MFMIS Negative Capacitance FinFET Design for Improving Drive Current

The effect of remnant polarization (Pr), coercive electric-field (Ec), and parasitic capacitance of baseline device on the drive current (ION) of a metal-ferroelectric-metal-insulator-semiconductor (MFMIS) negative capacitance FinFET (NC FinFET) was investigated. The internal gate voltage in the MFMIS structure was simulated considering gate leakage current. Using technology computer aided design (TCAD) tool, the device characteristic of 7 nm FinFET was quantitatively estimated, for the purpose of modeling the baseline device of MFMIS NC FinFET. The need for appropriate parasitic capacitance to avoid performance degradation in MFMIS NC FinFET was presented through the internal gate voltage estimation. With an appropriate parasitic capacitance, the effect of Pr and Ec was investigated. In the case of Ec engineering, it is inappropriate to improve the device performance for MFMIS NC FinFET without threshold voltage degradation. Rather than Ec engineering, an adequate Pr value for achieving high ION in MFMIS NC FinFET is suggested.

Super-coercive electric field hysteresis in ferroelectric plastic crystal tetramethylammonium bromotrichloroferrate(iii)

Ionic plastic crystals are part of an emerging class of hybrid organic–inorganic ferroelectrics. Their super-coercive electric field hysteresis bares the signatures of ferroelectric switching, including interesting contributions from defects.

Ferroelectric low-voltage ON/OFF switching of chiral benzene-1,3,5-tricarboxamide derivative

Chiral liquid crystalline benzene trialkylamide derivative showed much lower coercive electric field for ferroelectric switching.

Ferro- and piezo-electric properties of a poly(vinyl fluoride) film with high ferro- to para-electric phase transition temperature

Excellent ferro- and piezo-electricity is observed for the first time in poly(vinyl fluoride) with a ferro- to para-electric transition at 168 °C, a coercive electric field of 120 MV m−1 and a relatively large piezoelectric coefficient of −11 pC N−1.

Effects of (Li, Ce) Co-Doping on Microstructure, Dielectric and Ferroelectric Properties of Strontium Niobate Ceramics

Sr2-x(Li2/3, Ce1/3)x Nb2O7 (x = 0, 0.05, 0.1, 0.2, 0.3, 0.5) (SLCN) ceramics were prepared by solid-state reaction method. The microstructure, dielectric and ferroelectric properties were investigated. The results show that all ceramics have high relative densities. Li+ and Ce4+ co-doping can promote the grains growing, and improve the dielectric and ferroelectric properties of strontium niobate ceramics. The dielectric constant decreases firstly, and then increases with the increasing of x in Sr2-x(Li2/3, Ce1/3)x Nb2O7, and the sample with x = 0.5 exhibits enhanced dielectric properties (εr ≈ 250, tanδ ≈ 0.02). The remnant polarization (Pr) and coercive electric field (Ec) of SLCN ceramics increase firstly, and then decrease with the increasing of Li+ and Ce4+ content, finally reach the maximum value of remnant polarization (Pr ≈ 0.058μC/cm2, Ec ≈ 6.87 kV/cm ) for x = 0.2.

Ferroelectricity of PZT-Based Thin Films Doped with Mn and Nb

The ternary compound thin films doped with Mn and Nb, Pb(Mn1/3,Nb2/3)O3-PbZrO3- PbTiO3(PMnN-PZ-PT), with the same ratio of PZ/PT=52:48(PZT(52/48)) are fabricated on the heterostructure substrates of SrRuO3(SRO)/Pt(111)/Ti/SiO2/Si(100) by the radio frequency (RF) magnetron sputtering system, in which the quench method is used for the post heat treatments. The ternary compound films exhibit polycrystal phase combined with (001), (101) and (111) orientations with the 6% mole percent mixing ratio of PMnN, in which the (111) directions are the main orientations for non-mixed PZT(52/48) films and 6% mole percent PMnN mixing PZT(52/48) films(6%PMnN-94%PZT(52/48)), and so both of them are epitaxially grown on Silicon substrates with the (111) orientation. The ferroelectricities of the films are studied by the Sawyer Tower circuit, and the results show that the mixing of PMnN seriously improves the ferroelectricities of PZT(52/48), in which the 6% mixed PZT films own the rest polarization intensity , the saturation polarization intensity and the coercive electric-field intensity =139 kV/cm which are distinctly larger than the non-mixed PZT(52/48) films

Studies on the Preparation and Characterization of Ferroelectric PLZT Film Capacitors

(Pb0.92La0.08)(Zr0.65Ti0.35) O3(PLZT) thin films were fabricated on indium-doped tin oxide (ITO)-coated glass substrates to create transparent capacitor by the sol-gel method following annealing process. X-ray diffraction analysis shows that the PLZT thin films are polycrystalline with a single perovskite phase at 650°C. The ferroelectric, electrical and optical properties of these films were investigated in detail as a function of annealing temperature. Measurements with the PLZT films annealed at 650°C yielded the following: relative permittivity≈775 and dielectric loss (tanδ) ≈0.054, leakage current of 7.1× 10-9A, and remanent polarization of 38 μC/cm2 and the coercive electric field of 55 kV/cm and transparency of 88%. The pure perovskite films exhibit better properties than those films which have some fraction of pyrochlore phase.

Magnitude of Intrinsic Electrocaloric Effect in PbTiO3 at High Electric Fields

Based on Landau-Devonshire theory, the electrothermal properties of PbTiO3bulk and film are computed near the temperatures of their phase transitions. A first-order ferroelectric to paraelectric phase transition is present in PbTiO3bulk. The coercive electric field at 700 K is about 25 MV m-1. High applied electric fields drive the transition to higher temperatures and theP−Tcurves to be continuous. For PbTiO3 film, the second-order phase transition reduces the excess entropy, and thereby the isothermal entropy change. With increasing electric field, the excess specific heat capacity becomes small, despite higher transition temperatures. The change of in-plane tensile misfit stress lowers the transition temperature. Besides, the adiabatic temperature change and the refrigerant capacity of PbTiO3bulk are 4.76 K and 94.1 kJ m-3, respectively.

Fabrication and Electrical Properties of P(VDF-TrFE)/Bi3.5Nd0.5Ti3O12 Bi-Layer Composite Ferroelectric Thin Films

The microstructure and electrical properties of P(VDF-TrFE)/Bi3.5Nd0.5Ti3O12bi-layer composite ferroelectric thin films deposited on Pt/Ti/SiO2/Si using two successive spin coatings were investigated. It shows the pores in Bi3.5Nd0.5Ti3O12(BNT) films were effectively suppressed by the presence of P(VDF-TrFE) copolymer films by SEM. The ferroelectric, leakage and dielectric properties of the thin films with different thickness ratio of P(VDF-TrFE) and BNT thin films were measured. With increasing the thickness of P(VDF-TrFE), the remnant polarization, coercive electric field, leakage current density and dielectric constant of thin films were all decreased (except pure P(VDF-TrFE) thin film). Results indicate that the key electrical properties were improved effectively by a little loss of the remnant polarization, which infers potential application in the filed of ferroelectric memory.

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

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.