On the Ohmic Contact Formation Mechanism in the Au/Te/N-GaAs System

1990 ◽  
Vol 181 ◽  
Author(s):  
K. Wuyts ◽  
G. Langouche ◽  
H. Vanderstraeten ◽  
R.E. Silverans ◽  
M. Van Hove ◽  
...  
Keyword(s):  
Resonant Tunneling ◽  
Ohmic Contacts ◽  
Conduction Mechanism ◽  
Gaas Surface ◽  
Ohmic Conduction ◽  
X Ray Diffraction ◽  
X Ray ◽  
Barrier Metal ◽  
Ohmic Contact Formation ◽  
Contact Resistivities

ABSTRACTAlloyed Au/Te/n–GaAs ohmic contacts, with contact resistivities comparable to those of the AuGe device standard, have been developed and studied by Mässbauer spectroscopy, Raman scattering and X-Ray Diffraction. The formation of Au-doped Ga2Te3 crystallites, grown epitaxially on a defectively GaAs surface was observed. No evidence for the formation of an n++–GaAs surface layer could be derived. The interpretation of all experimental results leads to a description of the ohmic conduction mechanism based on a resonant tunneling process assisted by defect/impurity related deep levels through low barrier metal/Te/(Au)Ga2Te3/GaAs interfaces

scholarly journals Synthesis and Characterization of Lithium-Ion Conductive LATP-LaPO4 Composites Using La2O3 Nano-Powder

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3502
Author(s):  
Fangzhou Song ◽  
Masayoshi Uematsu ◽  
Takeshi Yabutsuka ◽  
Takeshi Yao ◽  
Shigeomi Takai
Keyword(s):  
Room Temperature ◽  
Conduction Mechanism ◽  
Lithium Ion ◽  
X Ray Diffraction ◽  
Temperature Conductivity ◽  
Room Temperature Conductivity ◽  
X Ray ◽  
Nano Powder ◽  
Powder Addition

LATP-based composite electrolytes were prepared by sintering the mixtures of LATP precursor and La2O3 nano-powder. Powder X-ray diffraction and scanning electron microscopy suggest that La2O3 can react with LATP during sintering to form fine LaPO4 particles that are dispersed in the LATP matrix. The room temperature conductivity initially increases with La2O3 nano-powder addition showing the maximum of 0.69 mS∙cm−1 at 6 wt.%, above which, conductivity decreases with the introduction of La2O3. The activation energy of conductivity is not largely varied with the La2O3 content, suggesting that the conduction mechanism is essentially preserved despite LaPO4 dispersion. In comparison with the previously reported LATP-LLTO system, although some unidentified impurity slightly reduces the conductivity maximum, the fine dispersion of LaPO4 particles can be achieved in the LATP–La2O3 system.

Hydrothermal Synthesis of Lead Titanate Epitaxial Film for Non-Volatile Memory Device Application

2013 ◽  
Vol 652-654 ◽  
pp. 1846-1850
Author(s):  
Thin Thin Thwe ◽  
Than Than Win ◽  
Yin Maung Maung ◽  
Ko Ko Kyaw Soe
Keyword(s):  
Electron Microscopy ◽  
Silicon Dioxide ◽  
Lead Titanate ◽  
Conduction Mechanism ◽  
Epitaxial Film ◽  
Memory Device ◽  
X Ray Diffraction ◽  
X Ray ◽  
Non Volatile Memory ◽  
Scanning Electron

Hydrothermal synthesized lead titanate (PbTiO3¬) powder was prepared in a Teflon-lined stainless steel bomb at different bath temperatures. X-ray diffraction was performed to examine the phase assignment and crystallographic properties of hydrothermal synthesized lead titanate powder. Silicon dioxide (SiO2) was thermally deposited and adapted as intermediate layer on p-Si (100) substrates for MFIS (Metal/Ferroelectric/ Insulator/Semi-conductor) design. The microstructures of PbTiO3 film for both MFS and MFIS designs were observed by scanning electron microscopy (SEM). Charge conduction mechanism was also interpreted by C-2-V relationship. Polarization and electric field characteristics were measured by Sawyer-Tower circuit and good hysteresis nature was formed for both structures of the films. The loop of MFIS was wider than that of MFS cell. Also, the higher value of polarization (Ps=3.21E-03µC/cm2) for MFIS could be explained on the basis of higher dipole moment in this SiO2 buffer layer.

scholarly journals Study on the Synthesize, Characterization, and Conductive Performance of Nickelzircomolybdnum Heteropoly Acid Salt with Keggin Structure

2019 ◽  
Vol 2019 ◽  
pp. 1-4
Author(s):  
Zhihong Zhang ◽  
Baoying Wang ◽  
Yijing Zhang ◽  
Gehong Zhang ◽  
Yujing Wang
Keyword(s):  
Conduction Mechanism ◽  
Heteropoly Acid ◽  
Electrochemical Impedance ◽  
Impedance Spectrum ◽  
Heteropoly Compound ◽  
Electrochemical Impedance Spectrum ◽  
Acid Salt ◽  
X Ray Diffraction ◽  
Protonic Conduction ◽  
X Ray

A novel heteropoly acid salt, Na6[Ni(Mo11ZrO39)]·20H2O, has been synthesized by the means of acidification and adding the reactants into the solution step by step. The heteropoly compound was characterized by elemental analysis, TGA/DSC, infrared spectrum, ultraviolet spectrum, X-ray diffraction, and SEM. Its protonic conduction was measured by the means of the electrochemical impedance spectrum. The results showed that it belongs to the Keggin type, and its conductivity value was 1.23 × 10–2 S/cm at 23°C when the relative humidity was 60%, and the conductivity enhanced with the elevated temperature. Its proton conduction mechanism was in accordance with vehicle mechanism, and the activation energy was 27.82 kJ/mol.

A structural analysis of the Pd/GaN ohmic contact annealing behavior

2002 ◽  
Vol 743 ◽  
Author(s):  
C. C. Kim ◽  
P. Ruterana ◽  
J. H. Je
Keyword(s):  
Ohmic Contact ◽  
Ohmic Contacts ◽  
Structural Evolution ◽  
Electron Beam Evaporation ◽  
Intermetallic Phases ◽  
X Ray Diffraction ◽  
Annealing Behavior ◽  
X Ray ◽  
Transmission Electron ◽  
The Relationship

AbstractFor ohmic contact on p GaN, palladium is one of the best candidates showing ohmic characteristics already without annealing. To be realized in devices, it is necessary to know the behavior of the ohmic contacts at accelerated conditions, especially for high temperatures and power. We report on the structural evolution of palladium layers (30 nm) deposited on GaN (0001) by electron beam evaporation without intentional annealing. They were next cut into various pieces which were individually submitted to rapid thermal annealing at 400, 500, 600, 700 and 800°C for 10 sec. We investigate the differences in the microstructure and the location of interfacial phases and their relationships as determined by X-ray diffraction and transmission electron microscopy, we then suggest the formation mechanism based on the relationship. It is shown that the interface is disrupted at annealing above 600°C and by 800°C only very small patches of Pd are still present, however they area completely imbedded in a matrix of intermetallic phases (gallides) formed by the reaction with GaN.

scholarly journals Electrical Conductivity and Chemical Equilibria of Coordination Biopolymeric Cerium (IV)-Alginate Complex with Correlation between the Structure and Complex Stability

2015 ◽  
Vol 7 (2) ◽  
pp. 57 ◽  
Author(s):  
Ishaq Zaafarany ◽  
Hatem Altass ◽  
Jabir Alfahemi ◽  
Khalid Khairou ◽  
Refat Hassan
Keyword(s):  
Electrical Conductivity ◽  
Conduction Mechanism ◽  
Research Study ◽  
Coordination Geometry ◽  
Complex Stability ◽  
X Ray Diffraction ◽  
Chemical Equilibria ◽  
X Ray ◽  
Infrared Absorption Spectra ◽  
Diffraction Patterns

In this research study, the cross-linked cerium (IV)-alginate complex, as coordination biopolymeric compound in the granules form, was prepared. It has been indicated from the x-ray diffraction patterns that the nature of alginate complex is amorphous. Additionally, it has been revealed from the infrared absorption spectra that cerium (IV) chelates the alginate macromolecular chains in the complex. The study has displayed that the range of us OCO- is 1424 cm-1and the range of uasOCO- is 1605 cm-1. This indicates that a complexation type between the cation Ce4+ and both carboxylate and hydroxyl functional groups of alginate macromolecule is usually takes place. The study has also measured the electrical conductivity (s) of coordination biopolymeric cerium (IV)-alginate complex, as function of temperature. It has been indicated from the measured value of the electrical conductivity, i.e., 1.04 x10-9 Siemens at 20oC that the conductance of the complex lies in the range of semiconductors. The research has profoundly discussed with evaluation of the thermodynamic parameters. Afterwards, appropriate conduction mechanism based on the electrical conductivity and chemical equilibrium has also been suggested and discussed in terms of the complex stability in correlation with its coordination geometry.

A combined x‐ray diffraction and Raman analysis of Ni/Au/Te‐ohmic contacts ton‐GaAs

1994 ◽  
Vol 75 (4) ◽  
pp. 2055-2060 ◽  
Author(s):  
J. Watté ◽  
K. Wuyts ◽  
R. E. Silverans ◽  
M. Van Hove ◽  
M. Van Rossum
Keyword(s):  
Ohmic Contacts ◽  
X Ray Diffraction ◽  
Raman Analysis ◽  
X Ray

Phase Formation at Rapid Thermal Annealing of Nickel Contacts on C-Face n-Type 4H-SiC

2005 ◽  
Vol 483-485 ◽  
pp. 733-736 ◽  
Author(s):  
Sergio Ferrero ◽  
A. Albonico ◽  
Umberto M. Meotto ◽  
G. Rambolà ◽  
Samuele Porro ◽  
...  
Keyword(s):  
Thermal Annealing ◽  
Rapid Thermal Annealing ◽  
Ohmic Contacts ◽  
Structural Evolution ◽  
Auger Spectroscopy ◽  
X Ray Diffraction ◽  
Electrical Measurements ◽  
X Ray ◽  
Ohmic Behavior ◽  
Semiconductor Interfaces

In this work we report an analysis on Ni/4H-SiC interfaces aimed at optimizing the ohmic contacts. Several thermal cycles have been performed by rapid thermal annealing checking the possible chemical reactions at the metal semiconductor interfaces. Micro x-ray diffraction and micro Raman techniques have been performed in order to study the interface micro structural evolution. Inter diffusion of each element at the Ni - SiC interface was examined using Auger spectroscopy. Electrical measurements have been performed in order to check the ohmic behavior of the contacts. Finally, a correlation between microstructures evolution and electrical behaviors is reported.

Formation and characterization of ohmic contacts to n–AlGaAs using Pd/AuGe/Ag/Au

1993 ◽  
Vol 8 (5) ◽  
pp. 1045-1051 ◽  
Author(s):  
L.R. Zheng ◽  
D.J. Lawrence ◽  
T.N. Blanton
Keyword(s):  
Liquid Phase ◽  
Ohmic Contacts ◽  
Phase Reaction ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sequential Deposition ◽  
The Stability ◽  
Ion Backscattering ◽  
Liquid Phase Reaction

Sequential deposition of Pd/AuGe/Ag/Au and rapid thermal annealing at 450 to 550 °C were employed to form a shallow ohmic contact to n–Alx Ga1−x As. Contact resistivity was in the range of (0.7–1) × 10−5 at x = 0.3 to (2–4) × 10−5 ohm-cm2 at x = 0.55. Limited interfacial reaction was verified by ion backscattering and x-ray diffraction techniques and attributed to the stability of Au–Ag solid solutions against underlying substrates. Contacts form at 450 to 500 °C, possibly via solid-state reaction, whereas liquid phase reaction may take place at 550 °C.

Phase Formation in Ti-Al-N MAX-Phase Contacts to GaN

2009 ◽  
Vol 615-617 ◽  
pp. 947-950 ◽  
Author(s):  
Michał A. Borysiewicz ◽  
Eliana Kamińska ◽  
Anna Piotrowska ◽  
Iwona Pasternak ◽  
Rafał Jakieła ◽  
...  
Keyword(s):  
Thin Film ◽  
Mass Spectrometry ◽  
Phase Formation ◽  
Ohmic Contacts ◽  
Secondary Ion Mass Spectrometry ◽  
Max Phase ◽  
X Ray Diffraction ◽  
Max Phases ◽  
X Ray ◽  
Secondary Ion

Presented are the results of studies on Ti-Al-N MAX phase formation in thin film multilayers of Ti, Al and TiN deposited on n-type GaN by magnetron sputtering. Two approaches to phase formation are shown, annealing Ti-Al-TiN multilayers at 600oC in argon and annealing Ti/Al multilayers at 600oC in nitrogen. Samples are characterized by means of High Resolution X-Ray Diffraction and Secondary Ion Mass Spectrometry profiling. As MAX phases are very stable at high temperatures the potential of their application as ohmic contacts to n-GaN devices is discussed.

Fabrication and Characterization of Ohmic Contacts to 3C-SiC Layers Grown on Silicon

2019 ◽  
Vol 963 ◽  
pp. 485-489
Author(s):  
Monia Spera ◽  
Giuseppe Greco ◽  
Raffaella Lo Nigro ◽  
Salvatore di Franco ◽  
Domenico Corso ◽  
...  
Keyword(s):  
Structural Analysis ◽  
Ohmic Contacts ◽  
Specific Contact Resistance ◽  
Silicon Substrates ◽  
X Ray Diffraction ◽  
X Ray ◽  
Specific Contact ◽  
Fabrication And Characterization ◽  
P Type

This paper reports on the formation and characterization of Ohmic contacts to n-type and p-type type 3C-SiC layers grown on silicon substrates. In particular, Ohmic contact behavior was obtained either using Ni or Ti/Al/Ni layers annealed at 950°C. The values of the specific contact resistance ρc estimated by means of circular TLM (C-TLM) structures varied in the range ~ 10-3-10-5 Ωcm2, depending on the doping level of the 3C-SiC layer. A structural analysis performed by X-Ray Diffraction (XRD) allowed to identify the main phases formed upon annealing, i.e., Ni2Si and Al3Ni2. The morphology of the reacted contacts depended on that of the underlying substrate. The results can be useful for the development of a variety of devices on the cubic 3C-SiC polytype.

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