Tuning the phase transition of ZnO thin films through lithography: an integrated bottom-up and top-down processing

An innovative approach towards the physico-chemical tailoring of zinc oxide thin films is reported. The films have been deposited by liquid phase using the sol-gel method and then exposed to hard X-rays, provided by a synchrotron storage ring, for lithography. The use of surfactant and chelating agents in the sol allows easy-to-pattern films made by an organic-inorganic matrix to be deposited. The exposure to hard X-rays strongly affects the nucleation and growth of crystalline ZnO, triggering the formation of two intermediate phases before obtaining a wurtzite-like structure. At the same time, X-ray lithography allows for a fast patterning of the coatings enabling microfabrication for sensing and arrays technology.