• Journal of the Institute of Electronics Engineers of Korea SD
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• v.40 no.1
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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.

• ETRI Journal
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• v.34 no.4
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• pp.633-636
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• 2012

A dynamic analysis of an amorphous silicon (a-Si) thin film transistor liquid crystal display (TFT-LCD) pixel is presented using new a-Si TFT and liquid crystal (LC) capacitance models for a Simulation Program with Integrated Circuit Emphasis (SPICE) simulator. This dynamic analysis will be useful when predicting the performance of LCDs. The a-Si TFT model is developed to accurately estimate a-Si TFT characteristics of a bias-dependent gate to source and gate to drain capacitance. Moreover, the LC capacitance model is developed using a simplified diode circuit model. It is possible to accurately predict TFT-LCD characteristics such as flicker phenomena when implementing the proposed simulation model.

• Journal of Information Display
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• v.5 no.2
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• pp.1-5
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• 2004

We developed an a-Si TFT-LCD panel with integrated gate driver circuit using a standard 5-MASK process. To minimize the effect of the a-Si TFT current and LC's capacitance variation with temperature, we developed a new a-Si TFT circuit structure and minimized coupling capacitance by changing vertical architecture above gate driver circuit. Integration of gate driver circuit on glass substrate enables single chip and 3-side free panel structure in a-Si TFT-LCD of QVGA ($240{\times}320$) resolution. And using double ASG structure the dead space of TFT-LCD panel could be further decreased.

• 한국정보디스플레이학회:학술대회논문집
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• 2004.08a
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• pp.395-398
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• 2004

We developed an a-Si TFT-LCD panel with integrated gate driver circuit using a standard 5-MASK process. To minimize the effect of the a-Si TFT current and LC's capacitance variation with temperature, we developed a new a-Si TFT circuit structure and minimized coupling capacitance by changing vertical architecture above gate driver circuit. Integration of gate driver circuit on glass substrate enables single chip and 3-side free panel structure in a-Si TFT-LCD of QVGA(240$^{\ast}$320) resolution. And using double ASG structure the dead space of TFT-LCD panel could be further decreased.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08b
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• pp.1168-1171
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• 2007

Integrating systems on TFT-LCD panels is more and more popular for the mobile display application. However, it may not be necessary to use LTPS TFT devices. A-Si TFTs are used to integrate systems on TFT-LCD panels, especially scan (gate) drivers. To further reduce the chip size of driver IC, the triplegate pixel structure is developed. Therefore, the number of the source lines is reduced to 1/3 times.

• Proceedings of the IEEK Conference
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• 2001.06b
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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

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.38 no.12
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• pp.25-35
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• 2001

In order to analyze the electrical characteristics of complicated thin film transistor-liquid crystal display (TFT-LCD) array circuits, it is indispensible to use simulation programs such as PSPICE and AIM-SPICE. In this paper, we present a systematic method of extracting the input parameters of poly-Si TFT for SPICE simulations. This method was applied to two different types of poly-Si TFTs, fabricated by excimer laser annealing and silicide mediated crystallization methods, and yielded good fitting results to experimental data. Among the SPICE simulators, PSPICE has the graphic user interface feature making the composition of complicated circuits easier. We added successfully a poly-Si TFT device model to the PSPICE simulator, and analyzed easily the electrical characteristics of pixels considering the line RC delay. The results of this work would contribute to efficient simulations of poly-Si TFT-LCD arrays.

• Proceedings of the IEEK Conference
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• 2000.06b
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• pp.314-317
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• 2000

In order to analyze the characteristics of complicated TFT-LCD (Thin Film Transistor-Liquid Crystal Display) circuits, it is indispensible to use simulation programs. In this study, we present a systematic method of extracting the input parameters of poly-Si TFT for Spice simulation. This method is applied to two different types of poly-Si TFTs fabricated in our group with good results. Among the Spice simulators, Pspice has the graphic user interface feature making the composition of complicated circuits easier. We added successfully a poly-Si TFT model on the Pspice simulator, which would contribute to efficient simulations of poly-Si TFT-LCD pixels and arrays.

• Journal of the Korean Vacuum Society
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• v.10 no.1
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• pp.72-80
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• 2001

In this paper, we present a systematic method of extracting the input parameters of poly-Si TFT(Thin-Film Transistor) for Spice simulations. This method has been applied to two different types of poly-Si TFTs such as ELA (Excimer Laser Annealing) and SMC (Silicide Mediated Crystallization) with good fitting results to experimental data. Among the Spice circuit simulators, the PSpice has the GUI(graphic user interface) feature making the composition of complicated circuits easier. We added successfully the poly-Si TFT model of AIM-Spice to the PSpice simulator, and analyzed easily to compare the electrical characteristics of pixels without or with the line RC delay. In the comparative results, the ELA poly-Si TFT is superior to the SMC poly-Si TFT in the charging time and the kickback voltage for the TFT-LCD (Thin Film Transistor-Liquid Crystal Display).

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.12A
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• pp.2002-2007
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• 1999

In this paper, the n-channel poly-Si thin-film transistors (poly-Si TFT's) formed by solid phase crystallization (SPC) on glass were investigated by measuring the electrical properties of poly-Si films, such as I-V characteristics, mobility, leakage current, threshold voltage, and subthreshold slope. It is done to decide to be applied on TFT-LCD with large-size and high density. In n-channel poly-Si TFT with 2, 10, 25$\mu\textrm{m}$ of channel length, the field effect mobilities are 111, 126 and 125 $\textrm{cm}^2$/V-s and leakage currents are 0.6, 0.1, and 0.02 pA/$\mu\textrm{m}$, respectively. Low threshold voltage and subthreshold slope, and good ON-OFF ratio are shown, as well. Thus, the poly-Si TFT’s used by SPC are expected to be applied on TFT-LCD with large-size and high density, which can integrate display panel and peripheral circuit on a large glass substrate.