The role of abnormal grain growth on solid-state dewetting kinetics

Abstract

Continuous thin films of Pt on A-plane 1 1 2 0 À Á sapphire substrates were dewetted to characterize the morphological evolution and dewetting kinetics at 800°C using an oxygen partial pressure of 10 À20 atm. Hole growth was studied, focusing on partially dewetted samples. Four different low-index orientation relationships were found between the Pt and sapphire substrate by electron backscattered diffraction combined with transmission electron diffraction patterns. Abnormal grains adjacent to the holes with a small deviation from one of the low-index orientation relationships were observed. The difference in the heights of the abnormal grains adjacent to the holes (rim-height) is influenced by the initial position of the hole, and the existence of grains with a low-energy interface orientation relationship, and not only by diffusivity rates dictated by surface orientation as described in existing edge-retraction models. The existence of low-index orientation relationships is seen as the driving force for abnormal grain growth in the vicinity of the holes, and is a dominant factor in controlling the dewetting rate of thin metal films on oxide surfaces.

The process of solid-state dewetting of Au thin films studied by in situ scanning transmission electron microscopy

“…Similar observations have been made by Tesler et al [51] on discontinuous Au films interpreting it as the onset of abnormal grain growth. The importance of grain growth prior to dewetting has also been remarked by Luber et al [50] studying Ni thin films on SiO 2 and in a recent work, Atiya et al [66] found the dewetting of Pt thin films on sapphire even to be dominated by abnormal grain growth. The initial transformation cannot be further discussed on the basis of the performed experiments, as it is temporally not resolved and occurs during the heating ramp.…”

Texture evolution and microstructural changes during solid-state dewetting: A correlative study by complementary in situ TEM techniques

“…Tesler et al [32] observed a dependence on the initial film thickness of Au thin films dewetting on glass substrates. Most recently Atiya et al [35] have elucidated the role of abnormal grain growth during dewetting of Pt thin films on a sapphire substrate. They observed abnormal grain growth of preferentially oriented grains, as soon as they are in contact with the retracting edge of a growing void.…”

Periodic Arrays of Diamond‐Shaped Silver Nanoparticles: From Scalable Fabrication by Template‐Assisted Solid‐State Dewetting to Tunable Optical Properties

“…Due to confinement at the surface of the substrate, both diffusion on the free surface of the film and at the interface with the substrate can participate in the process. Mechanisms and kinetics of dewetting depend on the nature of both film and substrate (crystalline or amorphous) as well as on the annealing atmosphere; they have been studied in particular for films of the platinum group and of noble metals . Yet, in the case of complex polycrystalline films on amorphous flat substrates, recent studies using various in situ and real‐time measurement imaging techniques have shed light on the major role played by grains in the kinetics of dewetting and in the evolution of the coverage/density of objects and holes .…”