Atomic Layer Deposition of CeO₂ Film with a Novel Heteroleptic Ce(III) Complex

In this paper, four heteroleptic Ce(III) complexes, including Ce(thd)₃-phen (thd = 2,2,6,6-tetramethyl-3,5-heptanedione, phen = 1, 10-phenanthroline (1), Ce(thd)₃-MEDA (MEDA = N-Methylethylenediamine (2), Ce(thd)₃-MOMA (MOMA = N-(2-Methoxyethyl)methylamine (3), and Ce(thd)₃-DMDE (DMDE = N,N″-dimethyl ethanol amine (4), were synthesized and characterized with ¹H-NMR, elemental analysis, and X-ray single-crystal diffraction. The thermogravimetric analysis and vapor pressure results indicated that the complexing ability of a nitrogen-containing bidentate ligand with a cerium ion was stronger than that of a mixed oxygen-nitrogen-containing bidentate ligand. Complex 2 was selected as an ALD precursor to deposit a CeO₂ film on a SiO₂/Si (100) wafer. The self-limited deposition results demonstrated that complex 2 was a potential ALD precursor.