MOCVD生长ZnO薄膜的气相寄生反应路径研究

摘要/Abstract

摘要： 本文利用量子化学的密度泛函理论(DFT),研究了金属有机化学气相沉积(MOCVD)生长ZnO薄膜过程中二乙基锌(DEZn)与叔丁醇(t-BuOH)体系的气相寄生反应机理。通过计算不同温度下反应路径的Gibbs自由能变化,从热力学角度详细分析关键中间产物(HOZnOBu^t、H(ZnO)₂Bu^t、HZnOH)的水解及二聚物(Zn₂O₂H₄、Zn₂O₄H₄、Zn₄O₄H₄)、三聚物(Zn₃O₆H₆)的形成,揭示不利于ZnO薄膜生长的纳米颗粒可能的形成路径和产物。研究发现在高温沉积条件下(673.15 K＜T＜713.15 K),DEZn热解后的中间产物H(ZnO)₂Bu^t容易与H₂O发生双分子碰撞直接生成有利于ZnO薄膜生长的(ZnOH)₂。但是这类中间产物同时会通过聚合消去反应形成二聚物和三聚物,这些聚合物是形成纳米颗粒的重要前体,其中由HOZnOBu^t聚合产生的聚合物(HOZnOBu^t)₂连续脱去C₄H₈,并最终形成Zn₂O₄H₄的反应最容易发生。因此,二聚物Zn₂O₄H₄是最有可能提供纳米颗粒的重要前体。

关键词: 氧化锌, 金属有机化学气相沉积, 密度泛函理论, 寄生反应, 薄膜, 二聚物

Abstract: This study utilized density functional theory (DFT) in quantum chemistry to investigate the gas-phase parasitic reaction mechanism between diethylzinc (DEZn) and tert-butanol (t-BuOH) during the metal-organic chemical vapor deposition (MOCVD) growth process of ZnO thin films. By calculating the Gibbs free energy changes along various reaction pathways at different temperatures, a comprehensive thermodynamic evaluation of key intermediates (HOZnOBu^t, H(ZnO)₂Bu^t, HZnOH), as well as the formation of dimers (Zn₂O₂H₄, Zn₂O₄H₄, Zn₄O₄H₄), and trimers (Zn₃O₆H₆) was performed. The main objective was to identify potential pathways and products that could lead to the formation of nanoparticles, which might impede ZnO thin film growth. Research has shown that under high-temperature deposition conditions (673.15 K<T<713.15 K), the intermediate product H(ZnO)₂Bu^t resulting from the thermal decomposition of DEZn readily reacts with H₂O to form (ZnOH)₂, supporting ZnO thin film growth. However, these intermediates can also undergo polymerization elimination reactions to generate dimers and trimers, serving as crucial precursors for nanoparticle formation. Notably, the most favorable pathway involved the formation of Zn₂O₄H₄ through the polymerization of (HOZnOBu^t)₂ followed by the elimination of C₄H₈. Therefore, the dimer Zn₂O₄H₄ emerged as a crucial precursor for nanoparticle formation.

Key words: ZnO, metal organic chemical vapor deposition, density functional theory, parasitic reaction, thin film, dimer

中图分类号:

TN304
O469

吴蕊, 胡洋, 唐荣芬, 阳倩, 王序, 吴怡逸, 聂登攀, 王环江. MOCVD生长ZnO薄膜的气相寄生反应路径研究[J]. 人工晶体学报, 2024, 53(9): 1608-1619.

WU Rui, HU Yang, TANG Rongfen, YANG Qian, WANG Xu, WU Yiyi, NIE Dengpan, WANG Huanjiang. Study of Gas-Phase Parasitic Reaction Pathways for ZnO Thin Film Grown by MOCVD[J]. JOURNAL OF SYNTHETIC CRYSTALS, 2024, 53(9): 1608-1619.

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