A Water-free Low Temperature Process for Atomic Layer Deposition of Al2O3 Films

Authors

  • Jiao-Jiao Guo,

    1. State Key Laboratory of ASIC and System, Department of Microelectronics, Fudan University, Shanghai 200433 (China)
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  • Ming-Da Li,

    1. State Key Laboratory of ASIC and System, Department of Microelectronics, Fudan University, Shanghai 200433 (China)
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  • Qing-Qing Sun,

    Corresponding author
    1. State Key Laboratory of ASIC and System, Department of Microelectronics, Fudan University, Shanghai 200433 (China)
    • State Key Laboratory of ASIC and System, Department of Microelectronics, Fudan University, Shanghai 200433 (China)
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  • Wen Yang,

    1. State Key Laboratory of ASIC and System, Department of Microelectronics, Fudan University, Shanghai 200433 (China)
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  • Peng Zhou,

    1. State Key Laboratory of ASIC and System, Department of Microelectronics, Fudan University, Shanghai 200433 (China)
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  • Shi-Jin Ding,

    Corresponding author
    1. State Key Laboratory of ASIC and System, Department of Microelectronics, Fudan University, Shanghai 200433 (China)
    • State Key Laboratory of ASIC and System, Department of Microelectronics, Fudan University, Shanghai 200433 (China)
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  • David Wei Zhang

    1. State Key Laboratory of ASIC and System, Department of Microelectronics, Fudan University, Shanghai 200433 (China)
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  • The work was supported by NSFC (61076114, 61106108 and 51172046), Shanghai Educational Develop Foundation (10CG04), SRFDP (20100071120027), the Fundamental Research Funds for the Central Universities and the S&T Committee of Shanghai (10520704200).

Abstract

A new low temperature atomic layer deposition (LT-ALD) Al2O3 process using trimethylaluminum (TMA) and acetic acid (CH3COOH) is studied both theoretically and experimentally. The atomistic mechanisms of the two deposition half-cycles on Al-CH3*, Al-OH*, and Al(η2-O2CCH3)* are investigated using density functional theory (DFT). The experimental demonstrations are performed on Si substrates over the growth temperature range 75–400°C. Consistent with the DFT simulation, lower linear growth rate and shorter required oxidant purge times are observed at 90°C, when compared to LT-ALD Al2O3 using H2O as the oxidant. The chemical characteristics of the Al2O3 films grown with both CH3COOH at 90°C and H2O at 100°C are determined and compared using X-ray photoelectron spectroscopy (XPS).

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