Fabrication and Characterization of Double-Layer Pb(Zr,Ti)O₃Thin Films for Micro-Electromechanical Systems

Abstract

In this paper, we address the fabrication and characterization of bimorph structures with relatively thick double-layered Pb(Zr,Ti)O3 (PZT) thin films. The PZT/PZT layers are deposited by RF magnetron sputtering. Hysteresis loops of polarization and electrical field for the top and bottom PZT thin films revealed good ferroelectric characteristics with remanent polarization at approximately 20 µC/cm2 and a coersive electric field of about 100 kV/cm. The vibration tests of fabricated bimorph cantilevers during electrical voltage application revealed a twofold displacement compared with single layer driving, and the piezoelectric coefficient value d 31 is estimated to be 13 pm/V. The residual stress difference between the top and bottom layers after the annealing process is calculated to be -0.32 MPa. For a further thickening of the bimorph structure, 6-µm-thick PZT/PZT is also sputtered. The thicker bimorph has a smaller residual stress difference, -30 MPa, between the two layers prepared without the annealing process. The evaluated results demonstrate that the PZT/PZT bimorph structures are applicable to micro-electromechanical systems (MEMS) devices.

Measurements of Nonlinear Dielectric Constants of Pb(Zr,Ti)O3 Thin Films Using a Dynamic Measuring Method

“…A variety of deposition techniques for PZT thin films and their electrical and electromechanical properties are widely studied because of their various applications including actuators, force sensors, infrared imaging detec-tors, and nonvolatile random access memories. [13][14][15][16][17][18][19][20][21][22] This enormous knowledge could also be informative for the investigation of the origin of the nonlinear dielectric response of the films.…”

Overview of the Structural, Electronic and Optical Properties of the Cubic and Tetragonal Phases of PbTiO3 by Applying Hubbard Potential Correction

“…Perovskite-type ABO 3 (A = Ba, Sr, Pb) oxides’ crystal structure as well as their physical and optical characteristics have been thoroughly explored recently, owing to their widespread development and their functional properties suitable for many technological applications [ 1 , 2 , 3 ]. In particular, PbTiO 3 itself has been frequently and intensively studied due to its excellent physical properties, which makes it a promising material for a variety of applications, including ferroelectric memory cells [ 4 , 5 ], optoelectronic devices [ 6 , 7 ], dielectric capacitors [ 8 ], electromechanical devices [ 9 , 10 ] and pyroelectric applications [ 11 ].…”

Enabling PZT bimorph actuator with passive polysilicon structure

“…In lead zirconium titanate based piezoelectric transducers, silicon has been used as a passive structural layer to enhance the mechanical stability and reliability of the system due to its excellent mechanical properties, but only in a unimorph configuration. To date, typical piezoelectric bimorph or multimorph configurations consist of lead zirconate titanate (PZT)/ZnO/PZT [1] or PZT/PZT stacks with Pt as the elastic shim [2–4]. Although such configurations are common in energy harvesting applications [5], their use has been limited in many applications due to low failure strain of PZT [6].…”