MW/cm2, which is the best performance among any lateral MOSFETs ever reported

Tsunenobu Kimoto

Papers

Unipolar Power Switching Devices

Bulk Growth of Silicon Carbide

High-temperature surface structure transitions and growth of α-SiC (0001) in ultrahigh vacuum

New Lines and Issues Associated with Deep Defect Spectra in Electron, Proton and 4He Ion Irradiated 4H SiC

Dose Designing and Fabrication of 4H-SiC Double RESURF MOSFETs