Large Area PbZr1−xTixO3 (PZT) Thin Films Deposited by MOCVD Processes

1997 ◽  
Vol 493 ◽  
Author(s):  
Tingkai Li ◽  
Elliot Hartford ◽  
Pete Zawadzki ◽  
Richard A. Stall
Keyword(s):  
Thin Films ◽  
Perovskite Phase ◽  
Process Conditions ◽  
Large Area ◽  
Homogeneous Microstructure ◽  
Pzt Thin Films ◽  
Si Substrates ◽  
Pt Electrodes ◽  
Pzt Films ◽  
Ray Patterns

ABSTRACTAn advanced oxide MOCVD tool and processes have been developed to deposit large area PbZr1−xTixO3 (PZT) thin films on 6” Si and Pt/Ti/SiO2/Si substrates. The experimental results show the advanced oxide MOCVD tool can achieve the growth of PZT thin films with thickness uniformity of 2% and composition uniformity better that 3% on both 6” Si and Pt/Ti/SiO,/Si wafers at high deposition rates. X-ray patterns showed a single PZT perovskite phase, and AFM showed homogeneous microstructure and low surface roughness. Typically, 300 nm thick PZT films with a grain size about 0.3 μm have Pr greater than 20 - 30 μC/cm2 at 5V, a dielectric constant around 1000, low coercive field (Ec 50 - 70 kV/cm), and fatigue rate (the normalized polarization is about 0.6 after 1010 cycles at 5 V), and leakage current of 2 - 6×lO−7 A/cm2 at 150 kV/cm and room temperature on Pt electrodes. In addition, the effects of reactor design and process conditions on the thickness and composition uniformity, as well as the m i ero structure and properties were also investigated.

A Study on the Selective Nucleations for Formation of Large Single Grains in PZT Thin Films

1999 ◽  
Vol 596 ◽  
Author(s):  
Jang-Sik Lee ◽  
Eung-Chul Park ◽  
Jung-Ho Park ◽  
Byung-Il Lee ◽  
Seung-Ki Joo
Keyword(s):  
Thin Films ◽  
Grain Boundary ◽  
Perovskite Phase ◽  
Breakdown Field ◽  
Pzt Thin Films ◽  
Random Nucleation ◽  
Saturation Polarization ◽  
Pt Electrodes ◽  
Pzt Films ◽  
Pt Films

AbstractSelective nucleation and lateral growing method have been developed for high quality ferroelectric PZT(65/35) thin films using perovskite-phase PZT island seed. The PZT films on PZT seed island were transformed into the perovskite phase at temperatures as low as 540°C, which is 150°C lower than compared to that of PZT thin films deposited on Pt films. The temperature difference enables lateral growth without undesirable random nucleation. Maximum grain sizes of the perovskite-phase PZT films were determined by the annealing temperature. The PZT thin films show a leakage current density of 8×10−8 A/cm2, breakdown field of 1240 kV/cm, saturation polarization of 42 μC/cm2, and remanent polarization of 30 μC/cm2, whose values were maintained up to 2×1011 cycles. In this study, we show that when there was no grain boundary in the area measured, degradation such as fatigue and retention was not observed even with Pt electrodes. So the main source of degradation is the grain boundary in the PZT thin films.

Preparation of pzt thin films on Pt/Ti/SiO2 and Pt/SiO2 Substrates by ECR Plasma Enhanced DC Magnetron Multi-target Reactive Sputtering

1996 ◽  
Vol 441 ◽  
Author(s):  
Sung-Tae Kim ◽  
Hyun-Ho Kim ◽  
Moon-Yong Lee ◽  
Won-Jong Lee
Keyword(s):  
Thin Films ◽  
Lead Zirconate Titanate ◽  
Electron Cyclotron Resonance ◽  
Perovskite Phase ◽  
Early Stage ◽  
Reactive Sputtering ◽  
Deposition Process ◽  
Pzt Thin Films ◽  
Si Substrates ◽  
Ecr Plasma

AbstractPerovskite-phase lead zirconate titanate (PZT) thin films were fabricated at 4751C by the electron cyclotron resonance (ECR) plasma enhanced DC magnetron multi-target reactive sputtering method on Pt/Ti/SiO2/Si and Pt/SiO2/Si substrates. Stoichiometric perovskite PZT films were readily obtained on Pt/Ti/SiO2/Si substrates because Ti atoms which were out-diffused to the Pt surface facilitated Pb incorporation by forming lead titanate at the early stage of deposition process. Activation of oxygen by ECR plasma facilitated the oxidation reaction and Pb incorporation into the film. Thus perovskite-phase PZT can be obtained on the Pt/SiO2/Si substrate.

Influence of Platinum Bottom Electrodes on the Piezoelectric Performance of PZT Thin Films Hot Sputtered in a High Volume Production Tool

2012 ◽  
Vol 1397 ◽  
Author(s):  
Dirk Kaden ◽  
Hans-Joachim Quenzer ◽  
Martin Kratzer ◽  
Lorenzo Castaldi ◽  
Bernhard Wagner ◽  
...  
Keyword(s):  
Thin Films ◽  
Volume Fraction ◽  
Perovskite Phase ◽  
Annealing Treatment ◽  
High Volume ◽  
Deposition Process ◽  
Pzt Thin Films ◽  
Pzt Films ◽  
High Volume Production ◽  
Volume Production

ABSTRACTIn this work high quality ferroelectric PZT films have been prepared in-situ by hot RF magnetron sputtering. 200 mm wafer were coated with PZT films of 1 μm and 2 μm thickness at sputter rates of 45 nm/min in a high volume production sputtering tool. The films were grown on oxidized Si substrates prepared either with sputtered Ti/TiO2/Pt, sputtered Ti/TiO2/Pt/TiO2 or evaporated Ti/Pt bottom electrodes at substrate holder temperatures in the range from 550 °C to 700 °C. At these temperatures, the material nucleates in the requisite piezoelectric perovskite phase without need of an additional post annealing treatment.The films were investigated with respect to their chemical composition and their crystallographic, piezoelectric and dielectric properties. At an intermediate chuck temperature of 600 °C the PZT thin films were characterized by a minimum volume fraction of secondary nonpiezoelectric phases. A Zr/(Zr+Ti) ratio of 0.53 has been achieved matching the morphotropic phase boundary. By improving the deposition process and poling procedure, a notable high e31,f coefficient of -17.3 C/m2 has been obtained. The corresponding longitudinal piezoelectric constant was determined to have an effective longitudinal piezoelectric coefficient d33,f of 160 pm/V.

Microstructural Properties of PZT Thin Films Deposited on LaNiO3-Coated Substrates

2007 ◽  
Vol 555 ◽  
pp. 315-320 ◽  
Author(s):  
Z. Branković ◽  
G. Branković ◽  
K. Vojisavljević ◽  
M. Počuča ◽  
Tatjana Srećković ◽  
...  
Keyword(s):  
Thin Films ◽  
Thermal Treatment ◽  
Pechini Method ◽  
Slow Heating ◽  
Microstructural Properties ◽  
Pzt Thin Films ◽  
Si Substrates ◽  
Treatment Conditions ◽  
Pzt Films ◽  
Size And Morphology

The modified polymeric precursor method (Pechini method) was successfully used for the preparation of epitaxial and polycrystalline ferroelectric Pb(Zr0.52Ti0.48)O3 (PZT) thin films. Films were deposited on LaNiO3 (LNO) – coated silicium (1 0 0) and platinum substrates (Pt (1 1 1)/Ti/SiO2/Si) by spin coating technique. LNO electrodes were also prepared by the Pechini method and treated under different thermal treatment conditions to obtain films with different structural and microstructural properties. Investigation of PZT microstructure was performed as a function of orientation and morphology of the bottom electrode, as well as of thermal treatment conditions. Grain size and morphology were analyzed by AFM, while the quality and orientation of PZT films were determined by GIXRD analysis. It has been found that the proposed thermal treatment on a hot plate, with slow heating rate and long annealing time, can result in the formation of epitaxial PZT films on Si and LNO-coated Si substrates.

OPTIMIZATION OF PROCESSING TEMPERATURE TO ACHIEVE HIGH QUALITY SOL–GEL-DERIVED PZT THIN FILM

2009 ◽  
Vol 08 (03) ◽  
pp. 299-303 ◽  
Author(s):  
SAJJAD DEHGHANI ◽  
ABDOLGHAFAR BARZEGAR ◽  
MOHAMMAD HOSSEIN SHEIKHI
Keyword(s):  
Thin Films ◽  
Spin Coating ◽  
Perovskite Phase ◽  
Sol Gel ◽  
Morphological Properties ◽  
Processing Temperature ◽  
High Quality ◽  
Pzt Thin Films ◽  
Polarization Voltage ◽  
Si Substrates

Ferroelectric PbZr 1-x Ti x O 3 (PZT) thin films have been extensively investigated because of their excellent piezoelectric, pyroelectric, ferroelectric, and dielectric properties. Sol–gel synthesis and spin-coating are popular routes to the formation of high quality, dense, and crack-free thin films. In this work, high quality, crack-free PZT thin films have been prepared by sol–gel method via spin-coating on Pt/Ti/SiO2/Si substrate by different temperature processings. The crystallographic and morphological properties of the films have been analyzed by X-ray diffraction and scanning electron microscopy. The electrical properties of thin films including the permittivity, loss tangent, and polarization–voltage hysteresis loop were measured and compared for different films. Finally, by optimizing temperature processing, highly textured and high quality films of PZT with perovskite phase were obtained on Pt/Ti/SiO2/Si substrates.

scholarly journals Characterization of Chemically Prepared PZT Thin Films

1990 ◽  
Vol 200 ◽  
Author(s):  
Bruce A. Tuttle ◽  
R.W. Schwartz ◽  
D.H. Doughty ◽  
J.A. Voigt ◽  
A.H. Carim
Keyword(s):  
Thin Films ◽  
Heating Rate ◽  
Process Parameters ◽  
Ferroelectric Properties ◽  
Process Variations ◽  
Processing Parameters ◽  
Process Conditions ◽  
Heating Rates ◽  
Pzt Thin Films ◽  
Si Substrates

ABSTRACTWe have systematically varied processing parameters to fabricate PZT 53/47 thin films. Polycrystalline PZT thin films were fabricated by spin depositing Pt coated Sio2/Si substrates with alkoxide solutions. Our study focused on two process parameters: 1) heating rate and 2) excess Pb additions. We used rapid thermal processing techniques to vary heating rates from 3°C/min to 8400°C/min. Films were characterized with the following excess Pb additions: 0, 3, 5, and 10 mol% For all process variations, films with greater perovskite content had better ferroelectric properties. Our best films were fabricated using the following process parameters: an excess Pb addition of 5 mol%, a heating rate of 8400°C/min and annealing conditions of 700°C for 1 min. Films fabricated using these process conditions had a remanent polarization of 0.27 C/m2and a coercive field of 3.4 MV/m.

Issues in the Flexible Integration of Sputter-Deposited PZT Thin Films with Polysilicon and Ti/Pt Electrode Layers for Use as Sensors and Actuators in Microelectromechanical Systems (MEMS)

2000 ◽  
Vol 657 ◽  
Author(s):  
C.F. Knollenberg ◽  
T.D. Sands ◽  
A.S. Nickles ◽  
R.M. White
Keyword(s):  
Thin Films ◽  
Lead Zirconate Titanate ◽  
Microelectromechanical Systems ◽  
Perovskite Phase ◽  
Ferroelectric Properties ◽  
Pt Electrode ◽  
Electrode Layer ◽  
Pzt Thin Films ◽  
Pzt Films ◽  
Sputter Deposited

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.

Laser-Assisted Low Temperature Processing of PZT Thin Films

1997 ◽  
Vol 493 ◽  
Author(s):  
Yongfei Zhu ◽  
Jinsong Zhu ◽  
Y. J. Song ◽  
S. B. Desu
Keyword(s):  
Thin Films ◽  
Low Temperatures ◽  
Laser Annealing ◽  
Perovskite Phase ◽  
Ferroelectric Properties ◽  
Processing Temperature ◽  
Pzt Thin Films ◽  
Step Process ◽  
Pzt Films ◽  
One Step

ABSTRACTA novel method for lowering processing temperature of ferroelectric Pb(Zr1−xTix)O3 (PZT) thin films was developed utilizing a laser-assisted two-step process. In the first step, perovskite phase was initiated in the PZT films by subjecting the films to a fornace anneal at low temperatures in the range of 470 °C to 550 °C depending on the Zr/Ti ratio. Later, the films were laser-annealed (using krF excimer laser) at room temperature to grow the perovskite phase, and to improve microstructure and ferroelectric properties. It was found that this two-step process was very effective in producing excellent quality ferroelectric PZT films at low temperatures. It should be noted that although laser annealing of amorphous and/or pyrochlore films directly (one-step process) produces perovskite phase, the ferroelectric properties of these films, irrespective of the composition, were rather unattractive. Some possible reasons for the ineffectiveness of the one-step process were discussed.

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

1993 ◽  
Vol 310 ◽  
Author(s):  
P. H. Ansari ◽  
A. Safari
Keyword(s):  
Thin Films ◽  
Lead Zirconate Titanate ◽  
Lead Titanate ◽  
Silicon Oxide ◽  
Perovskite Phase ◽  
Dissipation Factor ◽  
Lead Zirconate ◽  
Si Substrate ◽  
Pzt Thin Films ◽  
Pzt Films

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.

Dielectric and Ferroelectric Characterization of Sol-Gel Derived Ca-Doped PbTiO3 Thin Films

1996 ◽  
Vol 433 ◽  
Author(s):  
G. Teowee ◽  
K.C. McCarthy ◽  
E.K. Franke ◽  
J.M. Boulton ◽  
T.P. Alexander ◽  
...  
Keyword(s):  
Thin Films ◽  
Perovskite Phase ◽  
Ferroelectric Properties ◽  
Sol Gel ◽  
Test System ◽  
Impedance Analyzer ◽  
Si Substrates ◽  
Phase Development ◽  
Pt Electrodes

AbstractA series of sol-gel derived CaTiO3- PbTiO3 thin films ( i.e. Pb1−xCaxTiO3 with x = 0 − 1) was prepared on platinized Si substrates and fired to temperatures ranging from 550C to 650C. Multiple spincoating was performed to obtain films up to 0.5 μm thick with an intermediate firing of 400C between coatings. After the final crystallization firing, top Pt electrodes were sputtered to form monolithic capacitors. These capacitors were subjected to dielectric and ferroelectric characterization using an impedance analyzer and Radiant Technology RT66A Ferroelectric Test System. XRD was used to study the phase development and phase assembly of the fired films. All compositions were single perovskite phase after firing to 600C. The effects of Ca content on the crystallization behavior and ferroelectric properties are discussed.

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