The application discloses a preparation process of a
lead zirconate titanate (PZT) film layer, a film layer structure and application thereof, and relates to the technical field of piezoelectric material film layer preparation. The preparation process comprises the following steps: S1, forming a low tensile stress
silicon nitride layer on the surface of a substrate, which is used for homogenizing the in-
plane stress gradient of a
wafer; and S2, forming a piezoelectric functional layer on the surface of the
silicon nitride layer in a
sputtering mode, wherein the piezoelectric thin
film material of the piezoelectric functional layer is
lead zirconate titanate (PZT). The film layer structure and the preparation process thereof adopt the
silicon nitride layer to relieve the thermal mismatch stress of the piezoelectric functional layer
system, can improve the
piezoelectric constant e31 of the
central region of the
wafer, and improve the uniformity of the whole
wafer.