Tyndall National Institute, University College Cork, Dyke Parade, Cork, Ireland.
ACS Appl Mater Interfaces. 2013 May;5(9):3704-15. doi: 10.1021/am400310p. Epub 2013 Apr 16.
The surface reactivity of various metal precursors with different alkoxide, amide, and alkyl ligands during the atomic layer deposition (ALD) of ternary oxides was determined using simplified theoretical models. Quantum chemical estimations of the Brønsted reactivity of a metal complex precursor at a hydroxylated surface are made using a gas-phase hydrolysis model. The geometry optimized structures and energies for a large suite of 17 metal precursors (including cations of Mg, Ca, Sr, Sc, Y, La, Ti, Zr, Cr, Mn, Fe, Co, Ni, Cu, Zn, Al, and Ga) with five different anionic ligands (conjugate bases of tert-butanol, tetramethyl heptanedione, dimethyl amine, isopropyl amidine, and methane) and the corresponding hydrolyzed complexes are calculated using density functional theory (DFT) methods. The theoretically computed energies are used to determine the energetics of the model reactions. These DFT models of hydrolysis are used to successfully explain the reactivity and resulting stoichiometry in terms of metal cation ratios seen experimentally for a variety of ALD-grown ternary oxide systems.
使用简化的理论模型确定了不同烷氧基、酰胺和烷基配体的各种金属前体在三元氧化物原子层沉积（ALD）过程中的表面反应性。使用气相水解模型对金属络合物前体在羟基化表面上的 Brønsted 反应性进行了量子化学估算。使用密度泛函理论（DFT）方法计算了具有五种不同阴离子配体（叔丁醇、四甲基庚二酮、二甲基胺、异丙基脒和甲烷的共轭碱）的 17 种金属前体（包括 Mg、Ca、Sr、Sc、Y、La、Ti、Zr、Cr、Mn、Fe、Co、Ni、Cu、Zn、Al 和 Ga 的阳离子）及其相应水解配合物的大量套件的优化结构和能量。理论计算的能量用于确定模型反应的能量学。这些水解的 DFT 模型成功地解释了各种 ALD 生长的三元氧化物系统中实验观察到的金属阳离子比的反应性和由此产生的化学计量比。
