(387c) A Theoretical Model Based on a Group Contribution Method to Describe Atomic Layer Deposition of Zirconia on Silicon
AIChE Annual Meeting
Tuesday, November 12, 2019 - 4:06pm to 4:24pm
A model characterizing the growth of the deposited metal oxide on the substrate with increasing number of ALD cycles was proposed in the study using adsorbate solid solution theory (ASST). Experimental data were obtained from atomic layer deposition of zirconia on silicon (100) substrates using a custom-made ALD system (Patent #10214817) and a commercial ALD system (Model ALD150-LE, Kurt J. Lesker Co.). Multiple ALD depositions, involving ZyALD or TDMAZ as the metal precursor and oxygen/ozone or ethanol as the oxidizer/co-reactant were carried out. The interaction of precursor components with the substrate was estimated according to the Universal Quasi-chemical Functional-group Activity Coefficient Group Contribution Method (UNIFAC GCM) applying ASST and a theoretical growth rate was calculated for each experimental precursor pulse using an optimization algorithm. The growth rate of the deposited material over varying precursor pulse time should reach a plateau after a certain number of pulses displaying saturation of the substrate surface with the metal precursor and the plot is a characteristic feature of any ALD reaction. The model predicts the theoretical growth rate based on the calculated interaction parameters and compares it with the experimental growth rate which may help to identify a potential ALD window or to provide suggestions to rectify the recipe. Additionally, with sufficient information, a data bank can be formed that can be used to predict the outcome of an ALD reaction. Also, it can provide insights for formation of a new precursor or modification of the existing ones.