Synthesis of 10-m-Thick Lead Zirconate Titanate Films on 2-in. Si Substrates for Piezoelectric Film Devices
Abstract:To achieve micro-machined piezoelectric film devices, crack-free and dense 10-m-thick lead zirconate titanate (PZT) films were successfully deposited onto 2-in. Pt/Ti/SiO2/Si substrates using an automatic coating system, and disk-shaped structures with a diameter from 20 to 100 m were fabricated by an RIE process. The prepared PZT thick film disks showed well-saturated P–E hysteresis curves and butterfly-shaped longitudinal displacement curves. The AFM-measured piezoelectric constant of the 30-m-diameter PZT thick film disk after poling at 100 V for 10 min was AFM d33=290 pm/V. The resonant and anti-resonant frequencies of the thickness oscillation mode were observed at 180 MHz. The calculated thickness mode effective coupling factor was (keff)2=0.1 for the poled 30-m-diameter PZT thick film disks. These results suggest that the prepared PZT thick film disks are applicable for piezoelectric micro devices such as micro-machined ultrasonic transducers.
Document Type: Research Article
Affiliations: Research Institute of Instrumentation Frontier, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba 305-8568, Japan
Publication date: November 1, 2006