Influence of structure and chemistry on piezoelectric properties of lead zirconate titanate in a microelectromechanical systems power generation application

Lead zirconate titanate (PZT) films between 1 and 3 μm thick were grown using solution deposition techniques to study the effects of crystal structure and orientation on the direct piezoelectric output of these films on platinized Si membranes. By varying the chemistry of the film from Zr-rich to Ti-rich, the {100}/(111) relative intensity increased for films grown on randomly oriented Pt films. The 40:60 PZT had a tetragonal crystal structure and produced greater electrical output at a given strain than the rhombohedral film (Zr:Ti concentrations less than 50:50), while having a similar e31 constant, between 4.8 and 6.3 C/m2. Orientation and voltage output at a given strain were not strongly influenced by thickness in the ranges investigated. Defects in internal PZT/PZT crystallization interfaces were identified and include porosity on the order of tens of nm, with a corresponding depletion in Pb and accumulation of O at these interfaces. The {100} texture of rhombohedral films deposited upon (111) textured Pt films is significantly greater than the {100} texture of tetragonal films, which show both a {100} and {111} orientation on the same Pt film.

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

MRS Proceedings ◽

10.1557/proc-657-ee5.39 ◽

2000 ◽

Vol 657 ◽

Cited By ~ 18

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.

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

MRS Proceedings ◽

10.1557/proc-830-d6.21 ◽

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.

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Crystal Phase and Orientation Dependence of Electro-Optic Effect in Epitaxial PLZT an PZT Films

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.350.99 ◽

2007 ◽

Vol 350 ◽

pp. 99-102

Author(s):

Keisuke Satoh ◽

Akio Sugama ◽

Masatoshi Ishii ◽

Masao Kondo ◽

Kazuaki Kurihara

Keyword(s):

Lead Zirconate Titanate ◽

Lead Zirconate ◽

Epitaxial Films ◽

Orientation Dependence ◽

Pockels Effect ◽

Solution Deposition ◽

Zirconate Titanate ◽

Electro Optic ◽

Pzt Films ◽

Extraordinary Refractive Index

Lanthanum-modified lead zirconate titanate and lead zirconate titanate epitaxial films with (100) and (111) orientations were grown respectively on (100) and (111) niobium, lending conductivity to strontium titanate through chemical solution deposition. This study investigated changes in the ordinary and extraordinary refractive index no and ne induced in these films by an electric field using the prism-coupling method. In the (100) epitaxial PZT 30/70 film, anisotropic electro-optic effects arise from the Pockels effect. The isotropic electro-optic effect, which is no = ne , was achieved on (100) epitaxial PLZT 8/65/35 and PZT 70/30 films.

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Fabrication of Lead Zirconate Titanate Thick Film Disks for Micro Transducer Devices

MRS Proceedings ◽

10.1557/proc-785-d4.5 ◽

2003 ◽

Vol 785 ◽

Cited By ~ 1

Author(s):

Takashi Iijima ◽

Sachiko Ito ◽

Hirofumi Matsuda

Keyword(s):

Lead Zirconate Titanate ◽

Microelectromechanical Systems ◽

Relative Dielectric Constant ◽

Dissipation Factor ◽

Lead Zirconate ◽

Piezoelectric Response ◽

Displacement Curve ◽

Solution Deposition ◽

Zirconate Titanate ◽

Preparation Techniques

ABSTRACTA combination of the preparation techniques for the ferroelectric films and the micro machining of Si is considered to be an effective way to fabricate microelectromechanical systems (MEMS), such as piezoelectric micro-transducer devices for the electrical and medical fields. In this study, 10-μm-thick disk shape lead zirconate titanate (PZT) thick films were successfully fabricated using a chemical solution deposition (CSD) process. Pt top electrode and PZT layer were etched by reactive ion etching (RIE) process, and 100 to 500-μm-diameter PZT micro disks were fabricated on Pt/SiO2/Si substrate. The relative dielectric constant, dissipation factor, remnant polarization and coercive field were εr = 1130, tanδ = 0.02, Pr = 14 μC/cm2 and Ec = 25 kV/cm, respectively. This means that the ferroelectric and dielectric properties of the PZT micro disks were comparable with that of the bulk PZT ceramics. The PZT micro disk showed the butterfly-shaped displacement curve, related with piezoelectric response, in the case of bipolar measurement. The piezoelectric constant of the PZT disks poled at 80Vfor 10 min was estimated to be AFM d33 = 221 pm/V. A resonance frequency of the radial oscillation was evaluated to apply for micro transducer devices.

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Low-Temperature Synthesis and Dielectric Properties of Single-Phase Lead Zirconate Titanate Thin Film with a Nano Particle Seeding Technique

MRS Proceedings ◽

10.1557/proc-784-c3.32 ◽

2003 ◽

Vol 784 ◽

Cited By ~ 1

Author(s):

Tomokazu Tanase ◽

Yoshio Kobayashi ◽

Takao Miwa ◽

Mikio Konno

Keyword(s):

Dielectric Properties ◽

Low Temperature ◽

Lead Zirconate Titanate ◽

Single Phase ◽

Dissipation Factor ◽

Lead Zirconate ◽

Solution Deposition ◽

Si Substrates ◽

Zirconate Titanate ◽

Pzt Films

ABSTRACTThe low temperature synthetic method, which combines chemical solution deposition and nm-seeding technique, was applied to the fabrication of lead zirconate titanate (PZT) thin films. Nano-crystallines of barium strontium titanate (BST) particles were prepared by the hydrolysis reaction of the complex alkoxides. PZT precursor solutions containing the BST particles were spin-coated on Pt/Ti/SiO2/Si substrates to film thickness of 500 − 800 nm at particle concentrations of 0–25.1 mol%, and annealed at various temperatures. Seeding of BST particles prevented the formation of pyrochlore phases, which appeared at temperatures above 400 °C in unseeded PZT films, and crystallized PZT into perovskite structures at 420 °C, which was more than 100 °C below the crystallization temperature of the unseeded PZT films. Measurement of dielectric properties at 1 kHz showed that the 25.1 mol% BST-seeded PZT films annealed at 450 °C had a dielectric constant as high as 300 with a dissipation factor of 0.05. Leakage current density of the film was less than 1×10-6 A/cm2 at applied electric field from 0 to 64 kV/cm.

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Characterizat Ion of thin Pzt Films on Platinlm Films

MRS Proceedings ◽

10.1557/proc-243-179 ◽

1991 ◽

Vol 243 ◽

Cited By ~ 10

Author(s):

Koichi Kugimiya ◽

Ichiro Ueda ◽

Kenji Iizima

Keyword(s):

Lead Zirconate Titanate ◽

Ferroelectric Properties ◽

Lead Zirconate ◽

Film Deposition ◽

Pt Electrode ◽

Island Formation ◽

Pzt Film ◽

Zirconate Titanate ◽

Pzt Films ◽

Pt Films

AbstractAnomalous layers 20-40nm thick were found at the interfaces of lead zirconate-titanate films and Pt electrode films. Detailed study has shown evidence that absorption of PbO by Pt during sputtering resulted in a Pb deficiency in the PZT films and the formation of PbTi3O7 phase. The anomaly was also partly due to island formation at the initial PZT film deposition which allowed PbO to react with Pt films. The Pb controlled PZT films 50nm thick exhibited excellent ferroelectric properties comparable to thicker ones.

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Processing Method for Creating Ultra-Thin Lead Zirconate Titanate (PZT) Films Via Chemical Solution Deposition

10.21236/ada488542 ◽

2008 ◽

Author(s):

Richard Piekarz ◽

Ronald G. Polcawich

Keyword(s):

Lead Zirconate Titanate ◽

Chemical Solution Deposition ◽

Lead Zirconate ◽

Processing Method ◽

Chemical Solution ◽

Solution Deposition ◽

Zirconate Titanate ◽

Pzt Films

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Bottom Electrode Effects in Controlling Orientation of Lead Zirconate Titanate Films Deposited by Chemical Solution Deposition

MRS Proceedings ◽

10.1557/proc-596-253 ◽

1999 ◽

Vol 596 ◽

Cited By ~ 1

Author(s):

Deborah A. Neumayer ◽

Katherine L. Saenger ◽

Robert B. Laibowitz ◽

Thomas M. Shaw ◽

Rebecca Mih ◽

...

Keyword(s):

Lead Zirconate Titanate ◽

Chemical Solution Deposition ◽

Remanent Polarization ◽

Lead Zirconate ◽

Chemical Solution ◽

Solution Deposition ◽

Zirconate Titanate ◽

Pzt Films ◽

Fatigue Endurance ◽

Seed Layers

AbstractThe microstructure and electrical properties of lead zirconate titanate Pb(Zr,Ti)O3 (PZT) films prepared by chemical solution deposition (CSD) with and without lead titanate (PT) seed layers were examined as a function of Ir/lr oxide electrode type. The novel PZT CSD solution was prepared from a mixture of zirconium and titanium butoxyethoxides and lead ethylhexanoate dissolved in butoxyethanol. The use of excess-lead (PbxsTi) and stoichiometric PT seed layers was found to promote PZT(111) orientation on Ir but not on Ir oxide. Ir substrate thickness was observed to influence orientation of PZT deposited on stoichiometric PT with greater PZT(111) texturing on thinner Ir(111) substrates. PZT with greater PZT(111) texturing tended to have greater remanent polarization (2Pr, μC/cm2). PZT deposited on stoichiometric PT seed layers on Ir(111) was of higher film quality than PZT deposited on PbxsTi seed layers on Ir(111). The PZT films deposited on stoichiometric PT on Ir(111) had enhanced PZT(111) orientation, a reduced pyrochlore content, and tended to saturate at lower coercive fields, have higher remanent polarization, squarer hysteresis loops with less tilt and greater fatigue endurance. The use of iridium oxide top electrode was demonstrated to significantly improve fatigue endurance compared to use of an iridium top electrode.

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Mist Deposition of Micron-Thick Lead Zirconate Titanate Films

MRS Proceedings ◽

10.1557/proc-784-c11.28 ◽

2003 ◽

Vol 784 ◽

Cited By ~ 1

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.

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