• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제45회 하계 정기학술대회 초록집
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• pp.76.1-76.1
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• 2013

Atomic Layer Deposition (ALD) has remarkably developed in semiconductor and nano-structure applications since early 1990. Now, the advantages of ALD process are well-known as controlling atomic-level-thickness, manipulating atomic-level-composition control, and depositing impurity-free films uniformly. These unique properties may accelerate ALD related industries and applications in various functional thin film markets. On the other hand, one of big markets, Display industry, just starts to look at the potential to adopt ALD functional films in emerging display applications, such as transparent and flexible displays. Unlike conventional ALD process strategies (good quality films and stable precursors at high deposition processes), recently major display industries have suggested the following requirements: large area equipment, reasonable throughput, low temperature process, and cost-effective functional precursors. In this talk, it will be mentioned some demands of display industries for applying ALD processes and/or functional films, in terms of emerging display technologies. In fact, the AMOLED (active matrix organic light emitting diode) Television markets are just starting at early 2013. There are a few possibilities and needs to be developing for AMOLED, Flexible and transparent Display markets. Moreover, some basic results will be shown to specify ALD display applications, including transparent conduction oxide, oxide semiconductor, passivation and barrier films.

• 정보처리학회논문지:소프트웨어 및 데이터공학
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• 제7권9호
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• pp.335-344
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• 2018

모바일 AMOLED 디스플레이의 소모 전력을 소프트웨어 수준에서 참조하기 위해서는 소모 전력에 대한 모델이 필요하다. 하지만, 전력 모델을 얻기 위한 기존 연구들은 전력 측정 활동을 위한 실험 환경 및 장비가 필수적으로 요구되었다. 또한, 모델링을 위해 사용된 RGB 값의 조합이 무분별하고, 매우 적어 RGB 값들 간의 상호 영향을 모델에 반영하기 어려웠다. 본 연구는 이러한 문제점을 해결하기 위해 RGB 색 공간분할 기법 및 으로 구성된 맵핑 테이블 제공 방법을 제안한다. 제안된 분할 기법을 통해 색과 함께 전력을 고려하며 RGB 조합들을 샘플링하고, 제안된 맵핑 테이블 제공 방법에 따라 샘플링된 RGB 조합들로 구성된 맵핑 테이블을 생성한다. 실험을 통해 색 차원과 전력 차원에서의 분할 기법에 따른 샘플들의 특징을 분석하였고, 이를 바탕으로 AMOLED 디스플레이에 대한 맵핑 테이블을 생성하였다. 더불어, 맵핑 테이블을 활용하여 각기 다른 4개의 전력 모델을 평가함으로써 맵핑 테이블의 재사용 가능성을 확인하였다. 이러한 맵핑 테이블은 연구자들에게 제공되어 전력 측정 활동 없이도 전력 모델을 생성하는데 활용될 수 있다.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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• pp.1261-1262
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• 2008

Laser-based crystallization techniques are ideally-suited for forming high-quality crystalline Si films on active-matrix display backplanes, because the highly-localized energy deposition allows for transformation of the as-deposited a-Si without damaging high-temperature-intolerant glass and plastic substrates. However, certain significant and non-trivial attributes must be satisfied for a particular method and implementation to be considered manufacturing-worthy. The crystallization process step must yield a Si microstructure that permits fabrication of thin-film transistors with sufficient uniformity and performance for the intended application and, the realization and implementation of the method must meet specific requirements of viability, robustness and economy in order to be accepted in mass production environments. In recent years, Low Temperature Polycrystalline Silicon (LTPS) has demonstrated its advantages through successful implementation in the application spaces that include highly-integrated active-matrix liquid-crystal displays (AMLCDs), cost competitive AMLCDs, and most recently, active-matrix organic light-emitting diode displays (AMOLEDs). In the mobile display market segment, LTPS continues to gain market share, as consumers demand mobile devices with higher display performance, longer battery life and reduced form factor. LTPS-based mobile displays have clearly demonstrated significant advantages in this regard. While the benefits of LTPS for mobile phones are well recognized, other mobile electronic applications such as portable multimedia players, tablet computers, ultra-mobile personal computers and notebook computers also stand to benefit from the performance and potential cost advantages offered by LTPS. Recently, significant efforts have been made to enable robust and cost-effective LTPS backplane manufacturing for AMOLED displays. The majority of the technical focus has been placed on ensuring the formation of extremely uniform poly-Si films. Although current commercially available AMOLED displays are aimed primarily at mobile applications, it is expected that continued development of the technology will soon lead to larger display sizes. Since LTPS backplanes are essentially required for AMOLED displays, LTPS manufacturing technology must be ready to scale the high degree of uniformity beyond the small and medium displays sizes. It is imperative for the manufacturers of LTPS crystallization equipment to ensure that the widespread adoption of the technology is not hindered by limitations of performance, uniformity or display size. In our presentation, we plan to present the state of the art in light sources and beam delivery systems used in high-volume manufacturing laser crystallization equipment. We will show that excimer-laser-based crystallization technologies are currently meeting the stringent requirements of AMOLED display fabrication, and are well positioned to meet the future demands for manufacturing these displays as well.

• JSTS:Journal of Semiconductor Technology and Science
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• 제14권5호
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• pp.594-600
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• 2014

A threshold voltage compensation pixel circuit was developed for active-matrix organic light emitting diodes (AMOLEDs) using amorphous indium-gallium-zinc-oxide thin-film transistors (a-IGZO-TFTs). Oxide TFTs are n-channel TFTs; therefore, we developed a circuit for the n-channel TFT characteristics. The proposed pixel circuit was verified and proved by circuit analysis and circuit simulations. The proposed circuit was able to compensate for the threshold voltage variations of the drive TFT in AMOLEDs. The error rate of the OLED current for a threshold voltage change of 3 V was as low as 1.5%.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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• pp.119-122
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• 2008

In this paper, we describe the current status and issues of the oxide thin-film transistors (OTFTs), which attract much attention as an emerging new backplane technology replacing conventional silicon-based TFTs technologies. First, the unique benefits of OTFTs will be presented as a backplane for large-sized AMOLED including note-book PC, second TV and HD-TV. And then, the state-of-the-art transistor performance and uniformity characteristics of OTFTs will be highlighted. The obtained a-IGZO TFTs exhibited the field-effect mobility of $18\;cm^2/Vs$, threshold voltage of 1.8 V, on/off ratio of $10^9$, and subthreshold gate swing of 0.28 V/decade. In addition, the world largest-sized 12.1-inch WXGA active-matrix organic light emitting diode (AMOLED) display is demonstrated using indium-gallium-zinc oxide (IGZO) TFTs.

• 전기전자학회논문지
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• 제23권3호
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• pp.1104-1107
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• 2019

본 논문에서는 데드 타임을 줄여 전력 효율을 높이기 위해 데드 타임 제어기를 이용한 웨어러블 AMOLED 디스플레이용 DC-DC 부스트 변환기를 제안한다. 또한, 본 변환기에서는 경부하에서 전력 효율을 높이고 출력 전압 리플을 감소시키기 위해 PWM-SPWM (set-time variable pulse width modulation) 듀얼 모드를 이용한다. 제안하는 회로는 $0.18{\mu}m$ BCDMOS 공정을 이용하여 시뮬레이션을 한 결과 1 mA~70 mA의 부하 전류 범위에서 39%~96%의 전력 효율과 2 mV의 리플 전압을 가졌다. 본 회로의 전력 효율은 PWM-SPWM 방식보다 최대 2% 상승하였고, PWM 방식보다 최대 8% 상승하였다.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.II
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• pp.891-891
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• 2005

• 융합정보논문지
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• 제9권5호
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• pp.117-124
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• 2019

본 논문에서는 AMOLED 디스플레이 구동회로로 사용되는 박막트랜지스터의 구성요소 중에서 반도제 물질 제조의 최근 동향에 대해 논한다. 트랜지스터에 적용을 위해 특성이 좋은 반도체 막을 얻는 방법으로 비정질 실리콘을 다결정 실리콘으로 변화시켜야 하는데 레이저와 열처리 방법이 있으며, 레이저를 이용한 기술에는 SLS(Sequential Lateral Solidification), ELA(Excimer Laser Annealing), TDX(Thin-beam Directional Crystallization), 열처리 기술에는 SPC(Solid Phase Crystallization), SGS(Super Grain Silicon), MIC(Metal Induced Crystallization), FALC(Field Aided Lateral Crystallization)가 대표적이며, 이들에 대해 상세히 설명한다. 본 연구실에서 연구중인 레이저 결정화 기술의 대형 AMOLED 디스플레이 제작을 위한 연구 내용도 다룬다.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
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• pp.1803-1804
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• 2006

In this paper, device performances of organic lightemitting diodes (OLEDs) will be presented for AMOLED and general illumination applications. Various types of advanced devices were developed to enhance the power efficacy and luminous efficiency. Here we also demonstrated longer lifetime AM-OLED structures, which lifetime is about 100 hours until $L/L_0$ reaches 0.99.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2022년도 춘계학술대회
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• pp.550-551
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• 2022

In the present study, flexible display technology, which has attracted significant attention in recent years, is discussed. The technology has been widely applied to various devices, such as foldable smartphones and rollable TVs. Notably, different flexible display types from LCD to OLED and E-paper have been employed to implement such devices in practice. Among them, the OLED technology has thus far led the flexible display market. In the present study, the concept and current application fields of the technology are analyzed, and further its potential applications are discussed.