ABSTRACT
Microelectromechanical systems (MEMS) technologies have attracted considerable attention for the development of next-generation functional microdevices. This chapter describes the fabrication process of Pb(Zr,Ti)O3 (PZT) thin films and the evaluation method of the piezoelectric characteristics of the thin films from the viewpoint of MEMS applications. For the deposition of the piezoelectric materials, especially PZT-based perovskite thin films, several methods have been studied: chemical solution deposition, chemical vapor deposition, pulsed laser deposition, and sputtering. Those three methods can produce well-crystallized PZT thin films. The radio-frequency-magnetron sputtering is used for the deposition of the piezoelectric PZT thin films. Since PZT is a typical ferroelectric material, it shows a variety of functionality such as large spontaneous polarization and dielectric constant, pyroelectric coefficient, and piezoelectricity. Ferroelectric materials have spontaneous polarization, which can be reversed by the external electric field. Ferroelectric properties can be evaluated from the polarization–electric field (P–E) hysteresis curves taken by the Sowyer–Tower circuit.
