MOCVD生长ZnO薄膜的气相寄生反应路径研究  

Study of Gas-Phase Parasitic Reaction Pathways for ZnO Thin Film Grown by MOCVD

作　　者：吴蕊 胡洋 唐荣芬 阳倩 王序 吴怡逸 聂登攀 王环江 WU Rui;HU Yang;TANG Rongfen;YANG Qian;WANG Xu;WU Yiyi;NIE Dengpan;WANG Huanjiang(College of Chemical Engineering,Guizhou Minzu University,Guiyang 550025,China)

机构地区：[1]贵州民族大学化学工程学院,贵阳550025

出　　处：《人工晶体学报》2024年第9期1608-1619,共12页Journal of Synthetic Crystals

基　　金：国家自然科学基金(22262008);贵州省基础研究计划(自然科学)(ZK[2021]051);贵州省科技计划项目([2020]4Y014,[2020]1Y406,[2021]YB484,[2023]YB349);贵州省科学协会专题和研究课题(YZ2023001);贵州省教育厅自然科学研究项目(QJJ[2022]159)。

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(HOZnOBut、H(ZnO)_(2)But、HZnOH)的水解及二聚物(Zn_(2)O_(2)H_(4)、Zn_(2)O_(4)H_(4)、Zn_(4)O_(4)H_(4))、三聚物(Zn_(3)O_(6)H_(6))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)_(2)But容易与H_(2)O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HOZnOBut聚合产生的聚合物(HOZnOBut)2连续脱去C4 H8,并最终形成Zn_(2)O_(4)H_(4)的反应最容易发生。因此,二聚物Zn_(2)O_(4)H_(4)是最有可能提供纳米颗粒的重要前体。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(HOZnOBut,H(ZnO)_(2)But,HZnOH),as well as the formation of dimers(Zn_(2)O_(2)H_(4),Zn_(2)O_(4)H_(4),Zn_(4)O_(4)H_(4)),and trimers(Zn_(3)O_(6)H_(6))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)_(2)But resulting from the thermal decomposition of DEZn readily reacts with H_(2)O 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 Zn_(2)O_(4)H_(4)through the polymerization of(HOZnOBut)_(2)followed by the elimination of C_(4)H_(8).Therefore,the dimer Zn_(2)O_(4)H_(4)emerged as a crucial precursor for nanoparticle formation.

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 

分 类 号：TN304[电子电信—物理电子学] O469[理学—凝聚态物理]