Nanostructure Formation by controlled dewetting on patterned substrates: A combined theoretical, modeling and experimental study

Abstract

We perform systematic two-dimensional energetic analysis to study the stability of various nanostructures formed by dewetting solid films deposited on patterned substrates. Our analytical results show that by controlling system parameters such as the substrate surface pattern, film thickness and wetting angle, a variety of equilibrium nanostructures can be obtained. Phase diagrams are presented to show the complex relations between these system parameters and various nanostructure morphologies. We further carry out both phase field simulations and dewetting experiments to validate the analytically derived phase diagrams. Good agreements between the results from our energetic analyses and those from our phase field simulations and experiments verify our analysis. Hence, the phase diagrams presented here provide guidelines for using solid-state dewetting as a tool to achieve various nanostructures.

Catalyst shape engineering for anisotropic cross-sectioned nanowire growth

“…In addition to the already complex nature of this phenomenon, our work introduces two significant non-idealities: (i) the different nature of the mask and substrate, where different interface energies dictate the preferred wetting of the substrate33; (ii) significant interaction between the substrate and the catalyst, deviating from pure dewetting34. Nonetheless, the ideal model recently presented in ref.…”

“…Nonetheless, the ideal model recently presented in ref. 34, still points out to the critical role of dimension interplay between layer thickness, trench width and trench depth in the dewetting process. The tolerance of the method was checked by deposition of thinner and thicker metallizations (6 and 18 nm; see supporting information).…”

“…Figures 1b,c show a schematics and a corresponding SEM image of the growth site: three orientations of metal stripes inside lithography defined openings in a selective area mask, atop the InP growth wafer (see experimental section below for further details). A detailed study regarding controlled dewetting of gold on trench-patterned substrates was recently published by Lu et al ., demonstrating a high level of control over the resulting nano-patterns34.…”

Substrate melting during laser heating of nanoscale metal films

“…The process involves nanosecond pulsed-laser-induced melting of metallic films, filaments, and other geometries, followed by dewetting that may lead to formation of patterns characterized by a particular spatial order and size distribution [2,3,4,5,6,7,8]. Due to its relevance to a number of applications involving metal particles on nanoscale, the pulsed-laser dewetting has recently been studied in great detail [9,10,11,12,13,14,15,16,17,18,19,20,21]. While these studies lay out a clear picture of the basic physical mechanisms of the dewetting, understanding of relevant thermal phenomena is still limited, and there are only few studies discussing these effects [4,10,22,12,23].…”

Characteristics of Pd and Pt Nanoparticles Produced by Nanosecond Laser Irradiations of Thin Films Deposited on Topographically-Structured Transparent Conductive Oxides

“…Then, we can conclude, also, that 3 nm < d c < 7.5 nm for the Pd film and that 7.5 nm < d c < 12.2 nm for the Pt film. However, for sake of completeness, we also mention that, according to previous experimental and theoretical studies on dewetting of films on patterned surfaces [51][52][53][54], a critical thickness d c for the film separating different effects of the substrate topography on the dewetting process is related to additional parameters than the local excess of chemical potential ∆µ. In particular, it is known that a fixed substrate pattern can influence the dewetting pathways of supported film depending on the film thickness by acting on the length-scale of the processes (holes nucleation, film retreating, Rayleigh instability, etc.)…”