Title: | Ce(IV) complexes with donor-functionalized alkoxide ligands: improved precursors for chemical vapor deposition of CeO2 |
Author(s): | Aspinall HC; Bacsa J; Jones AC; Wrench JS; Black K; Chalker PR; King PJ; Marshall P; Werner M; Davies HO; Odedra R; |
Address: | "Department of Chemistry, Donnan and Robert Robinson Laboratories, University of Liverpool, Crown Street, Liverpool, L69 7ZD, UK. hca@liv.ac.uk" |
ISSN/ISBN: | 1520-510X (Electronic) 0020-1669 (Linking) |
Abstract: | "Thin films of ceria (CeO(2)) have many applications, and their synthesis by liquid-injection MOCVD (metal-organic chemical vapor deposition) or ALD (atomic layer deposition) requires volatile precursor compounds. Here we report the synthesis of a series of homoleptic and heteroleptic Ce(IV) complexes with donor-functionalized alkoxide ligands mmp (1-methoxy-2-methylpropan-2-olate), dmap (1-(dimethylamino)propan-2-olate), and dmop (2-(4,4-dimethyl-4,5-dihydrooxazol-2-yl)propan-2-olate) and their potential as precursors for MOCVD and ALD of CeO(2). New complexes were synthesized by alcohol exchange reactions with [Ce(OBu(t))(4)]. [Ce(mmp)(4)] and [Ce(dmap)(4)] were both found to be excellent precursors for liquid-injection MOCVD of CeO(2), depositing high purity thin films with very low carbon contamination, and both have a large temperature window for diffusion controlled growth (350-600 degrees C for [Ce(mmp)(4)]; 300-600 degrees C for [Ce(dmap)(4)]). [Ce(mmp)(4)] is also an excellent precursor for liquid-injection ALD of CeO(2) using H(2)O as oxygen source and demonstrates self-limiting growth from 150 to 350 degrees C. [Ce(dmap)(4)] has lower thermal stability than [Ce(mmp)(4)] and does not show self-limiting growth in ALD. Heteroleptic complexes show a tendency to undergo ligand redistribution reactions to form mixtures in solution and are unsuitable as precursors for liquid-injection CVD" |
Notes: | "PubMed-not-MEDLINEAspinall, Helen C Bacsa, John Jones, Anthony C Wrench, Jacqueline S Black, Kate Chalker, Paul R King, Peter J Marshall, Paul Werner, Matthew Davies, Hywel O Odedra, Rajesh eng 2011/10/25 Inorg Chem. 2011 Nov 21; 50(22):11644-52. doi: 10.1021/ic201593s. Epub 2011 Oct 21" |