Direct Writing of High Frequency Surface Acoustic Wave Devices on Epitaxial Pb(Zr_0.20Ti_0.80)O₃ Thin Layers Using Focus Ion Beam Etching

Abstract

The possibility to manufacture single devices allowing the 10 GHz threshold to be largely overcome has been demonstrated using Electron-beam lithography. In this paper, we propose an original alternative to lithographic techniques based on the Focused Ion Beam etching technique to fabricate SAW devices by directly "writing" the electrode pattern in the metal overlay. We also explore the RF capabilities of epitaxial Pb(Zr 0.20 Ti 0.80 )O 3 (PZT) thin films deposited onto SrTiO 3 single crystal substrates. We found that guided waves can be efficiently excited and detected at frequencies ranging from 3 to 5 GHz. Theory/experiment assessment shows a good predictability of the waves characteristics.