Medium Electric Field Electron Injection/Extraction at Metal-Dielectric Interface

2010 ◽  
Vol 636-637 ◽  
pp. 437-443
Author(s):  
Eugen R. Neagu ◽  
C.J. Dias ◽  
M.C. Lança ◽  
Rui Igreja ◽  
José N. Marat-Mendes
Keyword(s):  
Dielectric Material ◽  
Reverse Current ◽  
Charge Injection ◽  
Electron Injection ◽  
Dielectric Materials ◽  
Open Circuit ◽  
Threshold Field ◽  
Polarization Current ◽  
Dielectric Interface ◽  
Charging Current

The isothermal charging current and the isothermal discharging current in low mobility materials are analyzed either in terms of polarization mechanisms or in terms of charge injection/extraction at the metal-dielectric interface and the conduction current through the dielectric material. We propose to measure the open-circuit isothermal charging and discharging currents just to overpass the difficulties related to the analysis of the conduction mechanisms in dielectric materials. We demonstrate that besides a polarization current there is a current related to charge injection or extraction at the metal-dielectric interface and a reverse current related to the charge trapped into the shallow superficial or near superficial states of the dielectric and which can move at the interface in the opposite way that occurring during injection. Two important parameters can be determined (i) the highest value of the relaxation time for the polarization mechanisms which are involved into the transient current and (ii) the height of the potential barrier W0 at the metal-dielectric interface. The experimental data demonstrate that there is no threshold field for electron injection/extraction at a metal-dielectric interface.

The determination of the metal-dielectric interface barrier height from the open-circuit isothermal charging current

2008 ◽  
Vol 104 (3) ◽  
pp. 034102 ◽  
Author(s):  
E. R. Neagu ◽  
R. M. Neagu ◽  
C. J. Dias ◽  
M. Carmo Lança ◽  
J. N. Marat-Mendes
Keyword(s):  
Barrier Height ◽  
Open Circuit ◽  
Dielectric Interface ◽  
Interface Barrier ◽  
Charging Current

Mathematical model to predict the characteristics of polarization in dielectric materials: The concept of piezoelectrcity and electrostriction

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Mathematical Model ◽  
Electric Field ◽  
Lead Zirconate Titanate ◽  
Dielectric Material ◽  
Strain Curve ◽  
Dielectric Materials ◽  
Lead Zirconate ◽  
Simulation Software ◽  
Constitutive Law ◽  
Basic Material

Model was developed for the prediction of polarization characteristics in a dielectric material exhibiting piezoelectricity and electrostriction based on mathematical equations and MATLAB computer simulation software. The model was developed based on equations of polarization and piezoelectric constitutive law and the functional coefficient of Lead Zirconate Titanate (PZT) crystal material used was 2.3×10-6 m (thickness), the model further allows the input of basic material and calculation of parameters of applied voltage levels, applied stress, pressure, dielectric material properties and so on, to generate the polarization curve, strain curve and the expected deformation change in the material length charts. The mathematical model revealed that an application of 5 volts across the terminals of a 2.3×10-6 m thick dielectric material (PZT) predicted a 1.95×10-9 m change in length of the material, which indicates piezoelectric properties. Both polarization and electric field curve as well as strain and voltage curve were also generated and the result revealed a linear proportionality of the compared parameters, indicating a resultant increase in the electric field yields higher polarization of the dielectric materials atmosphere.

Low Temperature Curing - Aqueous Base Developable Photoimageable Dielectric for WLP (Wafer Level Packaging)

2012 ◽  
Vol 2012 (DPC) ◽  
pp. 000986-001015
Author(s):  
Eric Huenger ◽  
Joe Lachowski ◽  
Greg Prokopowicz ◽  
Ray Thibault ◽  
Michael Gallagher ◽  
...  
Keyword(s):  
Low Temperature ◽  
Dielectric Material ◽  
Broad Band ◽  
Dielectric Materials ◽  
Next Generation ◽  
Wafer Level ◽  
Moore’S Law ◽  
Moore's Law ◽  
3D Chip Stacking ◽  
The Impact

As advanced packaging application space evolves and continues to deviate from the conventional shrinkage pathway predicted by Moore's law, material suppliers need to continue to work with OEMs, OSATs and Foundries to identify specific opportunities. One such opportunity continues to present itself in developing new materials to support new platforms for next generation products to support 3D chip stacking and TSV applications. The newer material sets can be established to meet more challenging design requirements associated with the demands, presented by the application from both a physical/lithographical processing and design perspective. Next generation packages requires the development of new dielectric materials that can support both the physical demands of 3D chip stacking and TSV package design aspects while maintaining strengths of the existing material platform. While vertical integration necessitates the use of thinned substrates and its associated integration challenges, there is a continuing need to support horizontal shrinkage typical of the Moore's Law, which pushes the lithography envelope requiring finer pitch and smaller feature resolution capability. This presentation identifies the strategy we have taken and highlights approach taking in the development of low temperature curable photoimageable dielectric materials with enhanced lithographic performance. We will discuss the methodology used to create benzocyclobutene based dielectric material curable at 180 °C and show how lithographic performance can be tuned to allow sub 5 micron via using broad band illumination. Finally we will review the impact of low temperature processing on the mechanical, thermal and electrical properties of this novel photoimageable dielectric material.

scholarly journals Space Charge Accumulation and Decay in Dielectric Materials with Dual Discrete Traps

2019 ◽  
Vol 9 (20) ◽  
pp. 4253 ◽  
Author(s):  
Zhaoliang Xing ◽  
Chong Zhang ◽  
Haozhe Cui ◽  
Yali Hai ◽  
Qingzhou Wu ◽  
...  
Keyword(s):  
Space Charge ◽  
Analytical Solutions ◽  
Charge Injection ◽  
Charge Trapping ◽  
Dielectric Materials ◽  
Dynamic Processes ◽  
Charge Accumulation ◽  
Charge Densities ◽  
Short Period ◽  
Trapped Charge

Charge trapping and de-trapping properties can affect space charge accumulation and electric field distortion behavior in polymers. Dielectric materials may contain different types of traps with different energy distributions, and it is of interest to investigate the charge trapping/de-trapping dynamic processes in dielectric materials containing multiple discrete trap centers. In the present work, we analyze the charge trapping/de-trapping dynamics in materials with two discrete traps in two cases where charges are injected continuously or only for a very short period. The time dependent trapped charge densities are obtained by the integration of parts in the case of continuous charge injection. In the case of instantaneous charge injection, we simplify the charge trapping/de-trapping equations and obtain the analytical solutions of trapped charge densities, quasi-free charge density, and effective carrier mobility. The analytical solutions are in good agreement with the numerical results. Then, the space charge dynamics in dielectric materials with two discrete trapping centers are studied by the bipolar charge transport (BCT) model, consisting of charge injection, charge migration, charge trapping, de-trapping, and recombination processes. The BCT outputs show the time evolution of spatial distributions of space charge densities. Moreover, we also achieve the charge densities at the same position in the sample as a function of time by the BCT model. It is found that the DC poling duration can affect the energy distribution of accumulated space charges. In addition, it is found that the coupling dynamic processes will establish a dynamic equilibrium rather than a thermodynamic equilibrium in the dielectric materials.

Electrically Tunable Phase Shifters With Air-Dielectric Sandwich Structure

2002 ◽  
Vol 720 ◽  
Author(s):  
Minki Jeong ◽  
Victor Kazmirenko ◽  
Yuriy Poplavko ◽  
Beomjin Kim ◽  
Sunggi Baik
Keyword(s):  
Sandwich Structure ◽  
Phase Shifter ◽  
Dielectric Material ◽  
Dielectric Materials ◽  
Air Gap ◽  
Phase Shifters ◽  
Effective Dielectric Constant ◽  
Microwave Phase Shifter ◽  
Piezoelectric Control ◽  
Total Structure

AbstractElectrically tunable microwave phase shifter was developed by inserting dielectric slab and piezoelectric actuator inside a waveguide. Air-dielectric sandwich structure of dielectric material and thin air gap was placed inside a waveguide, where the thickness of air gap is controlled by the actuator. Small changes in the ratio between the thickness of dielectric material and air gap induce significant changes in the effective dielectric constant of the air-dielectric sandwich structure. Phase shifts of 20∼200 degrees were realized with the dielectric materials such as (Mg, Ca)TiO3 while the thickness of air gap is changed between 0 to 30 μm by piezoelectric control. Since the dielectric ceramics has very small loss (tand ∼ 10-4) and the air gap has practically no loss, the total structure shows low insertion loss.

Characterization of Brightness of ZnS Electroluminescent Device with Dielectric Materials of SOG or TEOS

2008 ◽  
Vol 55 ◽  
pp. 160-163
Author(s):  
Sung Min Park ◽  
Mun Ja Kim ◽  
Sang Hyun Park ◽  
Jin Young Kim ◽  
Ji Beom Yoo
Keyword(s):  
Spin Coating ◽  
Dielectric Material ◽  
Dielectric Materials ◽  
Organic Binder ◽  
Layer Formation ◽  
Phosphor Layer ◽  
Electroluminescent Device ◽  
Coating Method ◽  
Powder Type

Spin on glass (SOG) and Tetraethylorthosilicate (TEOS) as a dielectric material were applied for inorganic powder type electroluminescent (EL) device. The spin coating method was used for the SOG layer or TEOS layer formation and phosphor layer formation. The phosphor layer was composed of ZnS:Cu,Cl powders and organic binder. The brightness of powder EL has been measured.

All standard materials flat reflector made by transformation electromagnetics

2014 ◽  
Vol 6 (2) ◽  
pp. 201-206 ◽  
Author(s):  
Mark Clemente Arenas ◽  
Anne Claire Lepage ◽  
Xavier Begaud ◽  
Paul Henri Tichit ◽  
André de Lustrac
Keyword(s):  
Design Methodology ◽  
Dielectric Material ◽  
Dielectric Materials ◽  
Original Method ◽  
Classical Solutions ◽  
Radiation Characteristics ◽  
Mathematical Relation ◽  
Simulation Results ◽  
Half Power ◽  
Realistic Structure

In this paper, the design methodology of a flat reflector composed with standard dielectric material and using transformation electromagnetics (TE) is presented. First, the mathematical relation between a flat reflector and a parabolic one is described. The TE principle is then described. Some realization issues are highlighted, leading to approximations and compromises in order to design a more realistic structure. In this way, a flat reflector made only with standard dielectric materials is presented, using an original method to achieve the desired spatial permittivity variation. The simulation results of different configurations for the flat reflector are presented and compared to classical solutions in order to prove the thickness reduction and the improvement of radiation characteristics in terms of gain and half-power beamwidth.

Experimental Analysis of Alternative Dielectric Materials for DBD Plasma Actuators

2018 ◽  
Author(s):  
F. F. Rodrigues ◽  
J. C. Pascoa ◽  
M. Trancossi
Keyword(s):  
Dielectric Material ◽  
Experimental Testing ◽  
Low Cost ◽  
Active Flow Control ◽  
Dielectric Strength ◽  
Dielectric Materials ◽  
Plasma Actuators ◽  
Poly Lactic Acid ◽  
Dbd Plasma ◽  
Advantages And Disadvantages

Dielectric Barrier Discharge plasma actuators are simple devices with great potential for active flow control applications. They have very interesting features which have made them a topic of interest for many researchers, for instance they present very low mass, fast response time, low cost, easy implementation and they are fully electronic with no moving parts. The dielectric material used in the construction of these devices present an important role in their performance. The variety of dielectrics studied in the literature is very restrict and the majority of the authors make use of Kapton, Teflon, Macor ceramic or PMMA. Furthermore, several authors reported difficulties in the durability of the dielectric layer when actuators operate at high levels of voltage and frequency. Considering this background, the present study focus on the experimental testing of alternative dielectric materials which can be used for DBD plasma actuators fabrication. Considering this, plasma actuators with dielectric layers made of Poly-Isobutylene rubber, Poly-Lactic acid and Acetoxy Silicon were experimentally tested. Although these dielectric materials are not commonly used in plasma actuators, their values of dielectric strength and dielectric permittivity indicate they can be good solutions. The plasma actuators facbricated with these alternative dielectric materials were experimentally analysed in terms of electrical characteristics and induced flow velocity, and the obtained results were compared with an actuator made of Kapton which is, currently, the most common dielectric material for plasma actuators. The effectiveness of the actuators was estimated and the advantages and disadvantages of the use of each dielectric material were discussed.

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