Morphologies and kinetics of a dewetting ultrathin solid film

TL;DR

This study uses a geometric PDE model to analyze how ultrathin solid films dewet and form various morphologies around pinhole defects, influenced by anisotropic surface energy and substrate interactions.

Contribution

It introduces a numerical framework for understanding the dewetting kinetics and morphologies of ultrathin films with anisotropic surface energies and pinhole defects.

Findings

Pinhole evolution depends on initial size and substrate potential.

Films can rupture or reach quasi-equilibrium shapes.

Overhanging morphologies occur for deep, narrow pinholes.

Abstract

The surface evolution model based on geometric partial differential equation is used to numerically study the kinetics of dewetting and dynamic morphologies for the localized pinhole defect in the surface of the ultrathin solid film with the strongly anisotropic surface energy. Depending on parameters such as the initial depth and width of the pinole, the strength of the attractive substrate potential and the strength of the surface energy anisotropy, the pinhole may either extend to the substrate and thus rupture the film, or evolve to the quasiequilibrium shape while the rest of the film surface undergoes phase separation into a hill-and-valley structure followed by coarsening. Overhanging (non-graph) morphologies are possible for deep, narrow (slit-like) pinholes.