• Proceedings of the IEEK Conference
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• 1999.06a
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• pp.918-921
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• 1999

The breakdown voltage in fully depleted SOI N-MOSFET’s have been studied over a wide range of film thicknesses, channel doping, and channel lengths. An asynmmetric Source/Drain SOI technology is proposed, which having the advantages of Normal LDD SOI(Silicon-On-Insulator) for breakdown voltage and gives a high drivability of LDD SOI without sacrificings hot carrier immunity The two-dimensional simulations have been used to investigate the breakdown behavior in these device. It is found that the breakdown voltage(BVds) is almost same with high current drivability as that in Normal LDD SOI device structure.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.05a
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• pp.305-306
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• 2021

Breakdown structure (BS) is a tool used to allocate information packages for various management functions and drive computerized information systems. Although several BS exists, work breakdown structures (WBS) and cost breakdown structures (CBS) are the most widely studied and used in previous literature. Nevertheless, heterogeneity of BS and respective management capabilities in current practices are not adequately addressed. In this context, this paper compared the management capabilities of various BS in both building and plant industries through systematic literature. Management requirements and applications scope, in terms of life cycle and stakeholder, were analyzed, respectively. Finally, finding and lesson-learned are outlined.

• Proceedings of the KIEE Conference
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• 2001.11a
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• pp.26-28
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• 2001

A Trench schottky diode with guard ring is proposed to improve the forward current density and reverse breakdown voltage. The simulation results by Silvaco have shown that the reverse breakdown voltage of the proposed device was found to be 22.1V while that of conventional trench device was 17.25V. The breakdown voltage of the proposed structure was 28.1% higher than that of the conventional trench structure.

• Journal of Electrical Engineering and Technology
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• v.9 no.2
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• pp.686-694
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• 2014

A power semiconductor device, usually used as a switch or rectifier, is very significant in the modern power industry. The power semiconductor, in terms of its physical properties, requires a high breakdown voltage to turn off, a low on-state resistance to reduce static loss, and a fast switching speed to reduce dynamic loss. Among those parameters, the breakdown voltage and on-state resistance rely on the doping concentration of the drift region in the power semiconductor, this effect can be more important for a higher voltage device. Although the low doping concentration in the drift region increases the breakdown voltage, the on-state resistance that is increased along with it makes the static loss characteristic deteriorate. On the other hand, although the high doping concentration in the drift region reduces on-state resistance, the breakdown voltage is decreased, which limits the scope of its applications. This addresses the fact that breakdown voltage and on-state resistance are in a trade-off relationship with a parameter of the doping concentration in the drift region. Such a trade-off relationship is a hindrance to the development of power semiconductor devices that have idealistic characteristics. In this study, a novel structure is proposed for the Insulated Gate Bipolar Transistor (IGBT) device that uses conductivity modulation, which makes it possible to increase the breakdown voltage without changing the on-state resistance through use of a P-floating layer. More specifically in the proposed IGBT structure, a P-floating layer was inserted into the drift region, which results in an alleviation of the trade-off relationship between the on-state resistance and the breakdown voltage. The increase of breakdown voltage in the proposed IGBT structure has been analyzed both theoretically and through simulations, and it is verified through measurement of actual samples.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.33 no.2
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• pp.83-87
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• 2020

In this letter, we propose and analyze a new asymmetric structure that can be used for next-generation power semiconductor devices. We compare and analyze the electrical characteristics of the proposed device with respect to those of symmetric devices. The proposed device has a p-emitter on the right side of the cell. The peak electric field is reduced by the shielding effect caused by the p-emitter structure. Consequently, the breakdown voltage is increased. The proposed asymmetric structure has an approximately 100% higher Baliga's figure of merit (~94.22 MW/㎠) than the symmetric structure (~46.93 MW/㎠), and the breakdown voltage of the device increases by approximately 70%.

• Electrical & Electronic Materials
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• v.9 no.4
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• pp.364-371
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• 1996

In this study, in order to investigate the applicability of IPN structure to epoxy resin which has been widely used as electrical and electronic insulating materials, DC dielectric breakdown properties and morphology were compared and analyzed according to variation of network structure, using the single network structure specimen formed of epoxy resin alone, interpenetrating polymer network specimen formed of epoxy resin/methacrylic acid resin, and interpenetrating polymer network specimen formed of epoxy resin/methacrylic acid resin/polyurethane resin. As results of the measunnent of DC dielectric breakdown strength at 50[.deg. C] and 130[>$^{\circ}C$], IPN specimen formed of epoxn, resin 100[phr] and methacrylic acid resin 35[phr] was the most excellent, and which corresponded to the SEM phenomena. The effect of IPN was more remarkable at high temperature region than at low temperature region. It is supposed that the defect of epoxy resin, dielectric breakdown strength is lowered remarkably at high temperature region, be complemented according to introducing IPN method.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.21 no.11
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• pp.981-986
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• 2008

The conventional IGBT has two problems to make the device taking high performance. The one is high on state voltage drop associated with JFET region, the other is low breakdown voltage associated with concentrating the electric field on the junction of between p base and n drift. This paper is about the structure to effectively improve both the lower on state voltage drop and the higher breakdown voltage than the conventional IGBT. For the fabrication of the circular trench IGBT with the circular trench layer, it is necessary to perform the only one wet oxidation step for the circular trench layer. Analysis on both the on state voltage drop and the breakdown voltage show the improved values compared to the conventional IGBT structure. Because the circular trench layer disperses electric field from the junction of between p base and n drift to circular trench, the breakdown voltage increase. The on state voltage drop decrease due to reduction of JFET region and direction changed of current path which pass through reversed layer channel. The electrical characteristics were studied by MEDICI simulation results.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.52 no.6
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• pp.257-260
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• 2003

We have proposed the junction termination structure of IGBT (Insulated Gate Bipolar Transistor) by employing trench and FLR (Field Limiting Ring), which decrease the junction termination area at the same breakdown voltage. Our proposed junction termination structure, trench FLR is verified by numerical simulator MEDICI. In 600V rated device, the junction termination area is decreased 20% compared with that of the conventional FLR structure. The breakdown voltage of trench FLR with 4 trenches is 768 V, 99 % of ideal parallel-plane junction(1-D) $BV_ceo$.

• Journal of IKEEE
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• v.17 no.2
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• pp.129-134
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• 2013

For the conventional power metal-oxide semiconductor field-effect transistor (MOSFET) device structure, there exists a tradeoff relationship between specific on-resistance ($R_{ON.SP}$) and breakdown voltage ($V_{BR}$). In order to overcome the tradeoff relationship, a uniform super-junction (SJ) trench metal-oxide semiconductor field-effect transistor (TMOSFET) structure is studied and designed. The structure modeling considering doping concentrations is performed, and the distributions at breakdown voltages and the electric fields in a SJ TMOSFET are analyzed. The simulations are successfully optimized by the using of the SILVACO TCAD 2D device simulator, Atlas. In this paper, the specific on-resistance of the SJ TMOSFET is successfully obtained 0.96 $m{\Omega}{\cdot}cm^2$, which is of lesser value than the required one of 1.2 $m{\Omega}{\cdot}cm^2$ at the class of 100 V and 100 A for BLDC motor.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2006.11a
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• pp.571-573
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• 2006

This study suggests a reasonable method for visualizing risk management level by risk weight linked with 4D model. This study defines risk management procedures as preparation, identification, analysis, response and management to manage potential risks in the construction project. The modules for computerizing in this system consist of planning, construction, application of WBS (Work Breakdown Structure) and RBS (Risk Breakdown Structure), and risk analysis. The final results include a method for visualizing risk level by each element of the project by using 4D simulation technique. It can be used as a visualized risk management tool instead of current system using numerical data.