Nano-shaping of gold particles on silicon carbide substrate from solid-state to liquid-state dewetting

This work reports on the effect of annealing temperature on the size, shape and wetting of particles obtained on 4H-SiC substrate by the dewetting process of a deposited nanoscale-thick Au film, with focus on the difference between solid-state dewetting (below Au melting temperature) and liquid-state dewetting (above Au melting temperature). After depositing nanoscale-thick Au film on the SiC substrate, annealings are perfomed so to induce the solid-state or liquid-state dewetting process of the film with the consequent formation of particles. Plan-view and cross-view scanning electron microscopy analyses are carried out to quantify the evolution of the average planar size and vertical size of the particles and of the average contact angle of the particles to the SiC surface versus the annealing temperature. These analyses allow us to extract quantitative information on the wetting behaviour of the particles on the SiC surface by calculating the adhesion work versus the annealing temperature. Energy dispersive x-ray analyses are, also, performed on the dewetted particles to analyze their composition in the various annealing conditions. Overall, we set a general framework connecting process parameters to the nano-shape of the dewetted particles towards specific shape design for selected applications.