The research leading to these results has received funding from the European Community's Seventh Framework Programme (FP7/2007-2013) under grant agreement number ENHANCE-23840. The research has also been supported by the Finnish Centre of Excellence in Atomic Layer Deposition.
Atomic Layer Deposition of Groups 4 and 5 Transition Metal Oxide Thin Films: Focus on Heteroleptic Precursors†
Article first published online: 20 JUL 2014
© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Chemical Vapor Deposition
Special Issue: Atomic-Scale-Engineered Materials (ASEM)
Volume 20, Issue 7-8-9, pages 189–208, September 2014
How to Cite
Blanquart, T., Niinistö, J., Ritala, M. and Leskelä, M. (2014), Atomic Layer Deposition of Groups 4 and 5 Transition Metal Oxide Thin Films: Focus on Heteroleptic Precursors. Chem. Vap. Deposition, 20: 189–208. doi: 10.1002/cvde.201400055
- Issue published online: 10 SEP 2014
- Article first published online: 20 JUL 2014
- Manuscript Revised: 28 MAY 2014
- Manuscript Received: 9 DEC 2013
- Group 4 and 5 metal oxides;
- Thin films
The atomic layer deposition (ALD) process, an alternative to CVD, is universally appreciated for its unique advantages such as excellent repeatability, conformity, and thickness control at the atomic level. ALD precursor chemistry has mainly been based on homoleptic compounds such as, but not limited to, metal halides, alkylamides, and alkoxides, however these precursors have drawbacks such as possible halide contamination and low thermal stabilities in the case of the alkylamides and alkoxides. Consequently, heteroleptic precursors have been investigated as alternatives to the existing homoleptic counterparts, leading to the development of several advantageous processes. Nevertheless, there is no thematic review dedicated to the heteroleptic precursors and their properties, and it seems that no coherent strategy has been adopted for the development of heteroleptic precursors. This review gives a brief description of ALD and presents studies on the deposition of thin films of groups 4 and 5 metal oxides using ALD. A description of the general ALD properties of homoleptic precursors, in addition to a review on the thermal ALD of groups 4 and 5 metal oxides from heteroleptic precursors, is provided. Trends in the properties of heteroleptic ALD precursors, based on the literature review and recent experimental data, are discussed.