Optimization of Sol-Gel Derived PZT thin Films by the Incorporation of Excess PBO

1992 ◽  
Vol 271 ◽  
Author(s):  
G. Teowee ◽  
J. M. Boulton ◽  
D. R. Uhlmann

ABSTRACTA series of PZT precursor solutions was prepared which incorporated excess PbO to give the composition Pb1+xZr0.53Ti0.47O3+x, where 0 < × < 0.3. These solutions were spin coated on platinized Si wafers and fired at elevated temperatures up to 750C for 30 mins. After crystallization into single-phase perovskite, the films were studied using XRD, optical microscopy and electrical characterization techniques (hysteresis loops and dielectric properties). It was found that the presence of excess PbO significantly improved the PZT films in terms of phase assemblage, microstructure and electrical properties. Under optimized conditions, films with dielectric constants of around 3000 can be obtained.

2001 ◽  
Vol 688 ◽  
Author(s):  
Jinrong Cheng ◽  
Wenyi Zhu ◽  
Nan Li ◽  
L.Eric Cross

AbstractPZT thin films of different thicknesses and Zr/Ti ratios of 60/40, 52/48 and 45/55 were coated onto platinized silicon substrates by using 2 methoxyethanol (2-MOE) based sol-gel spinon technique and crystallized with a rapid thermal annealing (RTA) process. XRD analysis revealed that thin PZT films exhibit random texture, while the thicker ones exhibit (100) texture, which was independent of composition. Dielectric constants and dissipation factors of PZT thin films were measured at elevated temperatures and as a function of frequency. For films with a thickness of ∼ 4 μm, the Curie points are at 350, 375 and 422°C for Zr/Ti ratios of 60/40, 52/48 and 45/55, respectively. All these films exhibit a high remnant polarization. A remnant polarization of 35 μC/cm2 had been achieved for the 60/40 films. No enhancement of the dielectric constant was observed in films with a composition close to MPB. The higher dielectric constant observed in films with the highest Zr content was explained by the concept of domain engineering.


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.


1991 ◽  
Vol 243 ◽  
Author(s):  
G. Teowee ◽  
J.M. Boulton ◽  
S.C. Lee ◽  
D.R. Uhlmann

AbstractSol-gel derived PZT films were successfully prepared from precursor solutions based on lead acetate and Zr/Ti alkoxides. A pyrochlore phase was observed in films fired at low temperatures, while single-phase perovskite films were obtained at temperatures above 725C. The dielectric constant increased to above 1000 when there was a higher proportion of perovskite than pyrochlore. The films were essentially fatigue-free up to 108 cycles and exhibited a low aging rate of 5.7% / decade-sec.


1991 ◽  
Vol 243 ◽  
Author(s):  
Cheng-Chen Hsueh ◽  
Martha L. Mecartney

AbstractTransmission electron microscopy (TEM) was used to investigate the microstructural evolution of sol-gel derived ferroelectric PZT films. Aggregates of perovskite crystals nucleated and grew out of a pyrochlore matrix at 550°C. A dense, single-phase perovskite PZT film was obtained by fast firing the film at 650°C for 30 minutes. The grain size of this film was approximately 0.2-0.4 μm. Hot-stage TEM observed disappearance of ferroelectric domains as the temperature approaching 325°C.


2007 ◽  
Vol 336-338 ◽  
pp. 39-41
Author(s):  
Liang Sheng Qiang ◽  
Dong Yan Tang ◽  
Mu Han

In present work, sol-gel process is used to direct the organization of high quality and pore-free parasite PZT thin films with a composition near the morphotropic phase boundary (Zr/Ti = 52/48). The PZT transparent sol can be obtained by dissolving the zirconium oxynitrate, butyl titanate and lead acetate in ethylene glycol with the molar ratio of 0.52:0.48:1 and the PZT gel can be gained by spin-coating. In such process, PZT thin films can be readily prepared by hydrolysis on hot plate at 350°C for 20min and annealing in RTA at 650°C for 1 minute. The structural and electric characteristics of the films have been carried out by XRD, AFM and the C-V measurements, etc. Experimental results have indicated that by treating film RTA at 6508 for 1 minute film with perfect crystallization and good surface morphology with a RMS roughness of 2.0nm can be obtained, and the remnant polarization Pr (28.5 μC/cm2) and coercive field Ec (39.8kV/cm) are obtained in the P-E hysteresis loops. The films have a dielectric constant ε of 1080 and a dielectric loss tanδ of 0.01 at 1 kHz. Ferroelectric polarization fatigue test of the films has shown that high fatigue resistance up to 3 × 1010 cycles before Pr is decreased by 50%.


Author(s):  
V. Kaushik ◽  
P. Maniar ◽  
J. Olowolafe ◽  
R. Jones ◽  
A. Campbell ◽  
...  

Lead zirconium titanate films (Pb (Zr,Ti) O3 or PZT) are being considered for potential application as dielectric films in memory technology due to their high dielectric constants. PZT is a ferroelectric material which shows spontaneous polarizability, reversible under applied electric fields. We report herein some results of TEM studies on thin film capacitor structures containing PZT films with platinum-titanium electrodes.The wafers had a stacked structure consisting of PZT/Pt/Ti/SiO2/Si substrate as shown in Figure 1. Platinum acts as electrode material and titanium is used to overcome the problem of platinum adhesion to the oxide layer. The PZT (0/20/80) films were deposited using a sol-gel method and the structure was annealed at 650°C and 800°C for 30 min in an oxygen ambient. XTEM imaging was done at 200KV with the electron beam parallel to <110> zone axis of silicon.Figure 2 shows the PZT and Pt layers only, since the structure had a tendency to peel off at the Ti-Pt interface during TEM sample preparation.


1994 ◽  
Vol 361 ◽  
Author(s):  
Chang Jung Kim ◽  
Dae Sung Yoon ◽  
Joon Sung Lee ◽  
Chaun Gi Choi ◽  
Won Jong Lee ◽  
...  

ABSTRACTThe (100), (111) and randomly oriented PZT thin films were fabricated on Pt/Ti/Coming 7059 glass using sol-gel method. The thin films having different orientation were fabricated by different drying conditions for pyrolysis. The preferred orientations of the PZT thin films were observed using XRD, rocking curves, and pole figures. The microstructures were investigated using SEM. The hysteresis loops and capacitance-voltage characteristics of the films were investigated using a standardized ferroelectric test system. The dielectric constant and current-voltage characteristics of the films were investigated using an impedance analyzer and pA meter, respectively. The films oriented in a particular direction showed superior electrical characteristics to the randomly oriented films.


1991 ◽  
Vol 243 ◽  
Author(s):  
D. Dimos ◽  
R.W. Schwartz

AbstractThe photocurrent responses, photo-induced changes in hysteresis behavior, and electrooptic (birefringence) effects of sol-gel derived PZT films have been characterized as part of an effort to evaluate ferroelectric films for image storage and processing applications.


1991 ◽  
Vol 224 ◽  
Author(s):  
Zheng Wu ◽  
Roberto Pascual ◽  
C.V.R. Vasant Kumar ◽  
David Amd ◽  
Michael Sayer

AbstractThe preparation of ferroelectric lead zirconate titanate (PZT) thin films by rapid thermal processing (RTP) is reported. The films were deposited by chemical sol gel and physical sputter techniques. The heating rate of RTP was found to have significant influence on the crystallization behavior. Faster heating rates lead to lowering of the crystallization temperature and reduction of grain size. PZT films were obtained with dielectric constants ~ 1000, remanent polarizations between 20 and 30μC/cm2, coercive fields 20 to 60kV/cm, and no significant fatigue for 109 to 1010 stressing cycles.


1998 ◽  
Vol 541 ◽  
Author(s):  
H. Fujisawa ◽  
S. Nakashima ◽  
M. Shimizu ◽  
H. Niu

AbstractThe grain size of MOCVD-Pb(Zr,Ti)O3 (PZT) thin films was successfully controlled by changing the grain size of Ir bottom electrodes and by changing the growth rate of PZT films. In Ir/PZT/Ir/SiO2/Si capacitors, the grain size of PZT thin films increased from 120 to 240nm as the grain size of bottom Ir electrodes increased from 50 to 200nm. The dielectric constants of PZT thin films increased from 760 to 1440 as the grain size increased from 120 to 240nm. Remanent polarization increased and coercive field decreased as the grain size increased. This dependence of electrical properties on the grain size coincided with that of ceramics.


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