Robust ferroelectricity enhancement of PZT thin films by a homogeneous seed layer

Abstract With its excellent ferroelectric properties such as large dielectric constant and large remanent polarization, PZT thin films are extensively used in micro-sensors and other devices. In this study, the sol-gel process was used to fabricate Pb(Zr0.52Ti0.48)O3 thin films with Pb(ZrxTi1−x)O3 seed islands. The experimental consequences demonstrate that all the Pb(Zr0.52Ti0.48)O3 thin films with Pb(ZrxTi1−x)O3 seeds show pure perovskite phase with no other impurity phases, and the electrical properties of Pb(Zr0.52Ti0.48)O3 thin films modified by Pb(ZrxTi1−x)O3 seed islands with different Zr/Ti ratios are improved, such as remanent polarization increased, dielectric properties increased, coercive electric field decreased, leakage current density decreased, etc. In particular, the electrical properties of the Pb(Zr0.52Ti0.48)O3 thin films with Pb(ZrxTi1−x)O3 seed islands are the most optimal when the x is 0.52. This paper provides a new technique for optimizing the electrical properties of PZT thin films, which is of great significance for breaking through the bottleneck of the development of ferroelectric memory.

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The Characterization and Electrical Properties of DOPED PZT Thin Films Prepared by Sol-Gel Processing

MRS Proceedings ◽

10.1557/proc-361-421 ◽

1994 ◽

Vol 361 ◽

Cited By ~ 4

Author(s):

Wan In Lee ◽

J.K. Lee ◽

Elsub Chung ◽

C.W. Chung ◽

I.K. Yoo ◽

...

Keyword(s):

Thin Films ◽

Grain Size ◽

Remanent Polarization ◽

Ferroelectric Properties ◽

Sol Gel ◽

Current Level ◽

Pzt Thin Films ◽

Sol Gel Process ◽

Pzt Films ◽

Gel Processing

ABSTRACTPZT (Zr/Ti = 53/47), PNZT (4% Nb doped PZT), PSZT (2% Sc doped PZT), and PSNZT (1% Sc and 1% Nb doped PZT) thin films were prepared by a sol-gel process. They were characterized by XRD, SEM and TEM. Both crystallographic orientation and grain size of PZT films can be changed by doping. Pt/PZT/Pt capacitors were fabricated for the measurement of ferroelectric properties. By doping with both Sc and Nb, the fatigue performance of the PZT films was considerably improved and the coercive field was decreased, while the remanent polarization was not changed. In addition, the effect of dopants on the leakage current level of PZT films was studied.

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Enhanced Electrical properties in Mn-doped Bi3.25La0.75Ti3O12 thin films

MRS Proceedings ◽

10.1557/proc-0902-t03-52 ◽

2005 ◽

Vol 902 ◽

Author(s):

Sushil Kumar Singh ◽

Hiroshi Ishiwara

Keyword(s):

Thin Film ◽

Thin Films ◽

Electrical Properties ◽

Coercive Field ◽

Remanent Polarization ◽

Ferroelectric Properties ◽

Sol Gel ◽

Switching Field ◽

Mn Doping ◽

Mn Doped

AbstractMn-doped Bi3.25La0.75Ti3O12 (BLT) thin films were fabricated by depositing sol-gel solutions on Pt/Ti/SiO2/Si <100> substrates. The surface morphology and ferroelectric properties of Mn-doped BLT films depend upon the orientation of the films. Small amount of Mn-doping in BLT films influences the ferroelectric properties of the films, that is, it enhances the remanent polarization and reduces the coercive field. The 1% Mn-doped BLT films show enhanced remanent polarization and reduced the coercive field by about 22%. To the contrary, Mn-doping more than 1% decreases polarization gradually. Mn-doping significantly improves the fatigue resistance of BLT films. The reduced polarization in the 3.3% Mn-doped thin film recovers during switching cycles higher than 5 × 105. Under high switching field, the probability of field-assisted unpinning of domains is expected to be high and this may be the main cause for increase in polarization after 5 × 105 in the 3.3% Mn-doped BLT film.

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Ferroelectric Properties of Tb-doped PZT Thin films Prepared by Sol-gel Process

Journal of the Korean Institute of Electrical and Electronic Material Engineers ◽

10.4313/jkem.2004.17.9.947 ◽

2004 ◽

Vol 17 (9) ◽

pp. 947-952

Keyword(s):

Thin Films ◽

Ferroelectric Properties ◽

Sol Gel ◽

Pzt Thin Films ◽

Sol Gel Process

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Influence of Geometrical Parameters on the Electrical Properties of Ferroelectric Thin Films

MRS Proceedings ◽

10.1557/proc-243-129 ◽

1991 ◽

Vol 243 ◽

Cited By ~ 6

Author(s):

S.P. Faure ◽

P. Gaucher ◽

J.P. Ganne

Keyword(s):

Thin Films ◽

Electrical Properties ◽

Remanent Polarization ◽

Sol Gel ◽

Mean Value ◽

Ferroelectric Thin Films ◽

Geometrical Parameters ◽

Electrical Characteristics ◽

Electrode Size ◽

Sol Gel Process

AbstractFerroelectric thin films of PbZr0.5Ti0.5O3 were prepared by sol-gel process. Top electrodes of different sizes were deposited on thin films in order to study their influence on electrical properties. Histograms of the measured electrical characteristics are related to the electrode sizes. By reducing the electrode size, it is possible to improve the electrical properties of the film. Various properties, such as remanent polarization Pr and coercive voltage Vc, were measured statistically in order to show the evolution of their mean value and of their variance with the electrode size.

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THICKNESS-DEPENDENT MICROSTRUCTURES AND ELECTRICAL PROPERTIES OF LiTaO3 THIN FILMS PREPARED BY A Sol-Gel PROCESS

International Journal of Modern Physics B ◽

10.1142/s0217979207044640 ◽

2007 ◽

Vol 21 (18n19) ◽

pp. 3404-3411

Author(s):

M. C. KAO ◽

H. Z. CHEN ◽

S. L. YOUNG ◽

C. C. LIN ◽

C. C. YU

Keyword(s):

Thin Film ◽

Thin Films ◽

Grain Size ◽

Remanent Polarization ◽

Ferroelectric Properties ◽

Sol Gel ◽

Relative Dielectric Constant ◽

Coating Technology ◽

Si Substrates ◽

Sol Gel Process

LiTaO 3 thin films were deposited on Pt / Ti / SiO 2/ Si substrates by means of a sol-gel spin-coating technology and rapid thermal annealing (RTA). The influence of various annealing treatments on the characteristics of the thin films were studied by varying the single-annealed-layer thickness (50 ~ 200 nm ) and heating temperatures (500 ~ 800° C ) of the samples. Experimental results reveal that the single-annealed-layer strongly influences grain size, dielectricity and ferroelectricity of LiTaO 3 thin films. The grain size of LiTaO 3 thin film decreases slightly with increasing thickness of the single-annealed-layer, and highly c-axis orientated LiTaO 3 films can be obtained for a single-annealed-layer of 50 nm. When the thickness of the single-annealed-layer was increased from 50 to 200 nm, the relative dielectric constant of LiTaO 3 thin film decreased from 65 to 35, but the dielectric loss factor (tanδ) was increased. The LiTaO 3 films with the single-annealed-layer of 50 nm showed excellent ferroelectric properties in terms of a remanent polarization ( P r) of 12.3 μ C /cm2 (Ec ∼ 60 kV/cm), and a low current density of 5.2×l0-8 A /cm2 at 20 kV/cm.

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Solution Chemistry Optimization of Sol-Gel Processed Pzt Thin Films

MRS Proceedings ◽

10.1557/proc-310-275 ◽

1993 ◽

Vol 310 ◽

Cited By ~ 10

Author(s):

Steven J. Lockwood ◽

R. W. Schwartz ◽

B. A. Tuitle ◽

E. V. Thomas

Keyword(s):

Thin Films ◽

Acetic Acid ◽

Remanent Polarization ◽

Ferroelectric Properties ◽

Sol Gel ◽

Pyrochlore Phase ◽

Solution Chemistry ◽

Water Volume ◽

Original Solution ◽

Pzt Thin Films

AbstractWe have optimized the ferroelectric properties and microstructural characteristics of sol-gel PZT thin films used in a CMOS-integrated, 256 bit ferroelectric non-volatile memory. The sol-gel process utilized in our work involved the reaction of Zr n-butoxide, Ti isopropoxide, and Pb (IV) acetate in a methanol/acetic acid solvent system. A 10-factor screening experiment identified solution concentration, acetic acid addition, and water volume as the solution chemistry factors having the most significant effects on the remanent polarization, coercive field, ferroelectric loop quality, and microstruntural quality. The optimal values for these factors were determined by runnig a 3-factor uniform shell design, modelling the responses, and testing the models at the predicted optimal conditions. The optimized solution chemistry generated 3-layer, 300-400 nm thick films on RuO2 coated silicon substrates with coercive fields of less than 25 kV/cm (a 40-50 % improvement over the original solution chemistry), a remanent polarization of 25-30 μC/cm, and a reduction in the pyrochlore phase content below observable levels.

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Electrical Properties of Crystalline and Amorphous Pb(ZrxTi1−x)O3 Thin Films Prepared by the Sol-Gel Technique

MRS Proceedings ◽

10.1557/proc-271-359 ◽

1992 ◽

Vol 271 ◽

Cited By ~ 1

Author(s):

Yuhuan Xu ◽

Chih-Hsing Cheng ◽

Ren Xu ◽

John D. Mackenzie

Keyword(s):

Thin Films ◽

Electrical Properties ◽

Ferroelectric Properties ◽

Sol Gel ◽

Dip Coating ◽

Metal Substrate ◽

Pzt Thin Films ◽

Heat Treated ◽

Pzt Films ◽

Gel Technique

ABSTRACTPb(ZrxTi1−x)O3 (PZT) solutions were prepared by reacting lead 2-ethylhexanoate with titanium n-propoxide and zirconium n-propoxide. Films were deposited on several kinds of metal substrate by dip-coating. Crystalline PZT films and amorphous PZT films were heat-treated for 1 hour at 650°C and at 400°C, respectively. Electrical properties including dielectric, pyroelectric and ferroelectric properties of both crystalline and amorphous PZT films were measured and compared. The amorphous PZT thin films exhibited ferroelectric-like behaviors.

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The effect of Mn/Nb doping on dielectric and ferroelectric properties of PZT thin films prepared by sol–gel process

Journal of Sol-Gel Science and Technology ◽

10.1007/s10971-014-3608-x ◽

2015 ◽

Vol 74 (2) ◽

pp. 378-386 ◽

Cited By ~ 17

Author(s):

Huajun Sun ◽

Yong Zhang ◽

Xiaofang Liu ◽

Shanshan Guo ◽

Yi Liu ◽

...

Keyword(s):

Thin Films ◽

Ferroelectric Properties ◽

Sol Gel ◽

Pzt Thin Films ◽

Sol Gel Process ◽

Nb Doping

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Effect of La and W dopants on dielectric and ferroelectric properties of PZT thin films prepared by sol–gel process

Applied Physics A ◽

10.1007/s00339-017-1428-x ◽

2017 ◽

Vol 124 (1) ◽

Cited By ~ 7

Author(s):

Mi Xiao ◽

Zebin Zhang ◽

Weikang Zhang ◽

Ping Zhang

Keyword(s):

Thin Films ◽

Ferroelectric Properties ◽

Sol Gel ◽

Pzt Thin Films ◽

Sol Gel Process

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Residual Stress in Pzt Thin Films and its Effect on Ferroelectric Properties

MRS Proceedings ◽

10.1557/proc-243-341 ◽

1991 ◽

Vol 243 ◽

Cited By ~ 36

Author(s):

Terry J. Garino ◽

Mark Harrington

Keyword(s):

Thin Films ◽

Residual Stress ◽

Dielectric Constant ◽

Remanent Polarization ◽

Coefficient Of Thermal Expansion ◽

Perovskite Phase ◽

Ferroelectric Properties ◽

External Stress ◽

Circular Section ◽

Pzt Thin Films

AbstractThe residual stress in solution derived Pb(Zr.53Ti.47)o3, PZT 53:47, films was determined by measuring the bending of the substrate due to the stress. The substrate consisted of an oxidized (100) silicon wafer with 300 nm coating of platinum. In all cases the stress was tensile. Films fired at a temperature in the range where pyrochlore formation occurs (500° to 575°C) had the highest residual stresses, 200 to 350 MPa, whereas those fired at higher temperatures, 600° to 650°C, where the perovskite phase forms had stresses of 100 to 200 MPa. Stress measurements made during film firing indicate that the pyrochlore containing films had higher residual stress because their coefficient of thermal expansion was much larger than that of predominantly perovskite films. The effect of the amount of stress on ferroelectric properties was studied by making measurements on a film with and without the application of an external stress. The external stress was applied by bending a circular section of the substrate, which effectively lowered the amount of tensile stress in the film by ∼30%. Decreasing the stress in this manner was found to increase the remanent polarization by ∼11% and the dielectric constant by ∼2%.

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