Effect of the substrate temperature during gold-copper alloys thin film deposition by magnetron co-sputtering on the dealloying process

Nanoporous gold is of great interest for many applications due to its three dimensional interconnected porosity at nanoscale. Among all currently use techniques to obtain nanoporous gold, dealloying is one of the most used method to create a well-controlled nanoporous morphology. Only few studies report on the creation of nanoporous gold from alloy thin film deposited by magnetron co-sputtering. However, this deposition technique allows easy tune of the morphology at nanoscale. In this paper, we report on the creation of different morphologies of nanoporous gold obtained after dealloying in nitric acid of Au-Cu thin film deposited by magnetron co-sputtering. The influence of the substrate temperature during film deposition is studied by means of scanning electron microscopy and X-ray scattering analysis. We demonstrate the impact of the as-grown thin film morphology on the final nanoporous structure. We further explain the relationship between the different nanoporous morphologies and the residual stress on the as-grown thin film.