Analytical model for island growth mode in thin film deposition
Year: 2026
Type: article
Abstract: An analytical model for 3D island growth in Atomic Layer Deposition (ALD) was derived from geometric and statistical principles. The model accounts for a random island distribution and spontaneous nucleation. A spherical dome shape of islands is assumed, at a specified contact angle with the substrate. The model can be extended to alternative island shapes or processes beyond ALD, including chemical- or physical vapor deposition. Owing to the analytical nature of the model, an influence of process parameters is transparent and evaluation is instantaneous. The model was validated with a Monte Carlo simulation. The latter illustrated the deposit morphology at distinct growth stages: an island nucleation, an onset of coalescence, a peak mass gain per cycle and a convergence to a continuous film. The model can fit any experimentally measured signals in- or ex-situ relating to mass uptake or surface roughness during the nucleation process. The model fit to literature data of deposited mass upon island growth of Pt on Al2O3 and ZnO2 crystals showcased the insights that the model gives, such as estimation of island nucleation density and spontaneous island nucleation rate. If the model diverges from experimental data, it hints at additional phenomena that might govern the process, on top of the island growth. The model serves as a valuable tool to guide process design and optimization, whether the goal is to obtain specific nanoparticle morphologies, as for fields of catalysis or optics, or thin continuous films, for areas of semiconductor and coating technologies.
Source: Acta Materialia
Authors: Wojciech Szmyt, Ivo Utke
Language: English
Subfield: Electrical and Electronic Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $3,700
OpenAlex ID: W7130311989