Solution Chemistry Optimization of Sol-Gel Processed 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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Robust ferroelectricity enhancement of PZT thin films by a homogeneous seed layer

10.21203/rs.3.rs-763002/v1 ◽

2021 ◽

Author(s):

jie jiang ◽

Lei Liu ◽

Kuo Ouyang ◽

Zhouyu Chen ◽

Shengtao Mo ◽

...

Keyword(s):

Thin Films ◽

Electrical Properties ◽

Remanent Polarization ◽

Perovskite Phase ◽

Ferroelectric Properties ◽

Sol Gel ◽

Pzt Thin Films ◽

Large Dielectric Constant ◽

Sol Gel Process ◽

A New Technique

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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The Effect of RuO2/Pt Hybrid Bottom Electrode Structure on The Microstructure and Ferroelectric Properties of Sol-Gel Derived PZT Thin Films

MRS Proceedings ◽

10.1557/proc-493-131 ◽

1997 ◽

Vol 493 ◽

Cited By ~ 8

Author(s):

Seung-Hyun Kim ◽

J. G. Hong ◽

J. C. Gunter ◽

H. Y. Lee ◽

S. K. Streiffer ◽

...

Keyword(s):

Thin Films ◽

Leakage Current ◽

Bottom Electrode ◽

Ferroelectric Properties ◽

Sol Gel ◽

Chemical Solution ◽

Electrode Structure ◽

Solution Deposition ◽

Pzt Thin Films ◽

Chemical Solution Deposition Method

ABSTRACTFerroelectric PZT thin films on thin RuO2 (10, 30, 50nm)/Pt hybrid bottom electrodes were successfully prepared by using a modified chemical solution deposition method. It was observed that the use of a lOnm RuO2Pt bottom electrode reduced leakage current, and gave more reliable capacitors with good microstructure compare to the use of thicker RuO2/Pt bottom electrodes. Typical P-E hysteresis behavior was observed even at an applied voltage of 3V, demonstrating greatly improved remanence and coercivity. Fatigue and breakdown characteristics, measured at 5V, showed stable behavior, and only below 13-15% degradation was observed up to 1010 cycles. Thicker RuO2 layers resulted in high leakage current density due to conducting lead ruthenate or PZT pyrochlore-ruthenate and a rosette-type microstructure.

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Importance Of Solution Chemistry In Preparing Sol–Gel PZT Thin Films Directly On Copper Surfaces

Chemistry of Materials ◽

10.1021/cm070999q ◽

2008 ◽

Vol 20 (1) ◽

pp. 303-307 ◽

Cited By ~ 19

Author(s):

Mark D. Losego ◽

Jon F. Ihlefeld ◽

Jon-Paul Maria

Keyword(s):

Thin Films ◽

Sol Gel ◽

Solution Chemistry ◽

Pzt Thin Films ◽

Copper Surfaces

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Synthesis and Ferroelectric Properties of Sol–Gel Derived Intergrowth-Superlattice-Structured SrBi4Ti4O15-Bi4Ti3O12 Thin Films

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.197-198.1781 ◽

2011 ◽

Vol 197-198 ◽

pp. 1781-1784

Author(s):

Hua Wang ◽

Jian Li ◽

Ji Wen Xu ◽

Ling Yang ◽

Shang Ju Zhou

Keyword(s):

Thin Films ◽

Remanent Polarization ◽

Annealing Temperature ◽

Ferroelectric Properties ◽

Sol Gel ◽

Hysteresis Loops ◽

Si Substrates ◽

Gel Processing ◽

Coercive Electric Field ◽

Clockwise Hysteresis

Intergrowth-superlattice-structured SrBi4Ti4O15–Bi4Ti3O12(SBT–BIT) films prepared on p-Si substrates by sol-gel processing. Synthesized SBT–BIT films exhibit good ferroelectric properties. As the annealing temperature increases from 600°C to 700°C, the remanent polarization Prof SBT–BIT films increases, while the coercive electric field Ecdecreases. SBT–BIT films annealed at 700°C have a Prvalue of 18.9µC/cm2which is higher than that of SBT (16.8µC/cm2) and BIT (14.6µC/cm2), and have the lowest Ecof 142 kV/cm which is almost the same as that of SBT and BIT. The C-V curves of Ag/SBT-BIT/p-Si heterostructures show the clockwise hysteresis loops which reveal the memory effect due to the polarization. The memory window in C-V curve of Ag/SBT-BIT/p-Si is larger than that of Ag/SBT/p-Si heterostructure or Ag/BIT/p-Si heterostructure.

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The Microstructure, Phase and Ferroelectric Properties of PZT Thin Films on Oriented Multilayer Electrodes

MRS Proceedings ◽

10.1557/proc-596-199 ◽

1999 ◽

Vol 596 ◽

Cited By ~ 4

Author(s):

Tingkai Li ◽

Sheng Teng Hsu ◽

Yufei Gao ◽

Mark Engelhard

Keyword(s):

Thin Film ◽

Thin Films ◽

Hysteresis Loop ◽

Perovskite Phase ◽

Ferroelectric Properties ◽

Pyrochlore Phase ◽

Experimental Results ◽

Butyl Ether ◽

Pzt Thin Films ◽

Pzt Thin Film

AbstractThree kinds of oriented electrodes of Pt, Ir and Pt/Ir electrodes were prepared using electron beam evaporation techniques for deposition of PZT thin films. An oxide MOCVD reactor with liquid delivery system was used for the growth of PZT thin films. [Pb(thd)2], Zr(TMHD)4 and Ti(IPO)4 were dissolved in a mixed solvent of tetrahydrofuran or butyl ether, isopropanol and tetraglyme to form a precursor source. The deposition temperature and pressure were 500 - 650°C and 5 - 10 Torr, respectively. The experimental results showed PZT thin film deposited on various electrodes had different phase formation, microstructure and ferroelectric property. The X-ray patterns showed the perovskite phase of PZT was formed on both Ir and Pt/Ir electrodes at 550°C. The grain size of the PZT thin film increases after a further, higher temperature annealing. The as-deposited PZT thin film on Pt electrode exhibits pyrochlore phase at 550°C. The phase is transformed to perovskite phase after 650°C annealing. The experimental results also indicated that the MOCVD PZT thin film on Pt/Ir exhibits better ferroelectric and electrical properties compared to those deposited on Pt and Ir electrodes. A 300 nm thick PZT thin film on Pt/Ir electrode has a square, well saturated, and symmetrical hysteresis loop with 2Pr value of 40 μC/cm2 and 2Ec of 73 kV/cm at an applied voltage of 5 V. The hysteresis loop of the PZT thin film is almost saturated at 2 V. The leakage current of the film is 6.16 × 10−7 A/cm2 at 100 KV/cm. The electrode effects on ferroelectric properties of PZT thin films also have been investigated.

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Ten Analyses Of Sol-Gel Derived And Sputtered PZT Thin Films

MRS Proceedings ◽

10.1557/proc-200-219 ◽

1990 ◽

Vol 200 ◽

Cited By ~ 16

Author(s):

Cheng-Chen Hsueh ◽

Martha L. MeCartney

Keyword(s):

Thin Films ◽

Ferroelectric Properties ◽

Sol Gel ◽

Rf Magnetron Sputtering ◽

Pzt Thin Films ◽

Ferroelectric Domains ◽

Metal Organic ◽

Organic Precursors ◽

Acid Catalyzed ◽

Sol Gel Films

ABSTRACTFerroelectric PZT thin films were prepared by sol-gel methods and RF magnetron sputtering. Sputtered PZT fast fired at 650° for 30 minutes showed microporosity. For the sol-gel route, solution precursors had a significant effect on the microstructure of the crystalline PZT films. PZT thin films derived from metal-organic precursors dissolved in n-propanol were observed to have large and microporous spherulitic grains on the order of 2 μm and phase separation in acetic acid-catalyzed films. In contrast, PZT precursors originated from alcohol exchanges with 2-methoxyethanols resulted in dense films with fine grains of ∼0.2 μm and clear evidence of ferroelectric domains. The dense sol-gel films possessed superior dielectric and ferroelectric properties.

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Investigation of the Structural and Microstructural Characteristics of Sol-Gel Derived Lead Lanthanum Titanate Thin Films

MRS Proceedings ◽

10.1557/proc-596-375 ◽

1999 ◽

Vol 596 ◽

Cited By ~ 1

Author(s):

S. B. Majumder ◽

S. Bhaskar ◽

P. S. Dobal ◽

A. L. Morales. Cruz ◽

R. S. Katiyar

Keyword(s):

Thin Films ◽

Acetic Acid ◽

Electrical Properties ◽

Ferroelectric Properties ◽

Sol Gel ◽

Sharp Decrease ◽

Modified Technique ◽

Lanthanum Titanate ◽

La Addition ◽

Deposited Films

AbstractIn the present work we have studied the characteristics of Pb1.05-xLaxTil-x/4O3 ( x= 0 to 30 at%) thin films prepared by acetic acid and methoxy-ethanol based sol-gel techniques. We have found that higher intermediate temperature fired films (x=0.15), prepared by acetic acid modified technique yielded (100) textured growth with improved dielectric properties. It has been argued that homogeneous mixing of the film constituents in the sol is influenced by the choice of the precursor materials and preparation methodology which in turn controls the growth characteristics and electrical properties. Lanthanum as a dopant has a pronounced influence on the structure, microstructure and electrical properties of the deposited films. In the Raman spectra, the soft E(1TO) phonon shifts towards the lower frequency with a sharp decrease in its intensity and a tetragonal to cubic structural transformation (for 26.5 at % La) was observed at room temperature. In the ferroelectric composition range (up to 15 at % La doping), we have observed a significant improvement of ferroelectric properties with the La addition.

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Local Fatigue Evaluation in PZT Thin Films with Nanoparticles by Piezoresponse Force Microscopy

Smart Materials Research ◽

10.1155/2012/391026 ◽

2012 ◽

Vol 2012 ◽

pp. 1-9

Author(s):

B. S. Li

Keyword(s):

Thin Films ◽

Lead Zirconate Titanate ◽

Ferroelectric Properties ◽

Sol Gel ◽

Precursor Solution ◽

Grain Morphology ◽

Piezoresponse Force Microscopy ◽

Lead Zirconate ◽

Fatigue Performance ◽

Pzt Thin Films

Lead zirconate titanate (PZT) thin films with the morphotropic phase boundary composition (Zr/Ti = 52/48) have been prepared using a modified diol-based sol-gel route by introducing 1–5 mol% barium titanate (BT) nanoseeds into the precursor solution on platinized silicon substrates (Pt/Ti/SiO2/Si). Macroscopic electric properties of PZT film with nanoparticle showed a significant improvement of ferroelectric properties. This work aims at the systematic study of the local switching polarization behavior during fatigue in PZT films with and without nanoparticles by using very recent developed scanning piezoelectric microscopy (SPM). We show that the local fatigue performance, which is characterized by variations of local piezoloop with electric cycles, is significantly improved by adding some nanoseeds. It has been verified by scanning electron microscope (SEM) that the film grain morphology changes from columnar to granular structure with the addition of the nanoseeds. On the other hand, the existence of PtxPb transition phase, which existed in interface at early crystallization stage of pure PZT thin film, deteriorates the property of the interface. These microstructures and the interfaces of these films significantly affect the electrons injection occurred on the interfaces. The domain wall pinning induced by injected electrons and the succeeding penetration into the films is discussed to explain the fatigue performance.

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Preparation and Electrical Properties of Bi0.9Nd0.1Fe0.925Mn0.075O3 Thin Films

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.557-559.1933 ◽

2012 ◽

Vol 557-559 ◽

pp. 1933-1936

Author(s):

Ning Yan ◽

Sheng Hong Yang ◽

Yue Li Zhang

Keyword(s):

Thin Films ◽

Remanent Polarization ◽

Ferroelectric Properties ◽

Sol Gel ◽

X Ray Diffraction ◽

Electrical Measurements ◽

X Ray ◽

Low Leakage ◽

Bifeo3 Thin Films ◽

Low Leakage Current

Pure BiFeO3(BFO) and Bi0.9Nd0.1Fe0.925Mn0.075O3(BNFM) thin films were deposited on Pt(111)/Ti/SiO2/Si substrate by sol-gel method. X-ray diffraction analysis showed that all the films were single perovskite structure and a phase transition appeared in Nd–Mn codoped BiFeO3 thin films. Electrical measurements indicated that the ferroelectric properties of BFO thin films were significantly improved by Nd and Mn codoping. BNFM films exhibit a low leakage current and a good P-E hysteresis loop. The remanent polarization (Pr) value of 74μC/cm2has been obtained in BNFM films, while the coercive field (Ec) is 184kV/cm.

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