Micromachined ultrasonic transducers based on lead zirconate titanate (PZT) films

2012 ◽  
Vol 19 (2) ◽  
pp. 211-218 ◽  
Author(s):  
Junhong Li ◽  
Chenghao Wang ◽  
Jun Ma ◽  
Mengwei Liu
Keyword(s):  
Lead Zirconate Titanate ◽  
Lead Zirconate ◽  
Ultrasonic Transducers ◽  
Zirconate Titanate ◽  
Pzt Films

Mist Deposition of Micron-Thick Lead Zirconate Titanate Films

2003 ◽  
Vol 784 ◽  
Author(s):  
Mark D. Losego ◽  
Susan Trolier-McKinstry
Keyword(s):  
Lead Zirconate Titanate ◽  
Chemical Deposition ◽  
Lead Zirconate ◽  
Limiting Factors ◽  
Process Time ◽  
Silicon Substrates ◽  
Zirconate Titanate ◽  
Pzt Films ◽  
Chamber Temperature ◽  
Thick Lead

ABSTRACTA majority of the work published on liquid source misted chemical deposition (LSMCD) has focused on the fabrication of thin ferroelectric films for random access memory (RAM) applications. However, the ability of LSMCD to combine the characteristically good stoichiometry control of a chemical solution deposition process with good film conformality, makes this a desirable technique for other applications, including microactuators and integrated passive components. For these applications, though, LSMCD is limited by its low throughput. This paper describes the feasibility of depositing micron-thick lead zirconate titanate (PZT) films using the LSMCD tool. PZT films of 52/48 composition were deposited on both platinized silicon and platinized alumina substrates. The chamber temperature and the delivery geometry of the LSMCD tool were identified as limiting factors in the rate at which micron-thick samples can be prepared. By switching to a focused nozzle delivery geometry and increasing the chamber temperature from room temperature to 60°C, the total process time for 1 μm thick films can be reduced from 480 min to 90 min. Polarization hysteresis measurements indicated a 75% higher remanent polarization for PZT films deposited on platinized alumina substrates (35 μC/cm2) compared to those deposed on platinized silicon substrates (20 μC/cm2). The polarization loop for the silicon substrate sample was also tilted. These observations are evidence of higher tensile stresses in the PZT films deposited on silicon substrates due to a larger mismatch in the thermal expansion coefficients of the film and the substrate.

Wet-Etch Patterning of Lead Zirconate Titanate (PZT) Thick Films for Microelectromechanical Systems (MEMS) Applications

2000 ◽  
Vol 657 ◽  
Author(s):  
L.-P. Wang ◽  
R. Wolf ◽  
Q. Zhou ◽  
S. Trolier-McKinstry ◽  
R. J. Davis
Keyword(s):  
Lead Zirconate Titanate ◽  
Electromechanical Coupling ◽  
Microelectromechanical Systems ◽  
Sol Gel ◽  
Lead Zirconate ◽  
Metal Fluoride ◽  
Zirconate Titanate ◽  
Pzt Films ◽  
High Etch Rate ◽  
Wet Etch

ABSTRACTLead zirconate titanate (PZT) films are very attractive for microelectromechanical systems (MEMS) applications because of their high piezoelectric coefficients and good electromechanical coupling. In this work, wet-etch patterning of sol-gel PZT films for MEMS applications, typically with film thicknesses ranging from 2 to 10 microns, was studied. A two- step wet-etch process was developed. In the first step, 10:1 buffered HF is used to remove the majority of the film at room temperature. Then a solution of 2HCl:H2O at 45°C is used to remove metal-fluoride residues remaining from the first step. This enabled successful patterning of PZT films up to 8 microns thick. A high etch rate (0.13μm/min), high selectivity with respect to photoresist, and limited undercutting (2:1 lateral:thickness) were obtained. The processed PZT films have a relative permittivity of 1000, dielectric loss of 1.6%, remanent polarization (Pr) of 24μC/cm2, and coercive field (Ec) of 42.1kV/cm, all similar to those of unpatterned films of the same thickness.

Enhanced Spontaneous Polarization of Dysprosium-substituted Lead Zirconate Titanate Thin Films by a Chemical Solution Deposition Method

2004 ◽  
Vol 830 ◽  
Author(s):  
Hiroshi Uchida ◽  
Hiroshi Nakaki ◽  
Shoji Okamoto ◽  
Shintaro Yokoyama ◽  
Hiroshi Funakubo ◽  
...  
Keyword(s):  
Lead Zirconate Titanate ◽  
Spontaneous Polarization ◽  
Chemical Solution Deposition ◽  
Lead Zirconate ◽  
Chemical Solution ◽  
Solution Deposition ◽  
Crystal Anisotropy ◽  
Pzt Film ◽  
Zirconate Titanate ◽  
Pzt Films

ABSTRACTInfluences of the B-site substitution using Dy3+ ion on the crystal structure and ferroelectric properties of lead zirconate titanate (PZT) films were investigated. Dy3+-substituted PZT films with nominal chemical compositions of Pb1.00Dyx (Zr0.40Ti0.60)1-(3x/4)O3 (x = 0 ∼ 0.06) were fabricated by a chemical solution deposition (CSD). Polycrystalline PZT films with preferential orientation of (111)PZT were obtained on (111)Pt/TiO2/SiO2/(100)Si substrates, while epitaxially-grown (111)PZT films were fabricated on (111)SrRuO3//(111)Pt//(100)YSZ//(100)Si substrate. Ratio of PZT lattice parameters (c/a), which corresponds to its crystal anisotropy, was enhanced by the Dy3+-substitution with x = 0.02. Spontaneous polarization (Ps) of Dy3+-substituted PZT film (x = 0.02) along polar [001] axis of PZT lattice was estimated from saturation polarization (Psat) value of the epitaxially-grown (111)PZT film on (111)SrRuO3//(111)Pt//(100)YSZ//(100)Si to be 84 μC/cm2 that was significantly larger than that of non-substituted PZT (= 71 μC/cm2). We concluded that the enhancement of Ps value could be achieved by the Dy3+-substitution that promoted the crystal anisotropy of PZT lattice.

Lithium tantalate/lead zirconate titanate composite ultrasonic transducers

1999 ◽  
Vol 74 (17) ◽  
pp. 2552-2554 ◽  
Author(s):  
Y. Chen ◽  
M. Sayer ◽  
L. Zou ◽  
C.-K. Jen
Keyword(s):  
Lead Zirconate Titanate ◽  
Lithium Tantalate ◽  
Lead Zirconate ◽  
Ultrasonic Transducers ◽  
Zirconate Titanate

The effect of oxygen partial pressure during cooling on lead zirconate titanate thin film growth by using rf magnetron sputtering method

1998 ◽  
Vol 13 (12) ◽  
pp. 3442-3448 ◽  
Author(s):  
Dong Joo Kim ◽  
Tae Song Kim ◽  
Jeon Kook Lee ◽  
Hyung Jin Jung
Keyword(s):  
Thin Film ◽  
Magnetron Sputtering ◽  
Oxygen Partial Pressure ◽  
Partial Pressure ◽  
Lead Zirconate Titanate ◽  
Rf Magnetron Sputtering ◽  
Lead Zirconate ◽  
Zirconate Titanate ◽  
Pzt Films ◽  
Grain Distribution

The lead zirconate titanate (PZT) thin film was deposited on platinized silicon wafer substrate by the rf magnetron sputtering method. In order to investigate the effect of cooling ambient, oxygen partial pressure was controlled during cooling PZT films. The PZT films cooled at lower oxygen partial pressure had perovskite phase and pyrochlore phase in both as-grown and postannealed films, but in the PZT films cooled at higher oxygen partial pressure, pyrochlore phases were not detected by XRD. As the oxygen partial pressure became lower during cooling, the capacitors had low values of remanent polarization and coercive field for as-grown films. The PZT capacitor with such a low value was recovered by postannealing in air, but its electrical properties had the same tendency before and after annealing. Microstructure was also affected by cooling ambient. Higher oxygen partial pressure on cooling reduced the number of very fine grains, and enhanced uniform grain distribution. Fatigue characteristics were also enhanced by cooling at higher oxygen partial pressure. However, the imprint was negligible irrespective of oxygen partial pressure upon cooling. The cooling procedure at higher oxygen ambients is believed to reduce the amounts of nonferroelectric second phases and oxygen vacancies. We find that oxygen partial pressure during cooling is a considerable process parameter. Therefore, care should be taken in treating the parameter after depositing films.

Lead Zirconate Titanate Films Produced by ‘Facing Targets’ RF-Sputtering

1990 ◽  
Vol 200 ◽  
Author(s):  
R. A. Roy ◽  
K. F. Etzold ◽  
J. J. Cuomo
Keyword(s):  
Lead Zirconate Titanate ◽  
Silicon Oxide ◽  
Rf Sputtering ◽  
Lead Zirconate ◽  
Process Conditions ◽  
Electrical Measurements ◽  
Process Gas ◽  
Zirconate Titanate ◽  
Wide Range ◽  
Pzt Films

ABSTRACTThe growth of ferroelectric lead zirconate titanate (PZT) films by rf-sputtering using facing targets is described. This study has focused on producing thin (<500 nm) PZT films on a wide range of substrates including magnesium oxide, spinel, alumina, silicon oxide, and the respective substrates coated with platinum. Deposition was from two opposed targets separated by 10–15 cm, with the substrate plane normal to the targets and outside the cylinder defined by the two targets. This geometry was chosen to obtain compositional uniformity and avoid ion bombardment effects. The deposition temperatures ranged from RT to 700 °C and the process gas was a mixture of argon and oxygen. Effects of deposition conditions and post-deposition annealing on film composition, microstructure, and properties were evaluated using Rutherford backscattering spectroscopy (RBS), x-ray diffraction, optical and electron microscopy, and various electrical measurements. Optimization of process conditions is discussed in terms of phase purity, preferred orientation, and minimization of electrode interaction.

Raman analysis of microcircuits with lead zirconate titanate (PZT) films

1992 ◽  
Vol 50 (2) ◽  
pp. 1688-1689
Author(s):  
D. R. Tallant ◽  
R. W. Schwartz ◽  
B. A. Tuttle ◽  
S. C. Everist ◽  
B. C. Tafoya
Keyword(s):  
Raman Spectroscopy ◽  
High Temperature ◽  
Lead Zirconate Titanate ◽  
Ferroelectric Properties ◽  
Sol Gel ◽  
Lead Zirconate ◽  
Solution Chemistry ◽  
Zirconate Titanate ◽  
Pzt Films ◽  
High Temperature Processing

Certain compositions and structural forms of lead zirconate titanate (PZT) materials have potential applications in microelectronics because of their ferroelectric properties. One such application is in the development of new types of non-volatile memories. PZT films are integrated into microcircuit components using sol-gel deposition techniques. The solution chemistry effects attendant to different sol-gel preparation procedures have been investigated by several researchers.We have used Raman spectroscopy both to characterize the metallo-organic species initially laid down on macroscopic platinum substrates during sol-gel processing and to follow the evolution of Pb-Zr-Ti oxide species through high temperature processing. The high temperature processing removes residual organics and creates Pb-Zr-Ti oxide structures that have ferroelectric properties. Low temperature pyrochlore structures, which are not ferroelectric, can be distinguished by Raman spectroscopy from tetragonal and pseudo-cubic/rhombohedral perovskite structures, which are usefully ferroelectric (Top Figure). In addition Raman spectroscopy has identified lead and titanium oxides that form as intermediates in the high temperature crystallization of ferroelectric PZT structures.

scholarly journals Acoustic Properties of Porous Lead Zirconate Titanate Backing for Ultrasonic Transducers

2020 ◽  
Vol 67 (8) ◽  
pp. 1656-1666 ◽  
Author(s):  
Danjela Kuscer ◽  
Julien Bustillo ◽  
Tina Bakaric ◽  
Silvo Drnovsek ◽  
Marc Lethiecq ◽  
...  
Keyword(s):  
Lead Zirconate Titanate ◽  
Lead Zirconate ◽  
Ultrasonic Transducers ◽  
Acoustic Properties ◽  
Zirconate Titanate

Effect of oxygen partial pressure on texture development in lead zirconate titanate thin films processed from metalorganic precursors

1999 ◽  
Vol 14 (12) ◽  
pp. 4615-4620
Author(s):  
Jarrod L. Norton ◽  
Gerald L. Liedl ◽  
Elliott B. Slamovich
Keyword(s):  
Thin Films ◽  
Lead Zirconate Titanate ◽  
Lead Zirconate ◽  
Texture Development ◽  
Pure Oxygen ◽  
Maximum Temperature ◽  
Zirconate Titanate ◽  
Liquid Precursors ◽  
Pzt Films ◽  
Switching Temperature

Metalorganic liquid precursors were used to examine the effects of processing atmosphere on texture development in oriented Pb(Zr0.60Ti0.40)O3 thin films. After removal of organic ligands via pyrolysis, the films were heated at 25 °C/min in a 5% H2/Ar atmosphere until a switching temperature, after which the atmosphere was switched to pure oxygen. The films were heated to a maximum temperature of 650 °C with switching temperatures ranging from 450 to 600 °C. The degree of (111) orientation in the lead zirconate titanate (PZT) films increased with increasing switching temperature, resulting in highly textured (111) PZT films. These results suggest that atmosphere control plays a significant role in texture development during rapid thermal processing.

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