A low loss flexural plate wave (FPW) device through enhanced properties of sol-gel PZT (52/48) thin film and stable TiN-Pt bottom electrode

摘要

This paper presents the development of a robust process for the fabrication of a low loss FPW device. The transmission loss in the FPW is minimized by enhancing the texture and morphology of sol-gel PZT film through optimized pyrolysis and annealing processes. Reduction of lead loss in PZT coupled with the use of a new bottom electrode stack layer of Pt/TiN/Ti resulted in an eight-fold increase in the perovskite (111) phase, increasing the remanent polarization to 95.7 mu C/cm(2) and coercive field to 56.7 kV/cm. This represents 50% improvement in remanent polarization over the previously reported values for this sol-gel PZT. The FPW device was tested by driving the input Inter Digitated Transducers/ElecLrodes (IDTs) pair differentially out of phase by 180 degrees. A transmission loss of 15 dBm was observed for an IDT design of 160 mu m periodicity. (c) 2006 Elsevier B.V. All rights reserved.