고효율 열전소자 기술

장문규,전명심,노태문,김종대,Jang, M.G.,Jun, M.S.,Roh, T.M.,Kim, J.D. 한국전자통신연구원 2008 전자통신동향분석 Vol.23 No.6

최근 들어 나노기술의 발전에 힘입어 청정에너지를 구현할 수 있는 열전소자분야의 연구가 활발히 진행되고 있다. 열전소자는 태양에너지를 이용한 발전뿐만 아니라 체열, 폐열 및 지열 등을 이용한 발전 등 응용처가 매우 다양하며, 청정에너지를 생산할 수 있는 미래 지향적인 특성을 가진 분야라 할 수 있다. 그러나 아직까지 나노기술을 기반으로한 고효율의 열전소자는 기초 연구수준에서 그 가능성만 일부 선행 연구를 통하여 입증된 상태이다. 따라서 저비용, 고효율의 열전소자를 성공적으로 개발하게 된다면, 기술의 원천성 확보 및 초기 시장 점유에 매우 유리한 입지를 점할 수 있으리라 예측된다. 본 논문에서는 최근 들어 나노기술의 접목으로 새로이 주목받고 있는 열전소자의 동작 원리에 대한 간략한 소개와 이 분야의 최근 연구 동향 및 특허 동향에 대하여 살펴보고자 한다.

Physical Properties of Co-Mn-Si Films on SOI Prepared by Using a Silicidation Process

장문규,이성재,엄태윤,이영백,김진배,Taewoon Eom,Nguyen Van Dai,Young-Pak Lee,Seongjae Lee 한국물리학회 2009 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.55 No.6

We have measured the structural, magnetic, and transport properties of Co-Mn-Si films prepared on SOI wafers by using two different silicidation processes: rapid thermal annealing (RTA) at 650 ˚C for 3 and 5 min. X-ray analysis revealed that the RTA at 650˚C for 5 min produced a single-phase Co2MnSi film while the RTA at 650˚C for 3 min produced a multi-phase film composed mainly of CoSi2 and Co2MnSi. For the single-phase Co2MnSi films, we obtained a saturated magnetization of 4.1 µB/f.u. and a residual resistivity of 8.5 µ ·cm at 4.2 K, which are close to the values for single-crystalline Co2MnSi. Also, the absence of low-field magnetoresistance (MR) for the singlephase film, in contrast to the hysteretic MR for the multi-phase film, suggests that our single-phase Co2MnSi film has a single-crystal-like quality. We have measured the structural, magnetic, and transport properties of Co-Mn-Si films prepared on SOI wafers by using two different silicidation processes: rapid thermal annealing (RTA) at 650 ˚C for 3 and 5 min. X-ray analysis revealed that the RTA at 650˚C for 5 min produced a single-phase Co2MnSi film while the RTA at 650˚C for 3 min produced a multi-phase film composed mainly of CoSi2 and Co2MnSi. For the single-phase Co2MnSi films, we obtained a saturated magnetization of 4.1 µB/f.u. and a residual resistivity of 8.5 µ ·cm at 4.2 K, which are close to the values for single-crystalline Co2MnSi. Also, the absence of low-field magnetoresistance (MR) for the singlephase film, in contrast to the hysteretic MR for the multi-phase film, suggests that our single-phase Co2MnSi film has a single-crystal-like quality.

Current Flow Mechanisms of Platinum-Silicided p-Type Schottky Barrier MOSFETs

장문규,이성재 한국물리학회 2008 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.53 No.4

The curent flow mechanisms of platinum-silicided p-type Schotky barier metal-oxide- semiconductor field-effect-transistors (SB-MOSFETs) are analyzed by incorporating experimental results with an analytical model. In our analysis, we find that the off-current is mainly attributed to the thermionic curent component whereas the on-current is due to the tunneling current. Since the tunneling current component rapidly increases at voltage above the threshold voltage, a lower Schotky barier height and a thinner gate oxide are esential features to achieve a higher drive curentinSB-MOSFETs.

자기동을 가진 2상 SRM의 설계특성

장문규,오석규 진주산업대학교 산업과학기술연구소 2007 산업과학기술연구소보 Vol.- No.14

SRM drive systems are designed to meet operating standards such as low cost, constant torque independent of rotor position, a desired operating speed range, high efficiency, and high performance. In applications using small motors, low cost and high performance with self-starting capabilities are highly desired. This paper discusses a novel two phase 4/2 SRM that has high performance characteristics with self-starting capability, low manufacturing cost with a two phase inverter and simple magnetic structure, and high efficiency. The principle of operation, analysis, and simulation for design are presented. The machine design is verified using finite element analysis (FEA) software. Analysis and simulation results are given to validate the two phase 4/2 SRM design.

실리콘 열전소자 기술의 연구 동향

장문규,이진호,Jang, M.G.,Lee, J.H. 한국전자통신연구원 2013 전자통신동향분석 Vol.28 No.5

열전소자는 태양에너지를 이용한 발전뿐만 아니라, 체열, 차량 폐열 및 지열 등의 다양한 폐열을 이용한 발전 등으로 매우 다양하게 활용되고 있다. 하지만 상온부근에서 널리 사용되는 $Bi_2Te_3$의 재료 희귀성으로 인하여 산업화 기술로써의 활용에 어려운 측면이 있다. 이러한 이유로, 최근에는 $Bi_2Te_3$를 대체할 수 있는 새로운 열전재료를 전세계적으로 활발히 연구하고 있다. 본고에서는 최근 들어 나노기술 접목으로 새로이 주목받고 있는 열전소자의 동작 원리에 대한 간략한 소개와 특히, 실리콘을 이용한 나노기술의 접목을 통한 열전소자의 최근 연구 동향에 대하여 살펴보고자 한다.

Analysis of Schottky Barrier Height in Small Contacts Using a Thermionic-Field Emission Model

장문규,JunghwanLee 한국전자통신연구원 2002 ETRI Journal Vol.24 No.6

This paper reports on estimating the Schottky barrier height of small contacts using a thermionic-field emission model. Our results indicate that the logarithmic plot of the current as a function of bias voltage across the Schottky diode gives a linear relationship, while the plot as a function of the total applied voltage across a metal-silicon contact gives a parabolic relationship. The Schottky barrier height is extracted from the slope of the linear line resulting from the logarithmic plot of current versus bias voltage across the Schottky diode. The result reveals that the barrier height decreases from 0.6 eV to 0.49 eV when the thickness of the barrier metal is increased from 500 Å to 900 Å. The extracted impurity concentration at the contact interface changes slightly with different Ti thicknesses with its maximum value at about 2.9×1020 cm-3, which agrees well with the results from secondary ion mass spectroscopy (SIMS) measurements.

실리콘 열전소자 기술

장문규,Jang, M.G. 한국전자통신연구원 2012 전자통신동향분석 Vol.27 No.1

최근 들어 나노기술의 발전에 힘입어 청정 에너지를 구현할 수 있는 열전소자 분야의 연구가 활발히 진행되고 있다. 열전소자는 태양에너지를 이용한 발전뿐만 아니라, 체열, 폐열 및 지열 등을 이용한 발전 등 응용처가 매우 다양하며, 청정 에너지를 생산할 수 있는 미래 지향적인 특성을 가진 분야라 할 수 있다. 그러나 아직까지 나노기술을 기반으로 한 고효율의 열전소자는 기초 연구수준에서 그 가능성만 일부 선행 연구를 통하여 입증된 상태이다. 본고에서는 최근 들어 나노기술의 접목으로 새로이 주목 받고 있는 열전소자의 동작 원리에 대한 간략한 소개와 특히, 실리콘을 이용한 나노기술의 접목을 통한 열전소자의 최근 연구동향에 대하여 살펴보고자 한다.

Novel Properties of Erbium-Silicided n-type Schottky Barrier Metal-Oxide-Semiconductor Field-Effect Transistors

장문규,Yarkyeon Kim,신재헌,이성재,박경완 한국물리학회 2004 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.45 No.3

Erbium-silicided 50-nm-gate-length n-type Schottky barrier metal-oxide-semiconductor elde ect transistors (SB-MOSFETs) with 5 nm gate oxide thickness are manufactured. The saturation current is 120 A/m and on/o-current ratio is higher than 105 with low leakage current less than 10 nA/m. Novel phenomena of this device are discussed. The increase in tunneling current with an increase in drain voltage is explained by reference to a drain-induced Schottky barrier thicknessthinning eect. The abnormal increase of drain current with a decrease of gate voltage is explained by hole carrier injection from drain into channel. The mechanism of threshold voltage increase in SB-MOSFETs is discussed. Based on the extracted model parameters, the performance of 10-nmgate- length SB-MOSFETs is predicted. The results show that the subthreshold swing value can be lower than 60 mV/decade.

나노 영역에서의 전계 효과 트랜지스터의 연구동향

장문규 한국전기전자재료학회 2003 전기전자재료 Vol.16 No.6

Low Temperature Characteristics of Schottky Barrier Single Electron and Single Hole Transistors

장문규,전명심,정태형 한국전자통신연구원 2012 ETRI Journal Vol.34 No.6

Schottky barrier single electron transistors (SB-SETs) and Schottky barrier single hole transistors (SB-SHTs) are fabricated on a 20-nm thin silicon-on-insulator substrate incorporating e-beam lithography and a conventional CMOS process technique. Erbium- and platinum-silicide are used as the source and drain material for the SB-SET and SB-SHT, respectively. The manufactured SB-SET and SB-SHT show typical transistor behavior at room temperature with a high drive current of 550 μA/μm and –376 μA/μm, respectively. At 7 K, these devices show SET and SHT characteristics. For the SB-SHT case, the oscillation period is 0.22 V, and the estimated quantum dot size is 16.8 nm. The transconductance is 0.05 μS and 1.2 μS for the SB-SET and SB-SHT, respectively. In the SB-SET and SB-SHT, a high transconductance can be easily achieved as the silicided electrode eliminates a parasitic resistance. Moreover, the SB-SET and SB-SHT can be operated as a conventional field-effect transistor (FET) and SET/SHT depending on the bias conditions, which is very promising for SET/FET hybrid applications. This work is the first report on the successful operations of SET/SHT in Schottky barrier devices.