The Influence of Thermal Treatment on Defect Characteristics in Cz-Silicon Wafers Investigated by Positron Annihilation Spectroscopy

1992 ◽  
Vol 262 ◽  
Author(s):  
P. Mascher ◽  
W. Puff ◽  
S. Hahn ◽  
K. H. Cno ◽  
B. Y. Lee
Keyword(s):  
Heat Treatment ◽  
Fourier Transform ◽  
Positron Lifetime ◽  
Positron Annihilation Spectroscopy ◽  
Silicon Wafers ◽  
The Other ◽  
Doppler Broadening ◽  
Bulk Silicon ◽  
Distinctive Difference ◽  
Step Heat Treatment

ABSTRACTPositron lifetime and Doppler-broadening experiments as well as Fourier-transform infrared spectroscopy (FTIR) were performed on a variety of six-inch Czochralski (CZ) silicon wafers. Measurements were done at 14 equidistant locations across the wafers which were cut from the seed-, middle-, and tail-sections of two boules grown at different pull-speeds.In the as-grown wafers, the positron response consisted of components from small oxygen-related clusters and “perfect” bulk silicon only. Possible contributions from vacancy-type defects were at or just below the detection limit. After a two-step heat treatment (750°C/ 4 hrs + 1050°C/6 hrs in N2) FTIR showed that significant amounts of oxygen (4–8 ppma) had precipitated in wafers taken from the seed-sections of the boules but not in any of the other wafers. The positron data did not reflect this distinctive difference, however, both lifetime and Doppler-broadening results strongly indicate the creation of vacancy-type defects at concentrations in the 1016cm−3-range.

Synthesis of intermetallic NiAl and Ni3Al fine powders through organometallic precursors

1991 ◽  
Vol 6 (5) ◽  
pp. 928-934 ◽  
Author(s):  
Osami Abe ◽  
Akira Tsuge
Keyword(s):  
Heat Treatment ◽  
Thermal Decomposition ◽  
Particle Size ◽  
Aqueous Solutions ◽  
Single Phase ◽  
Initial Step ◽  
The Other ◽  
Fine Powders ◽  
Organometallic Precursors ◽  
Step Heat Treatment

Fine powders of intermetallic NiAl and Ni3Al were synthesized through organometallic precursors, which were coprecipitated from aqueous solutions of NiCl2 and AlCl3 by the addition of ammonium benzoate and hydradinium monochloride as precipitants. Ni3Al and NiAl were synthesized by a two-step heat treatment of the precursors. The initial step was the thermal decomposition of organic groups to form homogeneous mixtures of Ni3C, amorphous Al2O3, and free C below 1000 °C. The other step was the reaction above 1300 °C to form the intermetallics. Single phase powders of NiAl and Ni3Al with the particle size less than 3 μm were obtained above 1300 and 1400 °C, respectively.

Defect Investigations via Positron Annihilation Spectroscopy on Proton Implanted Silicon

2011 ◽  
Vol 178-179 ◽  
pp. 319-324
Author(s):  
Andreas J. Schriefl ◽  
Sokratis Sgouridis ◽  
Werner Schustereder ◽  
Werner Puff
Keyword(s):  
Annealing Temperature ◽  
Positron Lifetime ◽  
Positron Annihilation Spectroscopy ◽  
Implantation Dose ◽  
Crystal Defects ◽  
Doppler Broadening ◽  
Defect Complexes ◽  
Float Zone ◽  
Proton Implantation ◽  
Positron Lifetimes

The microscopic nature of hydrogen decorated defect complexes created by proton implantation in silicon and subsequental annealing is not well understood yet. We investigated the defects and donator complexes using positron lifetime measurements and Doppler-broadening spectroscopy. In particular, the influence of variations in implantation dose, annealing temperature and annealing time on crystal defects were examined in Czochralski and in float zone silicon samples. Due to well known positron lifetimes in silicon an identification of certain defect complexes was possible.

A Study of Defects in Czochralski-Grown Silicon by Positron Annihilation Spectroscopy

1992 ◽  
Vol 262 ◽  
Author(s):  
S. C. Sharma ◽  
N. Hozhabri ◽  
R. G. Hyer ◽  
T. Hossain ◽  
S. Kim ◽  
...  
Keyword(s):  
Positron Lifetime ◽  
Single Crystal Silicon ◽  
Positron Beam ◽  
Positron Annihilation Spectroscopy ◽  
Doppler Broadening ◽  
Crystal Silicon ◽  
Different Depths ◽  
Positron Lifetime Spectroscopy ◽  
Doppler Broadening Spectra ◽  
Variable Energy

ABSTRACTWe have studied defects in Cz-grown single crystal silicon by utilizing a variable energy positron beam and positron lifetime spectroscopy in conjunction with surface photovoltage measurements. We present results for the depth profile of defects obtained from the Doppler broadening spectra measured by implanting variable energy positrons at different depths ranging from the surface down to ∼ 1 /xm deep. We have also measured positron lifetime spectra at different locations on a wafer and have obtained a radial variation in the density of the vacancy-type defects.

scholarly journals Positron Annihilation Spectroscopy as a Diagnostic Tool for the Study of LiCoO2 Cathode of Lithium-Ion Batteries

2021 ◽  
Vol 6 (3) ◽  
pp. 28
Author(s):  
Gioele Pagot ◽  
Valerio Toso ◽  
Bernardo Barbiellini ◽  
Rafael Ferragut ◽  
Vito Di Noto
Keyword(s):  
Lithium Ion Batteries ◽  
Positron Annihilation ◽  
Positron Lifetime ◽  
Lithium Ion ◽  
Positron Annihilation Spectroscopy ◽  
State Of Charge ◽  
Doppler Broadening ◽  
Li Ion Batteries ◽  
Li Ion

Positron annihilation spectroscopy using lifetime and Doppler broadening allows the characterization of the lithiation state in LiCoO2 thin film used in cathode of lithium-ion batteries. The lifetime results reflect positron spillover because of the presence of graphite in between the oxide grains in real cathode Li-ion batteries. This spillover produces an effect in the measured positron parameters which are sensitive to delocalized electrons from lithium atoms as in Compton scattering results. The first component of the positron lifetime corresponds to a bulk-like state and can be used to characterize the state of charge of the cathode while the second component represents a surface state at the grain-graphite interface.

Synthesis of B4C/SiC Composite from Sugar Based Precursor

2009 ◽  
Vol 283-286 ◽  
pp. 268-272 ◽  
Author(s):  
S. Cihangir ◽  
Celaletdin Ergun ◽  
Suat Yılmaz ◽  
Filiz Çinar Şahin
Keyword(s):  
Heat Treatment ◽  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Inert Atmosphere ◽  
The Other ◽  
X Ray Diffraction ◽  
X Ray ◽  
Heat Treated ◽  
Precursor Material ◽  
Sic Composites

In the present study, a method based on sulfuric acid dehydration of sugar was developed to synthesize a precursor material, which can yield B4C/SiC composites at much lower temperatures compared to traditional carbothermal methods. The precursor material for pure B4C was heat treated at the temperatures between 400 and 1600oC under inert atmosphere. The precursor material for B4C /SiC composites was heat treated only at 1600oC under an inert atmosphere. Then the samples were characterized by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). The results showed that B-C bonds formed as low as 400oC. On the other hand, crystallized B4C and B4C / SiC composites can be obtained at the heat treatment temperatures between 1400 and 1600oC.

Vacancy-Solute Aggregates in Al-Zn-Mg-(Cu, Ag)

2006 ◽  
Vol 519-521 ◽  
pp. 309-314 ◽  
Author(s):  
Rafael Ferragut ◽  
A. Dupasquier ◽  
M.M. Iglesias ◽  
C.E. Macchi ◽  
Alberto Somoza ◽  
...  
Keyword(s):  
Positron Annihilation ◽  
Strong Interaction ◽  
Positron Annihilation Spectroscopy ◽  
The Other ◽  
Alloying Elements ◽  
Artificial Ageing ◽  
Doppler Broadening ◽  
Coincidence Doppler Broadening

Positron annihilation spectroscopy in two versions (lifetime and coincidence Doppler broadening) has been applied to investigate solute/vacancy interactions when minor amounts (<1wt.%) of Ag or Cu are added to the alloy Al-4Zn-3Mg (wt.%) during ageing at 150°C. The results show early clustering of vacancies with Zn (and with Cu, if present). Ag displays a strong interaction with vacancies in competition with Mg and forms clusters that may help further aggregation of the other alloying elements during artificial ageing. High Mg concentration is observed at the misfit interfaces of semi-coherent or incoherent precipitates.

Positron Annihilation Spectroscopy of Defects in Commercially Pure Titanium Saturated with Hydrogen

2014 ◽  
Vol 880 ◽  
pp. 134-140 ◽  
Author(s):  
Roman S. Laptev ◽  
Yuriy S. Bordulev ◽  
Viktor N. Kudiiarov ◽  
Andrey M. Lider ◽  
Georgy V. Garanin
Keyword(s):  
Gas Phase ◽  
Positron Lifetime ◽  
Pure Titanium ◽  
Metal Structure ◽  
Positron Annihilation Spectroscopy ◽  
Doppler Broadening ◽  
Commercially Pure Titanium ◽  
Commercially Pure ◽  
Hydrogen Interaction ◽  
Positron Lifetime Spectroscopy

The experimental study of the structure of commercially pure titanium after saturation with hydrogen from the gas phase by means of positron lifetime spectroscopy (PLS) and Doppler broadening spectroscopy (DBS) was carried out. In the result of penetration and accumulation of hydrogen, significant changes of annihilation characteristics occurred due to the defect structure changing. The investigated samples contained hydrogen in concentrations varying from 0 to 0.961 wt.%. Several stages of hydrogen interaction with the metal structure were revealed.

A Positron Study of Early Clustering in Al-Mg-Si Alloys

2014 ◽  
Vol 794-796 ◽  
pp. 33-38 ◽  
Author(s):  
Meng Liu ◽  
Jakub Čížek ◽  
Cynthia S.T. Chang ◽  
John Banhart
Keyword(s):  
Positron Lifetime ◽  
The Other ◽  
Annihilation Radiation ◽  
Doppler Broadening ◽  
Natural Ageing ◽  
Temperature Dependent ◽  
Continuous Growth ◽  
Positron Annihilation Lifetime ◽  
Vacancy Type Defect ◽  
Trapping Sites

Early stages of clustering in quenched Al-Mg-Si alloys during natural ageing were studied by positron annihilation lifetime spectroscopy utilizing its unique sensitivity to electron density differences in various atomic defects. Two different positron trapping sites could be identified, one related to a vacancy-type defect, the other to solute clusters. The first trap is deep, i.e. irreversibly traps positrons, the second shallow, from which positrons can escape, which creates the signature of a temperature-dependent positron lifetime. During the first 80 min of NA, the vacancy-related contribution decreases, while the solute clusters increasingly trap positrons, thus reflecting their continuous growth and power to trap positrons. Coincident Doppler broadening spectroscopy of the annihilation radiation shows that the annihilation sites are Si-rich after quenching but contain more Mg after 70 min.

Effect of Two-step Heat Treatment Processes on the Formation of Protein Particles and Oil Droplets in Soymilk

2020 ◽  
Vol 26 (3) ◽  
pp. 445-450
Author(s):  
Makoto Shimoyamada ◽  
Hironori Shikano ◽  
Shingo Mogami ◽  
Makoto Kanauchi ◽  
Hayato Masuda ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Oil Droplets ◽  
Treatment Processes ◽  
Protein Particles ◽  
Step Heat Treatment

Effect of Heat Treatment on the Microstructure and Property of TiAl Alloys Prepared by Gas Atomization Powders

2013 ◽  
Vol 747-748 ◽  
pp. 497-501
Author(s):  
Na Liu ◽  
Zhou Li ◽  
Guo Qing Zhang ◽  
Hua Yuan ◽  
Wen Yong Xu ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Heat Treatment Temperature ◽  
Tial Alloy ◽  
Lamellar Microstructure ◽  
Treatment Temperature ◽  
Gas Atomization ◽  
Thermally Induced ◽  
Heat Treated ◽  
Fine Duplex ◽  
Step Heat Treatment

Powder metallurgical TiAl alloy was fabricated by gas atomization powders, and the effect of heat treatment temperature on the microstructure evolution and room tensile properties of PM TiAl alloy was investigated. The uniform fine duplex microstructure was formed in PM TiAl based alloy after being heat treated at 1250/2h followed by furnace cooling (FC)+ 900/6h (FC). When the first step heat treatment temperature was improved to 1360/1h, the near lamellar microstructure was achieved. The ductility of the alloy after heat treatment improved markedly to 1.2% and 0.6%, but the tensile strength decreased to 570MPa and 600MPa compared to 655MPa of as-HIP TiAl alloy. Post heat treatment at the higher temperature in the alpha plus gamma field would regenerate thermally induced porosity (TIP).

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