Orientation control of sol-gel-derived lead zirconate titanate film by addition of polyvinylpyrrolidone

2005 ◽  
Vol 20 (4) ◽  
pp. 882-888 ◽  
Author(s):  
Gun-Tae Park ◽  
Chee-Sung Park ◽  
Jong-Jin Choi ◽  
Hyoun-Ee Kim

Highly (100)- and (111)-oriented lead zirconate titanate (PZT) films with a thickness of 350 nm were deposited on platinized Si substrates through a single spinning of a PZT sol containing polyvinylpyrrolidone (PVP) as an additive. The crystallographic orientation of the film was strongly influenced by pyrolysis conditions after spin coating. When the spin-coated sol was pyrolyzed at temperatures above 320 °C for relatively long periods of time (>5 min), (111)-oriented film was formed after annealing at 700 °C for 10 min. On the other hand, when the same sol was pyrolyzed at 320 °C for short periods of time (<5 min), the film was strongly oriented to the (100) direction after annealing. Organic residues derived from PVP decomposition acted as nucleation sites for the (100) oriented grains during annealing after the pyrolysis. The effective d33 of the (100)-oriented PZT film (100 pC/N) was much higher than that of the (111)-oriented film (62 pC/N) with the same thickness.

1994 ◽  
Vol 360 ◽  
Author(s):  
D.A. Barrow ◽  
T.E. Petroff ◽  
M. Sayer

AbstractLead zirconate titanate (PZT) films of up to 60 μm in thickness have been fabricated on a wide variety of substrates using a new sol gel process. The dielectric properties (∈ = 900), ferroelectric (Ec = 16 kV/cm and Pr = 35 μC/cm 2) and piezoelectric properties are comparable to bulk values. The characteristic Curie point of these films is at 420 °C. Piezoelectric actuators have been developed by depositing thick PZT films on both planar and coaxial substrates. Stainless steel cantilevers and optical fibres coated with a PZT film exhibit flexure mode resonant vibrations observable with the naked eye. A low frequency in-line fibre optic modulator has been developed using a PZT coated optical fibre. The high frequency resonance of a 60 μm film on a aluminum substrate has been observed.


2000 ◽  
Vol 657 ◽  
Author(s):  
L.-P. Wang ◽  
R. Wolf ◽  
Q. Zhou ◽  
S. Trolier-McKinstry ◽  
R. J. Davis

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.


2005 ◽  
Vol 20 (1) ◽  
pp. 243-246 ◽  
Author(s):  
Chee-Sung Park ◽  
Sang-Wook Kim ◽  
Gun-Tae Park ◽  
Jong-Jin Choi ◽  
Hyoun-Ee Kim

Highly oriented lead zirconate titanate (PZT) films were fabricated on a platinized silicon substrate using a combination of sol-gel and radio frequency (RF) magnetron sputtering deposition methods. A sol-gel derived PZT layer highly oriented to the (100) plane was deposited as a seed layer, and PZT with the same composition then was deposited on the seed layer by RF-magnetron sputtering. The film deposited on the seed layer showed a strong (100) preferred orientation, while the film deposited without the seed layer showed a (111) preferred orientation. Furthermore, a thick PZT film of up to 4 μm was able to be deposited without cracks by using the seed layer. The piezoelectric property of the (100) oriented film was much better than that of the (111) oriented film.


2004 ◽  
Vol 830 ◽  
Author(s):  
Hiroshi Uchida ◽  
Hiroshi Nakaki ◽  
Shoji Okamoto ◽  
Shintaro Yokoyama ◽  
Hiroshi Funakubo ◽  
...  

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.


Author(s):  
D. R. Tallant ◽  
R. W. Schwartz ◽  
B. A. Tuttle ◽  
S. C. Everist ◽  
B. C. Tafoya

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.


1999 ◽  
Vol 596 ◽  
Author(s):  
Zhenshan Zhang ◽  
Jeong Hwan Park ◽  
Susan Trolier-McKinstry

AbstractIn this work, highly (001)pc-oriented thin films of LaNiO3 (LNO) were deposited by DC magnetron sputtering onto Si substrates (pc = pseudocubic indices). The target powder was prepared using a molten salt technique with Na2CO3 as a flux. The final target density was greater than 85% of theoretical density. The best results were obtained when sputtering was carried out at a power of 186 W and a working pressure of 45 mtorr with a gas composition of 50% O2 + 50% Ar. The thickness of the deposited films was proportional to the sputtering time, and the growth rate was 300Å/hour. Highly (001)-oriented thin films of lead zirconate titanate Pb(Zr0.52Ti0.48)O3 (PZT) and Pb[(Mg1/3Nb2/3)0.7Ti0.3]O3 (PMN-PT) were fabricated by a sol-gel method on (001)-textured LNO metallic oxide electrodes. A remanent polarization of 12 μC/cm2 and d31 of -125 pC/N (assuming a Young's modulus of 35 GPa) were measured on the PMN-PT thin films with a thickness of 0.9 μm. This piezoelectric coefficient considerably exceeds that available from PZT films, and depends critically on the film orientation. Changes in the hysteresis loop due to externally applied stress will also be described.


2006 ◽  
Vol 21 (6) ◽  
pp. 1532-1536 ◽  
Author(s):  
Joon-Koo Kang ◽  
Chee-Sung Park ◽  
Jae-Wung Lee ◽  
Gun-Tae Park ◽  
Hyoun-Ee Kim ◽  
...  

Highly (100)- and (111)-oriented lead magnesium niobate–lead zirconate titanate (PMN-PZT) films were deposited on Pt(111)/Ti/SiO2/Si substrates using a sol containing polyvinylpyrrolidone (PVP). The molar ratio of Zr/Ti in the PZT was fixed at 60/40, and the PMN content was changed in the range of 0–30 mol%. The films had a dense and columnar microstructure with a thickness of about 1 μm as a result of being spun four times. The crystallographic orientation of the films was controlled by adjusting the pyrolysis temperature; a (100) orientation was obtained by pyrolyzing at 300 °C and a (111) orientation by pyrolyzing at 350 °C. The electrical properties of the films were strongly dependent on the crystallographic orientation and PMN content. With increasing PMN content, the dielectric constant of all of the films increased. On the other hand, the remnant polarization of the (111)-oriented films decreased steadily with increasing PMN content, while that of the (100)-oriented films remained unchanged up to a PMN content of 20%. The piezoelectric coefficients of the (100)-oriented film were consistently higher than those of the (111)-oriented film with the same composition. The highest piezoelectric coefficient was observed for the (100)-oriented film with a composition of 0.2PMN–0.8PZT, indicating the morphotropic phase boundary between the rhombohedral PZT phase and the pseudocubic PMN phase is in the vicinity of this composition.


2003 ◽  
Vol 784 ◽  
Author(s):  
Tomokazu Tanase ◽  
Yoshio Kobayashi ◽  
Takao Miwa ◽  
Mikio Konno

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.


1991 ◽  
Vol 243 ◽  
Author(s):  
Koichi Kugimiya ◽  
Ichiro Ueda ◽  
Kenji Iizima

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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