Title
Understanding cominatorial atomic layer deposition and chemical vapor deposition.
Abstract
The transformation of molecular precursor to solid film begins with an
understanding of molecular structure, proceeds through delivery of the molecule to the
surface and ends with the decomposition of precursor on the surface to form a deposit.
An understanding of the physical and chemical processes leading from molecule to film
enables the utilization of chemical precursors in effective deposition processes.
Single crystal X-ray crystallography was used to study the structure of
[NO]0.5[NO2]0.5[Zr(NO3)5] and [NO]0.5[NO2]0.5[Hf(NO3)5]. Infrared spectroscopy was
employed to identify the nature of the cation in the crystal structure, and characteristic
absorptions of both nitronium and nitrosonium cations were observed.
Fluidized bed reactor technology has been used to study the sublimation behavior
of solid-state chemicals. Fluidization behavior, precursor mass transfer rates and delivery
uniformity for aluminum trichloride were studied and the results reported.
Mixed metal oxide nanolaminate films of hafnium oxide and zirconium oxide
interspersed with layers of silicon oxide have been deposited on silicon substrates by a
combinatorial atomic layer deposition (ALD) technique. Exposure of repeated cycles of
co-dosed alkoxide precursors Hf[OC(CH3)3]4 and Zr[OC(CH3)3]4 with counter-reactant
pulses of Si[OC(CH3)3]3(OH) formed films of uniform thickness (±5%) and uniform
silicon oxide concentration (85% per total metals basis). The hafnium and zirconium
concentrations exhibited smooth gradation across the film from 18% - 82% (per Hf and
Zr metals basis). Self-limiting deposition rates of 1.5 nm / cycle were measured, and a
linear relationship of film thickness to number of deposition cycles was observed, both
consistent with a true ALD process. Rutherford backscattering spectrometry,
ellipsometry and X-ray reflectivity results were used to map the composition and
determine the film microstructure.
Single precursor depositions have been performed and compared to computational
models created using CFD-ACE in order to further the understanding of the interaction of
fluid dynamics and chemistry in the combinatorial chemical vapor deposition process.
The physical and chemical processes contributing to film growth in combinatorial
chemical vapor deposition were evaluated.
Description
University of Minnesota Ph.D. dissertation. January 2009. Major: Chemistry. Advisor: Wayne L. Gladfelter. 1 computer file (PDF); viii, 102 pages, appendices I-IV. Ill. (some col.)
Suggested Citation
Moersch, Tyler Leighton.
(2009).
Understanding cominatorial atomic layer deposition and chemical vapor deposition..
Retrieved from the University of Minnesota Digital Conservancy,
https://hdl.handle.net/11299/48025.