• Journal of the Korean Institute of Telematics and Electronics A
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• v.31A no.6
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• pp.134-142
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• 1994

A kink due to the lasing of the first transverse mode in laser diodes is investigated using rate equations based on the spatial hole burning model. An analytic expression for the kink power is derived and the result agrees well with experimental results. It is also shown that the position of a kink can be identified in the electrical derivative characteristics as well as in light output vs, current characteristics.

• Journal of the Korean Institute of Telematics and Electronics T
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• v.35T no.2
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• pp.6-12
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• 1998

Thin film SOI(Silicon-on-insulator) device offer unique advantages such as reduction in short channel effects, improvement of subthreshold slope, higher mobility, latch-up free nature, and so on. But these devices exhibit floating-body effet such as current kink which inhibits the proper device operation. In this paper, the SOI NMOSFET with a T-type gate structure is proposed to solve the above problem. To simulate the proposed device with TSUPREM-4, the part of gate oxide was considered to be 30nm thicker than the normal gate oxide. The I-V characteristics were simulated with 2D MEDICI. Since part of gate oxide has different oxide thickness, the gate electric field strength is not same throughout the gate and hence the impact ionization current is reduced. The current kink effect will be reduced as the impact ionization current drop. The reduction of current kink effect for the proposed device structure were shown using MEDICI by the simulation of impact ionization current, I-V characteristics, and hole current distribution.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.12
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• pp.15-19
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• 2016

The gate bias dependence of kink phenomenon with a large deviation from the resistance circle in Smith chart is observed in the frequency response of $S_{11}$-parameter for large multi-finger RF MOSFETs. For the first time, this bias dependence is analyzed by measuring magnitude and phase of $S_{11}$-parameter, input resistance and input capacitance. As a result, $V_{gs}$ dependent $S_{11}$-parameter is largely changed by the magnitude of input capacitance as well as dominant pole and zero frequencies of input resistance. At $V_{gs}=0V$, the kink phenomenon occurs in the high frequency region because of very small phase difference of $S_{11}$-parameter and high pole frequency of input resistance. However, the kink phenomenon at higher $V_{gs}$ is generated in the low frequency region owing to large phase difference and low pole frequency.

• Journal of the Korea Computer Industry Society
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• v.6 no.5
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• pp.783-790
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• 2005

In this paper, we have simulated a Symmetric Dual-gate Single-Si TFT which has three split floating n+ zones. This structure reduces the kink-effect drastically and improves the on-current. Due to the separated floating n+ zones, the transistor channel region is split into four zones with different lengths defined by a floating n+ region, This structure allows an effective reduction of the kink-effect depending on the length of two sub-channels. The on-current of the proposed dual-gate structure is 0.9mA while that of the conventional dual-gate structure is 0.5mA at a 12V drain voltage and a 7V gate voltage. This result shows a 80% enhancement in on-current. Moreover we observed the reduction of electric field in the channel region compared to conventional single-gate TFT and the reduction of the output conductance in the saturation region. In addition, we also confirmed the reduction of hole concentration in the channel region so that the kink-effect reduces effectively.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.18 no.5
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• pp.423-430
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• 2005

In this paper, we have simulated a Symmetric Dual-gate Single-Si TFT which has three split floating $n^{+}$ zones. This structure reduces the kink-effect drastically and improves the on-current. Due to the separated floating $n^{+}$ zones, the transistor channel region is split into four zones with different lengths defined by a floating $n^{+}$ region. This structure allows an effective reduction of the kink-effect depending on the length of two sub-channels. The on-current of the proposed dual-gate structure is 0.9 mA while that of the conventional dual-gate structure is 0.5 mA at a 12 V drain voltage and a 7 V gate voltage. This results show a $80 {\%}$ enhancement in on-current by adding two floating $n^{+}$ zones. Moreover we observed the reduction of electric field In the channel region compared to conventional single-gate TFT and the reduction of the output conductance in the saturation region. In addition we also confirmed the reduction of hole concentration in the channel region so that the kink-effect reduces effectively.

• Transactions on Electrical and Electronic Materials
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• v.7 no.2
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• pp.53-57
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• 2006

In this paper, a Symmetric Dual-gate Single-Si TFT, which includes three split floating n+ zones, is simulated. This structure drastically reduces the kink-effect and improves the on-current. This is due to the separated floating n+ zones, the transistor channel region is split into four zones with different lengths defined by a floating n+ region. This structure allows effective reduction in the kink-effect, depending on thy length of the two sub-channels. The on-current of the proposed dual-gate structure is 0.9 mA, while that of the conventional dual-gate structure is 0.5 mA, at both 12 V drain and 7 V gate voltages. This result shows an 80% enhancement in on-current. In addition, the reduction of electric field in the channel region compared to a conventional single-gate TFT and the reduction of the output conductance in the saturation region, is observed. In addition, the reduction in hole concentration, in the channel region, in order for effectively reducing the kink-effect, is also confirmed.

• Proceedings of the KIEE Conference
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• 2005.11a
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• pp.84-86
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• 2005

본 논문에서는 역 방향 전하공핍(reverse bias depletion)을 적용한 새로운 구조의 다결정 실리콘 박막 트랜지스터(poly-Si TFT)를 제안한다. 제안된 소자는 kink 전류 억제를 목적으로 counter-doped(p+) 영역이 채널 내로 확장되어 유효채널 폭을 감소시키는 구조이다. 감소된 채널 폭에 의하여 포화 영역의 채널 내 저항이 증가하고, 훌 전류를 통하여 kink 효과가 억제된다. 제작된 새로운 poly-Si TFT는 기존의 소자에 비해 효과적으로 kink 전류를 억제할 수 있음을 실험을 통해 검증하였다.

• KCI Concrete Journal
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• v.12 no.1
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• pp.57-68
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• 2000

The effect of structure size on the nominal strength of unidirectional fiber-polymer composites, failing by propagation of a kink band with fiber microbuckling, is analyzed experimentally and theoretically. Tests of novel geometrically similar carbon-PEEK specimens, with notches slanted so as to lead to a pure kink band (without shear or splitting cracks), are conducted. The specimens are rectangular strips of widths 15.875, 31.75. and 63.5 mm (0.625, 1.25 and 2.5 in and gage lengths 39.7, 79.375 and 158.75 mm (1.563, 3.125 and 6.25 in.). They reveal the existence of a strong (deterministic. non-statistical) size effect. The doubly logarithmic plot of the nominal strength (load divided by size and thickness) versus the characteristic size agrees with the approximate size effect law proposed for quasibrittle failures in 1983 by Bazant This law represents a gradual transition from a horizontal asymptote, representing the case of no size effect (characteristic of plasticity or strength criteria), to an asymptote of slope -1/2 (characteristic of linear elastic fracture mechanics. LEFM) . The size effect law for notched specimens permits easy identification of the fracture energy of the kink bandand the length of the fracture process zone at the front of the band solely from the measurements of maximum loads. Optimum fits of the test results by the size effect law are obtained, and the size effect law parameters are then used to identify the material fracture characteristics, Particularly the fracture energy and the effective length of the fracture process zone. The results suggest that composite size effect must be considered in strengthening existing concrete structural members such as bridge columns and beams using a composite retrofitting technique.

• Proceedings of the KIEE Conference
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• 1997.07d
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• pp.1286-1288
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• 1997

In this study, partially-depleted SOI MOSFET with multi-gate was fabricated on p-type SIMOX(Seperation by Implanted Oxygen). As increase the number of its gate, increase the breakdown voltage. But kink effect was not affected by the number of its gate. However, it is known that the asymmetric gate structure reduce kink effect. So if asymmetric multi-gate applied to partially-depleted SOI MOSFET, it is expected that the breakdown voltage of SOI MOSET with asymmetric multi-gate is higher than that of SOI MOSFET with single gate and that kink effect is reduced by SOI MOSFET with asymmetric multi-gate.

• Proceedings of the KIEE Conference
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• 2005.07c
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• pp.2031-2033
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• 2005

poly-Si TFT의 kink 전류를 억제하는 L-shaped dual-gate TFT 구조를 제안하고 이를 제작하였다. 제안된 소자는 채널의 그레인 방향을 일정하게 성장시키는 SLS나 CW laser 결정화 방법을 사용한다. L자 모양의 게이트 구조를 사용하여 서고 다른 전계효과 이동도를 갖는 두 개의 sub-TFT를 구현할 수 있으며, 이러한 sub-TFT간의 특성차이가 kink 전류를 억제시킨다. 직접 제작한 L-shaped dual-gate 구조의 소자가 poly-Si TFT의 kink 전류를 억제하고, 전류포화 영역에서 전류량을 고정시킴으로써 신뢰성이 향상됨을 확인하였다.