Ferroelectric Thin Films for Microactuator Applications

1991 ◽  
Vol 243 ◽  
Author(s):  
Jiayu Chen ◽  
K. R. Udayakumar ◽  
Keith G. Brooks ◽  
L. Eric. Cross
Keyword(s):  
Thin Films ◽  
Laser Interferometer ◽  
Breakdown Strength ◽  
Sol Gel ◽  
Dielectric Constants ◽  
Ferroelectric Thin Films ◽  
Electromechanical Properties ◽  
High Dielectric

AbstractFerroelectric thin films of PZT and PMN-PT were fabricated by the solgel spin-on technique. The films show high dielectric constants, polarization and breakdown strength values. Using a laser interferometer (ultradilatometer), the piezoelectric and electrostrictive coefficients of the films were measured. The results indicate that the sol-gel derived ferroelectric thin films have good electromechanical properties and can be used in rnicroactuator applications.

Microstructure and Dielectric Properties of LixTixNi1-2xO Thin Films

2008 ◽  
Vol 368-372 ◽  
pp. 1817-1819
Author(s):  
Cui Hua Zhao ◽  
Bo Ping Zhang ◽  
Yong Liu ◽  
Song Jie Li
Keyword(s):  
Thin Films ◽  
Dielectric Properties ◽  
Spin Coating ◽  
Sol Gel ◽  
Dielectric Constants ◽  
Co Doping ◽  
Grain Sizes ◽  
Uniform Microstructure ◽  
Coating Method ◽  
High Dielectric

LixTixNi1-2xO (x =0, 10 and 20 at. %) thin films with 200 nm in thickness were deposited on Pt/Ti/SiO2/Si (100) by a sol-gel spin-coating method. All samples have a uniform microstructure. The grain sizes grew from 100 nm to 300 nm by co-doping Li and Ti. The LiTiNiO thin films consist of NiO, NiTiO3 and Li2NiO2, while the Li-free thin films consist of NiO, NiTiO3 and NiTi0.99O3. The dielectric properties of the LiTiNiO thin films improved obviously by co-doping Li and Ti, but excess Li increases the amount of Li2NiO2 phase and decreases the dielectric properties. The dielectric constants at 100 Hz for the Li0.1Ti0.1Ni0.8O and Li0.2Ti0.2Ni0.6O thin films are 506 and 388 respectively. Appropriate co-doping contents of Li and Ti are important to obtain a high dielectric property.

Ferroeleciric Thin Films Intended for Electronic Device Applications

1993 ◽  
Vol 310 ◽  
Author(s):  
A. Patel ◽  
E.A. Logan ◽  
R. Nicklin ◽  
N.B. Hasdell ◽  
R.W. Whatmore ◽  
...  
Keyword(s):  
Thin Films ◽  
Flip Chip ◽  
Electronic Device ◽  
Dielectric Material ◽  
Sol Gel ◽  
Deposition Process ◽  
Dielectric Constants ◽  
Excess Lead ◽  
Starting Solutions ◽  
High Dielectric

AbstractThe need for integrated ferroelectrics as charge storage capacitors has increased dramatically not only for use in radiation hardened and commercial non-volatile memories, but also as possible high dielectric material suitable for capacitor applications. These properties combined with a thin film format, offer the capability of forming very compact capacitor structures suitable for MCM applications through Flip-Chip Bonding, or even integrated directly onto MMIC's. In this paper, the material PbZrxTi1-xO3, where x=l, 0.53, and 0.60 has been assessed. Thin films were produced using a sol-gel technique onto metallised thermally oxidised silicon. The effects on film microstructure and crystallinity with variation in the deposition process will be described. The best films were obtained by incorporating excess lead in the starting solutions, and also by the addition of acetylacetone which was used as a solution modifier. It will be demonstrated that fully perovskite films can be readily obtained at temperatures as low as 450°C. The films were normally 0.3-0.44μm thick with grain sizes of the order of 0.2μm. These films exhibited dielectric constants and loss in the range 170-800 and 1-3% respectively. Measurements upto 3MHz, indicated useful performance with low dispersion. The measured Pr and Ec were in the range 16-22μC/cm2, and 60-120kV/cm respectively.

Dielectric Properties of BST/(Y2O3)x(ZrO2)1-x/BST Trilayer Films

2011 ◽  
Vol 1292 ◽  
Author(s):  
Santosh K. Sahoo ◽  
D. Misra
Keyword(s):  
Thin Films ◽  
Dielectric Constant ◽  
Dielectric Properties ◽  
Dielectric Loss ◽  
Dielectric Breakdown ◽  
Breakdown Strength ◽  
Sol Gel ◽  
Middle Layer ◽  
Slight Variation ◽  
High Dielectric

ABSTRACTThin films of Ba1-xSrxTiO3 (BST) are being actively investigated for applications in dynamic random access memories (DRAM) because of their properties such as high dielectric constant, low leakage current, and high dielectric breakdown strength. Various approaches have been used to improve the dielectric properties of BST thin films such as doping, graded compositions, and multilayer structures. We have found that inserting a ZrO2 layer in between two BST layers results in a significant reduction in dielectric constant as well as dielectric loss. In this work the effect of Y2O3 doped ZrO2 on the dielectric properties of BST/ZrO2/BST trilayer structure is studied. The structure Ba0.8Sr0.2TiO3/(Y2O3)x(ZrO2)1-x/Ba0.8Sr0.2TiO3 is deposited by a sol-gel process on platinized Si substrate. The composition (x) of the middle layer is varied while keeping the total thickness of the trilayer film constant. The dielectric constant of the multilayer film decreases with the increase of Y2O3 amount in the film whereas there is a slight variation in dielectric loss. In Y2O3 doped multilayer thin films, the dielectric loss is lower in comparison to other films and also there is good frequency stability in the loss in the measured frequency range and hence very suitable for microwave device applications.

Preparation, Property, and Mechanism Studies of Amorphous Ferroelectric (Ba, Sr)TiO3 Thin Films for Novel Metal–ferroelectric–metal Type Hydrogen Gas Sensors

2000 ◽  
Vol 15 (6) ◽  
pp. 1291-1302 ◽  
Author(s):  
W. Zhu ◽  
O. K. Tan ◽  
J. Deng ◽  
J. T. Oh
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Gas Sensing ◽  
Sol Gel ◽  
Interfacial Polarization ◽  
Polarization Potential ◽  
Hydrogen Gas ◽  
Ferroelectric Thin Films ◽  
Interesting Phenomenon ◽  
High Dielectric

Ferroelectric(Ba0.67Sr0.33)TixO3 (BST) thin films with x = 0.98, 1.00, 1.02, and 1.04 were prepared by the sol-gel technology, and their thermal, structural, dielectric, and gas sensing properties were systematically characterized. The amorphous (Ba0.67Sr0.33)TixO3 thin film capacitive devices were made on Si substrate to detect hydrogen gas and to study hydrogen-induced interfacial polarization potential.Experimental results showed that the Schottky I–V behavior appears in these Pd/amorphous BST thin film/metal capacitive devices and that enhanced interfacial dipole potentials as large as 4.5 V at 1000 ppm hydrogen gas in air were newly observed, which is about 7 times larger than the best value reported under similar testing conditions. It was clearly shown that the hydrogen-induced interfacial polarization potential is closely correlated with the microstructure of ferroelectric thin films and the enhancement of this interfacial polarization potential is mainly attributed to the high dielectric constant of amorphous ferroelectric thin films. A simple hydrogen interface-blocking model is also presented to explain this interesting phenomenon.

The Impact of Domains on the Dielectric and Electromechanical Properties of Ferroelectric Thin Films

1997 ◽  
Vol 493 ◽  
Author(s):  
S. Trolier-McKinstry ◽  
P. Aungkavattana ◽  
F. Chu ◽  
J. Lacey ◽  
J-P. Maria ◽  
...  
Keyword(s):  
Thin Films ◽  
Grain Size ◽  
Domain Walls ◽  
Sol Gel ◽  
Ferroelectric Thin Films ◽  
Piezoelectric Response ◽  
Electromechanical Properties ◽  
Phase Switching ◽  
Pzt Films ◽  
The Impact

ABSTRACTIn ferroelectric thin films for capacitive and piezoelectric applications, it is important to understand which mechanisms contribute to the observed dielectric constant and piezoelectricity. In soft PZT (PbZr1−xTixO3) ceramics, over half the room temperature response is associated with domain wall contributions to the properties. However, recent studies on bulk ceramics have demonstrated that the number of domain variants within grains, and the mobility of the twin walls depend on the grain size. This leads to a degradation in the dielectric and piezoelectric properties for grain sizes below a micron. This has significant consequences for thin films since a lateral grain size of 1 μm is often the upper limit on the observed grain size. In addition, since the pertinent domain walls are ferroelastic, the stress imposed on the film by the substrate could also clamp the piezoelectric response. To investigate these factors, controlled stress levels were imposed on PZT films of different thickness while the dielectric and electromechanical properties were measured. It was found that for undoped sol-gel PZT 40/60, 52/48, and 60/40 thin films under a micron in thickness, the extrinsic contributions to the dielectric and electromechanical properties make very modest contributions to the film response. No significant enhancement in the properties was observed even when the film was brought through the zero global stress condition. Comparable results were obtained from laser ablated films grown from hard and soft PZT targets. Finally, little twin wall mobility was observed in AFM experiments. The consequences of this in terms of the achievable properties in PZT films will be presented. Work on circumventing these limitations via utilization of antiferroelectric phase switching films and relaxor ferroelectric single crystal films will also be discussed.

Electron microscopy studies of PZT ferroelectric film capacitor structures

1992 ◽  
Vol 50 (2) ◽  
pp. 1364-1365
Author(s):  
V. Kaushik ◽  
P. Maniar ◽  
J. Olowolafe ◽  
R. Jones ◽  
A. Campbell ◽  
...  
Keyword(s):  
Electric Fields ◽  
Sol Gel ◽  
Ferroelectric Material ◽  
Dielectric Constants ◽  
Dielectric Films ◽  
Lead Zirconium Titanate ◽  
Si Substrate ◽  
Film Capacitor ◽  
Pzt Films ◽  
High Dielectric

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.

Dielectric and ferroelectric response of sol–gel derived Pb0.85La0.15TiO3 ferroelectric thin films on different bottom electrodes

2002 ◽  
Vol 406 (1-2) ◽  
pp. 30-39 ◽  
Author(s):  
S. Bhaskar ◽  
S.B. Majumder ◽  
P.S. Dobal ◽  
S.B. Krupanidhi ◽  
R.S. Katiyar
Keyword(s):  
Thin Films ◽  
Sol Gel ◽  
Ferroelectric Thin Films

Mechanical and electromechanical properties of PZT sol-gel thin films measured by nanoindentation

2001 ◽  
Vol 41 (1-4) ◽  
pp. 53-62 ◽  
Author(s):  
M. Algueró ◽  
A. J. Bushby ◽  
P. Hvizdoscar ◽  
M. J. Reece ◽  
R. W. Whatmore ◽  
...  
Keyword(s):  
Thin Films ◽  
Sol Gel ◽  
Electromechanical Properties
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