Integrated Piezoelectric and Pyroelectric Devices from Thin Film Ferroelectrics

1991 ◽  
Vol 243 ◽  
Author(s):  
M. Sayer ◽  
C.V.R. Vasant Kumar ◽  
D. Barrow ◽  
Li Zou ◽  
D.T. Amm

AbstractThin PZT films 1-4 μm in thickness prepared by sputtering or sol gel methods allow PZT films to be integrated with silicon technology to achieve piezoelectric or pyroelectric structures having small size or mass. Design criteria, materials and processing techniques for such devices are discussed, and the implementation of small size devices on silicon substrates is demonstrated. Factors of importance are the piezoelectric and pyroelectric characteristics achievable in the films, mechanical strength and fatigue, and the stability and compatibility of the films and electrodes with device fabrication procedures and operating conditions.

2011 ◽  
Vol 331 ◽  
pp. 270-274 ◽  
Author(s):  
Yan Yan Chu ◽  
Qing Wang ◽  
Shi Zhong Cui

Abstract:Pure TiO2 water sol, pure ZnO water sol and three compound TiO2/ZnO water sols are prepared under low temperature. Then the padding and baking process is used to put the functional sol liquid on the fabric. SEM is use to analyzed the change of surface feature and the result show that all of the water sol except pure ZnO water sol liquid formed a thin film on the fiber The stability of pure ZnO water sol is the best one and the pure TiO2 water sol is the worst one at temperature of 15°C. The compound water sols stabilities are between these two water sols and with the more amount of ZnO, the stability last longer. Both mole of TiO2 and ZnO with the rate of 5 to 5 and 7 to 3 display the best antistatic behavior, but the washing fastnesses are not good. After treatment, the moisture regain displays most dramatically changes; the next one is whiteness of fabric, but the other physical and mechanical properties have a little change.


2011 ◽  
Vol 415-417 ◽  
pp. 715-719 ◽  
Author(s):  
Akhmad Herman Yuwono ◽  
Yu Zhang ◽  
John Wang

Nanocomposite thin film containing TiO2nanoparticles in polymethyl methacrylate (PMMA) is a new class of potential materials for optoelectronic applications. Among the various processing techniques for these nanocomposites, in situ sol−gel process is well known to be versatile as it enables control of the inorganic-organic interaction at various molecular, nanometer and micrometer scales. However, the resulting TiO2phase is largely amorphous, as a consequence of the relatively low processing temperatures. Therefore, the current research is aimed at enhancing the nanocrystallinity of TiO2nanoparticles in nanocomposites. For this purpose, pre-hydrothermal treatment was carried on the inorganic sols. The nanocrystallinity degree of the resulting TiO2nanoparticles was studied by XRD and FTIR. The studies showed that the nanocrystallinity of TiO2nanoparticles synthesized from the inorganic sol can be enhanced significantly by the pre-hydrothermal treatment, as a result of the completion of hydrolysis stage during sol-gel process.


1989 ◽  
Vol 152 ◽  
Author(s):  
S. L. Swartz ◽  
P. J. Melling ◽  
C. S. Grant

ABSTRACTThe sol-gel processing of ferroelectric thin films is being investigated at Battelle. The ferroelectric materials included in this study are PbTiO3, Pb(Zr, Ti)O3 (PZT), and KNbO3. The sol-gel processing and crystallization of these films on fused silica, silicon, alumina, and single crystal SrTiO3 substrates is described.Sol-gel derived PbTiO3 thin films crystallized into the expected tetragonal perovskite structure when heated to 500 C and above. However, the crystallization of sol-gel PZT (20/80) thin films was found to be substratedependent. The heat-treated PZT films were amorphous when deposited on silica and silicon substrates. Crystalline perovskite PZT films were produced on alumina substrates, and epitaxial PZT films were produced on single-crystal SrTiO3. Heat treatment of sol-gel KNbO3 films on silicon and alumina substrates resulted in the crystallization of a variety of non-perovskite phases, but epitaxial growth of KNbO3 was observed on single crystal SrTiO3.


1994 ◽  
Vol 368 ◽  
Author(s):  
C. Jeffrey Brinker ◽  
Rakesh Sehgal ◽  
Narayan K. Raman ◽  
Sai S. Prakash ◽  
Laurent Delatire

ABSTRACTUsing sol-gel processing techniques it is possible to vary the condensation pathway over wide ranges to form primary species ranging in structure from oligomers to polymers to particles. The porosity of the corresponding dry gels depends on the size and structure of the primary species, the organization of these structures, often by aggregation, to form a gel, and the collapse of the gel by drying. This paper reviews these ideas in the context of forming thin film or bulk specimens. Several strategies are introduced to control porosity on length scales of interest for catalysis and catalytic membrane reactors: 1) aggregation of fractals; 2) management of capillary pressure; 3) surface derivatization; 4) relative rates of condensation and evaporation; 5) the use of organic templates and 6) sintering. These strategies are contrasted with the more traditional particle packing approach to preparing controlled porosity materials.


2013 ◽  
Vol 658 ◽  
pp. 237-241 ◽  
Author(s):  
Intan Syaffinazzilla Zaine ◽  
Z.M. Zabidi ◽  
A.N. Alias ◽  
M.H. Jumali

Tungsten organometallic sol and tungsten organometallic-PANi sol were deposited onto SiO2 coated silicon substrates by a sol-gel spin coating technique. SEM studies on tungsten organometallic film show that it consists of many hollows compared to tungsten organometallic doped 1 wt.% PANi while SEM studies on tungsten organometallic doped 4 wt.% PANi show the sample became porous and agglomerated. Tungsten organometallic sensor was responsive towards isopropanol vapour at room remperature with sensitivity of 13.03%. Although the sensitivity of tungsten organometallic-PANi is lower than undoped PANi sensor, the hybrid sensor exhibited good reversibility meanwhile response of undoped PANi sensor decrease extremely with time. The small amount of PANi doping into tungsten organometallic sol improved the sensing properties of the sensor in terms of reversibility and recovery time.


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.


2002 ◽  
Vol 741 ◽  
Author(s):  
Jacek Baborowski ◽  
Nicolas Ledermann ◽  
Paul Muralt

ABSTRACTTest structures for piezoelectric micromachined ultrasonic transducers have been fabricated and investigated. The basic element consisted of a oxidized and platinized silicon membrane coated with a 2 μm thick (100)-textured Pb(Zr,Ti)O3 (PZT) thin film deposited by sol-gel techniques. SOI wafers have been applied to obtain a good definition of the silicon part of the membrane. Test devices have been characterized in air and in an insulating liquid.


Author(s):  
E. L. Hall ◽  
A. Mogro-Campero ◽  
L. G. Turner ◽  
N. Lewis

There is great interest in the growth of thin superconducting films of YBa2Cu3Ox on silicon, since this is a necessary first step in the use of this superconductor in a variety of possible electronic applications including interconnects and hybrid semiconductor/superconductor devices. However, initial experiments in this area showed that drastic interdiffusion of Si into the superconductor occurred during annealing if the Y-Ba-Cu-O was deposited direcdy on Si or SiO2, and this interdiffusion destroyed the superconducting properties. This paper describes the results of the use of a zirconia buffer layer as a diffusion barrier in the growth of thin YBa2Cu3Ox films on Si. A more complete description of the growth and characterization of these films will be published elsewhere.Thin film deposition was carried out by sequential electron beam evaporation in vacuum onto clean or oxidized single crystal Si wafers. The first layer evaporated was 0.4 μm of zirconia.


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.


Author(s):  
H. L. Tsai ◽  
J. W. Lee

Growth of GaAs on Si using epitaxial techniques has been receiving considerable attention for its potential application in device fabrication. However, because of the 4% lattice misfit between GaAs and Si, defect generation at the GaAs/Si interface and its propagation to the top portion of the GaAs film occur during the growth process. The performance of a device fabricated in the GaAs-on-Si film can be degraded because of the presence of these defects. This paper describes a HREM study of the effects of both the substrate surface quality and postannealing on the defect propagation and elimination.The silicon substrates used for this work were 3-4 degrees off [100] orientation. GaAs was grown on the silicon substrate by molecular beam epitaxy (MBE).


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