Height transitions, shape evolution, and coarsening of equilibrating quantum nanoislands

TL;DR

This paper models the evolution and coarsening of metal nanoislands considering quantum effects, surface energy anisotropy, and stress, revealing how film height influences morphology and coarsening behavior.

Contribution

It introduces a comprehensive surface diffusion model that incorporates quantum confinement, charge spillage, and anisotropic surface energy to study nanoisland morphology evolution.

Findings

Large islands with flat tops and steep edges are favored under certain conditions.

Film height significantly affects coarsening dynamics and final shapes.

Conditions for interrupted coarsening are identified.

Abstract

Morphology evolution and coarsening of metal nanoislands is computed within the framework of a surface diffusion-type model that includes the effects of the electron energy confinement within the film, the charge spillage at the film/substrate interface, the energy anisotropy of the film surface and the surface stress. The conditions that result in large islands with flat tops, steep edges, and strongly preferred heights are determined. A strong influence of the film height on the coarsening dynamics and final morphologies is found; the conditions leading to interrupted coarsening are highlighted. The dependence of the geometric parameters of the equilibrium island on the film height and on the island initial volume is computed.