Reaction Chemistry during the Atomic Layer Deposition of Sc2O3 and Gd2O3 from Sc(MeCp)3, Gd(iPrCp)3, and H2O

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• 作者：Jeong Hwan Han ; Laura Nyns ; Annelies Delabie ; Alexis Franquet ; Sven Van Elshocht ; Christoph Adelmann
• 刊名：Chemistry of Materials
• 出版年：2014
• 出版时间：February 11, 2014
• 年：2014
• 卷：26
• 期：3
• 页码：1404-1412
• 全文大小：460K
• ISSN：1520-5002

文摘

The reaction chemistry during the atomic layer deposition (ALD) of Sc₂O₃ and Gd₂O₃ from Sc(MeCp)₃, Gd(ⁱPrCp)₃, and H₂O was investigated by in situ time-resolved quadrupole mass spectrometry. Despite the similarity of the ligands of the Sc and Gd precursors, the growth characteristics and ligand dissociation patterns of the Sc₂O₃ and Gd₂O₃ ALD processes showed considerably different behavior. For both processes, the precursors reacted with the hydroxylated surface by proton transfer and release of the protonated ligand. The remaining ligands were then removed by hydrolysis during the H₂O pulse. However, for the Sc(MeCp)₃/H₂O process, 56% of MeCpH was released during the Sc(MeCp)₃ exposure, whereas in the case of the Gd(ⁱPrCp)₃/H₂O process, as much as 90% of ⁱPrCpH was released during the Gd(ⁱPrCp)₃ pulse. The observation that almost all ⁱPrCp ligands were removed during the initial Gd(ⁱPrCp)₃ absorption step can be ascribed to CVD-like reactions between the Gd(ⁱPrCp)₃ precursor and excess hydroxide or physisorbed H₂O on the hygroscopic Gd₂O₃ surface. The influence of the growth temperature on the ligand exchange behavior and the resulting film properties (thickness uniformity, impurity concentration) was studied in the temperature range between 200 and 350 掳C. In addition, the transient growth behavior of Gd₂O₃ on Sc₂O₃ and vice versa was studied, indicating that the hygroscopic nature of Gd₂O₃ also strongly influences the deposition of Gd_xSc_1鈥?i>xO₃ ternary oxides.