Self-limiting Growth of Metal Oxides by Pulsed PECVD 

Atomic layer deposition (ALD) has become the gold standard for thin film growth. The process imparts digital control over film thickness, high quality and excellent conformality. Its primary drawback is the low deposition rate, which precludes its use for a number of applications. The Wolden group has pioneered the use of pulsed plasma-enhanced chemical vapor deposition (PECVD) as an alternative approach for self-limiting growth, i.e. 1 Å/pulse. growth behavior. With appropriate reactor design and operation deposition rates of 10-30 nm/min have been obtained, which will allow us to extend the atomic scale control of ALD to mesocale structure ( 50 -500 nm). The goals of this project are twofold. First, we want to develop an improved  understanding of the deposition chemistry through a combination of extensive diagnostics and detailed modeling. Having established the process for a number of oxides (Ta₂O₅, Al₂O₃, ZnO, TiO₂, SiO₂), PhD candidate Pieter Rowlette is now exploring mixed metal oxides with controlled composition.   Combined BS/MS candidate Nick Kubala has developed the pulsed PECVD process for titania synthesis, and is exploring its potential for application in optics, as a high perfrormance dielectric, and for  hybrid organic/inorganic photoelectrochemistry devices.  Undergraduates Amy Dubetz and Rambert Nahm and  provide extensive support in terms of thin film characterization.

Support for this project is being provided by the National Science Foundation's Chemical, Bioengineering, Environmental, and Transport Systems (CBET) organization through award #0626226  and an associated REU supplements.