The thickness and temperature dependence of moisture permeation in highly defective (10–20at% hydrogen) Al2O3 thin films grown by atomic layer deposition onto polymer substrates, were measured. It was found that, when films were grown at a higher temperature or were thicker, regardless of the growth temperature, they were better moisture barriers. The threshold thickness for measurement-limited barrier performance was determined to be 7.5nm for growth at 100C, compared to 9.6nm at 50C. The permeability of these highly defective films was explained using a new model which related the moisture permeability to a critical density of defects and not to pinholes.

Permeation Measurements and Modeling of Highly Defective Al2O3 Thin Films Grown by Atomic Layer Deposition on Polymers. P.F.Carcia, R.S.McLean, M.H.Reilly: Applied Physics Letters, 2010, 97[22], 221901