Theoretical study of reaction mechanisms of ZrCl4 with hydrated and hydroxlated Si(1 0 0) surfaces

This paper investigates the reaction of ZrCl4 with Si(1 0 0) substrates as found during the early stages of atomic layer deposition (ALD) of ZrO2. Hydrated and hydroxlated are studied in order to understand any deterioration of the Si–ZrO2 interface due to formation of SiO2. Particularly, a synchronous transit method combined with density functional theory is used to locate transition states of these reactions. The simulation results show that ZrCl4 preferentially reacts at OH groups present of the substrate, whereas reactions at hydrated substrates is energetically clearly disfavored.