• Title/Summary/Keyword: $AlO_x$ thin film

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Characteristics of HfO2-Al2O3 Gate insulator films for thin Film Transistors by Pulsed Laser Deposition

  • Hwang, Jae Won;Song, Sang Woo;Jo, Mansik;Han, Kwang-hee;Kim, Dong woo;Moon, Byung Moo
    • Proceedings of the Korean Vacuum Society Conference
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    • 2016.02a
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    • pp.304.2-304.2
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    • 2016
  • Hafnium oxide-aluminum oxide (HfO2-Al2O3) dielectric films have been fabricated by Pulsed Laser Deposition (PLD), and their properties are studied in comparison with HfO2 films. As a gate dielectric of the TFT, in spite of its high dielectric constant, HfO2 has a small energy band gap and microcrystalline structure with rough surface characteristics. When fabricated by the device, it has the drawback of generating a high leakage current. In this study, the HfAlO films was obtained by Pulsed Laser Deposition with HfO2-Al2O3 target(chemical composition of (HfO2)86wt%(Al2O3)14wt%). The characteristics of the thin Film have been investigated by x-ray diffraction (XRD), atomic force microscopy (AFM) and spectroscopic ellipsometer (SE) analyses. The X-ray diffraction studies confirmed that the HfAlO has amorphous structure. The RMS value can be compared to the surface roughness via AFM analysis, it showed HfAlO thin Film has more lower properties than HfO2. The energy band gap (Eg) deduced by spectroscopic ellipsometer was increased. HfAlO films was expected to improved the interface quality between channel and gate insulator. Apply to an oxide thin Film Transistors, HfAlO may help improve the properties of device.

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Dry Etching Properties of HfAlO3 Thin Film with Addition O2 gas Using a High Density Plasma

  • Woo, Jong-Chang;Lee, Yong-Bong;Kim, Jeong-Ho
    • Transactions on Electrical and Electronic Materials
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    • v.15 no.3
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    • pp.164-169
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    • 2014
  • We investigated the etching characteristics of $HfAlO_3$ thin films in $O_2/Cl_2/Ar$ and $O_2/BCl_3/Ar$ gas, using a high-density plasma (HDP) system. The etch rates of the $HfAlO_3$ thin film obtained were 30.1 nm/min and 36 nm/min in the $O_2/Cl_2/Ar$ (3:4:16 sccm) and $O_2/BCl_3/Ar$ (3:4:16 sccm) gas mixtures, respectively. At the same time, the etch rate was measured as a function of the etching parameter, namely as the process pressure. The chemical states on the surface of the etched $HfAlO_3$ thin films were investigated by X-ray photoelectron spectroscopy. Auger electron spectroscopy was used for elemental analysis on the surface of the etched $HfAlO_3$ thin films. These surface analyses confirm that the surface of the etched $HfAlO_3$ thin film is formed with nonvolatile by-product. Also, Cl-O can protect the sidewall due to additional $O_2$.

Atomic Layer Deposited ZrxAl1-xOy Film as High κ Gate Insulator for High Performance ZnSnO Thin Film Transistor

  • Li, Jun;Zhou, You-Hang;Zhong, De-Yao;Huang, Chuan-Xin;Huang, Jian;Zhang, Jian-Hua
    • Electronic Materials Letters
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    • v.14 no.6
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    • pp.669-677
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    • 2018
  • In this work, the high ${\kappa}$ $Zr_xAl_{1-x}O_y$ films with a different Zr concentration have been deposited by atomic layer deposition, and the effect of Zr concentrations on the structure, chemical composition, surface morphology and dielectric properties of $Zr_xAl_{1-x}O_y$ films is analyzed by Atomic force microscopy, X-ray diffraction, X-ray photoelectron spectroscopy and capacitance-frequency measurement. The effect of Zr concentrations of $Zr_xAl_{1-x}O_y$ gate insulator on the electrical property and stability under negative bias illumination stress (NBIS) or temperature stress (TS) of ZnSnO (ZTO) TFTs is firstly investigated. Under NBIS and TS, the much better stability of ZTO TFTs with $Zr_xAl_{1-x}O_y$ film as a gate insulator is due to the suppression of oxygen vacancy in ZTO channel layer and the decreased trap states originating from the Zr atom permeation at the $ZTO/Zr_xAl_{1-x}O_y$ interface. It provides a new strategy to fabricate the low consumption and high stability ZTO TFTs for application.

Characteristics of AlN thin films for SAW filters based on substrates (기판의 종류에 따른 SAW 필터용 AlN 박막의 특성)

  • Ko, Bong-Chul;Nam, Chang-Woo
    • Journal of Sensor Science and Technology
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    • v.16 no.3
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    • pp.240-245
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    • 2007
  • AlN thin film for SAW filter application was deposited on (100) silicon, sapphire, $Si_{3}N_{4}$/Si, and $Al_{2}O_{3}$/Si substrates by reactive magnetron sputtering method, respectively. The structural characteristics were dependent on the structure of substrates. Scanning Electron Microscope (SEM), X-ray Diffraction (XRD) and Atomic Force Microscope (AFM) have been used to analyze structural properties and preferred orientation of AlN thin films. Preferred orientation and SAW characteristic of AlN were improved by insertion of $Al_{2}O_{3}$ buffer layer. Insertion loss of SAW devices using AlN/Si and AlN/$Al_{2}O_{3}$/Si were about 33.27 dB and 30.20 dB, respectively.

Dry Etching of Al2O3 Thin Film by Cl2/Ar Plasma (Cl2/Ar 플라즈마를 이용한 Al2O3 박막의 식각)

  • Yang, Xue;Um, Doo-Seung;Kim, Gwan-Ha;Song, Sang-Hun;Kim, Chang-Il
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.22 no.12
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    • pp.1005-1008
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    • 2009
  • In this study, adaptively coupled plasma (ACP) source was used for dry etching of $Al_2O_3$ thin film. During the etching process, the wafer surface temperature is an important parameter to influent the etching characteristics. Therefore, the experiments were carried out in ACP to measuring the etch rate, the selectivities of $Al_2O_3$ thin film to mask materials and the etch profile as functions of $Cl_2$/Ar gas ratio and substrate temperature. The highest etch rate of $Al_2O_3$ was 65.4 nm/min at 75% of $Cl_2/(Cl_2+Ar)$ gas mixing ratio. The etched profile was characterized using field effect scanning electron microscopy (FE-SEM). The chemical states of $Al_2O_3$ thin film surfaces were investigated with x-ray photoelectron spectroscopy (XPS).

$NO_x$ Sensing Characteristic of $TiO_2$ Thin Film Deposited by R.F Magnetron Sputtering (R.F 마그네트론 스퍼트링으로 작성된 $TiO_2$박막의 $NO_x$ 감지 특성)

  • 고희석;박재윤;박상현
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.51 no.12
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    • pp.567-572
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    • 2002
  • In these days, diesel vehicle or power plant emits $NO_X\; and SO_2$ which cause air pollution like acid-rain, ozone layer destroy and optical smoke, therefore there are many kinds of methods considered for removing them such as SCR, catalyst, plasma process, and plasma-catalyst hybrid process. T$TiO_2$ is commonly used as catalyst to remove $NO_X$ gas because it have very excellent chemical characteristic as photo catalyst. In this paper, $NO_X$ sensing characteristic of $TiO_2$ thin film deposited by R.F Magnetron sputtering is investigated. A finger shaped electrode on $Al_2$O$_3$ substrate is designed and $TiO_2$ is deposited on the electrode by the magnetron sputtering deposition system. Chemical composition of the deposited $TiO_2$ thin film is $TiO_{1.9}$ by RBS analysis. When the UV is irradiated on it with flowing air, capacitance of $TiO_2$ thin film increases, however, when NO gas is put into the system with air, it immediately decreases because of photo chemical reaction. and it monotonously decreases with increasing NO concentration.

Effect of ZnO buffer layer on the property of ZnO thin film on $Al_{2}O_{3}$ substrate (사파이어 기판 위에 증착된 ZnO 박막 특성에 대한 ZnO 버퍼층의 영향)

  • Kim, Jae-Won;Kang, Jeong-Seok;Kang, Hong-Seong;Lee, Sang-Yeol
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2003.04a
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    • pp.140-142
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    • 2003
  • ZnO thin films are demanded for device applications, so ZnO buffer layer was used to improve for good properties of ZnO thin film. In this study, the structural, electrical and optical properties of ZnO thin films deposited with various buffer thickness was investigated by X-ray diffraction (XRD), Hall measurements, Photoluminescence(PL). ZnO buffer layer and ZnO thin films on sapphire($Al_{2}O_{3}$) substrate have been deposited $200^{\circ}C$ and $400^{\circ}C$ respectively by pulsed laser deposition. It is observed the variety of lattice constant of ZnO thin film by (101) peak position shift with various buffer thickness. It is founded that ZnO thin film with buffer thickness of 20 nm was larger resistivity of 200 factor and UV/visible of 2.5 factor than that of ZnO thin films without buffer layer. ZnO thin films with buffer thickness of 20 nm have shown the most properties.

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Ultra Thin Film Barrier Layer for Plastic OLED

  • Kopark, Sang-Hee;Oh, Ji-Young;Hwang, Chi-Sun;Yang, Yong-Suk;Chu, Hye-Yong
    • 한국정보디스플레이학회:학술대회논문집
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    • 2004.08a
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    • pp.44-47
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    • 2004
  • Fabrication of barrier layer on PES substrate and plastic OLED device by atomic layer deposition are carried out. Simultaneous deposition of 30nm of $AlO_x$ film on both sides of PES gives film MOCON value of 0.0615g/$m^2$.day (@38$^{\circ}C$, 100% R.H). Introduction of conformal $AlO_x$ film by ALD resulted in enhanced barrier properties for inorganic double layered film including PECVO $SiN_x$. Preliminary life time to 91% of initial luminance (1300 cd/$m^2$ ) for 100nm of PECVD $SiN_x$/30nm of ALD $AlO_x$ coated plastic OLED device was 260 hours.

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Preparation of Al2O3 Thin Films by Atomic Layer Deposition Using Dimethylaluminum Isopropoxide and Water and Their Reaction Mechanisms

  • An, Ki-Seok;Cho, Won-Tae;Sung, Ki-Whan;Lee, Sun-Sook;Kim, Yun-Soo
    • Bulletin of the Korean Chemical Society
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    • v.24 no.11
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    • pp.1659-1663
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    • 2003
  • $Al_2O_3$ thin films were grown on H-terminated Si(001) substrates using dimethylaluminum isopropoxide [DMAl: $(CH_3)_2AlOCH(CH_3)_2$], as a new Al precursor, and water by atomic layer deposition (ALD). The selflimiting ALD process by alternate surface reactions of DMAI and $H_2O$ was confirmed from measured thicknesses of the aluminum oxide films as functions of the DMAI pulse time and the number of DMAI-$H_2O$ cycles. Under optimal reaction conditions, a growth rate of ~1.06 ${\AA}$ per ALD cycle was achieved at the substrate temperature of $150\;^{\circ}C$. From a mass spectrometric study of the DMAI-$D_2O$ ALD process, it was determined that the overall binary reaction for the deposition of $Al_2O_3\;[2\;(CH_3)_2AlOCH(CH_3)_2\;+\;3\;H_2O\;{\rightarrow}\;Al_2O_3\;+\;4\;CH_4\;+\;2\;HOCH(CH_3)_2]$can be separated into the following two half-reactions: where the asterisks designate the surface species. Growth of stoichiometric $Al_2O_3$ thin films with carbon incorporation less than 1.5 atomic % was confirmed by depth profiling Auger electron spectroscopy. Atomic force microscopy images show atomically flat and uniform surfaces. X-ray photoelectron spectroscopy and cross-sectional high resolution transmission electron microscopy of an $Al_2O_3$ film indicate that there is no distinguishable interfacial Si oxide layer except that a very thin layer of aluminum silicate may have been formed between the $Al_2O_3$ film and the Si substrate. C-V measurements of an $Al_2O_3$ film showed capacitance values comparable to previously reported values.

Structural and electrical properties of ZnO:Al, In thin film (ZnO:Al,In 박막의 구조적 및 전기적 특성)

  • 박경일;서무룡;홍범표;김정규;전춘배;박기철
    • Proceedings of the IEEK Conference
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    • 1998.06a
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    • pp.395-397
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    • 1998
  • NH$_{3}$ gas sensitive ZnO:Al, In thin films were prepared by the heat treatment following continuous deposition of very thin In layer and ZnO:Al layer to obtain the modified surface morphology for good sensitivity. Dependence of the structural electrical and optical properties of them on heat treatment temperature was investigated by x-ray diffraction, SEM, 4-point probe method and spectrophotometer.

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