Deep Level Characterization of LP-MOCVD Grown Al0.48In0.52As

1993 ◽  
Vol 325 ◽  
Author(s):  
F. Ducroquet ◽  
G. Guillot ◽  
K. Hong ◽  
C.H. Hong ◽  
D. Pavlidis ◽  
...  
Keyword(s):  
Deep Level ◽  
Shallow Donor ◽  
Electrical Characteristics ◽  
Oxygen Contamination ◽  
Deep Donor ◽  
Low Pressure Mocvd ◽  
Different Origins ◽  
Inp Substrates ◽  
Preferential Incorporation

AbstractDeep levels in unintentionally doped A10. 48In0.52As layers epitaxially grown on InP substrates by low-pressure MOCVD have been investigated as a function of growth temperature (Tg ranging from 570 to 690°C). Two different origins for the residual carrier concentration are deduced depending on Tg: i) low growth temperatures favor the creation of a deep donor located at Ec-(0.13±0.04)eV; ii) At higher Tg, a preferential incorporation of a shallow donor occurs, which can be attributed to silicon by SIMS measurements. The oxygen contamination deduced by SIMS and the electrical characteristics of the AlInAs layers do not appear to be correlated.

Photo EPR Study of Trapping and Recombination Processes in Semi-Insulating 4H-SiC Crystals as Function of Temperature

2001 ◽  
Vol 680 ◽  
Author(s):  
E.N. Kalabukhova ◽  
S.N. Lukin ◽  
A. Saxler ◽  
W.C. Mitchel ◽  
S R. Smith ◽  
...  
Keyword(s):  
Fermi Level ◽  
Deep Level ◽  
Antisite Defect ◽  
Shallow Donor ◽  
Epr Spectrum ◽  
Paramagnetic Resonance ◽  
Line Intensities ◽  
Donor And Acceptor ◽  
Recombination Processes ◽  
Deep Donor

ABSTRACTPhoto-Electron Paramagnetic Resonance (photo-EPR) measurements of semi-insulating (s.-i.) 4H SiC have been made at 37 GHz including photo excitation and photo quenching techniques in the temperature interval from 77 K to 50 K. At T = 77 K in the dark the EPR spectrum consists of a low intensity line due to boron on the cubic lattice site and a single line with isotropic g∥ = g⊥ = 2.0025 due to a carbon-related surface defect. During illumination with ultraviolet light the EPR lines of hexagonal boron and cubic nitrogen appear in the EPR spectrum and persist after the illumination is removed. Subsequent illumination of the sample with sub-band gap, visible, light resulted in the quenching of the EPR lines from nitrogen and appearance of the IP1EPR line with g∥ = 2.0048, g⊥ = 2.0030 caused by direct transfer of electrons from nitrogen donor to the P1 center. The lifetime of the photo-generated carriers trapped by the P1 centers is found to be more than 15- 20 hours after the photo-excitation was turned off. The deep donor P1 local center is suggested to be the as yet unidentified deep level located at EC – 1.1 eV which pins the Fermi level in this sample at this energy in the dark. As the temperature is lowered from 77K and the quasi Fermi level positions reach shallow donor and acceptor states, an additional EPR line, ID, with g∥ = 2.0063, g⊥ = 2.0006, appears at 50 K in the excitation EPR spectrum and is attributed to the antisite defect Si−c with an energy level shallower than nitrogen. At the same time the ratio of the photo-excited EPR line intensities responsible for boron on the cubic and hexagonal sites, IkB:IhB, returns to the value observed at 77 K and becomes equal to 0.4 at 50 K, showing that the concentration of boron in the hexagonal site is higher than on the cubic site.

Deep-Level Defects in AlN Single Crystals: EPR Studies

2010 ◽  
Vol 645-648 ◽  
pp. 1195-1198
Author(s):  
Ivan V. Ilyin ◽  
Alexandra A. Soltamova ◽  
V.A. Soltamov ◽  
V.A. Khramtsov ◽  
E.N. Mokhov ◽  
...  
Keyword(s):  
Deep Level ◽  
Shallow Donor ◽  
Nitrogen Vacancy ◽  
Donor Center ◽  
Paramagnetic Resonance ◽  
X Band ◽  
Two Samples ◽  
Before And After ◽  
Deep Donor ◽  
Electron Paramagnetic

Electron paramagnetic resonance (EPR) at X-band (9.4 GHz) and Q-band (35 GHz) have been used to study defects in two samples of AlN monocrystals, grown by a sublimation sandwich method. These investigations reveal the presence of Fe2+ impurities in the reddish sample. The spectra of substitutional Fe2+ are highly anisotropic and could be observed even up to the room temperature. After illumination the signals showing the DX behavior were detected in the same sample. We assume these signals to arise due to the presence of the shallow donor center namely the isolated substitutional oxygen ON occupying the nitrogen position. In the second slightly amber-coloured sample EPR measurements before and after X-ray showed the presence of a deep-donor center which was assumed to be nitrogen vacancy VN. Based on thermoluminescence measurements the depth of the level was estimated to 0.45-0.5 eV.

Electrical Characterization of Thick InGaN Films for Photovoltaic Applications

2014 ◽  
Vol 1635 ◽  
pp. 29-34
Author(s):  
Yoshitaka Nakano ◽  
Liwen Sang ◽  
Masatomo Sumiya
Keyword(s):  
Deep Level ◽  
Electrical Characterization ◽  
Chemical Vapor ◽  
Shallow Donor ◽  
Organic Chemical ◽  
Photovoltaic Applications ◽  
Metal Organic ◽  
Electronic Defects ◽  
Organic Chemical Vapor Deposition

ABSTRACTWe have electrically characterized a 300 nm-thick unintentionally-doped In0.09Ga0.91N film grown by metal-organic chemical vapor deposition on a GaN template, employing capacitance-voltage (C-V), thermal admittance spectroscopy (TAS), and steady-state photocapacitance spectroscopy (SSPC) techniques on Schottky barrier diodes. TAS measurements revealed a degenerating-like shallow-donor defect with a thermal activation energy of ∼7 meV, which most likely acts as a source of residual carriers with their concentration of ∼1017 cm-3 determined from C-V measurements. Additionally, SSPC measurements revealed two characteristic deep-level defects located at ∼2.07 and ∼3.05 eV below the conduction band, which were densely enhanced near the underlayer. These electronic defects are probably introduced by alloying InN with GaN.

Structural and Electrical Characterization of Shaped Beam Laser Recrystallized Polysilicon on Amorphous Substrates

1981 ◽  
Vol 4 ◽  
Author(s):  
T. J. Stultz ◽  
J. F. Gibbons
Keyword(s):  
Grain Size ◽  
Electrical Characterization ◽  
Grain Structure ◽  
Electrical Characteristics ◽  
Shaped Beam ◽  
Beam Laser ◽  
Cw Laser ◽  
Amorphous Substrates ◽  
Circular Beam

ABSTRACTStructural and electrical characterization of laser recrystallized LPCVD silicon films on amorphous substrates using a shaped cw laser beam have been performed. In comparing the results to data obtained using a circular beam, it was found that a significant increase in grain size can be achieved and that the surface morphology of the shaped beam recrystallized material was much smoother. It was also found that whereas circular beam recrystallized material has a random grain structure, shaped beam material is highly oriented with a <100> texture. Finally the electrical characteristics of the recrystallized film were very good when measured in directions parallel to the grain boundaries.

Nanoprobing Application on Characterization of 6T-SRAM Single Bit Failures with Different Gox Breakdown Defect

2006 ◽  
Author(s):  
Cheng-Piao Lin ◽  
Chin-Hsin Tang ◽  
Cheng-Hsu Wu ◽  
Cheng-Chun Ting
Keyword(s):  
Copper Metallization ◽  
Physical Analysis ◽  
Electrical Characteristics ◽  
Gate Leakage Current ◽  
Data Retention ◽  
Simulation Data ◽  
Failure Data ◽  
Dual Gate ◽  
Soft Breakdown

Abstract This paper analyzes several SRAM failures using nano-probing technique. Three SRAM single bit failures with different kinds of Gox breakdown defects analyzed are gross function single bit failure, data retention single bit failure, and special data retention single bit failure. The electrical characteristics of discrete 6T-SRAM cells with soft breakdown are discussed and correlated to evidences obtained from physical analysis. The paper also verifies many previously published simulation data. It utilizes a 6T-SRAM vehicle consisting of a large number of SRAM cells fabricated by deep sub-micron, dual gate, and copper metallization processes. The data obtained from this paper indicates that Gox breakdown location within NMOS pull-down device has larger a impact on SRAM stability than magnitude of gate leakage current, which agrees with previously published simulation data.

Evaluation of Molecular Markers Specific for 1BL∙1RS Translocation and Characterization of 1RS Chromosome in Wheat Varieties from Different Origins

2009 ◽  
Vol 35 (11) ◽  
pp. 2107-2115 ◽  
Author(s):  
Huai-Jun TANG ◽  
Gui-Hong YIN ◽  
Xian-Chun XIA ◽  
Jian-Jun FENG ◽  
Yan-Ying QU ◽  
...  
Keyword(s):  
Molecular Markers ◽  
Wheat Varieties ◽  
Different Origins

Growth of GaN without Yellow Luminescence

1995 ◽  
Vol 395 ◽  
Author(s):  
X. Zhang ◽  
P. Kung ◽  
D. Walker ◽  
A. Saxler ◽  
M. Razeghi
Keyword(s):  
Vapor Deposition ◽  
Metalorganic Chemical Vapor Deposition ◽  
Deep Level ◽  
Chemical Vapor ◽  
Growth Conditions ◽  
Native Defect ◽  
Yellow Luminescence ◽  
Gallium Vacancy ◽  
Rich Condition

ABSTRACTWe report the growth and photoluminescence characterization of GaN grown on different substrates and under different growth conditions using metalorganic chemical vapor deposition. The deep-level yellow luminescence centered at around 2.2eV is attributed to native defect, most possibly the gallium vacancy. The yellow luminescence can be substantially reduced By growing GaN under Ga-rich condition or doping GaN with Ge or Mg.

scholarly journals Streptogramin B biosynthesis in Streptomyces pristinaespiralis and Streptomyces virginiae: molecular characterization of the last structural peptide synthetase gene.

1997 ◽  
Vol 41 (9) ◽  
pp. 1904-1909 ◽  
Author(s):  
V de Crécy-Lagard ◽  
W Saurin ◽  
D Thibaut ◽  
P Gil ◽  
L Naudin ◽  
...  
Keyword(s):  
Amino Acid ◽  
Acid Activation ◽  
Activation Domains ◽  
Amino Acid Activation ◽  
Streptomyces Virginiae ◽  
Streptomyces Pristinaespiralis ◽  
Degenerate Oligonucleotide ◽  
Peptide Synthetase ◽  
Different Origins

Streptomyces pristinaespiralis and S. virginiae both produce closely related hexadepsipeptide antibiotics of the streptogramin B family. Pristinamycins I and virginiamycins S differ only in the fifth incorporated precursor, di(mono)methylated amine and phenylalanine, respectively. By using degenerate oligonucleotide probes derived from internal sequences of the purified S. pristinaespiralis SnbD and SnbE proteins, the genes from two streptogramin B producers, S. pristinaespiralis and S. virginiae, encoding the peptide synthetase involved in the activation and incorporation of the last four precursors (proline, 4-dimethylparaaminophenylalanine [for pristinamycin I(A)] or phenylalanine [for virginiamycin S], pipecolic acid, and phenylglycine) were cloned. Analysis of the sequence revealed that SnbD and SnbE are encoded by a unique snbDE gene. SnbDE (4,849 amino acids [aa]) contains four amino acid activation domains, four condensation domains, an N-methylation domain, and a C-terminal thioesterase domain. Comparison of the sequences of 55 amino acid-activating modules from different origins confirmed that these sequences contain enough information for the performance of legitimate predictions of their substrate specificity. Partial sequencing (1,993 aa) of the SnbDE protein of S. virginiae allowed comparison of the proline and aromatic acid activation domains of the two species and the identification of coupled frameshift mutations.

Deep Level Related Yellow Luminescence in P-Type GaN Grown by MBE on (0001) Sapphire

1999 ◽  
Vol 595 ◽  
Author(s):  
Giancarlo Salviati ◽  
Nicola Armani ◽  
Carlo Zanotti-Fregonara ◽  
Enos Gombia ◽  
Martin Albrecht ◽  
...  
Keyword(s):  
Volume Fraction ◽  
Deep Level ◽  
Cubic Phase ◽  
Donor Level ◽  
Yellow Luminescence ◽  
Wurtzite Phase ◽  
Shallow Acceptor ◽  
Deep Donor ◽  
P Type ◽  
Deep Donor Level

AbstractYellow luminescence (YL) has been studied in GaN:Mg doped with Mg concentrations ranging from 1019 to 1021 cm−3 by spectral CL (T=5K) and TEM and explained by suggesting that a different mechanism could be responsible for the YL in p-type GaN with respect to that acting in n-type GaN.Transitions at 2.2, 2.8, 3.27, 3.21, and 3.44 eV were found. In addition to the wurtzite phase, TEM showed a different amount of the cubic phase in the samples. Nano tubes with a density of 3×109 cm−2 were also observed by approaching the layer/substrate interface. Besides this, coherent inclusions were found with a diameter in the nm range and a volume fraction of about 1%.The 2.8 eV transition was correlated to a deep level at 600 meV below the conduction band (CB) due to MgGa-VN complexes. The 3.27 eV emission was ascribed to a shallow acceptor at about 170-190 meV above the valence band (VB) due to MgGa.The 2.2 eV yellow band, not present in low doped samples, increased by increasing the Mg concentration. It was ascribed to a transition between a deep donor level at 0.8-1.1 eV below the CB edge due to NGa and the shallow acceptor due to MgGa. This assumption was checked by studying the role of C in Mg compensation. CL spectra from a sample with high C content showed transitions between a C-related 200 meV shallow donor and a deep donor level at about 0.9- 1.1 eV below the CB due to a NGa-VN complex. In our hypothesis this should induce a decrease of the integrated intensity in both the 2.2 and 2.8 eV bands, as actually shown by CL investigations.

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