Novel precursors for the growth of TiO2 by liquid injection MOCVD

Clarke, CL

Abstract

A comprehensive examination of the feasibility of producing new titania precursors by
ligand substitution reactions involving the reaction between titanium tetra-isopropoxide
and various dimethylamino alcohols has resulted in the synthesis, characterization and
application of five new titanium dioxide thin film precursors, titanium
tetra(dimethylaminopropan-l-ol) (Ti(DMAP1 )4), titanium tetra(dimethylaminopropan-
2-ol) (Ti(DMAP2)4), titanium isopropoxide tri(dimethylaminoethanol)
(Ti(OPr')(DMAE)3), titanium tri-isopropoxide dimethylaminopropan-1-ol
(Ti(OPr')3(DMAP')) and titanium tri-isopropoxide dimethylaminopropan-2-ol
(Ti(OPri)3(DMAP2)). The new compounds have been characterized by *H and 13C
NMR spectroscopy, mass spectrometry, infrared spectroscopy and thermogravimetric
analysis (TGA).
The precursors were tested for their ability to produce TiOa films on un-doped silicon
and glass substrates by Liquid Injection Metal Organic Chemical Vapor Deposition.
The effects of varying a wide range of deposition conditions has been studied using in
situ monitoring by interferometry and ex-situ analysis using X-ray diffraction (XRD),
scanning electron microscopy (SEM) and Rutherford back scattering (RBS).
Data resulting from the use of the new precursors has been compared to that obtained
using the current industry standard precursor, titanium tetra-isopropoxide (TTIP). It is
demonstrated that the new precursors are potentially easier to handle than TTIP as a
result of the internal coordination to the Ti centre via the N atoms in the replacement
ligands, while all of the precursors studied are able to produce TiC>2 films. Comparisons
are made between the precursors in terms of placing them in a rank order based upon
ease of use and ability to produce TiC>2 films. Additionally, to demonstrate the
applicability of these precursors, films of the mixed metal oxide strontium barium
titanate have been grown and characterised.

Citation

Clarke, C. Novel precursors for the growth of TiO2 by liquid injection MOCVD. (Thesis). Salford : University of Salford

• Thesis Type: Thesis
• Deposit Date: Oct 3, 2012
• Award Date: Jan 1, 2009