Quantification of Water Impurity in an Atomic Layer Deposition Reactor Using Group Contribution Method

Atomic Layer Deposition (ALD) is a vapor phase process to deposit thin films using precursors and co-reactants on a variety of substrates. The ALD system, the data of which is used here, had aimed to deposit TiO2 thin films on polymethyl methacrylate (PMMA) and silicon reference substrates using tetrakis(dimethylamido)titanium and ozone. Absorbed water molecules in PMMA were released into the reactor during deposition, acted as a co-reactant, and affected the growth rate on the silicon reference substrate. The objective of this work is to theoretically calculate the amount of water impurities in the ALD reactor during several number of cycles. A group contribution method based on Adsorbate Solid Solution Theory (ASST) is employed to theoretically estimate the number of moles of water in the above-mentioned ALD reactor.