Measurement of d15 Shear-Mode Piezoelectric Response in PZT Thin Film

2009 ◽  
Vol 421-422 ◽  
pp. 95-98
Author(s):  
Tsuyoshi Aoki ◽  
Shigeyoshi Umemiya ◽  
Masaharu Hida ◽  
Kazuaki Kurihara
Keyword(s):  
Thin Film ◽  
Fem Analysis ◽  
Active Part ◽  
Piezoelectric Response ◽  
Small Displacement ◽  
Shear Mode ◽  
Mems Devices ◽  
Pzt Film ◽  
Pzt Thin Film ◽  
Piezoelectric Constants

Piezoelectric films using d15 shear-mode can be applied to many useful MEMS devices. The small displacement derived from the d15 shear-mode was directly observed by a SPM measurement. An isolated PZT(52/48) active part having a pair of driving Cu electrodes was processed in a 5 m-thick sputtering film. The displacement measurement of the active part and its FEM analysis suggested that the estimated d15 piezoelectric constant of the film was 590 pm/V. And, the d31 value of the film was -120 pm/V measured by a conventional cantilever method. The obtained piezoelectric constants of the PZT film are near those of bulk.

scholarly journals Synchrotron X-ray Microdiffraction Images of Polarization Switching in Epitaxial PZT Capacitors with Pt and SrRuO3 Top Electrodes

2003 ◽  
Vol 784 ◽  
Author(s):  
Dal-Hyun Do ◽  
Dong Min Kim ◽  
Chang-Beom Eom ◽  
Eric M. Dufresne ◽  
Eric D. Isaacs ◽  
...  
Keyword(s):  
Thin Film ◽  
Bottom Electrode ◽  
Sputter Deposition ◽  
Ferroelectric Polarization ◽  
X Rays ◽  
X Ray ◽  
Pzt Film ◽  
Thin Film Capacitors ◽  
Pzt Thin Film ◽  
Switchable Polarization

ABSTRACTThe evolution of stored ferroelectric polarization in PZT thin film capacitors was imaged using synchrotron x-ray microdiffraction with a submicron-diameter focused incident x-ray beam. To form the capacitors, an epitaxial Pb(Zr,Ti)O3 (PZT) thin film was deposited on an epitaxially-grown conductive SrRuO3 (SRO) bottom electrode on a SrTiO3 (STO) (001) substrate. Polycrystalline SRO or Pt top electrodes were prepared by sputter deposition through a shadow mask and subsequent annealing. The intensity of x-ray reflections from the PZT film depended on the local ferroelectric polarization. With 10 keV x-rays, regions of opposite polarization differed in intensity by 26% in our PZT capacitor with an SRO top electrode. Devices with SRO electrodes showed just a 25% decrease in the remnant polarization after 107 switching cycles. In devices with Pt top electrodes, however, the switchable polarization decreased a by 70% after only 5×104 cycles.

PZT Thin Films Deposited by RF Magnetron Sputtering

2013 ◽  
Vol 302 ◽  
pp. 8-13
Author(s):  
Shun Fa Hwang ◽  
Wen Bin Li
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Annealing Temperature ◽  
Bottom Electrode ◽  
Rf Sputtering ◽  
Rf Magnetron Sputtering ◽  
Pzt Thin Films ◽  
Pzt Film ◽  
Pzt Thin Film

PZT thin film was fabricated by using RF-sputtering process, and platinum was used as bottom electrodes. The sputtering gases were Ar：O2＝25：0 sccm, Ar：O2＝20：5 sccm, or Ar：O2＝15：10 sccm. After sputtering, the PZT film was annealed for 5 minutes under O2 gas environment and at the temperature of 600 0C, 650 0C, 700 0C or 750 0C. To judge the quality of the deposited PZT film, its physical properties and electric properties were evaluated. The results indicate that the best crystallization temperature of PZT thin film is about 700 0C. Also, the roughness of the PZT thin film becomes larger with the increasing of annealing temperature. By adding more oxygen in the sputtering gas, one could have better crystallization of the PZT film. As for the electrical properties, the leakage current of PZT thin film increases with the increasing of annealing temperature. Furthermore, the ferroelectric property is affected by the crystallization amount of perovskite, the thickness of PZT thin film, and the diffusion situation between the bottom electrode and the PZT film.

The Role of the Lead Zirconate Titanate (PZT)-Pt Interface in the Anomalous Phase Transformation Kinetics in Sputtered Pzt Thin Film Capacitors at Sub-2000 Å Thicknesses

1991 ◽  
Vol 243 ◽  
Author(s):  
Vinay Chikarmane ◽  
Jiyoung Kim ◽  
C. Sudhama ◽  
Jack Lee ◽  
Al Tasch ◽  
...  
Keyword(s):  
Thin Film ◽  
Phase Transformation ◽  
Lead Zirconate Titanate ◽  
Lead Zirconate ◽  
Initial Increase ◽  
Transformation Kinetics ◽  
Pzt Film ◽  
Zirconate Titanate ◽  
Phase Transformation Kinetics ◽  
Pzt Thin Film

AbstractThe Pt-Lead Zirconate Titanate (PZT) thin film interface plays a key role in determining the electrical properties and phase transformation kinetics of Pt-PZT-Pt thin film capacitor structures. The results of the electrical and material properties of PZT (65/35) films that vary in thickness between 500 Å to 4000 Å deposited by DC-magnetron sputtering under identical deposition conditions, and subjected to the same post-deposition thermal processing conditions shows that the Pt-PZT interface dominates thin film properties at low thicknesses (≦ 2000 Å). The charge storage density (Qc') and maximum polarization (Pmax) shows an anomalous variation with thickness, showing an initial increase followed by a drastic decrease as the film thickness is scaled down to 500Å. Significant interdiffusion at the PZT film-Pt electrode retards the pyrochlore-to-perovskite phase transformation nucleation and growth rate in PZT films of thickness 2000Å and lower. Gate polarity dependence of the time-tobreakdown and the degradation field is observed for all PZT film thicknesses (including 4000Å). This indicates that the ferroelectric film-electrode interface has an important role to play in determining the electrical reliability properties even in the 4000Å thick PZT film, although Qc' and Pmax are not adversely affected at these thicknesses.

Oxygen transport during annealing of Pb(Zr,Ti)O3 thin films in O2 gas and its effect on their conductivity

2001 ◽  
Vol 16 (10) ◽  
pp. 3005-3008 ◽  
Author(s):  
F. Ayguavives ◽  
B. Agius ◽  
B. EaKim ◽  
I. Vickridge
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Leakage Current ◽  
Lead Zirconate Titanate ◽  
Lead Zirconate ◽  
Low Leakage ◽  
Pzt Film ◽  
Low Leakage Current ◽  
Pzt Thin Film ◽  
Current Densities

Lead zirconate titanate (PZT) thin films were deposited in a reactive argon/oxygen gas mixture by radio-frequency-magnetron sputtering. The use of a metallic target allows us to control the oxygen incorporation in the PZT thin film and also, using oxygen 18 as a tracer, to study the oxygen diffusion in the thin films. Electrical properties and crystallization were optimized with a 90-nm PZT thin film grown on RuO2 electrodes. These PZT films, annealed with a very modest thermal budget (550 °C) show very low leakage current densities (J = 2 × 10−8 A/cm2 at 1 V). In this article we show that a strong correlation exists between the oxygen composition in the PZT film and the leakage current density.

Actuation Enhancement of PZT Thin-Film Membrane Actuators via Stress Relief Grooves

2008 ◽  
Author(s):  
Cheng-Chun Lee ◽  
G. Z. Cao ◽  
I. Y. Shen
Keyword(s):  
Thin Film ◽  
Finite Element ◽  
Film Thickness ◽  
Stress Relief ◽  
Design Parameters ◽  
Finite Element Analyses ◽  
Membrane Area ◽  
Aspect Ratios ◽  
Pzt Film ◽  
Pzt Thin Film

Lead Zirconate Titanate Oxide (PbZrxTi1−xO3 or PZT) is a piezoelectric material widely used as sensors and actuators. For microactuators, PZT often appears in the form of thin films to maintain proper aspect ratios. A common design is PZT membrane microactuator, whose actuation portion takes a form of a thin diaphragm driven by a PZT thin film. To maximize actuation displacements, finite element analyses are conducted to identify critical design parameters of the PZT film. In the simulation, a constant driving electric field is maintained and boundary conditions of the PZT film are varied. The finite element analyses lead to two important results. First, the actuator displacement increases as the PZT film thickness increases, but saturates at a critical PZT film thickness. Second, when stress relief grooves are introduced and the PZT film surrounding the membrane area is removed, the actuator displacement increases substantially by at least a factor of 5.

Effects of Corner Frequency on Bandwidth and Resonance Amplitude in Designing PZT Thin-Film Actuators: An Experimental Demonstration

2005 ◽  
Author(s):  
Chia-Che Wu ◽  
Cheng-Chun Lee ◽  
G. Z. Cao ◽  
I. Y. Shen
Keyword(s):  
Thin Film ◽  
Film Thickness ◽  
Lead Zirconate Titanate ◽  
Corner Frequency ◽  
Frequency Bandwidth ◽  
Resonance Amplitude ◽  
Pzt Film ◽  
Pzt Thin Film ◽  
Wide Range ◽  
Silicon Beam

In the last decade, Lead Zirconate Titanate Oxide (PZT) thin-film actuators have received increasing attention because of their high frequency bandwidth, large actuation strength, fast response, and small size. The PZT film thickness is usually less than several microns as opposed to hundreds of microns for bulk PZT patches that are commercially available. As a result, PZT thin-film actuators pose unique vibration issues that do not appear in actuators with bulk PZT. Two major issues affecting actuator performance are the frequency bandwidth and the resonance amplitude. As an electromechanical device, a PZT thin-film actuator’s bandwidth and resonance amplitude depend not only on the lowest natural frequency ωn of the actuator’s mechanical structure but also on the corner frequency ωc of the actuator’s RC-circuit. For PZT thin-film actuators, the small film thickness implies large film capacitance C and small ωc. When the size of the actuator decreases, frequency ωn increases dramatically. As a result, improper design of PZT thin-film actuators could lead to ωc ≪ ωn substantially reducing the actuator bandwidth and the resonance amplitude. This paper is to demonstrate this phenomenon through calibrated experiments. In the experiments, frequency response functions of a fixed-fixed silicon beam with a 1-μm thick PZT film are measured through use of a laser Doppler vibrometer and a spectrum analyzer. The silicon beam has multiple electrodes with a wide range of resistance R and corner frequency ωc. The experimental results confirm that the actuator bandwidth and resonance amplitude are substantially reduced when ωc ≪ ωn.

Interconnect-Related Degradation of PZT Capacitor for FeRAM

1998 ◽  
Vol 541 ◽  
Author(s):  
S. Kobayashi ◽  
K. Amanuma ◽  
H. Hada
Keyword(s):  
Thin Film ◽  
Ferroelectric Properties ◽  
Film Capacitor ◽  
Thin Film Capacitor ◽  
Pzt Film ◽  
Pzt Thin Film ◽  
Possible Cause

AbstractFerroelectric properties of a Pb(Zr,Ti)O3 (PZT) thin film capacitor with a conventional Al/TiN/Ti interconnect are seriously degraded by annealing at around 400°C. The degradation of the PZT capacitor is reduced as the interconnects are narrowed while the total area of the interconnects on the capacitor is fixed. This result cannot be understood by supposing that Ti diffusion into PZT degrades the ferroelectric properties. A possible cause for the degradation is stress placed on the PZT film during the 400°C annealing.

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