Subpicosecond Luminescence Studies of Carrier Dynamics in Nitride Semiconductors Grown Homoepitaxially By MBE On GaN Templates

2002 ◽  
Vol 743 ◽  
Author(s):  
G. A. Garrett ◽  
A. V. Sampath ◽  
C. J. Collins ◽  
F. Semendy ◽  
K. Aliberti ◽  
...  
Keyword(s):  
Light Emission ◽  
Uv Light ◽  
Nitride Semiconductors ◽  
Al Content ◽  
Subsequent Time ◽  
A New Technique ◽  
Gap States ◽  
Homoepitaxial Layers ◽  
Heteroepitaxial Layers

ABSTRACTA new technique is presented that employs luminescence downconversion using an ultrashort gating pulse to enable the characterization of UV light emission from III-nitride semiconductors with subpicosecond temporal resolution. This technique also allows one to measure PL rise times and fast components of multiple decays in the subsequent time evolution of the PL intensity. Comparison of luminescence emission intensity and lifetime in GaN and AlGaN with ∼0.1 Al content grown homoepitaxially on GaN templates with the same quantities measured in heteroepitaxial layers grown on sapphire indicate significant improvement in the homoepitaxial layers due to reduction in dislocation density. Fast (<15 ps) initial decays in the AlGaN are attributed to localization associated with alloy fluctuations and subsequent recombination through gap states.

A Novel Fault Isolation Technique Using Noise Detection and Characterization of Light Emitted From Integrated Circuits

1998 ◽  
Author(s):  
Hong Zheng ◽  
Joe Patterson ◽  
G. P. Li
Keyword(s):  
Integrated Circuits ◽  
Integrated Circuit ◽  
Light Emission ◽  
Fault Isolation ◽  
Noise Detection ◽  
Isolation Technique ◽  
Potential Effectiveness ◽  
Defect Sites ◽  
A New Technique

Abstract This paper describes a new technique for identifying defects on integrated circuit. This technique detects the noise content in light emitted from defect sites. The purpose of this technique is to determine which of many light emission sites represent a defect and which represent normal devices. It reports the first phase of studies to evaluate the feasibility and potential effectiveness of this technique. The feasibility of this technique has been demonstrated by simultaneously monitoring electrical noise and the noise in the light emitted from a gallium arsenide light emission diode (LED) and a bipolar transistor. The paper will present the methodology and apparatus used to detect and analyze the noise in light emission.

scholarly journals Characterization of m-GaN and a-GaN Crystallographic Planes after Being Chemically Etched in TMAH Solution

Energies ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4241
Author(s):  
Nedal Al Taradeh ◽  
Eric Frayssinet ◽  
Christophe Rodriguez ◽  
Frederic Morancho ◽  
Camille Sonneville ◽  
...  
Keyword(s):  
Uv Light ◽  
Etching Rate ◽  
Lower Surface ◽  
Smooth Channel ◽  
A New Technique ◽  
Crystallographic Planes ◽  
Gan Crystal ◽  
The Impact ◽  
Tmah Solution

This paper proposes a new technique to engineer the Fin channel in vertical GaN FinFET toward a straight and smooth channel sidewall. Consequently, the GaN wet etching in the TMAH solution is detailed; we found that the m-GaN plane has lower surface roughness than crystallographic planes with other orientations, including the a-GaN plane. The grooves and slope (Cuboids) at the channel base are also investigated. The agitation does not assist in Cuboid removal or crystallographic planes etching rate enhancement. Finally, the impact of UV light on m and a-GaN crystal plane etching rates in TMAH has been studied with and without UV light. Accordingly, it is found that the m-GaN plane etching rate is enhanced from 0.69 to 1.09 nm/min with UV light; in the case of a-GaN plane etching, UV light enhances the etching rate from 2.94 to 4.69 nm/min.

Case Studies in Atomic Force Probe Analysis

2006 ◽  
Author(s):  
Randal Mulder ◽  
Sam Subramanian ◽  
Tony Chrastecky
Keyword(s):  
Failure Analysis ◽  
Case Studies ◽  
Light Emission ◽  
Electrical Characterization ◽  
Logic Circuits ◽  
Contrast Imaging ◽  
Atomic Force ◽  
Measuring Surface ◽  
Analysis Environment

Abstract The use of atomic force probe (AFP) analysis in the analysis of semiconductor devices is expanding from its initial purpose of solely characterizing CMOS transistors at the contact level with a parametric analyzer. Other uses found for the AFP include the full electrical characterization of failing SRAM bit cells, current contrast imaging of SOI transistors, measuring surface roughness, the probing of metallization layers to measure leakages, and use with other tools, such as light emission, to quickly localize and identify defects in logic circuits. This paper presents several case studies in regards to these activities and their results. These case studies demonstrate the versatility of the AFP. The needs and demands of the failure analysis environment have quickly expanded its use. These expanded capabilities make the AFP more valuable for the failure analysis community.

scholarly journals Development and characterization of probiotic mucilage based edible films for the preservation of fruits and vegetables

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Seyed Mohammad Davachi ◽  
Neethu Pottackal ◽  
Hooman Torabi ◽  
Alireza Abbaspourrad
Keyword(s):  
Fruits And Vegetables ◽  
Uv Light ◽  
Barrier Properties ◽  
Edible Films ◽  
Food Preservation ◽  
Elongation At Break ◽  
The Public ◽  
Medical Benefits ◽  
Seed Mucilage

AbstractThere is growing interest among the public and scientific community toward the use of probiotics to potentially restore the composition of the gut microbiome. With the aim of preparing eco-friendly probiotic edible films, we explored the addition of probiotics to the seed mucilage films of quince, flax, and basil. These mucilages are natural and compatible blends of different polysaccharides that have demonstrated medical benefits. All three seed mucilage films exhibited high moisture retention regardless of the presence of probiotics, which is needed to help preserve the moisture/freshness of food. Films from flax and quince mucilage were found to be more thermally stable and mechanically robust with higher elastic moduli and elongation at break than basil mucilage films. These films effectively protected fruits against UV light, maintaining the probiotics viability and inactivation rate during storage. Coated fruits and vegetables retained their freshness longer than uncoated produce, while quince-based probiotic films showed the best mechanical, physical, morphological and bacterial viability. This is the first report of the development, characterization and production of 100% natural mucilage-based probiotic edible coatings with enhanced barrier properties for food preservation applications containing probiotics.

Growth and characterization of ammonium nickel-cobalt sulfate Tutton’s salt for UV light applications

2018 ◽  
Vol 487 ◽  
pp. 104-115 ◽  
Author(s):  
Santunu Ghosh ◽  
Michelle Oliveira ◽  
Tiago S. Pacheco ◽  
Genivaldo J. Perpétuo ◽  
Carlos J. Franco
Keyword(s):  
Uv Light ◽  
Cobalt Sulfate ◽  
Nickel Cobalt

Mechanical Characterization of UV Photopolymerized PMMA with Different Photo-Initiator Concentration

2021 ◽  
Vol 903 ◽  
pp. 11-16
Author(s):  
M.A. Manjunath ◽  
K. Naveen ◽  
Prakash Vinod ◽  
N. Balashanmugam ◽  
M.R. Shankar
Keyword(s):  
Mechanical Properties ◽  
Light Source ◽  
Polymethyl Methacrylate ◽  
Biomedical Applications ◽  
Mechanical Characterization ◽  
Uv Light ◽  
Curing Time ◽  
Uv Led ◽  
Pmma Resin

Polymethyl methacrylate (PMMA) is one among few known photo-polymeric resin useful in lithography for fabricating structures having better mechanical properties to meet the requirement in electronics and biomedical applications. This study explores the effect of Photo Initiator (PI) concentration and also curing time on strength and hardness of Polymethyl methacrylate (PMMA) obtained by UV photopolymerization of Methyl methacrylate (MMA) monomer. The UV LED light source operating at the wavelength of 364 nm is used with Benzoin Ethyl Ether (BEE) as photo initiator. The curing of PMMA resin is supported with peltier cooling device placed at the bottom of the UV light source. The characterisation study of UV photo cured PMMA is analysed through nano indenter (Agilent Technologies-G200). The current work investigates the influence of PI concentration and curing time in achieving maximum mechanical properties for UV photopolymerized PMMA.

scholarly journals Algorithms for 3D Particles Characterization Using X-Ray Microtomography in Proppant Crush Test

2018 ◽  
Vol 4 (11) ◽  
pp. 134 ◽  
Author(s):  
Ilia Safonov ◽  
Ivan Yakimchuk ◽  
Vladimir Abashkin
Keyword(s):  
Laboratory Method ◽  
X Ray ◽  
Geometric Moments ◽  
Before And After ◽  
Statistical Hypotheses ◽  
Image Processing Algorithms ◽  
A New Technique ◽  
Individual Particles ◽  
Remarkable Advantage

We present image processing algorithms for a new technique of ceramic proppant crush resistance characterization. To obtain the images of the proppant material before and after the test we used X-ray microtomography. We propose a watershed-based unsupervised algorithm for segmentation of proppant particles, as well as a set of parameters for the characterization of 3D particle size, shape, and porosity. An effective approach based on central geometric moments is described. The approach is used for calculation of particles’ form factor, compactness, equivalent ellipsoid axes lengths, and lengths of projections to these axes. Obtained grain size distribution and crush resistance fit the results of conventional test measured by sieves. However, our technique has a remarkable advantage over traditional laboratory method since it allows to trace the destruction at the level of individual particles and their fragments; it grants to analyze morphological features of fines. We also provide an example describing how the approach can be used for verification of statistical hypotheses about the correlation between particles’ parameters and their crushing under load.

Evaluation of the Effect of Ultraviolet Light Excitation during Characterization of Silicon Carbide Epitaxial Layers

2018 ◽  
Vol 924 ◽  
pp. 261-264
Author(s):  
Hrishikesh Das ◽  
Swapna Sunkari ◽  
Oener Akdik ◽  
Andrei Konstantinov ◽  
Krister Gumaelius ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
Ultraviolet Light ◽  
Defect Detection ◽  
Uv Light ◽  
Surface Treatments ◽  
Uv Laser ◽  
Original State ◽  
Optimal Surface ◽  
Light Excitation

The scanning of Silicon Carbide (SiC) epitaxy wafers for defects by ultraviolet (UV) laser or lamps is widely prevalent. In this work, we document the effects of UV light excitation on the SiC epitaxy material. An increase in background photoluminescence (PL) is observed after repeated scans. The effect of this increase on defect detection is shown. Optimal surface treatments to recover the material back to the original state are demonstrated. Further, some surface treatments are proposed which reduce the effect of the UV light excitation and prevent to a large extent the rise in background PL.

A New Technique for Characterization of Low Impedance Materials at Acoustic Frequencies

2018 ◽  
Vol 58 (8) ◽  
pp. 1311-1324 ◽  
Author(s):  
W. Nantasetphong ◽  
Z. Jia ◽  
M.A. Hasan ◽  
A.V. Amirkhizi ◽  
S. Nemat-Nasser
Keyword(s):  
New Technique ◽  
A New Technique ◽  
Low Impedance Materials
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