Highly tunable Mn-doped PZT thin films for integrated RF devices

2015 ◽  
Vol 2015 (DPC) ◽  
pp. 002095-002127
Author(s):  
Warda Benhadjala ◽  
Florence Sonnerat ◽  
Jennifer Guillaume ◽  
Christel Dieppedale ◽  
Philippe Renaux ◽  
...  
Keyword(s):  
Thin Films ◽  
Leakage Current ◽  
Bias Voltage ◽  
Low Noise ◽  
Pzt Thin Films ◽  
Wide Range ◽  
Metal Insulator Metal ◽  
Dc Bias ◽  
High Dielectric ◽  
Mn Doped

Modern RF systems have triggered an important and urgent demand for inexpensive voltage controlled capacitors used for a wide range of applications such as tunable antennas or low-noise voltage-controlled oscillators (VCO). Ferroelectric materials have received considerable interest for electrically tunable dielectrics due to their high dielectric constant and large dielectric nonlinearity under dc bias field. Lead zirconate titanate (PZT) ceramics which have been under intense investigation for various industrial domains including micro-electro-mechanical systems (MEMS), non-volatile memories, and high-k capacitors, are especially well-known candidate materials due to their unequalled ferroelectric properties and stability in device operating ranges. However, reported voltage tunability of PZT films is relatively low (~35%@4GHz) and remains insufficient for microwave tunable devices. Therefore, much attention has been focused on the PZT modification by adding a small amount of dopants. Shao et al., studied strontium-doped PZT (PSZT) thin films and achieved a tunability of 48% @1MHz. More recently, Hu et al. reported a tunability of 65%@10kHz for lanthanum-modified PZT (PLZT) films. In the presented study, effect of manganese (Mn) doping on electrical properties of PZT (PMZT) thin films has been investigated. Metal/insulator/metal (MIM) capacitors using PZT-based thin films and ruthenium (Ru) top electrodes were processed on platinized (Pt) silicon wafers by a sol gel method. Dielectric properties of PMZT thin films were studied by varying the dopant amount and compared to those of pure PZT layers. At this end, on-wafer electrical measurements were conducted with a particular attention on leakage current characterization and RF measurements under DC bias voltage. We have shown that leakage current density decreased from 6.5 μA/cm2 to 1 μA/cm2 at 850kV/cm by doping PZT with Mn. Observed conduction mechanisms will be discussed in detail in the full-length paper. Moreover, developed PZT-based thin films exhibit high dielectric strengths achieving 2.1MV/cm and outstanding tunability as high as 85% (~7:1) @1GHz at bias voltage of 20V. Thus, PMZT tunability is among the highest ones reported in the literature for PZT-derived thin films but also for other piezoelectric materials. Indeed, in comparison, the tunability of BST-based materials, typically studied for voltage tunable applications, does not exceed 5:1. These remarkable results indicate that Mn-doped PZT thin films are promising candidates for RF tunable capacitors.

Sol-gel doped-PZT thin films for integrated tunable capacitors

2015 ◽  
Vol 2015 (1) ◽  
pp. 000256-000261 ◽  
Author(s):  
Warda Benhadjala ◽  
Gwenael Le Rhun ◽  
Christel Dieppedale ◽  
Florence Sonnerat ◽  
Jennifer Guillaume ◽  
...  
Keyword(s):  
Thin Films ◽  
Leakage Current ◽  
Breakdown Voltage ◽  
Piezoelectric Materials ◽  
Sol Gel ◽  
Wafer Level ◽  
Pzt Thin Films ◽  
Tunable Capacitors ◽  
Metal Insulator Metal ◽  
Dc Bias

Integrated metal-insulator-metal (MIM) capacitors using sol-gel PZT doped with lanthanum (La, PLZT), manganese (Mn, PMZT) and niobium (Nb, PNZT) were successfully processed and characterized for tunable applications. Dielectric properties of doped-PZT were investigated and compared to those of pure PZT. Wafer-level measurements were conducted with a particular attention on tunability evaluation under DC bias voltage. Tunability, leakage current density and breakdown voltage of pure PZT thin films were 77.6% (i.e. 4.5:1) at 10kHz/10V, 4.8.10−5 A/cm2 at 870kV and 37.5V (i.e. 1.63 MV/cm) respectively. The breakdown voltage increased by 25% with La doping and by 50% with Nb and Mn. The lowest leakage current were achieved by PNZT (7.0.10−7 A/cm2 at 870kV) while PMZT films exhibited an outstanding tunability reaching 88.8% (i.e. 8.9:1) at 100 kHz and 20V. Enhanced performances of the developed doped-PZT were compared to the state of the art. Results indicate that electrical properties of sol-gel doped-PZT achieved those of conventionally deposited materials. It is noteworthy that obtained PMZT tunability is among the highest ones reported in the literature for PZT-derived thin films but also for other piezoelectric materials.

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

1997 ◽  
Vol 493 ◽  
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.

scholarly journals Nanostructure Analysis of Sol-gel PZT Thin Films Derived from Different Chemical Routes

2009 ◽  
Vol 15 (S3) ◽  
pp. 53-54
Author(s):  
Aiying Wu ◽  
P. M. Vilarinho
Keyword(s):  
Thin Films ◽  
Data Storage ◽  
Chemical Reactivity ◽  
Sol Gel ◽  
Random Access ◽  
Lead Zirconate ◽  
Piezoelectric Response ◽  
Metal Alkoxides ◽  
Pzt Thin Films ◽  
Wide Range

AbstractLead zirconate - lead titanate (PZT) materials are commercially important piezoelectric and ferroelectrics in a wide range of applications, such as data storage (dynamic access and ferroelectric random access memories) and sensing and actuating devices. PZT with the morphotropic phase boundary composition offers the highest piezoelectric response and at the present there are no fullydeveloped alternative materials to PZT. The importance of PZT associated with the continuous requirements of device miniaturization, imposes the development of high quality PZT thin films with optimized properties. Concomitantly due to the dependence of the final properties of thin films on the details of the microstructure a thoroughly analysis at the local scale of their microstructure is necessary. Sol-gel method, is one of the Chemical Solution Deposition techniques used to prepare oxide thin films, such as PZT. Starting from a solution, a solid network is progressively formed via inorganic polymerisation reactions. Most metal alkoxides used for sol-gel synthesis are highly reactive towards hydrolysis and condensation. Therefore their chemical reactivity has to be tailored via the chemical modification (or complexation) of metal alkoxides to avoid uncontrolled reactions and precipitation. For PZT sol gel thin film preparation, two chemical routes are frequently used depending on the nature of the molecular precursor, namely methotoxyethanol (MOE) route and diol-route.

Photoferroelectric Effects of Undoped and Extrinsic Ion-Doped PZT Thin Films

1994 ◽  
Vol 361 ◽  
Author(s):  
Li Li ◽  
Chhiu-Tsu Lin ◽  
Martin S. Leung ◽  
Paul M. Adams ◽  
Russell A. Lipeles
Keyword(s):  
Thin Films ◽  
Optical Memory ◽  
Hysteresis Loops ◽  
Band Gap Energy ◽  
Acetate Solution ◽  
X Ray Diffraction ◽  
Pzt Thin Films ◽  
Photocurrent Spectroscopy ◽  
Visible Wavelengths ◽  
Mn Doped

ABSTRACTDeposition by aqueous acetate solution (DAAS) technique was used to synthesize undoped and 5 wt% Cr-, Mn-, Eu-, or Pr-doped Pb(Zr0.53Ti0.47O3 [PZT] thin films. The dopant was incorporated into PZT either in the precursor coating solution or via thermal diffusion into undoped PZT. X-ray diffraction shows that ion-doped PZT thin films on Pt<l 1 l>/Ti/SiO2/Si<100> (in particular, the Mn- and Eu- doped samples) display better crystallinity and smaller lattice parameters than those on sapphire substrates. The enhancement of photoconductivity at visible wavelengths measured by excitation photocurrent spectroscopy (EPS) goes as Cr-doped∼Mn-doped > Eu-doped ∼ Pr-doped. Only Mn-doped PZT perovskites have the band gap energy red-shifted to 360 nm from 330 nm. The space charge (or photovoltaic) field was estimated to be < 8 v when about 100 v was applied to ion-doped PZT thin films with 260 or 320 nm light. By using laser irradiation at selected wavelengths and switching the polarity of applied bias voltage, the expected changes in resistance (Ry) and remanent polarization (±Pr) states were observed in the P-E hysteresis loops. The possible applications of extrinsic ion-doped PZT thin films in optical memory devices are discussed.

scholarly journals Estimation of steady-state leakage current in polycrystalline PZT thin films

AIP Advances ◽  
2016 ◽  
Vol 6 (9) ◽  
pp. 095025 ◽  
Author(s):  
Yury Podgorny ◽  
Konstantin Vorotilov ◽  
Alexander Sigov
Keyword(s):  
Thin Films ◽  
Steady State ◽  
Leakage Current ◽  
Pzt Thin Films

Adhesion and Dielectric Strength of Ultra-Low Dielectric Constant PTFE Thin Films

1997 ◽  
Vol 476 ◽  
Author(s):  
C.T. Rosenmaver ◽  
J. W. Bartz ◽  
J. Hammes
Keyword(s):  
Thin Films ◽  
Dielectric Constant ◽  
Dielectric Strength ◽  
Low Dielectric Constant ◽  
Thermal Treatments ◽  
Test Results ◽  
Low Dielectric ◽  
Metal Insulator Metal ◽  
Thickness Standard ◽  
High Dielectric

AbstractPrevious work has demonstrated the potential of polytetrafluoroethylene (PTFE) thin films for ULSI applications. The films are deposited from PTFE nanoemulsions. They have an ultra-low dielectric constant of 1.7 to 2.0, a leakage current of less than 1.0 nA/cm2 @ 0.2 MV/cm and a dielectric strength of from 0.5 to 2.4 MV/cm. They are thermally stable (isothermal weight loss < 1.0 %/hr at 450 °C), uniform (thickness standard deviation < 2%), and have excellent gap-fill properties (viscosity of 1.55 cP and surface tension of 18 mN/m). The films are inert with respect to all known semiconductor process chemicals, yet they are easily etched in an oxygen plasma.This paper discusses the processing technology that has been developed to process PTFE films with these properties. Specifically, it addresses two recent discoveries: 1) Good adhesion of spin-coated PTFE to SiO2 surfaces; and 2) high dielectric strength of PTFE thin films spin-coat deposited onto rigid substrates. The adhesion-promoting and thermal treatments necessary to produce these properties are detailed. Stud pull test results and test results from metal-insulator-metal (MIM) capacitor structures are given.

Excellent Room-Temperature Ferroelectricity in Mn-substituted BiFeO3 Thin Films Formed by Chemical Solution DepositionΨ

2006 ◽  
Vol 933 ◽  
Author(s):  
Sushil Kumar Singh ◽  
Hiroshi Ishiwara
Keyword(s):  
Thin Films ◽  
Leakage Current ◽  
Lattice Structure ◽  
Hysteresis Loops ◽  
Secondary Phase ◽  
Low Leakage ◽  
Low Leakage Current ◽  
Chemical Solutions ◽  
Mn Substitution ◽  
Mn Doped

AbstractMn-substituted BiFeO3 (BFO) thin films were formed by chemical solutions deposition on Pt/Ti/SiO2/Si(100) structures. Effects of the Mn-substitution on the structure and ferroelectricity of BFO films were examined. We found that the lattice structure of the film is sensitive to the Mn-substitution and the secondary phase is appears in 50% Mn-substituted BFO films. The leakage current were increased with the Mn-substitution. However, the 5% Mn-substituted BFO film shows low leakage current than undoped BFO films in a high electric field than 0.5 MV/cm. Due to the low leakage current in Mn-doped 3, 5 and 7% BFO films, the saturated P-E hysteresis loops with remanent polarization around 100 μC/cm2 were obtained at RT.

Zirconia Coatings Deposited by Inductively Coupled Plasma Assisted CVD

1998 ◽  
Vol 555 ◽  
Author(s):  
P. Colpo ◽  
G. Ceccone ◽  
B. Leclercq ◽  
P. Salvatore ◽  
F. Rossi
Keyword(s):  
Thin Films ◽  
Bias Voltage ◽  
Inductively Coupled Plasma ◽  
Gas Mixture ◽  
Negative Bias ◽  
Negative Bias Voltage ◽  
Inductively Coupled ◽  
Deposition Parameters ◽  
Coating Characteristics ◽  
Dc Bias

AbstractThin films of zirconia have been deposited by an Inductively Coupled Plasma Assisted CVD (ICP-PACVD) reactor from tetra (tert-butoxy)-zircon precursor diluted in Ar and O2 gas mixture. An independent RF generator is used to control carefully the substrate negative bias voltage during the deposition. Zirconia thin films, with thickness up to 10 microns were deposited on Si (100) polished wafers under different plasma conditions. Correlation between deposition parameters, and microstructure has been established showing that the ion bombardment has a large influence on the coating characteristics. In particular, the possibility of tailoring mechanical properties of the films by controlling the applied DC bias voltage is discussed.

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