This R&D Atomic Layer Deposition system can provide atomic layer-by-layer growth of ultra thin films. It is a computer controlled rack-sized system with a viscous flow ALD reactor, an enclosed design accommodating a large number of reactant inputs, and can load up to 8” substrates, with uniform heating to 500°C. It is currently used to deposit Al2O3 films. By changing the precursors, other films can be deposited.