Abstract: An atomic layer deposition (ALD) method is utilized to deposit a thin film barrier layer of a metal oxide, such as titanium dioxide, onto a substrate. Excellent barrier layer properties can be achieved when the titanium oxide barrier is deposited by ALD at temperatures below approximately 100° C. Barriers less than 100 angstroms thick and having a water vapor transmission rate of less than approximately 0.01 grams/m2/day are disclosed, as are methods of manufacturing such barriers.