• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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• pp.461-463
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• 2009

We report on the fabrication of ZnO-based thin-film transistor (TFT) inverters with top and bottom gate structures with $Al_2O_3$ dielectrics grown by atomic layer deposition (ALD). Since the top gate ZnO-based TFT showed somewhat lower field effect mobility than that of the bottom gate device, our ZnO-based TFT inverters were designed with identical dimensions for both channels. This TFT inverter device demonstrated an high voltage gain at a low supply voltage of 5 V and clear dynamic behavior.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제42회 동계 정기 학술대회 초록집
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• pp.403-404
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• 2012

We fabricated TFT devices with the GeSe channel. A single device consists of a Pt source and drain, a Ti glue layer and a GeSe chalcogenide channel layer on SiO2/Si substrate which worked as the gate. We confirmed the drain current with variations of gate bias and channel size. The I-V curves of the switching device are shown in Fig. 1. The channel of the device always contains amorphous state, but can be programmed into two states with different threshold voltages (Vth). In each state, the device shows a normal Ovonic switching behavior. Below Vth (OFF state), the current is low, but once the biasing voltage is greater than Vth (ON state), the current increases dramatically and the ON-OFF ratio is high. Based on the experiments, we draw the conclusion that the gate voltage can enhance the drain current, and the electric field by the drain voltage affects the amorphous-amorphous transition. The switching device always contains the amorphous state and never exhibits the Ohmic behavior of the crystalline state.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2004년도 Asia Display / IMID 04
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• pp.923-926
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• 2004

Active-matrix field emission display (AMFED) based on carbon nanotube (CNT) emitter and amorphous silicon thin-film transistor (a-Si TFT) is reviewed. The AMFED pixels consisted of a high-voltage a-Si TFT and mesh-gated CNT emitters. The developed AMFED panel showed a high performance with a driving voltage of below 15 V. The low-cost and large-area AMFED approach with a metal mesh technology will be discussed.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 춘계학술대회 논문집 디스플레이 광소자 분야
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• pp.169-172
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• 2000

A-Si:H and poly-Si TFT characteristics were investigated using an inverted staggered type TFT. The poly-Si films were achieved by various anneal techniques ; isothermal, RTA, and excimer laser anneal. The TFT on as-grown a-Si:H exhibited a low field effect mobility, transconductance, and high gate threshold voltage. Some films were annealed at temperatures from $200^{\circ}C$ to $1000^{\circ}C$. The TFT on poly-Si showed an improved $I_{on}/I_{off}$ ratio of $10^6$, reduced gate threshold voltage, and increased field effect mobility by three orders. Inverter operation was examined to verify logic circuit application using the poly-Si TFTs.

• 한국전기전자재료학회논문지
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• 제24권7호
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• pp.525-531
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• 2011

In this paper, experimental analyses have been performed to compare the electrical characteristics of n channel LT(low temperature) and HT(high temperature) poly-Si TFTs(polycrystalline silicon thin film transistors) on quartz substrate according to activated step annealing. The size of the particles step annealed at low temperature are bigger than high temperature poly-Si TFTs and measurements show that the electric characteristics those are transconductance, threshold voltage, electric effective mobility, on and off current of step annealed at LT poly-Si TFTs are high more than HT poly-Si TFT's. Especially we can estimated the defect in the activated grade poly crystalline silicon and the grain boundary of LT poly-Si TFT have more high than HT poly-Si TFT's due to high off electric current. Even though the size of particles of step annealed at low temperature, the electrical characteristics of LT poly-Si TFTs were investigated deterioration phenomena that is decrease on/off current ratio depend on high off current due to defects in active silicon layer.

• 대한전자공학회논문지SD
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• 제40권1호
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• pp.20-28
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• 2003

In this paper, we present results of the comparative analysis of the flicker phenomena in the poly-Si TFT-LCD and a-Si:H TFT-LCD arrays for the development and manufacturing of wide-area and high-quality TFT-LCD displays. We used four different types of TFTs; a-Si:H TFT, excimer laser annealed (ELA) poly-Si TFT, silicide mediated crystallization (SMC) poly-Si TFT, and counter-doped lateral body terminal (LBT), poly-Si TFT. We defined the electrical quantity of the flicker so that we could compare the flickers quantitatively for four different 40" UXGA TFT-LCDs. We identify three factors contributing to the flicker, such as charging time, kickback voltage and leakage current, and analyze how much each of three factors give rise to the flincker in the different TFT-LCD arrays. In addition, we suggest and show that, in the case of the poly-Si TFT-LCD arrays, the low-level (minimum) gate voltages should be carefully chosen to minimize the flicker because of their larger leakage currents compared with a-Si TFT-LCD arrays.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 D
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• pp.1809-1811
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• 1999

In recent years, attempts have been made to greatly improve the display quality of active-matrix liquid crystal display devices, and many techniques have been proposed to solve such problems as gate delay, feed-through voltage and image sticking. Gate delay is one of the biggest limiting factors for large-screen-size, high-resolution thin-film transistor liquid crystal display (TFT/LCD) design. Many driving method proposed for TFT/LCD progress. Thus we developed gate driving signal generator. Since Pixel-Design Array Simulation Tool (PDAST) can simulate the gate, data and pixel voltages of a certain pixel on TFT array at any time and at any location on an array, the effect of the driving signals of gate lines on the pixel operations can be effectively analyzed.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 하계종합학술대회 논문집(2)
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• pp.225-228
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• 2001

We simulated and analyzed the flicker phenomena in the poly-Si TFT-LCD using PSpice for the development of wide-area and high-quality LCD display We define the electric quantity of flicker in the TFT-LCD, which is the ratio of half frame frequency (30Hz) to DC (0 Hz) frequency. We compared two different types of TFTs, excimer laser annealed (ELA) poly-Si TFT and silicide mediated crystallization (SMC) poly-Si TFT, and found that the ELA and SMC TFTs show different flicker characteristics because of their mobility and leakage current. In addition, we showed that the gate voltage should be chosen carefully at the minimum flicker because of the larger leakage current of poly-Si Tn as compared with a-Si TFT

• 대한전기학회:학술대회논문집
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• 대한전기학회 1995년도 하계학술대회 논문집 C
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• pp.1239-1241
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• 1995

The different hydrogen passivation effects on low-temperature processed and high-temperature processed poly-Si thin film transistors have been investigated. The hydrogen passivation on low-temperature processed poly-Si TFT results in the increase of the field-effect mobility and the decrease or the threshold voltage, while the hydrogenation increases the field-effect mobility and decreases the leakage current in high-temperature processed poly-Si TFT. The effective trap state densities of low-temperature processed poly-Si TFT before and after 5 hours of hydrogenation are estimated at about $4.0{\times}10^{12}/cm^2$ and $1.5{\times}10^{12}/cm^2$, while those of high-temperature processed poly-Si TFT are about $1.5{\times}10^{12}/cm^2$ and $1.2{\times}10^{12}/cm^2$, respectively.

• Journal of Information Display
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• 제2권3호
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• pp.32-38
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• 2001

The most important parameter for TV application of LCD is a fast switching time for the display of moving image. To achieve faster switching time, the novel LC single materials with large dielectric anisotropies ($16{\sim}20$), high clearing temperatures ($195.5{\sim}237.4^{\circ}C$), broad nematic ranges (up to 169.9 $^{\circ}C$) and high birefringence ($0.254{\sim}0.2200$) were developed. KUR-series LC mixtures blended these single materials having significantly higher clearing temperatures and dielectric anisotropy values compared with conventional LC mixture. Especially, their clearing temperatures are $10{\sim}30^{\circ}C$ higher than their host mixture. These LC mixtures showing about lOms of high-speed switching time in Tv/Monitor of TFT LCD, is short enough to be addressed in a single time frame of 60Hz (16.7 ms). The threshold voltage $V_{th}$ was low enough to operate at a driving voltage of 5 V. The VHR values were found to be high enough for TFT-LCD in wide temperature range. Our novel LC mixtures are suitable materials for the inclusion in to LC mixtures for TV application of TN-LCD