Design and Fabrication of a Lead Zirconate Titanate (PZT) Thin Film Acoustic Sensor

Abstract

Piezoelectric MEMS acoustic sensors have potential applications in a wide variety of applications including hearing aids, surveillance, heart monitoring, etc. For each of these systems and many others, the acoustic sensors must be miniaturized and have low power requirements. A piezoelectric based microphone can provide a solution to these requirements, as they offer the ability to passively sense without the power requirements of condenser or piezoresistive microphone counterparts. This research effort reports on the design and fabrication of a piezoelectric PZT based acoustic sensor. A circular clamped membrane consisting of a dielectric for structural support and a piezoelectric actuator has been fabricated on a silicon wafer using silicon deep reactive ion etching (DRIE). Sensors ranging from 500-2000 microns in diameter have been fabricated and characterized using scanning laser Doppler vibrometry and calibrated acoustic tone sources. The PZT sensors exhibited a sensitivity of 97.9-920 nV/Pa depending on geometry.

Highly textured Pb(Zr0.3Ti0.7)O3 thin films on GaN/sapphire by metalorganic chemical vapor deposition

“…[1][2][3][4][5] In the past couple of decades, the impetus for research on Si-integrated PZT films has primarily been on the development of nonvolatile ferroelectric random access memories (FeRAMs), 6-10 piezoelectricbased microelectromechanical systems, [11][12][13][14] and pyroelectric infrared (IR) detectors. [15][16][17] An early report on the deposition of epitaxial (Pb, La)(Zr, Ti)O 3 (PLZT) thin films on GaAs and GaP substrates for electro-optics and nonlinear optics 18 was followed by the deposition of PZT films on GaAs for FeRAMs.…”

Design and fabrication of microtunnel and Si-diaphragm for ZnO based MEMS acoustic sensor for high SPL and low frequency application

“…however, these materials except aln are not fully compatible with cMOS fabrication process. The PZT-based ultrasonic trans-ducer (Yamanaka et al 2003;Muralt et al 2005;Wang et al 2007;Peng et al 2010) and acoustic sensor (Polcawich et al 2003;Wang et al 2005) were presented by different researchers. however, PZT-based acoustic sensor exhibits Abstract The purpose of the paper is to design and fabricate a ZnO-based MeMS acoustic sensor for higher sound pressure level (SPl) measurement in the range of 120-200 dB and low frequency infrasonic wave detection.…”

Zinc oxide thin film-based MEMS acoustic sensor with tunnel for pressure compensation

“…Recently micromachined acoustic devices such as microphones and micro-speakers are being focused for applications [9] such as hearing and cellular phone, micro-personal digital assistant (micro-PDA) and earphone and micro-speaker, etc. Since last decades attempts have been made for the development of acoustic microsensors by integrating a piezoelectric layer of lead zirconate titanate (PZT) with MEMS technology and reported to have low sensitivity in the range 0.75-68 V/Pa [10,11].…”