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

## TL;DR

Researchers developed a new cerium complex for depositing CeO2 films using atomic layer deposition, showing promising results for potential applications.

## Contribution

A novel heteroleptic Ce(III) complex was synthesized and tested as an effective ALD precursor for CeO2 film deposition.

## Key findings

- Complex 2 (Ce(thd)3-MEDA) was identified as a potential ALD precursor for CeO2 film deposition.
- Nitrogen-containing bidentate ligands showed stronger complexing ability with cerium ions compared to mixed ligands.
- Self-limited deposition was successfully demonstrated on SiO2/Si (100) wafers using complex 2.

## Abstract

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.