• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.413-418
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• 2006

Highly stable thin-film transistor (TFT) pixel employing both low temperature polycrystalline silicon (LTPS) and amorphous silicon (a-Si) for active matrix organic light emitting diode (AMOLED) is discussed. ELA (excimer laser annealing) LTPS-TFT pixel should compensate $I_{OLED}$ variation caused by the non-uniformity of LTPS-TFT due to the fluctuation of excimer laser energy and amorphous silicon TFT pixel is desired to suppress the decrease of $I_{OLED}$ induced by the degradation of a-Si TFT. We discuss various compensation schemes of both LTPS and a-Si TFT employing the voltage and the current programming.

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07b
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• pp.1123-1126
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• 2005

For creation of low temperature polycrystallinesilicon (LTPS) the line beam excimer laser annealing (ELA) is a well known and established technique in mass production. With introduction of Sequential Lateral Solidification (SLS) some aspects such as crystalline quality, throughput and flexibility regarding the substrate size could be improved, but for OLED manufacturing still further process development is necessary. This paper discusses line beam ELA and SLS techniques that might enable process engineers to make polycrystalline-silicon (poly-Si) films with a high degree of uniformity and quality as required for system on glass (SOG) and active matrix organic light emitting displays (AMOLED). Equipment requirements are discussed and compared to previous standards. SEM images of process examples are shown in order to demonstrate the viability.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.52 no.12
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• pp.559-561
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• 2003

We report a new excimer laser annealing method which successfully results in a single grain boundary formation in the channel of polycrystalline silicon thin film transistor. The proposed method is based on lateral grain growth and employs aluminum patterns which act as selective beam mask and lateral heat sink. The maximum grain size obtained by the proposed method is about 1.6${\mu}{\textrm}{m}$ in the length. The grainboundaries should be arranged parallel with the direction of current flow for the best device performance, so we propose a new device fabrication method and a new poly-Si TFT structure. Poly-Si TFT fabricated by the proposed method exhibits considerably improved electrical characteristics, such as high field effect mobility exceeding 240 $cm^2$/Vsec.

• Proceedings of the IEEK Conference
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• 2002.06b
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• pp.29-32
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• 2002

This paper describes a novel structure of NMOSFET with elevated SiGe source/drain region and ultra-shallow source/drain extension(SDE)region. A new ultra-shallow junction formation technology. Which is based on damage-free process for rcplacing of low energy ion implantation, is realized using ultra-high vacuum chemical vapor deposition(UHVCVD) and excimer laser annealing(ELA).

• Journal of the Korean Ceramic Society
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• v.43 no.3 s.286
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• pp.185-192
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• 2006

The effects of annealing on structural and electrical properties of ITO/PES (Indium Tin Oxide/Polyethersulfone) films was investigated. Amorphous ITO thin films were grown on plastic substrates, PES using low temperature DC magnetron sputtering. Various post annealing techniques were attempted to research variations of microstructure and electrical properties: i) conventional thermal annealing, ii) excimer laser annealing, iii) UV irradiation. The electrical properties were obtained using Hall effect measurements and DC 4-point resistance measurement. The microstructural features were characterized by FESEM, XRD, Raman spectroscopy in terms of morphology and crystallinity. Optimized UV treatment exhibits the enhanced conductivity and crystallinity, compared to those of conventional thermal annealing.

• Journal of the Korean Electrochemical Society
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• v.3 no.1
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• pp.19-24
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• 2000

It is increasingly necessary to use poly-Si n's as high resolution and integration of Tn for LCD. Excimer Laser Crystallization (ELC) of a-Si is mainly used as a low temperature process. But the ELC method for the fabrication of poly-Si has the eruption problems associated with hydrogen in the a-Si film. So we need a dehydro-genation process additionally. Hydrogen in a-Si film can degrade the quality of poly-Si film and electrical properties of device due to the hydrogen eruption and voids which occur during the excimer laser annealing. In this study, we propose mesh-type PECVD as the a-Si film deposition method for achieving the low concentration hydrogen. Mesh-type PECVD was found to reduce the hydrogen content substantially. We could obtain a as-deposited a-Si film with hydrogen contents less than $1\%$ at $300^{\circ}C$. We also investigated the behavior by XeCl excimer laser annealing of a-Si fabricated by mesh-type PECVB. As a result, we were able to confirm the broad process window in contrast to the narrow process range typically obtained in ELC. Hydrogen eruption was not observed in poly-Si films after ELC These results suggests that mesh-type PECVD is a viable method to achieve the low hydrogen content a-Si and improve the process windows for ELC.

• Journal of Convergence for Information Technology
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• v.9 no.5
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• pp.117-124
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• 2019

This paper discusses recent trends in the fabrication of semiconducting materials among the components of thin film transistors used in AMOLED display. In order to obtain a good semiconductor film, it is necessary to change the amorphous silicon into polycrystalline silicon. There are two ways to use laser and heat. Laser-based methods include sequential lateral solidification (SLS), excimer laser annealing (ELA), and thin-beam directional crystallization (TDX). Solid phase crystallization (SPC), super grain silicon (SGS), metal induced crystallization (MIC) and field aided lateral crystallization (FALC) were crystallized using heat. We will also study research for manufacturing large AMOLED displays.

• Proceedings of the KIEE Conference
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• 2001.11a
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• pp.106-108
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• 2001

본 실험에서는 플라즈마 화학기상증착(PECVD)으로 증착한 비경질 실리콘(amorphous silicon, a-Si) 박막에 국부적으로 Si+ 이온을 주입한 후 엑시머 레이저 어닐링(exicimer laser annealing, ELA)을 수행하여 그레인의 수평 성장(lateral growth)에 미치는 영향을 관찰한다. Si+ 이온 주입은 비정질 실리콘 박막의 원자 결합 에너지를 효과적으로 감소시키는 역할을 하여 박막이 녹기 시작하는 문턱(threshold) 에너지가 $105mJ/cm^2$에서 $85mJ/cm^2$ 까지 낮아지는 것을 확인하였다. 결과적으로 선택적인 Si 이온 주입을 통해 비정질 박막의 결정화 시 온도 구배에 의한 결정핵(nucleation) 형성의 차이를 유발시킴으로써 위치 제어가 가능한 1um 크기를 갖는 수평 성장 그레인을 얻었다.

• Journal of the Korean Magnetics Society
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• v.5 no.5
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• pp.720-725
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• 1995

Bi-substituted gadolinium iron garnet films were deposited on GGG(111) and NGG (111) substrates by irradiating KrF excimer laser onto targets having compositions of $Bi_{x}Gd_{3-x}Fe_{5}O_{12}$ ($2.0{\leq}x{\leq}3.0$) under substrate temperature of $580~620^{\circ}C$. Analysis on structure, composition and angle of Faraday rotation, ${\theta}_{F}$, were carried out. The composition, the structure and the magneto-optical properties of the obtained films were found to be strongly dependent both on the compositions of the targets and on the pressure of oxygen. Before annealing in air, all films showed ${\theta}_{F}{\geq}0$ at ${\lambda}=6328{\AA}$, while several films showed ${\theta}_{F}{\leq}0$ after the annealing. The highest value of Bi-substitution up to x = 1.76 with uniform composition was obtained.

• Electrical & Electronic Materials
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• v.11 no.11
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• pp.22-27
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• 1998

We have investigated the effect of an ion shower doping of the laser annealed poly-Si films at an elevated substrate temperatures. The substrate temperature was varied from room temperature to 300$^{\circ}C$ when the poly-Si film was doped with phosphorus by a non-mass-separated ion shower. Optical, structural, and electrical characterizations have been performed in order to study the effect of the ion showering doping. The sheet resistance of the doped poly-Si films was decreased from7${\times}$106 $\Omega$/$\square$ to 700 $\Omega$/$\square$ when the substrate temperature was increased from room temperature to 300$^{\circ}C$. This low sheet resistance is due to the fact that the doped film doesn't become amorphous but remains in the polycrystalline phase. The mildly elevated substrate temperature appears to reduce ion damages incurred in poly-Si films during ion-shower doping. Using the ion-shower doping at 250$^{\circ}C$, the field effect mobility of 120 $\textrm{cm}^2$/(v$.$s) has been obtained for the n-channel poly-Si TFTs.