• 전자공학회논문지A
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• 제30A권6호
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• pp.14-21
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• 1993

MODFETs using the heterostructure of phosphorous-contained a-SiN:H: and undoped a-Si:H films have been fabricated by PECVD of SiH$_{4}$, PH$_{3}$ gases. Thecharacteristics of the devices have been invetigated and compared with conventional TFTs(CTFTs). The threshold voltage of the MODFETs was smaller than that of CTFTs, in the case of the devices using the a-SiN:H film with the relatively high phosphorous content, the threshold voltage was negative and the operation of the devices followed the depletion mode. On the other hand, on/off current ratio of the MODFETs was more than one order of magnitude higher than the CTFTs, and the field effect mobility of the former was approximately two times as high as that of the latter.

• 대한금속재료학회지
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• 제50권3호
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• pp.248-255
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• 2012

AlN thin films containing various amounts of Co, AlN-Co, and Al-Co alloy particles were prepared using a two-facing-target type dc reactive sputtering (TFTS) system. The as-deposited films exhibited the variable nature expected from an AlN-rich phase, and an amorphous-like phase, depending on the Co content in the films. Specific favorable microstructures were prepared by optimizing annealing conditions. Those microstructures and their magnetic properties and resistivity were investigated. As-deposited films showed very small saturation magnetization and an amorphous-like structure. However, when annealed, the as-deposited amorphous-like phase decomposes into phases of AlN, Co and Al-Co. These annealing induced changes in the microstructure improve the magnetization and resistivity of the films. Further improvement of soft magnetic properties could lead to the material being used for high density magnetic recording head material.

• 대한금속재료학회지
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• 제49권3호
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• pp.256-263
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• 2011

We have synthesized Al-Co/AlN-Co multilayer films with different layer thicknesses by using a Two-Facing Target Type dc Sputtering (TFTS) system. The deposited films were annealed isothermally at different temperatures and their microstructure, magnetic properties and resistivity were investigated. The magnetization of the as-deposited films was found to be very small, irrespective of layer thickness. It was found that the annealing conditions and layer thickness ratio of Al-Co to AlN-Co (LTR) were able to control the microstructure, as well as the physical properties of the prepared films. The resistivity and magnetization increased and the coercivity decreased with a decreasing LTR. A high resistivity of 2500 ${\mu}{\Omega}-cm$, a magnetization of 360 $emu/cm^3$, and a coercivity of 5 Oe were obtained for the films with LTR=0.175.

• 대한금속재료학회지
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• 제48권3호
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• pp.268-275
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• 2010

A new approach is described for preparing AlN thin films containing various amounts of Co content by using a two-facing targets type sputtering (TFTS) system. The deposited films were annealed isothermally at different temperatures and their microstructure, magnetic properties and resistivity were investigated. A small saturation magnetization ($4{\pi}Ms=0.52{\sim}0.85kG$) was observed irrespective of Co content in the asdeposited films. It was found that annealing conditions can control physical properties as well as the microstructure of the films. A high saturation magnetization (3.7 kG) and resistivity of $2200{\mu}{\Omega}-cm$ was obtained for AlN films containing 25 at.% Co.

• 한국진공학회지
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• 제10권1호
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• pp.72-80
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• 2001

본 논문에서는 ELA(excimer laser annealing) 및 SMC(silicide mediated crystallization) 공정으로 제작된 다결정 실리콘 TFT-LCD(Thin Film Transistor-Liquid Crystal Display) 화소의 전기적 특성을 Spice회로 시뮬레이션을 통해 비교 분석하였다. 복잡한 TFT-LCD 어레이 (array) 회로의 전기적 특성 분석을 위하여 GUI(Graphic User Interface) 방식으로 손쉽게 복잡한 회로를 구성할 수 있는 PSpice에 AIM-Spice의 다결정 실리콘 박막 트랜지스터 소자 모델을 이식하고, AIM-Spice의 변수 추출법을 개선 체계화하였으며 ELA 및 SMC공정으로 각기 제작된 다결정 실리콘 박막트랜지스터에 적용하여 단위 화소 및 라인 RC 지연을 고려한 화소 특성을 비교 분석하였다. 비교 결과 ELA 다결정 실리콘 박막 트랜지스터 소자가 SMC에 비해 TFT-LCD의 화소 충전 시간 및 킥백(kickback) 전압 특성이 모두 우수하게 나타남을 확인하였다.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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• pp.964-967
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• 2009

A new hybrid-type touch screen panel (TSP) has been developed based on a-Si:H TFT which can detect the change of both $C_{LC}$ and photo-current. This TSP can detect the difference of $C_{LC}$ between touch and no-touch states in unfavorable conditions such as dark ambient light and shadows. The hybrid TSP sensor consists of a detection area which includes one TFT for photo sensing and two TFTs for amplification. Compared to a single internal capacitive TSP or an optical sensing TSP, this new proposed hybrid-type TSP enables larger sensing margin due to embedding of both optical and capacitive sensors.

• 대한전자공학회논문지
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• 제26권3호
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• pp.130-136
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• 1989

보론이 도우핑된 수소화된 비정질 실리콘을 이용한 박막 트랜지스터를 플라즈마 CVD 방법으로 제작하여 트랜지스터의 특성 및 준안정성에 관한 연구를 수행하였다. 보론이 도우핑된 비정질 실리콘 ambipolar 트랜지스터를 열평형 온도 이상에서 급냉하면, active dopants가 증가하고 경계면 상태밀도가 감소하여 정공채널에 의한 드레인 전류가 증가하고 전자채널의 드레인 전류는 급냉 온도에 따라 증가하다 감소되는 현상을 측정하였다. 이런 급냉 효과는 실리콘내에 있는 수소의 운동과 밀접한 관계가 있고 active dopants, 댕글링 본드 및 경계면 상태밀도의 변화로 해석된다.

• 센서학회지
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• 제28권2호
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• pp.133-138
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• 2019

The a-InGaZnO (a-IGZO) thin film transistor (TFT) has the advantages of larger mobility than that of amorphous silicon TFTs, acceptable reliability and uniformity over a large area, and low process cost. A capacitive-type touch sensor was studied with an a-IGZO TFT that can be used on the front side of a display due to its transparency. A capacitive sensor detects changes of capacitance between the surface of the finger and the sensor electrode. The capacitance varies according to the distance between the sensor plate and the touching or non-touching of the sensing electrode. A capacitive touch sensor using only one a-IGZO TFT was developed with the reduction of two bus lines, which made it easy to reduce the pixel pitch. The proposed sensor circuit maintained the amplification performance, which was investigated for various drive conditions.

• Bulletin of the Korean Chemical Society
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• 제33권9호
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• pp.3061-3070
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• 2012

Novel 2-hexylthieno[3,2-b]thiophene-containing conjugated molecules have been synthesized via a reduction reaction using tin chloride in an acidic medium. They exhibited good solubility in common organic solvents and good self-film and crystal-forming properties. The single-crystalline objects were fabricated by a solvent slow diffusion process and then were employed for fabricating field-effect transistors (FETs) along with thinfilm transistors (TFTs). TFTs made of 5 and 6 exhibited carrier mobility as high as 0.10-0.15 $cm^2V^{-1}s^{-1}$. The single-crystal-based FET made of 6 showed 0.70 $cm^2V^{-1}s^{-1}$ which was relatively higher than that of the 5-based FET (${\mu}=0.23cm^2V^{-1}s^{-1}$). In addition, we fabricated organic photovoltaic (OPV) cells with new 2-hexylthieno [3,2-b]thiophene-containing conjugated molecules and methanofullerene [6,6]-phenyl C61-butyric acid methyl ester ($PC_{61}BM$) without thermal annealing. The ternary system for a bulk heterojunction (BHJ) OPV cell was elaborated using $PC_{61}BM$ and two p-type conjugated molecules such as 5 and 7 for modulating the molecular energy levels. As a result, the OPV cell containing 5, 7, and $PC_{61}BM$ had improved results with an open-circuit voltage of 0.90 V, a short-circuit current density of 2.83 $mA/cm^2$, and a fill factor of 0.31, offering an overall power conversion efficiency (PCE) of 0.78%, which was larger than those of the devices made of only molecule 5 (${\eta}$~0.67%) or 7 (${\eta}$~0.46%) with $PC_{61}BM$ under identical weight compositions.

• 한국재료학회지
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• 제19권1호
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• pp.33-36
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• 2009

Inorganic-organic composite thin-film-transistors (TFTs) of ZnO nanowire/Poly(3-hexylthiophene) (P3HT) were investigated by changing the nanowire densities inside the composites. Crystalline ZnO nanowires were synthesized via an aqueous solution method at a low temperature, and the nanowire densities inside the composites were controlled by changing the ultrasonifiaction time. The channel layers were prepared with composites by spin-coating at 2000 rpm, which was followed by annealing in a vacuum at $100^{\circ}C$ for 10 hours. Au/inorganic-organic composite layer/$SiO_2$ structures were fabricated and the mobility, $I_{on}/I_{off}$ ratio, and threshold voltage were then measured to analyze the electrical characteristics of the channel layer. Compared with a P3HT TFT, the electrical properties of TFT were found to be improved after increasing the nanowire density inside the composites. The mobility of the P3HT TFT was approximately $10^{-4}cm^2/V{\cdot}s$. However, the mobility of the ZnO nanowire/P3HT composite TFT was increased by two orders compared to that of the P3HT TFT. In terms of the $I_{on}/I_{off}$ ratio, the composite device showed a two-fold increase compared to that of the P3HT TFT.