Mo—In—Mn Based Ohmic Contact to P—GaAs

1989 ◽  
Vol 146 ◽  
Author(s):  
T.S. Kalkur ◽  
Y.C. Lu ◽  
Robert Caracciolo
Keyword(s):  
Ohmic Contact ◽  
Heat Pulse ◽  
X Ray Diffraction ◽  
X Ray ◽  
Resistivity Measurements ◽  
Contact Metallization ◽  
Current Voltage ◽  
Gas Atmosphere ◽  
Secondary Ion ◽  
Scanning Electron

ABSTRACTMo—In—Mn metallization is used to form ohmic contact on Be—implanted Rapid Thermally annealed GaAs. The rapid thermal alloying of Mo—In—Mn contact metallization is performed at various temperatures and times in A.G. Associates Heat Pulse 410 system in forming gas atmosphere. The electrical properties of the contacts were analyzed by current-voltage and contact resistivity measurements. The microstructures of the contacts were analyzed using scanning electron microscope, energy dispersive x-ray analysis, x-ray diffraction and secondary ion mass spectroscopy.

Effect of Sintering Temperature on Microstructure and Electrical Properties of Nanozinc Oxide Varistor

2011 ◽  
Vol 495 ◽  
pp. 190-193 ◽  
Author(s):  
Mehdi Mirzayi ◽  
Mohammad Hoseen Hekmatshoar ◽  
Abdolazim Azimi
Keyword(s):  
Electrical Properties ◽  
Sintering Temperature ◽  
Voltage Characteristic ◽  
X Ray Diffraction ◽  
Current Voltage Characteristic ◽  
X Ray ◽  
Current Voltage ◽  
Polyacrylamide Gel Method ◽  
Zno Powder ◽  
Scanning Electron

Nanometer-sized ZnO powder was synthesized at low decomposing temperature by polyacrylamide-gel method where Acrylamide was used as monomer, and N,N-methylene-bisacrylamide as lattice reagent. The characteristic of powders were studied by X-ray diffraction and scanning electron microscope (SEM). The results indicated uniform distribution of nanoZnO particles. Also electrical properties were investigated at different sintering temperatures of 800, 900 and 1000 ° C. It was observed that increase in sintering temperature, resulted in increase in the grain size of the varistor ceramics. The observed nonlinearity in current – voltage characteristic was explained by the existence of potential barrier at the grain boundaries and lowering of the barriers.

scholarly journals Kesterites and Chalcopyrites: A Comparison of Close Cousins

2011 ◽  
Vol 1324 ◽  
Author(s):  
Ingrid Repins ◽  
Nirav Vora ◽  
Carolyn Beall ◽  
Su-Huai Wei ◽  
Yanfa Yan ◽  
...  
Keyword(s):  
Density Functional ◽  
Materials Characterization ◽  
Induced Current ◽  
X Ray Diffraction ◽  
Functional Theory ◽  
X Ray ◽  
Electron Beam Induced Current ◽  
Similarities And Differences ◽  
Secondary Ion ◽  
Scanning Electron

ABSTRACTChalcopyrite solar cells based on CuInSe2 and associated alloys have demonstrated high efficiencies, with current annual shipments in the hundreds of megawatts (MW) range and increasing. Largely due to concern over possible indium (In) scarcity, a related set of materials, the kesterites, which comprise Cu2ZnSnS4 and associated alloys, has received increasing attention. Similarities and differences between kesterites and chalcopyrites are discussed as drawn from theory, depositions, and materials characterization. In particular, we discuss predictions from density functional theory, results from vacuum co-evaporation, and characterization via x-ray diffraction, scanning electron microscopy, electron beam-induced current, quantum efficiency, secondary ion mass spectroscopy, and luminescence.

500℃ high-temperature reliability of Ni/Nb Ohmic contact on n-type 4H-SiC

2021 ◽  
Author(s):  
Vuong Van Cuong ◽  
Tadashi Sato ◽  
Takamichi Miyazaki ◽  
Tetsuya Meguro ◽  
Seiji Ishikawa ◽  
...  
Keyword(s):  
High Temperature ◽  
Ohmic Contact ◽  
Chemical Compounds ◽  
Etching Process ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ohmic Behavior ◽  
Transmission Electron ◽  
Current Voltage ◽  
The Stability

Abstract The reliability of Ni/Nb ohmic contact on n-type 4H-SiC at 500℃ was investigated. The current-voltage characteristics showed that, while the Ni(50)/Nb(50)/4H-SiC sample without applying the CF4:O2 etching process degraded just after 25-hour and lost ohmic behavior after 50-hour aging, the Ni(75)/Nb(25)/4H-SiC contact undergone CF4:O2 surface treatment still showed excellent stability after aging for 100 hours at 500℃. Though X-ray diffraction results indicated that the chemical compounds remained stable during the aging process, transmission electron microscopy showed that there was a redistribution of the chemical compounds at the interface of the contact after 500℃ aging. The depth distribution of the elements and energy dispersive X-ray analyses revealed that the contribution of carbon agglomeration at the interface accounted for the degradation of the sample without applying the etching process. Whereas the well-controlled excess carbon atoms of the contact undergone CF4:O2 treatment ensured the stability of this contact when operating at high-temperature ambient.

A Facile Method to Preparation of Amphiphilic Perylene Tetracarboxylic Diimide/ZnS Hybrid Nanocomposites and Improved Semiconducting Property

2014 ◽  
Vol 936 ◽  
pp. 295-299 ◽  
Author(s):  
Jin Gang Song ◽  
Hong Yan Wang ◽  
Nian Shuai An ◽  
Yan Li Chen
Keyword(s):  
Organic Semiconductors ◽  
Hybrid Nanocomposites ◽  
Organic Template ◽  
X Ray Diffraction ◽  
X Ray ◽  
Current Voltage ◽  
Order Of Magnitude ◽  
Zns Nanocrystals ◽  
Semiconducting Property ◽  
Scanning Electron

A self-assembled film of an amphiphilic perylene tetracarboxylic diimide derivative (N-hexane-N'-(1-phenyl-4-aminoethanol)-1,7-di (4-tert-butylphenoxy) perylene-3,4;9,10-tetracarboxylate diimide, HH-PDI) has been used as the organic template to produce the first example of monodispersed nanoparticles of HH-PDI/ZnS composites. The HH-PDI pure film and HH-PDI/ZnS nanocomposites were characterized by UV-vis absorption, X-ray diffraction (XRD), scanning electron microscopy (SEM) and current-voltage (I-V) measurements. Experimental results revealed the film crystallinity and general molecular order for HH-PDI molecules in the nanocomposites are improved effectively in comparison with those in the pure film due to the introduction of ZnS nanocrystals. The electrical conductivity of the HH-PDI/ZnS nanocomposites (6.6×10-5 S cm-1) is more than ca. 2 order of magnitude higher than that of (3.6×10-7 S cm-1). The present result provides an efficient way to improve the performance of organic semiconductors through introducing inorganic semiconducting nanocrystals.

Effects of NaBH4 Additions on Hydrogen Absorption by Nanostructured FeTi Powders

2008 ◽  
Vol 587-588 ◽  
pp. 921-925 ◽  
Author(s):  
Sofia F. Marques ◽  
Raquel A. Silva ◽  
Jose Brito Correia ◽  
Nobumitsu Shohoji ◽  
Carmen M. Rangel
Keyword(s):  
Hydrogen Absorption ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Low Cost ◽  
Reaction Products ◽  
X Ray Diffraction ◽  
X Ray ◽  
Gas Atmosphere ◽  
Scanning Electron

FeTi intermetallic powders are very promising media for reversible hydrogen storage. However, difficult activation treatments including annealing at elevated temperatures in high pressure H2 gas atmosphere are mandatory. In the present work nanostructured FeTi powders were produced and activated in situ at room temperature using mechanical alloying/milling (MA/MM) of pure metallic constituents, Fe and Ti, added with sodium borohydride. The resultant powders, FeTiHx, already H2 pre-charged, absorbed a significant amount of H2 but require optimization for reversible absorption/desorption. This system has one of the highest volumetric storage capacities and can be produced at low cost. Several parameters of the as-milled powders were controlled. The phase constitution of the reaction products was characterized by X-ray diffraction and scanning electron microscopy and the absorption isotherms of the activated powders were determined.

Study of Ru barrier failure in the Cu/Ru/Si system

2007 ◽  
Vol 22 (9) ◽  
pp. 2505-2511 ◽  
Author(s):  
M. Damayanti ◽  
T. Sritharan ◽  
S.G. Mhaisalkar ◽  
E. Phoon ◽  
L. Chan
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Reaction Mechanisms ◽  
Diffraction Field ◽  
X Ray Diffraction ◽  
X Ray ◽  
Barrier Failure ◽  
Transmission Electron ◽  
Secondary Ion ◽  
Scanning Electron

The reaction mechanisms and related microstructures in the Cu/Si, Ru/Si, and Cu/Ru/Si metallization system were studied experimentally. With the help of sheet resistance measurements, x-ray diffraction, field-emission scanning electron microscopy, secondary ion mass spectroscopy, and transmission electron microscopy, the metallization structure with Ru barrier layer was observed to fail completely at temperatures around 700 °C, regardless of the Ru thickness because of the formation of polycrystalline Ru2Si3 followed by Cu3Si protrusions.

Varistor Beahavior in Lead Based Perovskite Comounds

2001 ◽  
Vol 685 ◽  
Author(s):  
Seema Sharma ◽  
R.N.P. Choudhary
Keyword(s):  
Room Temperature ◽  
X Ray Diffraction ◽  
Solid State Reaction Technique ◽  
X Ray ◽  
Current Voltage ◽  
Wide Range ◽  
Ptcr Effect ◽  
Different Temperatures ◽  
Structure And Microstructure ◽  
Scanning Electron

Polycrystalline samples of Pb(Cd1/2W1/2)O3 and Pb(Mo1/2W1/2)O3 were synthesized by a high-temperature solid-state reaction technique. Preliminary crystal structure and microstructure of the compounds at room temperature were studied using X-ray diffraction (XRD) technique and Scanning electron microscopy (SEM), respectively. The dielectric permittivity (⊏) and losstangent (tan ⊏) of the compounds were obtained both as a function of frequency(103-104Hz) atroom temperature and temperature (30-3200C) at 10 kHz. Both the ac and dc conductivity have been studied over a wide range of temperature. The current– voltage (I-V) characteristics of the compound studied at different temperatures reveal that the Pb(Cd1/2W1/2)O3 also has excellent varistor behavior. A PTCR effect and NTCR effect was exhibited by Pb(Cd1/2W1/2)O3 and Pb(Cd1/2Mo1/2)O3 respectively.

scholarly journals X-ray diffraction analysis of hydroxyapatite-coated in different plasma gas atmosphere on Ti and Ti-6Al-4V

2017 ◽  
Vol 11 (04) ◽  
pp. 438-446 ◽  
Author(s):  
Ravindra Kotian ◽  
P Prasad Rao ◽  
Prashanthi Madhyastha
Keyword(s):  
Thermal Stresses ◽  
Degree Of Crystallinity ◽  
X Ray Diffraction ◽  
Metal Substrates ◽  
X Ray ◽  
Ha Coating ◽  
Micro Cracks ◽  
Gas Atmosphere ◽  
The Degree Of Crystallinity ◽  
Scanning Electron

ABSTRACTObjective: The aim is to study the effect of plasma working gas on composition, crystallinity, and microstructure of hydroxyapatite (HA) coated on Ti and Ti-6Al-4V metal substrates. Materials and Methods: Ti and Ti-6Al-4V metal substrates were coated with HA by plasma spray using four plasma gas atmospheres of argon, argon/hydrogen, nitrogen, and nitrogen/hydrogen. The degree of crystallinity, the phases present, and microstructure of HA coating were characterized using X-ray diffraction and scanning electron microscopy. Results: Variation in crystallinity and the microstructure of HA coating on plasma gas atmosphere was observed. Micro-cracks due to thermal stresses and shift in the 2θ angle of HA compared to feedstock was seen. Conclusion: Plasma gas atmosphere has a significant influence on composition, crystallinity, and micro-cracks of HA-coated dental implants.

Metallurgical and Electrical Properties of Capped Au-based Metallizations on GaAs

1993 ◽  
Vol 300 ◽  
Author(s):  
X. W. Lin ◽  
A. Piotrowska ◽  
E. Kaminska ◽  
Z. Liliental-Weber ◽  
J. Washburn
Keyword(s):  
Electron Microscopy ◽  
Electrical Properties ◽  
Ohmic Contact ◽  
X Ray Diffraction ◽  
X Ray ◽  
Flat Interface ◽  
Transmission Electron ◽  
Current Voltage ◽  
Ohmic Contact Formation ◽  
Electrical Data

ABSTRACTGold-based contacts on GaAs, i.e., Au(Te)/n-GaAs, Au(Ge)/n-GaAs, and Au(Zn)/p- GaAs, were annealed with or without an Al2O3 cap, in order to examine the effects of capping on their metallurgical and electrical properties. Current-voltage measurements showed that ohmic contact can be formed for all the metallizations, except capped Au(Te) which remained nonohmic even after annealing up to 480°C. Transmission electron microscopy and x-ray diffraction observations showed that the reactions between a contact and GaAs can be strongly affected by a capping layer. For all uncapped contacts, annealing generally resulted in growth of Au-Ga compounds and nonuniform contact morphology, whereas capped Au(Ge) and Au(Zn) contacts were stable and retained flat interface with GaAs. Capped Au(Te) was found to be unstable, reacting extensively with GaAs, due to the presence of Te. Electrical data are explained in terms of the doping model for ohmic contact formation.

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