• 전기의세계
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• v.28 no.7
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• pp.56-59
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• 1979

평면구조를 가진 고내압 다이오드를 Guard ring을 사용하여 제작하고 다이오드의 파괴전압이 최대가 되는 Guard ring의 최적위치를 실험적으로 구하였다. 측정된 파괴전압은 Guard ring을 사용하지 않은 경우에는 550volt이었고 Guard ring을 사용한 경우에는 1,000volt까지 증가시킬 수 있었다.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.18 no.10
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• pp.877-882
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• 2005

In order to fabricate a high breakdown SiC-SBD (Schottky barrier diode), we investigate an effect on metal guard ring (MGR) in breakdown characteristics of the SiC-SBD. The breakdown characteristics of MGR-type SiC-SBD is significantly dependent on both the guard ring metal and the alloying time of guard ring metal. The breakdown characteristics of MGR-type SiC-SBDs are essentially improved as the alloying time of guard ring metal is increased. The SiC-SBD without MGR shows less than 200 V breakdown voltage, while the SiC-SBD with Al MGR shows approximately 700 V breakdown voltage. The improvement in breakdown characteristics is attributed to the field edge termination effect by the MGR, which is similar to an implanted guard ring-type SiC-SBD. There are two breakdown origins in the MGR-type SiC-SBD. One is due to a crystal defects, such as micropipes and stacking faults, in the Epi-layers and the SiC substrate, and occurs at a lower electric field. The other is due to the destruction of guard ring metal, which occurs at a higher electric field. The demolition of guard ring metal is due to the electric field concentration at an edge of Schottky contact metal.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.41 no.5
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• pp.573-576
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• 1992

Novel A1-Si Schottky diodes with self-aligned guard rings have been proposed and fabricated using RIE(Reactive Ion Etch). The breakdown voltage of the Schottky diode with the guard ring has been drastically increased to 200V or more in comparison with 46V for the metal overlap Schottky diode.

• Proceedings of the KIEE Conference
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• 1994.07b
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• pp.1413-1415
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• 1994

A novel magnetotransistor using a separated drift field with the guard ring around the emitter has been designed and fabricated. The operating principle of the proposed magnetic field sensor is based on the emitter injection modulation. The $p^+$ guard ring around the n-type emitter confines drifted electrons in the emitter, hence the induced Hall voltage in the emitter is increased. The measured relative sensitivity of the separated drift magnetotransistor with the guard ring is about 100 times larger than that without the guard ring.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07b
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• pp.1084-1087
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• 2002

The guard-ring type 3-terminal parallel plate electrodes proposed by ASTM D 150-81 and IEC 250 have been widely used for measurement of dielectric constants of solid dielectrics. However the method using this electrodes causes many uncertainty associated with the measurement errors of the diameter of the guarded electrode. the gap between guarded and guard-ring electrode. the distance of two active electrodes(the thickness of specimen), the roughness and contamination of surface of electrode and specimen. close adherence grade of electrode and specimen. In this paper. a new electrode system of cross capacitance type based on Thompson-Lampard theorem is designed and is employed for the measurement of dielectric constant. The results of simulation of guard-ring electrode and cross capacitance electrode using FEM program show that distance measurement between two electrodes in guard-ring electrode produces large uncertainty. on the other hand this effect in cross capacitance electrode is negligible. Furthermore. the air gap effects in the cross capacitance electrode is 5.6 times less sensitive than that in guard-ring electrode by assuming air gap of $50{\mu}m$.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.1
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• pp.23-29
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• 2006

From a point of view of suggesting the method to avoid ship's collision, the speed of ships has to be considered sufficiently according to encounter angle of ships. But with respect to the establishment of Safe-Guard Ring of Ship Collision Avoidance Support Model in Close Quarters Situation that had been newly studied to avoid ship's collision, the ratio of own ship' speed to a target ship's speed was limited to about less than 1.7. Therefore in this paper, as doing a study concerned with the establishment of Safe-Guard Ring reflected the encounter angle and the speed of ships, we will propose the new model of ship collision avoidance for safe maneuver of ship's collision avoidance.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.44 no.4
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• pp.32-42
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• 2007

The substrate resistance is modeled to estimate the performance degradation of analog circuits by substrate noise in a $0.35{\mu}m$ twin-well non-epitaxial CMOS process. The substrate resistance model equations are applied to the P+ guard-ring isolation structure and a good match was achieved between measurements and models. The substrate resistance is divided into four types and a semi-empirical model equation is obtained for each type of substrate resistance. The rms(root-mean-square) error of the substrate resistance model is below 10% compared with the measured resistance. To apply this substrate resistance model to the P+ guard ring structure, ADS(Advanced Design System) circuit simulation results are compared with the measurement results using Network Analyzer, and relatively good agreements are obtained between measurements and simulations.

• Journal of IKEEE
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• v.23 no.1
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• pp.193-199
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• 2019

In this study, we have proposed a floating metal guard ring structure based on TCAD simulation in order to enhance the breakdown voltage characteristics of gallium oxide ($Ga_2O_3$) vertical high voltage switching Schottky barrier diode. Unlike conventional guard ring structures, the floating metal guard rings do not require an ion implantation process. The locally enhanced high electric field at the anode corner was successfully suppressed by the metal guard rings, resulting in breakdown voltage enhancement. The number of guard rings and their width and spacing were varied for structural optimization during which the current-voltage characteristics and internal electric field and potential distributions were carefully investigated. For an n-type drift layer with a doping concentration of $5{\times}10^{16}cm^{-3}$ and a thickness of $5{\mu}m$, the optimum guard ring structure had 5 guard rings with an individual ring width of $1.5{\mu}m$ and a spacing of $0.2{\mu}m$ between rings. The breakdown voltage was increased from 940 V to 2000 V without degradation of on-resistance by employing the optimum guard ring structure. The proposed floating metal guard ring structure can improve the device performance without requiring an additional fabrication step.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.37 no.2
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• pp.208-214
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• 2024

This reports the electrical properties of single-crystal β-gallium oxide (β-Ga₂O₃) vertical Schottky barrier diodes (SBDs) with a different guard ring structure. The vertical Schottky barrier diodes (V-SBDs) were fabricated with two types guard ring structures, one is with metal deposited on the Al₂O₃ passivation layer (film guard ring: FGR) and the other is with vias formed in the Al₂O₃ passivation layer to allow the metal to contact the Ga₂O₃ surface (metal guard ring: MGR). The forward current values of FGR and MGR V-SBD are 955 mA and 666 mA at 9 V, respectively, and the specific on-resistance (R_on,sp) is 5.9 mΩ·cm² and 29 mΩ·cm². The series resistance (R_s) in the nonlinear section extracted using Cheung's formula was 6 Ω, 4.8 Ω for FGR V-SBD, 10.7 Ω, 6.7 Ω for MGR V-SBD, respectively, and the breakdown voltage was 528 V for FGR V-SBD and 358 V for MGR V-SBD. Degradation of electrical characteristics of the MGR V-SBD can be attributed to the increased reverse leakage current caused by the guard ring structure, and it is expected that the electrical performance can be improved by preventing premature leakage current when an appropriate reverse voltage is applied to the guard ring area. On the other hand, FGR V-SBD shows overall better electrical properties than MGR V-SBD because Al₂O₃ was widely deposited on the Ga₂O₃ surface, which prevent leakage current on the Ga₂O₃ surface.

• Journal of Navigation and Port Research
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• v.30 no.10 s.116
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• pp.779-785
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• 2006

From a point of view of suggesting the method to avoid ship's collision, the speed of ships has to be considered sufficiently according to encounter angle of ships. But the new safe-guard ring of ship's collision avoidance support model in the close quarters is established assuming that the ratio of own ship' speed to a target ship's speed is less than about 1.7. Therefore in this paper, as doing a study concerned with the establishment of safe-guard ring reflected the encounter angle and the speed of ships, we will propose the new model of ship collision avoidance for safe maneuver of ship's collision avoidance.