scholarly journals Influence of antiferroelectric-like behavior on tuning properties of ferroelectric HZO-based varactors

MRS Advances ◽  
2021 ◽  
Author(s):  
Sukhrob Abdulazhanov ◽  
Maximilian Lederer ◽  
David Lehninger ◽  
Tarek Ali ◽  
Jennifer Emara ◽  
...  
Keyword(s):  
Thin Film ◽  
Elevated Temperatures ◽  
Temperature Measurements ◽  
Thin Film Capacitors ◽  
Capacitance Voltage ◽  
Field Cycling ◽  
The Impact ◽  
Cycle Dependence ◽  
Reduced Temperature

Abstract In this article, we investigate the capacitance–voltage (C–V) characteristics of $$\text {Hf}_{x}\text {Zr}_{1-x}\text {O}_{2}$$ Hf x Zr 1 - x O 2 metal-ferroelectric-metal (MFM) thin-film capacitors with various Zr doping for varactor applications. The impact of field cycling during the wake-up process on the capacitance was analyzed. In addition, the effect of antiferroelectric-like (AFE) behavior on tuning was investigated. The transition between ferroelectric (FE) and AFE regime is particularly interesting for varactor application, as a reduced bias is required for tuning. The cycle dependence of the FE and AFE properties at elevated temperatures was also investigated, where it was shown that with an increase of temperature, the tunability is reduced. Temperature measurements also comply with recent studies of ferroelastic nature of AFE behavior. Graphic abstract

Ca-doped lead zirconate titanate thin film capacitors on base metal nickel on copper foil

2004 ◽  
Vol 19 (10) ◽  
pp. 2841-2848 ◽  
Author(s):  
Taeyun Kim ◽  
Angus I. Kingon ◽  
Jon-Paul Maria ◽  
Robert T. Croswell
Keyword(s):  
Thin Film ◽  
Lead Zirconate Titanate ◽  
Electrical Transport ◽  
Electroless Nickel ◽  
Lead Zirconate ◽  
Phase Assemblage ◽  
Ca Doping ◽  
Zirconate Titanate ◽  
Thin Film Capacitors ◽  
The Impact

Ca-doped lead zirconate titanate (52/48) thin film capacitors were prepared on electroless nickel-coated copper foils for embedded capacitor applications. The impact of Ca doping and process parameter variations was studied. Ca addition significantly reduced the temperature coefficient of capacitance. Specifically, the temperature variation was reduced to less than 10% between 300 and 580 K through calcium addition. Optimized capacitance densities and loss tangents were 400 nF/cm2 and 0.02, respectively. Crystallization temperatures of 600 °C yielded these optimized electrical properties, while higher temperatures resulted in interfacial reactions. The influence of oxygen partial pressure during crystallization was also studied. Dielectric properties were sensitive to pO2, with optimal properties occurring in a narrow pO2 window centered about 10−3 Torr. The trends with oxygen pressure were mirrored by changes in phase assemblage. Electrical transport across the dielectric layers was not strongly dependent upon doping level. This insensitivity was attributed to a thin interfacial layer present in all samples. Interface analysis using equivalent circuit analogues showed the nature of the interface to be highly resistive (insulating), rather than semiconducting or conducting.

Influence of Schottky Interfaces on Dielectric Properties in Perovskite-Type Oxide Thin-Film Capacitors

2011 ◽  
Vol 485 ◽  
pp. 203-206
Author(s):  
Naohiro Horiuchi ◽  
Takuya Hoshina ◽  
Hiroaki Takeda ◽  
Takaaki Tsurumi
Keyword(s):  
Thin Film ◽  
Estimation Method ◽  
Hysteretic Behavior ◽  
Perovskite Oxide ◽  
Oxide Thin Film ◽  
Perovskite Type Oxide ◽  
Thin Film Capacitors ◽  
Capacitance Voltage ◽  
Perovskite Type ◽  
Schottky Model

An estimation method of the influence of interfaces on properties in perovskite-type oxide thin-film capacitors is presented. We proposed a modified Schottky model that can be employed to explain the electric properties of metal/perovskite-type oxide junctions. The modified model considers the electric field dependence of permittivity and the flow of electrons from metal to defect states located in the band gap of the perovskite oxide. The simulation based on this model could successfully describe the results of capacitance-voltage measurements of junctions between metals (Pt, Au, and Ag) and Nb-doped SrTiO3, which were not explained by the conventional Schottky model. Additionally, a simulation for a thin-film capacitor with hysteretic behavior could depict an asymmetric capacitance-voltage curve.

Capacitance Voltage Characteristics of Polysilicon–Polysilicon Oxide–Polysilicon Structures for Three-Dimensional Memory

2000 ◽  
Vol 609 ◽  
Author(s):  
John R. Lindsey ◽  
T. S. Kalkur
Keyword(s):  
Thin Film ◽  
Elevated Temperatures ◽  
Three Dimensional ◽  
Oxide Thickness ◽  
Bulk Silicon ◽  
Shunt Resistance ◽  
Chip Area ◽  
Capacitance Voltage ◽  
Silicon Structures ◽  
Cv Measurements

ABSTRACTThree-dimensional integration offers a dramatic reduction in chip area required per bit and has long been a research objective. Three-dimensional integration with thin film transistors (TFTs) requires detailed parametric analysis with techniques such as Capacitance-Voltage (CV) Characterization. CV analysis of polysilicon TFTs uses polysilicon-oxide-polysilicon thin film structures. Most of the CV analysis involving polysilicon available to date, however, is with polysilicon-oxide-bulk silicon structures. In this paper, we report the results of modeling andmeasurement of the CV characteristics of polysilicon-polysilicon oxide-polysilicon for doped and undoped polysilicon. To increase the conductivity of the polysilicon, elevated temperatures were used for measurement. CV measurements matching the theoretical curves were made for these polysilicon thin films. Oxide thickness, series and shunt resistance were extracted and correlated to process problems and splits.

Study of the Interface Properties of TiO2/SiO2/SiC by Photocapacitance

2011 ◽  
Vol 679-680 ◽  
pp. 350-353 ◽  
Author(s):  
Ming Hung Weng ◽  
Simon Barker ◽  
Rajat Mahapatra ◽  
Benjamin J.D. Furnival ◽  
Nicolas G. Wright ◽  
...  
Keyword(s):  
High Temperature ◽  
Elevated Temperatures ◽  
Temperature Measurements ◽  
Mis Structure ◽  
Interface Properties ◽  
Post Deposition Annealing ◽  
Oxide Charge ◽  
Real Time Measurement ◽  
Capacitance Voltage ◽  
Post Deposition

We have investigated the annealing of fixed oxide charge and interfacial traps in MISiC strucures by means of the photo capacitance voltage technique at temperatures up to 500°C. Elevated temperature measurements show reduced hysteresis and reduced fixed oxide charge at the interface. The photo capacitance technique shows a real-time measurement at elevated temperatures, in which electrons are populated by photo energy, in a 4H-SiC MIS structure. We also confirm the reduction of fixed oxide charge at the interface by means of high temperature post deposition annealing, which occurs during the high temperature measurements.

The combined effect of mechanical strain and electric field cycling on the ferroelectric performance of P(VDF-TrFE) thin films on flexible substrates and underlying mechanisms

2016 ◽  
Vol 18 (42) ◽  
pp. 29478-29485 ◽  
Author(s):  
Deepa Singh ◽  
Deepak Deepak ◽  
Ashish Garg
Keyword(s):  
Thin Film ◽  
Electric Field ◽  
Ferroelectric Properties ◽  
Mechanical Strain ◽  
Combined Effect ◽  
Flexible Substrates ◽  
Thin Film Capacitors ◽  
Field Cycling ◽  
Underlying Mechanisms ◽  
Memory Applications

In this manuscript, we study the combined effect of mechanical strain and electric field cycling on the ferroelectric properties and polarization fatigue of P(VDF-TrFE) based flexible thin film capacitors from the perspective of flexible memory applications.

Thermo-switchable Polymer Dielectrics

2011 ◽  
Vol 1312 ◽  
Author(s):  
Ross S. Johnson ◽  
Fenil M. Kholwadwala ◽  
Shawn M. Dirk
Keyword(s):  
Thin Film ◽  
Elevated Temperatures ◽  
Main Chain ◽  
Electrical Characterization ◽  
Phenylene Vinylene ◽  
Polymer Backbone ◽  
Polymer Main Chain ◽  
Thin Film Capacitors ◽  
Leaving Groups

ABSTRACTWe are interested in utilizing the thermo-switchable properties of precursor poly(p-phenylene vinylene) (PPV) polymers to develop capacitor dielectrics that will fail at specific temperatures due to the material irreversibly switching from an insulator to a conducting polymer. By utilizing different leaving groups on the polymer main chain, the temperature at which the polymer transforms into a conductor can be varied over a range of temperatures. Electrical characterization of thin-film capacitors prepared from several precursor PPV polymers indicates that these materials have good dielectric properties until they reach elevated temperatures, at which point conjugation of the polymer backbone effectively disables the device. Here, we present the synthesis, dielectric processing, and electrical characterization of a new thermo-switchable polymer dielectric.

scholarly journals Fire Resistance Behaviour of Geopolymer Concrete:An Overview

Buildings ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 82
Author(s):  
Salmabanu Luhar ◽  
Demetris Nicolaides ◽  
Ismail Luhar
Keyword(s):  
Compressive Strength ◽  
Thermal Resistance ◽  
Building Materials ◽  
Elevated Temperatures ◽  
Construction Materials ◽  
Flexural Behavior ◽  
Thermal Shrinkage ◽  
Physico Chemical ◽  
The Impact ◽  
Loss Of Strength

Even though, an innovative inorganic family of geopolymer concretes are eye-catching potential building materials, it is quite essential to comprehend the fire and thermal resistance of these structural materials at a very high temperature and also when experiencing fire with a view to make certain not only the safety and security of lives and properties but also to establish them as more sustainable edifice materials for future. The experimental and field observations of degree of cracking, spalling and loss of strength within the geopolymer concretes subsequent to exposure at elevated temperature and incidences of occurrences of disastrous fires extend an indication of their resistance against such severely catastrophic conditions. The impact of heat and fire on mechanical attributes viz., mechanical-compressive strength, flexural behavior, elastic modulus; durability—thermal shrinkage; chemical stability; the impact of thermal creep on compressive strength; and microstructure properties—XRD, FTIR, NMR, SEM as well as physico-chemical modifications of geopolymer composites subsequent to their exposures at elevated temperatures is reviewed in depth. The present scientific state-of-the-art review manuscript aimed to assess the fire and thermal resistance of geopolymer concrete along with its thermo-chemistry at a towering temperature in order to introduce this novel, most modern, user and eco-benign construction materials as potentially promising, sustainable, durable, thermal and fire-resistant building materials promoting their optimal and apposite applications for construction and infrastructure industries.

Sign in / Sign up

Export Citation Format

Share Document