Dewetting mechanisms and their exploitation for the large-scale fabrication of advanced nanophotonic systems

Abstract

Recent progress in submicron-and nano-fabrication technologies has led to the emergence of novel photonic structures such as optical nanoantennas and metasurfaces. Real-life applications of these advanced photonic structures still require substantial improvement of the fabrication processes, in terms of their throughput and cost-effectiveness. Because of its simplicity and effectiveness, dewetting of a thin film has attained increasing attention as a feasible process for improving the scalability and productivity. Here, we provide an overview of the mechanisms and phenomenologies of dewetting to foster an improved fundamental understanding necessary for the optimisation of the dewetting process condition and template design. We then review the strategies demonstrating the use of templateddewetting for producing well-aligned arrays of submicron-and nanostructures with great control over their size, shape and arrangement. Recent applications of dewetted structures in advanced nanophotonics are reviewed with an emphasis on the exploitation of dewetting mechanisms. Special attention is given to the fabrication of resonant optical nanoantennas and nanophotonic applications in which high repeatability and throughput are important parameters: sensing, colourisation, photovoltaics and nonlinear light frequency conversion. We expect this review to provide a basis for the use of thin-film dewetting to realise the industrial-level fabrication of various practical advanced photonic systems.

Plasmonic nanosponges filled with silicon for enhanced white light emission

“…However, standard top-down approaches, combining these elements within a single nano-objects, are complicated and often restricted by the material properties. For instance, the synthesis of Si/Au nanoparticles (NPs) is confronted with two major physical limitations, namely the low solubility of the elements and the dewetting 14 of metals on the surface of semiconductors. From this point of view non-equilibrium processes using lasers attract an increasing attention as they can make it possible to overcome some limitations imposed by thermodynamics and therefore widens the possibilities in nanofabrication for the creation of hybrid metal dielectric nanosponges.…”

Direct and High-Throughput Fabrication of Mie-Resonant MetasurfacesviaSingle-Pulse Laser Interference

“…If the material melting temperature is reached, the mass transport is also governed by a hydrodynamic flow as described by the mechanism of liquid-state dewetting. 26,61 The irradiated material exhibits large temperature gradients and using the same interference pattern, but controlling the laser energy density with respect to the material damage threshold, we may obtain diverse patterns. 31,38 In case of thin films, the film-substrate interfacial free energy γ fs determines the shape of the surface.…”

Dewetting behavior of Ge layers on SiO2 under annealing

“…The solid-state dewetting phenomenon can be used for the development of the simple and highly productive fabrication methods of dense nano-and micro-sized particle arrays [1][2][3][4][5][6] . The metal particles obtained by dewetting are widely used due to their ability of surface plasmon generation [7][8][9] .…”

“…There are two mechanisms of the dewetting phenomenon, which are usually distinguished in thin layers deposited on non-wettable surfaces. One of them is called spinodal dewetting, which is associated with a spontaneous amplification of layer thickness perturbation 6,59 . The spontaneous growth of the perturbation can eventually reach the substrate surface.…”

“…The spontaneous growth of the perturbation can eventually reach the substrate surface. Dewetting can also proceed through the hole formation, which begins at the inhomogeneities in the layer surface or layer/substrate interface 6,51 . In our case, as discussed below, the first or both dewetting mechanisms are involved, depending on d Ge and T ann .…”