The Effect of Carbon on the Precipitation of Oxygen in Czochralski Silicon

1980 ◽  
Vol 2 ◽  
Author(s):  
R. F. Pinizzotto ◽  
H. F. SCHAAKE
Keyword(s):  
Interfacial Energy ◽  
Carbon Material ◽  
Single Step ◽  
Low Carbon ◽  
High Carbon ◽  
X Ray ◽  
Czochralski Silicon ◽  
Oxygen Precipitation ◽  
Carbon Impurities ◽  
Light Precipitation

ABSTRACTResearchers in both the U. S. and Japan have reported that carbon impurities can significantly alter the precipitation of oxygen in CZ silicon. We have employed FTIR, x-ray topography and TEM to study this phenomenon in silicon containing < 2 × 1016 C cm−3 or 1.3 × 1017 C cm−3. A single step anneal of 16 hours at 1000°C will cause oxygen precipitation to occur in the high carbon material, while a 32 hour pre-anneal at 600°C is necessary for precipitation in the low carbon material. If a single anneal of 120 hours at 750°C is used, light precipitation occurs in both types of material. A pre-anneal of 15 minutes at 1000°C followed by 120 hours at 750°C reduces precipitation in the high carbon material only slightly, but completely eliminates precipitation in the low carbon material. It can be concluded that carbon causes heterogeneous nucleation of oxygen precipitation in CZ silicon and it is proposed that it does so by lowering the interfacial energy of the precipitates.

A Study of Gettering Efficiency and Stability in Czochralski Silicon

1995 ◽  
Vol 378 ◽  
Author(s):  
Scott A. McHugo ◽  
E. R. Weber ◽  
M. Mizuno ◽  
F. G. Kirscht
Keyword(s):  
Carbon Material ◽  
Strain Field ◽  
Annealing Treatment ◽  
Site Formation ◽  
Low Carbon ◽  
High Carbon ◽  
Carbon Doped ◽  
Annealing Conditions ◽  
Oxygen Precipitation ◽  
Induced Defects

AbstractGettering efficiencies and stabilities of internal gettering sites for metallic impurities in high and low carbon doped silicon have been compared with ramped and standard two-step pre-annealing conditions. This study was intended to compare two proposed techniques to shorten the long low temperature nucleation step in the standard Hi-Lo-Hi internal gettering site formation treatment. Specifically, we compare the affect of carbon and a ramped annealing sequence on oxygen precipitate formation and gettering effectiveness. Our results show both techniques accelerate oxygen precipitation, however, only the low carbon ramped materials produced efficient and stable gettering sites. The high carbon materials did not with either annealing treatment. This disparity in performance is due to a difference in the oxygen precipitate’s strain field. The precipitates in the low carbon material possessed a high strain field with strain-induced defects while in the high carbon material they were strain-free with no defects. These results indicate the strain stabilizes the gettered impurity such that the gettering rate is increased and stability is enhanced.

Synchrotron X-Ray Topographic Study of the Behavior of Defects in High Carbon-Content Si Wafers during RTP

1991 ◽  
Vol 225 ◽  
Author(s):  
Thomas Fanning ◽  
Michael Dudley ◽  
Franklyn F.Y. Wang ◽  
David Gordon-Smith ◽  
David T. Hodul
Keyword(s):  
Carbon Content ◽  
Thermal Processing ◽  
Rapid Thermal Processing ◽  
Defect Structures ◽  
Low Carbon ◽  
High Carbon ◽  
High Carbon Content ◽  
Strain Fields ◽  
X Ray ◽  
Transmission Geometry

ABSTRACTCzochralski (CZ) grown Si wafers, specially prepared with unusually high carbon content (ranging from 3 to 7 ppma), were subjected to a rapid thermal processing (RTP) treatment at 1050°C for 60s. Synchrotron white beam x-ray topography in transmission geometry was used to study defect structures in these Si wafers, both prior and subsequent to this RTP treatment. Observations of both the partial relaxation of the strain fields of precipitates and widespread nucleation and propagation of dislocations accompanying RTP are presented and discussed. Results are contrasted with those from parallel studies previously conducted on low carbon content wafers.

The Effect of Annealing Temperature on the Morphology of Stacking Faults in Czochralski Silicon

1980 ◽  
Vol 2 ◽  
Author(s):  
R. F. Pinizzotto ◽  
H. F. Schaake
Keyword(s):  
Annealing Temperature ◽  
Stacking Faults ◽  
Nucleation And Growth ◽  
X Ray ◽  
Czochralski Silicon ◽  
Oxygen Precipitation ◽  
Oxygen Precipitate

ABSTRACTNucleation and growth of stacking faults formed in CZ silicon during oxygen precipitation have been studied using x-ray topography, TEM and FTIR. Samples were annealed in argon for various times at 550°C and 750°C followed by a 16 hour anneal in dry oxygen at 1000°C. In samples annealed at 550°C, the stacking faults were several layers thick with colonies of precipitates at their centers. The faults in samples annealed at 750°C contained only one particle and were single in nature. It is proposed that the faults are formed by thin oxygen precipitate platelets and that the different morphologies are due to different oxygen precipitation rates. The platelets are probably a modified cristobalite, as determined by micro-diffraction results.

Precipitation at the transformation interface of pearlite in steel

1990 ◽  
Vol 48 (4) ◽  
pp. 912-913
Author(s):  
F. A. Khalid ◽  
D. V. Edmonds
Keyword(s):  
Thin Foil ◽  
Carbon Steels ◽  
Model Alloy ◽  
Low Carbon ◽  
High Carbon ◽  
Growth Interface ◽  
Medium Carbon ◽  
Interphase Precipitation ◽  
Solution Treated ◽  
Wide Range

The austenite/pearlite growth interface in a model alloy steel (Fe-1lMn-0.8C-0.5V nominal wt%) is being studied in an attempt to characterise the morphology and mechanism of VC precipitation at the growth interface. In this alloy pearlite nodules can be grown isothermally in austenite that remains stable at room temperature thus facilitating examination of the transformation interfaces. This study presents preliminary results of thin foil TEM of the precipitation of VC at the austenite/ferrite interface, which reaction, termed interphase precipitation, occurs in a number of low- carbon HSLA and microalloyed medium- and high- carbon steels. Some observations of interphase precipitation in microalloyed low- and medium- carbon commercial steels are also reported for comparison as this reaction can be responsible for a significant increase in strength in a wide range of commercial steels.The experimental alloy was made as 50 g argon arc melts using high purity materials and homogenised. Samples were solution treated at 1300 °C for 1 hr and WQ. Specimens were then solutionised at 1300 °C for 15 min. and isothermally transformed at 620 °C for 10-18hrs. and WQ. Specimens of microalloyed commercial steels were studied in either as-rolled or as- forged conditions. Detailed procedures of thin foil preparation for TEM are given elsewhere.

scholarly journals Interfacial Phenomena and Inclusion Formation Behavior at Early Melting Stages of HCFeCr and LCFeCr Alloys in Liquid Iron

2021 ◽  
Author(s):  
Yong Wang ◽  
Andrey Karasev ◽  
Joo Hyun Park ◽  
Wangzhong Mu ◽  
Pär G. Jönsson
Keyword(s):  
Liquid Iron ◽  
Diffusion Zone ◽  
Early Stage ◽  
Interfacial Phenomena ◽  
Solid Alloy ◽  
Low Carbon ◽  
High Carbon ◽  
Free Zone ◽  
Formation Behavior ◽  
Predetermined Time

AbstractChromium is normally added to liquid alloy in the form of different grades of ferrochromium (FeCr) alloys for the requirement of different alloy grades, such as stainless steels, high Cr cast iron, etc.. In this work, inclusions in two commercially produced alloys, i.e., high-carbon ferrochromium (HCFeCr) and low-carbon ferrochromium (LCFeCr) alloys, were investigated. The FeCr alloy/liquid iron interactions at an early stage were investigated by inserting solid alloy piece into contact with the liquid iron for a predetermined time using the liquid-metal-suction method. After quenching these samples, a diffusion zone between the alloys and the liquid Fe was studied based on the microstructural characterizations. It was observed that Cr-O-(Fe) inclusions were formed in the diffusion zone, FeOx inclusions were formed in the bulk Fe, and an “inclusion-free” zone was detected between them. Moreover, it was found that the HCFeCr was slowly dissolved, but LCFeCr alloy was rapidly melted during the experiment. The dissolution and melting behaviors of these two FeCr alloys were compared and the mechanism of the early-stage dissolution process of FeCr alloys in the liquid Fe was proposed.

scholarly journals Carbon Emission Governance Zones at the County Level to Promote Sustainable Development

Land ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 197
Author(s):  
He Zhang ◽  
Jingyi Peng ◽  
Dahlia Yu ◽  
Lie You ◽  
Rui Wang
Keyword(s):  
Sustainable Development ◽  
Carbon Emission ◽  
Total Carbon ◽  
Small Scale ◽  
County Level ◽  
Low Carbon ◽  
High Carbon ◽  
Governance System ◽  
Medium Carbon ◽  
Indicator Evaluation

Low-carbon governance at the county level has been an important issue for sustainable development due to the large contributions to carbon emission. However, the experiences of carbon emission governance at the county level are lacking. This paper discusses 5 carbon emission governance zones for 1753 counties. The zoning is formed according to a differentiated zoning method based on a multi-indicator evaluation to judge if the governance had better focus and had formulated a differentiated carbon emission governance system. According to zoning results, there is 1 high-carbon governance zone, 2 medium-carbon governance zones, and 2 low-carbon zones. The extensive high-carbon governance zone and medium-carbon zones are key governance areas, in which the counties are mainly located in the northern plain areas and southeast coastal areas and have contributed 51.88% of total carbon emissions. This paper proposes differentiated governance standards for each indicator of the 5 zones. The differentiated zoning method mentioned in this paper can be applied to other governance issues of small-scale regions.

scholarly journals Laser-Induced Deposition of Plasmonic Ag and Pt Nanoparticles, and Periodic Arrays

Materials ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 10
Author(s):  
Daria V. Mamonova ◽  
Anna A. Vasileva ◽  
Yuri V. Petrov ◽  
Denis V. Danilov ◽  
Ilya E. Kolesnikov ◽  
...  
Keyword(s):  
Substrate Surface ◽  
Pt Nanoparticles ◽  
Single Step ◽  
X Ray Diffraction ◽  
Ag Nps ◽  
X Ray ◽  
Periodic Arrays ◽  
Potential Applications ◽  
Surface Decoration ◽  
Wide Potential

Surfaces functionalized with metal nanoparticles (NPs) are of great interest due to their wide potential applications in sensing, biomedicine, nanophotonics, etc. However, the precisely controllable decoration with plasmonic nanoparticles requires sophisticated techniques that are often multistep and complex. Here, we present a laser-induced deposition (LID) approach allowing for single-step surface decoration with NPs of controllable composition, morphology, and spatial distribution. The formation of Ag, Pt, and mixed Ag-Pt nanoparticles on a substrate surface was successfully demonstrated as a result of the LID process from commercially available precursors. The deposited nanoparticles were characterized with SEM, TEM, EDX, X-ray diffraction, and UV-VIS absorption spectroscopy, which confirmed the formation of crystalline nanoparticles of Pt (3–5 nm) and Ag (ca. 100 nm) with plasmonic properties. The advantageous features of the LID process allow us to demonstrate the spatially selective deposition of plasmonic NPs in a laser interference pattern, and thereby, the formation of periodic arrays of Ag NPs forming diffraction grating

scholarly journals Dislocation densities in a low-carbon steel during martensite transformation determined by in situ high energy X-Ray diffraction

2021 ◽  
Vol 800 ◽  
pp. 140249
Author(s):  
Juan Macchi ◽  
Steve Gaudez ◽  
Guillaume Geandier ◽  
Julien Teixeira ◽  
Sabine Denis ◽  
...  
Keyword(s):  
Carbon Steel ◽  
Martensite Transformation ◽  
Low Carbon Steel ◽  
High Energy ◽  
Low Carbon ◽  
X Ray Diffraction ◽  
X Ray ◽  
Dislocation Densities
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