Piezoelectric nano-structures (islands of dimensions in the lateral size range 50-500 nm) have been fabricated by Focused Ga3+ Ion Beam (FIB) etching on PbZr0.54Ti0.46O3 thin films obtained by magnetron sputtering. The degradation induced by the etching process is investigated through the evolution of electromechanical activity measured by means of local piezoelectric hysteresis loops produced by Piezo-response Force Microscopy (PFM). Two kinds of structures, namely one based on crystallized films and the other based on amorphous ones, were studied. In this latter case, the amorphous films are post-annealed after etching to obtain crystallized structure. For the structures based on the crystallized and then etched films, no piezoelectric signal was registered that evidences a serious degradation of material induced by Ga3+ ion implantation. For the structures based on the films etched in amorphous state and then crystallized the piezo response signal was near to that the reference films (crystallized and not etched) whatever were the ion dose and the island dimensions. Even for very small lateral size (50 nm), no size effect was observed. The island shapes fabricated by Ga3+ FIB etching process (islands with less than 50 nm lateral size) show a limitation of FIB processing and electron beam lithography seems to be necessary.
Focused ion beam Ga3+ for the realization of piezoelectric PZT nano structures