Correlation of materials and ferroelectric properties of sputtered and sol-gel PZT films

Author(s):  
R.X. Fu ◽  
R. Mamazza ◽  
T. S. Zheleva ◽  
K.W. Kirchner ◽  
B. H. Piekarski
1991 ◽  
Vol 243 ◽  
Author(s):  
Chi Kong Kwok ◽  
Seshu B. Desu

AbstractThe properties of ferroelectric thin films can be significantly influenced by the presence of point defects. The concentration of vacancies presented in these thin films is known to be one of the key parameters causing the degradation of these films when these films are subjected to polarization reversals.To study the effects of the vacancy concentration on the ferroelectric properties, sol gel PZT films and powders were annealed in different oxygen partial pressures. For the PZT films, the reduction of oxides to pure metals was not observed even with films annealed at 2×10−5 atmosphere of oxygen partial pressure. Samples annealed at low oxygen partial pressure (for instance, 10−3 and 2×10−5 atmosphere), which has more Pb and O2 depletions and consequently has more Pb and O2 vacancies, cannot be switched easily. The ratios of coercive field after and before fatigue increase as the defect concentrations of the annealed samples increase.


2007 ◽  
Vol 14 (02) ◽  
pp. 229-234
Author(s):  
SARAWUT THOUNTOM ◽  
MANOCH NAKSATA ◽  
KENNETH MACKENZIE ◽  
TAWEE TUNKASIRI

Lead zirconate titanate (PZT) films with compositions near the morphotropic phase boundary were fabricated on Pt (111)/ Ti / SiO 2/ Si (100) using the triol sol–gel method. The effect of the pre-heating temperature on the phase transformations, microstructures, electrical properties, and ferroelectric properties of the PZT thin films was investigated. Randomly oriented PZT thin films pre-heated at 400°C for 10 min and annealed at 600°C for 30 min showed well-defined ferroelectric hysteresis loops with a remnant polarization of 26.57 μC/cm2 and a coercive field of 115.42 kV/cm. The dielectric constant and dielectric loss of the PZT films were 621 and 0.0395, respectively. The microstructures of the thin films are dense, crack-free, and homogeneous with fine grains about 15–20 nm in size.


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.


1992 ◽  
Vol 271 ◽  
Author(s):  
Yuhuan Xu ◽  
Chih-Hsing Cheng ◽  
Ren Xu ◽  
John D. Mackenzie

ABSTRACTPb(ZrxTi1−x)O3 (PZT) solutions were prepared by reacting lead 2-ethylhexanoate with titanium n-propoxide and zirconium n-propoxide. Films were deposited on several kinds of metal substrate by dip-coating. Crystalline PZT films and amorphous PZT films were heat-treated for 1 hour at 650°C and at 400°C, respectively. Electrical properties including dielectric, pyroelectric and ferroelectric properties of both crystalline and amorphous PZT films were measured and compared. The amorphous PZT thin films exhibited ferroelectric-like behaviors.


2006 ◽  
Vol 45 ◽  
pp. 1268-1274
Author(s):  
A. Etin ◽  
G.E. Shter ◽  
G.S. Grader

The R&D of state of the art PZT (PbZrxTi1-xO3) films is important due to their piezoelectric, pyroelectric and ferroelectric properties. Currently, Chemical Solution Deposition (CSD) methods (e.g. spin coating of a sol-gel precursor solution) are successfully used in our lab to deposit PZT films with intermediate thickness. This method employs multiple coating procedures and different microstructure is observed after each coating. We report on the film microstructure evolution studied by quantitative analysis of HRSEM images as a function of thickness.


1994 ◽  
Vol 361 ◽  
Author(s):  
Wan In Lee ◽  
J.K. Lee ◽  
Elsub Chung ◽  
C.W. Chung ◽  
I.K. Yoo ◽  
...  

ABSTRACTPZT (Zr/Ti = 53/47), PNZT (4% Nb doped PZT), PSZT (2% Sc doped PZT), and PSNZT (1% Sc and 1% Nb doped PZT) thin films were prepared by a sol-gel process. They were characterized by XRD, SEM and TEM. Both crystallographic orientation and grain size of PZT films can be changed by doping. Pt/PZT/Pt capacitors were fabricated for the measurement of ferroelectric properties. By doping with both Sc and Nb, the fatigue performance of the PZT films was considerably improved and the coercive field was decreased, while the remanent polarization was not changed. In addition, the effect of dopants on the leakage current level of PZT films was studied.


1991 ◽  
Vol 6 (10) ◽  
pp. 2208-2217 ◽  
Author(s):  
Cheng-Chen Hsueh ◽  
Martha L. Mecartney

A systematic investigation of the microstructural evolution of fast fired, sol-gel derived Pb(Zr, Ti)O3 films (Zr/Ti = 54/46) was performed by analytical transmission electron microscopy (TEM). It was found that the nucleation and growth of the sol-gel PZT films were influenced by the precursor chemistry. The precursor solution was composed of Pb 2-ethylhexanoate, Ti isopropoxide, and Zr n-propoxide in n-propanol. Porous and spherulitic perovskite grains nucleated and grew from a pyrochlore matrix for NH4OH-modified films, but no chemical segregation was found. These thin films consisted completely of porous spherulitic PZT grains (∼2 μm) when the firing temperature was increased. Chemical phase separation with regions of Zr-rich pyrochlore particles separated by Zr-deficient perovskite grains was observed in the initial stages of nucleation and growth for CH3COOH-modified PZT films. This phase separation is attributed to the effect of acetate ligands on the modification of molecular structure of the PZT precursor. Firing the acid-modified films at higher temperatures for long times resulted in porous perovskite grain structures. The residual porosity in these films is suggested to be a result of differential evaporation/condensation rates during the deposition process and the gas evolution at high temperatures due to trapped organics in the films. Dielectric and ferroelectric properties were correlated to the microstructure of the films. Lower dielectric constants (∼500) and higher coercive fields (∼65 kV/cm) were found for the acid-modified PZT films with phase separation in comparison to those measured from the sol-gel films with a uniform microstructure (∽ > 600, Ec < 50 kV/cm). All films fired at 650 °C showed relatively good remanent polarization on the order of 20 μC/cm2.


Author(s):  
Hamed A. Gatea

Background: Lead Zirconate Titanate (PZT) films were synthesized by sol gel technique. The growth of films on ITO, Si\SiO2\Ti\Au, Si\Au and Si\SiO2\Ti\Al substrates discussed. In this study, Zirconium nitrate, lead acetate, and Ti (IV) isoproxide used as raw materials. Besides, acetic acid used as a solvent and 2-methoxy ethanol used as a stabilizer for Ti structure. Along with this, PZT films have perovskite structure, thin-film perovskite structure with high dielectric properties and hysteresis loop have been investigated. Methods: The effects of the type’s substrate on dielectric properties the ferroelectric properties were investigated and compared PZT film which deposited in different substrates. The films annealed at 600 C to complete crystalline films. XRD shows tetragonal PZT films have a strong perovskite structure with [100] prefer plane orientation. SEM and crosssection technique used to study for PZT surface films. Results: The dielectric constant at room temperature was different values depending on the types of substrate. The dielectric properties of the PZT films measured at 1 kHz were 120-400 dielectric constant and dielectric loss 0.02-0.08 at room temperature and 1 kHz. Conclusion: The largest remnant polarization (Pr) and coercive field (Ec) are obtained for PZT film deposited on Si\SiO2\Ti\Au substrate, equal to 26.6 mC/cm2 and 38.3 kV/cm, as compared to 16.3 mC/cm2 and 32.2 kV/cm2 for PZT film deposited on ITO substrate.


1999 ◽  
Vol 596 ◽  
Author(s):  
Zhan-jie Wang ◽  
Ryutaro Maeda ◽  
Kaoru Kikuchi

AbstractLead zirconate titanate (PZT) thin films were fabricated by a three-step heat-treatment process which involves the addition of -10, 0 and 10 mol% excess Pb to the starting solution and spin coating onto Pt/Ti/SiO2/Si substrates. Crystalline phases as well as preferred orientations in PZT films were investigated by X-ray diffraction analysis (XRD). The microstructure and composition of the films were studied by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and electron probe microanalysis (EPMA), respectively. The well-crystallized perovskite phase and the (100) preferred orientation were obtained by adding 10% excess Pb to the starting solution. It was found that PZT films to which 10% excess Pb was added had better electric properties. The remanent polarization and the coercive field of this film were 34.8 μC/cm2 and 41.7 kV/cm, while the dielectric constant and loss values measured at 1 kHz were approximately 1600 and 0.04, respectively. Dielectric and ferroelectric properties were correlated to the microstructure of the films.


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