Flexible heterogeneous integration of PZT film by controlled spalling technology

Abstract

Because of high temperature process, it has been a challenge to fabricate flexible piezoelectric or ferroelectric devices based on PbZr0.53Ti0.47O3 (PZT). In this work, a high-quality flexible PZT film is successfully fabricated by the controlled spalling technology (CST). The PZT film deposited on sapphire substrate using sol-gel method is transferred onto a flexible polyimide (PI) substrate through electroplating Ni stressor layer, realizing the flexible heterogeneous integration of PZT film and PI substrate. The obtained PZT film exhibits a good crystalline perovskite structure and a smooth surface before and after spalling process. The ferroelectric response of the spalled PZT film based on Au/PZT/Au structure does not show obvious deterioration under different mechanical deformation, which indicates good ferroelectric property and stable mechanical performance. Further, the film on flexible Ni layer has the better piezoelectric property compared with that on conventional rigid Pt/Ti/SiO2/Si substrate. This work has the important significance for the development of flexible ferroelectric and piezoelectric devices like sensors, memorizers and nanogenerators. © 2019 Elsevier B.V.