Pzt Thin Films on a Lead Titanate Interlayer Prepared by rf Magnetron Sputering

1993 ◽  
Vol 310 ◽  
Author(s):  
P. H. Ansari ◽  
A. Safari

AbstractFerroelectric lead zirconate titanate (PZT) films with a composition near the morphotropic phase boundary have been deposited by if magnetron sputtering on a Si substrate coated with silicon oxide, titanium, and platinum (Si/SiO2/Ti/Pt). Substrate temperature and oxygen partial pressure were changed during deposition to prepare films with controlled stoichiometry and perovskite structure. The effects of lead titanate (PT) as a buffer layer were investigated. Thin films of PT/PZT have a dielectric constant of 800 with a dissipation factor of 0.04 at 1 kHz. The remnant polarization of 8μC/cm2 and the coercive field of 50 kV/cm were measured. The effect of processing on the formation of perovskite phase and the electrical properties will be discussed.

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.


2006 ◽  
Vol 326-328 ◽  
pp. 613-616
Author(s):  
Dae Jin Yang ◽  
Seong Je Cho ◽  
Jong Oh Kim ◽  
Won Youl Choi

Lead zirconate titanate (Pb(Zr0.48Ti0.52)O3 or PZT) films were grown on platinized silicon wafers (Pt/SiO2/Si) by d.c. reactive sputtering method with multi targets. The Pb content of PZT films has been widely recognized as affecting not only the phase formation and microstructure but also the dielectric and ferroelectric properties. Pb content of PZT films was controlled by the variation of Pb target current. The relation between Pb content and Pb target current was expressed as y=0.89x-11.09. The x and y are Pb target current and Pb content, respectively. The pyrochlore phase was transformed to perovskite phase as Pb content was increased. This phase transformation improved the ferroelectric properties of PZT films. In PZT films with perovskite phase, fatigue properties were not improved with excess Pb content. Fatigue properties of PZT films began to be fatigued after 106 switching cycles and coincided with the typical PZT fatigue behavior. Excess Pb content (Pb vacancy) did not affect the fatigue properties of PZT films.


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):  
T. J. Headley ◽  
B. A. Tuttle ◽  
J. A. Voigt ◽  
J. R. Michael

Lead zirconate titanate (PZT) thin films are of technological interest for a variety of electronic and optical applications such as nonvolatile memories, decoupling capacitors, infrared detectors, and optical storage media. Fabrication of PZT films by solution deposition techniques is attractive because of uniform, stoichiometric control at the molecular level, ease of processing, and both low capital investment and total cost. Control of phase evolution, microstructure, crystallite size and orientation, and ferroelectric domain assemblage during processing is essential to optimize electrical and/or optical properties of the films. Factors which play a major role in controlling these parameters are details of the solution chemistry and mixing, thermal processing, Pb stoichiometry, Zr/Ti ratio, and substrate characteristics. Electron microscopy techniques have been used extensively to correlate microstructural features with film processing parameters as will be emphasized in this presentation.As annealing temperature is increased, phase evolution in PZT thin films typically proceeds from amorphous to pyrochlore to the ferroelectric perovskite phase. Fine-grained pyrochlore crystallizes from the amorphous film at low annealing temperatures and also precedes crystallization of the perovskite phase at higher temperatures. There is evidence that the Zr/Ti stoichiometry influences the microstructure of the amorphous-to-pyrochlore transformation.


2013 ◽  
Vol 750 ◽  
pp. 220-223
Author(s):  
Xian Wei Wang ◽  
Zhan Jie Wang ◽  
Yan Na Chen ◽  
Yu Qing Zhang ◽  
Zhi Dong Zhang

Ferroelectric Pb(Zr0.52Ti0.48)O3 (PZT) thin films rapidly crystallized by microwave irradiation were compared with those obtained by conventional furnace process. The PZT films under microwave irradiation at 650 °C for 60 s were crystallized well in to the perovskite phase, and showed butter electrical properties than those crystallized by conventional furnace annealing at 650 °C for 30 min. It is clear that microwave irradiation is effective for obtaining well-crystallized PZT films with good properties in a short process time.


2007 ◽  
Vol 280-283 ◽  
pp. 239-242 ◽  
Author(s):  
Wen Gong ◽  
Xiang Cheng Chu ◽  
Jing Feng Li ◽  
Zhi Lun Gui ◽  
Long Tu Li

Lead zirconate titanate (PZT) thin films with a composition near the morphotropic phase boundary were deposited on silicon wafers by using a modified sol-gel method. Introducing a seeding layer between the interface of PZT film and platinum electrode controlled the texture of PZT films. The lead oxide seeding layer results in highly (001)-textured PZT film, while the titanium dioxide seeding layer results in (111)-textured one. SEM and XRD were used to characterize the PZT thin films. The ferroelectric and piezoelectric properties of the PZT films were evaluated and discussed in association with different preferential orientations.


1994 ◽  
Vol 361 ◽  
Author(s):  
B. Ea Kim ◽  
M.C. Hugon ◽  
F. Varniere ◽  
B. Agius ◽  
H. Achard ◽  
...  

ABSTRACTDue to their high dielectric constant, good chemical stability and good insulating properties, lead zirconate titanate (PZT) thin films are considered as promising materials to replace Si3N4 and Ta2O5 for use as the capacitor dielectric in future high density DRAMs. Moreover, the ferroelectric quality of PZT films also allows use of this material in non volatile memories. In this paper, we investigate the properties of PZT films deposited from an oxide target of nominal composition {Pb1.1(Zr0.55,Ti0.45)O3} in a radio frequency (rf) magnetron sputtering system. The Pt(deposited at 450°C)/[TiN/Ti/BPSG/Si] structure annealed at 450°C at 10−6 mbar (Pt(450°C)/{TiN/Ti/BPSG/Si}450°c,10–6mbar) was used as a substrate material in this work. The PZT films were deposited at different pressures, and different substrate temperatures ranging from floating temperature to 400°C; the thicknesses of the sputtered films were in the 15–720 nm range. The kinetics of the sputtering process and the effect of sputtering parameters on film composition have been studied and related to the continuously monitored optical emission of the plasma. The relative cation and oxygen compositions of the films were determined by a new method based on the simultaneous use of Rutherford Backscattering Spectrometry (RBS) and Nuclear Reaction Analysis (NRA) induced by a deuteron beam. The conditions for the deposition of stoichiometric PZT thin films were established.Electrical characterizations of the PZT films including resistivity, dielectric constant, dissipation factor were studied as a function of the temperature. From initial electrical measurements, it appears that a dielectric constant of 740 can be obtained for PZT 55/45 films deposited on a previously annealed Pt/TiN/Ti/BPSG/Si structure.


2000 ◽  
Vol 657 ◽  
Author(s):  
C.F. Knollenberg ◽  
T.D. Sands ◽  
A.S. Nickles ◽  
R.M. White

ABSTRACTSputter-deposited piezoelectric lead zirconate titanate (PZT) thin films with Ti/Pt and polysilicon electrode layers are being investigated for use in Microelectromechanical Systems (MEMS). Existing research shows the nucleation of the perovskite phase of the PZT is linked to the lattice spacing of the underlying Pt electrode and/or seed layers, and is key in obtaining PZT layers with good piezoelectric/ferroelectric properties. Our research with piezoelectric PZT films on Ti/Pt electrode layers aims at employing these films to generate and receive acoustic waves in flexural plate wave devices (FPWs). Our experiments indicate the formation of a random polycrystalline perovskite phase is linked to the emergence of oriented <100> Pt grains within the dominant <111>-oriented crystal structure during rapid thermal annealing in an oxygen environment. Pt films annealed in nitrogen, in contrast, retained their <111> preferential orientation without the formation of Pt <100> grains. PZT films deposited on these electrodes and annealed in nitrogen were strongly oriented in the <111> direction, but exhibited lossy ferroelectric behavior and were prone to delamination. We are also investigating the feasibility of using doped polysilicon electrode layers with PZT thin films. The multiple layers used with the Pt electrode (Pt, Ti, and SiO2 adhesion layer) have significant interactions with one another, and replacing these layers with a single electrode layer should alleviate these complications. A low-temperature PZT deposition process (300°C) and short annealing cycles (30 sec.), coupled with a TiO2 barrier/seed layer should prevent interdiffusion and reactions between the polysilicon and PZT layers. Our experiments show that PZT films deposited and annealed on doped polysilicon layers develop a random polycrystalline perovskite phase, but are subject to tensile cracking. The use of polysilicon as an electrode layer should also facilitate the integration of piezoelectric PZT layers with polysilicon surface micromachined structures using SiGe sacrificial layers.


1995 ◽  
Vol 10 (12) ◽  
pp. 3149-3159 ◽  
Author(s):  
Ellen M. Griswold ◽  
L. Weaver ◽  
M. Sayer ◽  
I.D. Calder

The crystallization kinetics of the pyrochlore to perovskite phase transformation in lead zirconate titanate (PZT) thin films have been analyzed using rapid thermal processing (RTP). Sol-gel PZT thin films, fabricated on platinum electrodes, were annealed at 550 °C to 650 °C with hold times ranging from 1 s to 5 min. Glancing angle x-ray diffraction (XRD) was used for depth profiling to identify the location of phases in the films. Transmission electron microscopy (TEM) provided information on grain structure, nucleation, and growth. The phase information was correlated to the ferroelectric and dielectric properties. The perovskite phase nucleated in the pyrochlore phase throughout the film thickness, and at 650 °C the transformation was complete in 15 s. Fast growing (100) PZT nucleated at the platinum and consumed a small-grained matrix until a columnar structure was obtained. A ramp rate of 100 °C/s was sufficiently fast to prevent transformation during heating and allowed the direct application of an Avrami model for transformation kinetics. An activation energy of 610 kJ/mol was determined.


1991 ◽  
Vol 223 ◽  
Author(s):  
Thomas M. Graettinger ◽  
O. Auciello ◽  
M. S. Ameen ◽  
H. N. Al-Shareef ◽  
K. Gifford ◽  
...  

ABSTRACTFerroelectric oxide films have been studied for their potential application as integrated optical materials and nonvolatile memories. Electro-optic properties of potassium niobate (KNbO3) thin films have been measured and the results correlated to the microstructures observed. The growth parameters necessary to obtain single phase perovskite lead zirconate titanate (PZT) thin films are discussed. Hysteresis and fatigue measurements of the PZT films were performed to determine their characteristics for potential memory devices.


Sign in / Sign up

Export Citation Format

Share Document