• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.10a
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• pp.611-613
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• 2016

The characteristics of tunnel field-effect transistor(TFET) structure with source-overlapped gate was investigated using a TCAD simulations. Tunneling is mostly divided into line-tunneling and point-tunneling, and line-tunneling is higher performance than point-tunneling in terms of subthreshold swing(SS) and on-current. In this paper, from the simulation results of source-overlapped gate length effects at silicon(Si), germanium(Ge), Si-Ge hetero TFET structure, the guideline of optimal structure with highest performance are proposed.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.10a
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• pp.167-169
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• 2016

The structure guide lines of pocket tunnel field effect transistor(TFET) considering Line and Point tunneling are introduced. As the pocket doping concentration or thickness increase, on-current $I_{on}$ increases. As the pocket thickness or gate insulator increase, subthreshold swing(SS) increases. Optimal structure reducing the hump effects should be proposed in order to enhance SS.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.5
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• pp.876-884
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• 2017

The current-voltage characteristics of Silicon(Si), Germanum(Ge), and hetero tunnel field-effect transistors(TFETs) with source-overlapped gate structure was investigated using TCAD simulations in terms of tunneling. A Si-TFET with gate oxide material $SiO_2$ showed the hump effects in which line and point tunneling appear simultaneously, but one with gate oxide material $HfO_2$ showed only the line tunneling due to decreasing threshold voltage and it shows better performance than one with gate oxide material $SiO_2$. Tunneling mechanism of Ge and hetero-TFETs with gate oxide material of both $SiO_2$ and $HfO_2$ are dominated by point tunneling, and showed higher leakage currents, and Si-TFET shows better performance than Ge and hetero-TFETs in terms of SS. These simulation results of Si, Ge, and hetero-TFETs with source-overlapped gate structure can give the guideline for optimal TFET structures with non-silicon channel materials.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.5
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• pp.869-875
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• 2017

Using TCAD simulation, performances of tunnel field-effect transistors (TFETs) was investigated. Drain current-gate voltage types of TFET structure such as single-gate TFET (SG-TFET), double-gate TFET (DG-TFET), L-shaped TFET (L-TFET), and Pocket-TFET (P-TFET) are simulated, and then as dielectric constant of gate oxide and channel length are varied their subthreshold swing (SS) and on-current ($I_{on}$) are compared. On-currents and subthreshold swings of the L-TFET and P-TFET structures with high electric constant and line tunneling were 10 times and 20 mV/dec more than those of the SG-TFET and DG-TFET using point tunneling, respectively. Especially, it is shown that hump effect which dominant current element changes from point tunneling to line tunneling, is disappeared in P-TFET with high-k gate oxide such as $HfO_2$. The analysis of 4 types of TFET structure provides guidelines for the design of new types of TFET structure which concentrate on line tunneling by minimizing point tunneling.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2018.10a
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• pp.512-513
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• 2018

Trap-assisted-tunneling (TAT) degrades subthreshold slope of real-world tunneling field-effect-transistors (TFET) and it should be considered in the simulation. However, its mechanism is not very well understood in line tunneling type L-shaped TFET (LTFET). This study investigates TAT mechanism in LTFETs using dynamic nonlcoal Schenk model. Both phonon assisted and direct band to trap tunneling events are considered in this study.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.05a
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• pp.166-168
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• 2016

This paper introduces about the structure guide lines of pocket tunneling Field effect transistor. As the pocket length or thickness increase, on-current $I_{on}$ increases. As the pocket thickness is less than 3nm, subthreshold swing (SS) increase. As the dielectric constants of the gate insulator increases, the performance of on-current and subthreshold swing enhances.

• Proceedings of the IEEK Conference
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• 2003.07c
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• pp.2541-2544
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• 2003

새로운 원리에 의한 원격 거리 및 각도측정 시스템［1］［2］(이하 TS, Total Station)을 개발하였다. 본 시스템은 마이크로 터널링 공법의 굴진기의 후미 또는 임의의 기준점에 원격으로 점멸할 수 있는 십자형의 발광체를 부착하고, 추진관에 고정시킨 상하좌우 각도측정 및 비접촉식 레이저 거리측정기가 부착된 무인 원격 제어장치에 의하여 십자형 발광체의 중심을 자동으로 검출한다. 또한. 회전각과 CCD 라인 스캔 센서의 조합에 의하여 각도를 정밀하게 원격 측정하게 된다. 한편 본 시스템을 이용하면 마이크로 터널링 공법에 의한 추진관내의 측정 가능한 범위를 연결하는 위치에 복수의 TS를 배치하여 서로의 위치를 자동으로 계측하고 그들 데이터를 컴퓨터에 의하여 계산함으로써, 맨홀의 임의의 기준점으로부터 굴진기의 현재 좌표를 신속하고 정확하게 계산할 수 있다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.10a
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• pp.616-618
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• 2016

Four types of structure of tunnel field-effect transistors (TFETs) have been investigated by TCAD simulation. Pocket and L-shaped TFETs are better performance than single-gate and double-gate TFETs in terms of on-current and subthreshold swing. New guideline of TFETs is presented for the structure design.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.11
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• pp.148-154
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• 2016

Video security has recently emerged as an important issue owing to CCTV video image spill accidents over the Internet. KISA recommends the use of encryption protocols for remote access through its guidelines for CCTV personal video information protection. But still, many products do not adhere to the guidelines, and those products are easily exposed to security threats, such as hacking. To solve these security vulnerabilities, this paper proposes a CCTV system that connects from remote locations, and is implemented by using secure shell (SSH) tunneling techniques. The system enhances security by transmitting encrypted data by using SSH. By using the tunneling technique, it also solves the problem of not being able to access a CCTV recorder located inside a firewall. For evaluation of the system, this paper compares various CCTV remote access schemes and security. Experimental results on the effectiveness of the system show it is possible to obtain remote access without a significant difference in transmission quality and time. Applying the method proposed in this paper, you can configure a system secure from the threats of hacking.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.05a
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• pp.527-528
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• 2017

Current-voltage characteristics of source-overlapped gate tunnel field-effect transistor (SOG-TFET) with different channel doping concentration are proposed. Due to the gaussian doping in which the channel region near the source is highly doped and that far from the source is lightly doped, the ambipolar current was reduced, compared with the uniformly-doped SOG-TFET. On-current is almost similar in P-P-N and P-I-N structure but subthreshold swing (SS) of P-P-N TFET enhanced 5 times higher than those of P-I-N TFET. off-current and ambiploar current of the proposed SOG-TFET decrease 10 times and 100 times than those of the uniformly-doped SOG-TFET.