Focused ion-beam patterning of nanoscale ferroelectric capacitors

A 50 kV Ga+ focused ion beam was applied for milling submicron Pt-(La0.5Sr0 .5) CoO3-Pb(NbxZryTiz) O-3- (La0.5Sr0.5)CoO3-Pt-based ferroelectric capacit or heterostructures prepared by pulsed laser and sol-gel deposition techniq ues. The milling yields were found to be 0.22+/-0.02 mu m(3)/nC for Pb(NbxZ ryTiz)O-3, 0.3.4+/-0.01 mu m(3)/nC for (La0.5Sr0.5)CoO3, and 0.34 +/- 0.06 mu m(3)/nC for Pt layers. The influence of the ion beam current and its sca n strategy, as well as depth of milling, on the quality of fabricated struc tures was' studied. The minimum sizes down to 0.017 mu m(2) for the top ele ctrode, and 0.04 mu m(2) for the capacitor structures milled to the bottom electrode were achieved without an additional sacrificial, layer. A scannin g probe microscopy technique was employed to test the properties of the mil led capacitor structures. (C) 1998 American Vacuum Society. [S0734-211X(98) 14006-4].