Influence of Interactions between Adsorbate and Substrate on the Statistical Properties of Surface Structures at Condensation

We investigate the effects of elastic adsorbate-substrate interactions on the kinetics of nano-structuring of thin films during condensation and statistical properties of the surface structures in the framework of theoretical approaches and numerical simulations. We derive the reaction-diffusion model for the spatiotemporal evolution of the adsorbate concentration on the substrate by taking into account adsorption, de-sorption, transferring of adatoms between neighbor layers, adsorbate-substrate and adsorbate-adsorbate interactions and lateral diffusion. By exploiting stability analysis of the stationary homogeneous states to in-homogeneous perturbations we have shown that an increase in the elastic adsorbate-substrate interaction strength induces formation of stable adsorbate structures on the substrate under low-pressure condensation. We perform numerical simulations of the processes of adsorbate structures formation during deposition with varying adsorbate-substrate interaction strengths. It is found that an increase in the strength of elastic ad-sorbate-substrate interactions accelerates processes of adsorbate self-organization into stable clusters and leads to the formation of larger number of adsorbate islands with elevated sizes. It is shown that in the stationary regime the distribution of stable adsorbate islands over sizes remains universal for different values of the elastic interaction strength between adsorbate and substrate. This study provides valuable insights into the mechanisms governing nano-structured thin film growth in low-pressure systems with varying elastic adsorbate-substrate bonding strengths by depositing different materials onto different substrates.