"Chemical Effects in Multiphase Thin Film Growth" 

Ying-Cheng Chen, MSE PhD Candidate 

Advisor: Professor Anter El-Azab

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ABSTRACT

Thin films are utilized in applications such as coatings, electronic devices, and catalysis. The mechanical and electrical properties of single-phase thin films can be tailored by adjusting grain size and dislocation density. In contrast, multiphase thin films offer additional variables, including compositional ratio and lattice mismatch between phases, enabling further property manipulation. The optimal method for producing desired multiphase thin films is often established through iterative experimentation. Advancements in computational power and algorithms now enable theoretical modeling to enhance the understanding of the micro- and mesoscopic mechanisms underlying macroscopic properties and morphologies. This research aims to find a solution to consider the binding and transition of different configurations of deposited molecules, known as chemical effects, on the substrate during multiphase thin film growth modeling. Since the morphology of the multiphase thin film is controlled by the strain between different phases, the strain susceptibility of the binding and transition of molecules during the thin film growth is expected to play a crucial role in modeling the multiphase thin film growth as close to reality as possible. The structure of the content is organized as follows: Section 1 reviews thin film growth phenomena, covering experimental approaches, vertically aligned nanocomposite thin films, and growth modelling; Section 2 addresses kinetic Monte Carlo (KMC) simulations of thin film growth; Section 3 discusses density functional theory (DFT) parameterization in KMC simulations; Section 4 examines strain effects in thin film growth; Section 5 presents conclusions; Section 6 shares preliminary research results; and Section 7 outlines future work.