Measurement of d15 shear-mode displacement in ferroelectric PZT film

d15shear-mode displacements in a ferroelectric PZT(52/48) film could be observed by using a FIB processing and SPM probe measurement for the first time ever. The PZT sample with a beam shape was fabricated by a combination of a sputtering deposition, a FIB machining, and a Cu damascene process. In order to compensate for the effect of constraints arisen from the beam sample structure, FEM simulation analyses were employed. The obtained d15piezoelectric constant of the sputter PZT film was 590 pm/V. The d31piezoelectric constant of the same PZT film was also measured by a conventional tip displacement of cantilever method. The obtained d31value was -120 pm/V. Though the d15value is as large as that of bulk shape, the d31value was slightly smaller than that of bulk. The difference may be explained that an intrinsic stress existed in the lower portion of the PZT film.