The Role of Implant Temperature in the Formation of Thin Buried Oxide Layers

1986 ◽  
Vol 74 ◽  
Author(s):  
Alice E. White ◽  
K. T. Short ◽  
L. N. Pfeiffer ◽  
K. W. West ◽  
J. L. Batstone
Keyword(s):  
High Temperature ◽  
Crystalline Material ◽  
High Dose ◽  
Si Substrate ◽  
High Temperature Anneal ◽  
Damage Structure ◽  
Amorphous Si ◽  
Substrate Temperatures

AbstractFrom the early work on high dose oxygen implantation for buried SiO2 formation, it is apparent that the temperature of the Si substrate during the implant has a strong influence on the quality of both the SiO2 layer and the overlying Si. This, in turn, can be related to the damage from the oxygen implant. For substrate temperatures < ∼ 300°C, amorphous Si is created during the implant and leads to the formation of twins or polycrystalline Si during the subsequent high temperature (>1300°C) anneal. At higher substrate temperatures (<∼400°C), dynamic annealing eliminates the amorphous Si, but the implanted oxygen appears to segregate during the implant leading to oxygen-rich amorphous regions imbedded in regions of crystalline material. As the amorphous regions start to coalesce and form SiO2 during the high temperature anneal, they trap crystalline Si which cannot escape by diffusion. This process can be circumvented by using a randomizing Si implant to change the damage structure from the oxygen implant before annealing. We have seen these effects clearly in sub-stoichiometric implants, and believe they are also operative during stoichiometric implants.

scholarly journals Current Nanocarrier Strategies Improve Vitamin B12 Pharmacokinetics, Ameliorate Patients’ Lives, and Reduce Costs

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 743
Author(s):  
Marco Fidaleo ◽  
Stefano Tacconi ◽  
Carolina Sbarigia ◽  
Daniele Passeri ◽  
Marco Rossi ◽  
...  
Keyword(s):  
Side Effects ◽  
Vitamin B12 ◽  
Memory Performance ◽  
Oral Route ◽  
High Dose ◽  
Human Beings ◽  
Inborn Errors ◽  
Essential Nutrient

Vitamin B12 (VitB12) is a naturally occurring compound produced by microorganisms and an essential nutrient for humans. Several papers highlight the role of VitB12 deficiency in bone and heart health, depression, memory performance, fertility, embryo development, and cancer, while VitB12 treatment is crucial for survival in inborn errors of VitB12 metabolism. VitB12 is administrated through intramuscular injection, thus impacting the patients’ lifestyle, although it is known that oral administration may meet the specific requirement even in the case of malabsorption. Furthermore, the high-dose injection of VitB12 does not ensure a constant dosage, while the oral route allows only 1.2% of the vitamin to be absorbed in human beings. Nanocarriers are promising nanotechnology that can enable therapies to be improved, reducing side effects. Today, nanocarrier strategies applied at VitB12 delivery are at the initial phase and aim to simplify administration, reduce costs, improve pharmacokinetics, and ameliorate the quality of patients’ lives. The safety of nanotechnologies is still under investigation and few treatments involving nanocarriers have been approved, so far. Here, we highlight the role of VitB12 in human metabolism and diseases, and the issues linked to its molecule properties, and discuss how nanocarriers can improve the therapy and supplementation of the vitamin and reduce possible side effects and limits.

Non Destructive Determination of the Threading Dislocation Density of Smooth Simox Substrates using Atomic Force Microscopy

2000 ◽  
Vol 6 (S2) ◽  
pp. 1088-1089
Author(s):  
A. Domenicucci ◽  
R. Murphy ◽  
D. Sadanna ◽  
S. Klepeis
Keyword(s):  
Atomic Force Microscopy ◽  
High Temperature ◽  
Single Crystal Silicon ◽  
Silicon Layer ◽  
High Dose ◽  
Threading Dislocation ◽  
Crystal Silicon ◽  
Force Microscopy ◽  
Atomic Force ◽  
High Temperature Anneal

Atomic force microscopy (AFM) has been used extensively in recent years to study the topographic nature of surfaces in the nanometer range. Its high resolution and ability to be automated have made it an indispensable tool in semiconductor fabrication. Traditionally, AFM has been used to monitor the surface roughness of substrates fabricated by separation by implanted oxygen (SIMOX) processes. It was during such monitoring that a novel use of AFM was uncovered.A SIMOX process requires two basic steps - a high dose oxygen ion implantation (1017 to 1018 cm-3) followed by a high temperature anneal (>1200°C). The result of these processes is to form a buried oxide layer which isolates a top single crystal silicon layer from the underlying substrate. Pairs of threading dislocations can form in the top silicon layer during the high temperature anneal as a result of damage caused during the high dose oxygen implant.

Aspects of the Shi–Seinfeld–Okuyama theory of transient nucleation

1995 ◽  
Vol 10 (7) ◽  
pp. 1674-1679 ◽  
Author(s):  
G. Sundar ◽  
J.J. Hoyt
Keyword(s):  
High Temperature ◽  
Singular Perturbation ◽  
Incubation Time ◽  
Cluster Size ◽  
Analytic Solution ◽  
Time Dependent ◽  
Transient Kinetics ◽  
High Temperature Anneal ◽  
Transient Nucleation

The analytic solution to the time-dependent nucleation problem by Shi-Seinfeld-Okuyama (SSO) [Phys. Rev. A 41, 2101 (1990)] is reviewed. The singular perturbation solution employed by SSO is extended to examine the effect of initial quench position on the incubation time. Two cases are discussed. The first investigates the role of excess vacancies from the high temperature quench on the transient kinetics. The second case examines the change in the incubation time due to the effects of a preexisting subcritical cluster size distribution which forms during the high temperature anneal.

scholarly journals Role of high dose octreotide LAR for the treatment of GEP-NETs

2009 ◽  
Vol 3 (1) ◽  
pp. 7-14
Author(s):  
Giulia M. Franchi ◽  
Chiara Cappelletti ◽  
Valentina V. Villa ◽  
Emanuele Bosi ◽  
Marco F. Manzoni
Keyword(s):  
Quality Of Life ◽  
Tumour Growth ◽  
Neuroendocrine Tumours ◽  
Clinical Symptoms ◽  
Standard Dose ◽  
Diagnostic Tools ◽  
High Dose ◽  
Octreotide Lar

Neuroendocrine Tumours (NETs) are a heterogeneous group of rare neoplasms that account for 0,5% of all malignancies. The increased incidence observed in the last few decades may be accounted for by increased awareness, improved diagnostic tools and a revision in the definition. The main primary sites are the gastro-entero-pancreatic (GEP) tract (62-67%), and the lung (22-27%). In patients with GEP-NETs, the strongest predictor of 5-years survival is the staging. An adequate clinical management of GEP-NETs should be multidisciplinary and should aim at assuring a good quality of life. Somatostatin (sst) analogues are widely used in these tumours, which often express sst receptors, since they are demonstrated to reduce clinical symptoms and tumour growth. Herein we explore the usefulness of doubling octreotide LAR dose in selected patients after escaping from symptoms control and/or tumour stabilization in course of treatment with standard dose.

Studies of CoSi2 nano-structures produced by high-dose ion implantation in Si

1989 ◽  
Vol 47 ◽  
pp. 454-455
Author(s):  
S.D. Berger ◽  
D. Loretto ◽  
H.A. Huggins ◽  
Alice E. White ◽  
K.T. Short ◽  
...  
Keyword(s):  
Electron Beam ◽  
High Temperature ◽  
Electron Beam Lithography ◽  
Growth Process ◽  
High Dose ◽  
Nano Structures ◽  
High Temperature Anneal ◽  
Discrete Structures ◽  
Buried Layers ◽  
High Doses

Recently it has been shown that buried layers of single crystal, orientated CoSi2 Can be produced in silicon by implanting high doses of Co followed by a high temperature anneal. This process is known as mesotaxy. The original implant produces a skewed Gaussian distribution of ions. However, on annealing it is found that the distribution sharpens dramatically to give layers which nave flat and abrupt interfaces and are of very good structural and electrical quality.Using a combination of electron beam lithography and reactive ion etching we have fabricated masks which confine the implant dose laterally. In this way we are able to produce discrete structures of CoSi2 with nanometer dimensions. Furthermore, we can now investigate the epitaxial growth process which occurs during the anneal by varying the structure's dimensions, shape and crystallographic orientation with respect to the substrate.

scholarly journals The Role of Chloroquine and Hydroxychloroquine in Prophylaxis of Covid-19: A Literature Review

2020 ◽  
Author(s):  
Dewi Indra Sari ◽  
◽  
Mardiati Nadjib ◽  
Keyword(s):  
Public Health ◽  
Observational Studies ◽  
Cochrane Library ◽  
Post Exposure Prophylaxis ◽  
High Dose ◽  
Inclusion Criteria ◽  
Exclusion Criteria ◽  
Exposure Prophylaxis

ABSTRACT Background: A pandemic potential Covid-19 spread rapidly worldwide. Ministry of Health, Republic Indonesia recommended one of the Covid-19 treatments with combination of hydroxychloroquine/ chloroquine and azithromycin. However, the effectiveness and safety of antimalaria regime remain debating topic. This study aimed to investigate the role of chloroquine and hydroxychloroquine in prophylaxis of Covid-19. Subjects and Method: A systematic review was conducted by searching from PubMed, SpringerLink, and Cochrane Library databases. The keywords were “prophylaxis”, “chloroquine” OR “hydroxychloroquine” “SARS-CoV-2” OR “Covid-19”. The inclusion criteria were phase IIb clinical trials, double masking, comparative observational studies, open access articles published until August 2020. The exclusion criteria were inaccessible and duplicate articles. The quality of selected articles was critically appraised. The data were reported by PRISMA flow chart. Results: Three articles out of 117 articles met the criteria inclusion. The findings showed that hydroxychloroquine could not prevent Covid-19 compatible disease or confirmed infections when used as post-exposure prophylaxis. High dose chloroquine was not recommended for critically ill COVID-19 patients because of its potential side effects, especially when administered with azithromycin and oseltamivir. Covid-19 patients with the need for oxygenation were not suggested to use hydroxychloroquine. Conclusion: There is scarce evidence to support prophylaxis and treatment effects of chloroquine or hydroxychloroquine in COVID-19 patients. Further research on the safety and use of chloroquine or hydroxychloroquine is required in the management of Covid-19. Keywords: prophylaxis, Chloroquine, Hydroxychloroquine, SARS-CoV-2, Covid-19 Correspondence: Dewi Indra Sari. Masters Program in Public Health, Faculty of Public Health, Universitas Indonesia, Depok, West Java. Email: [email protected]. Mobile: +628121983-6600. DOI: https://doi.org/10.26911/the7thicph.05.33

MBE Growth of GaAs on Si through Direct Ge Buffers

2005 ◽  
Vol 869 ◽  
Author(s):  
Xiaojun Yu ◽  
Yu-Hsuan Kuo ◽  
Junxian Fu ◽  
James S Harris
Keyword(s):  
High Temperature ◽  
Buffer Layer ◽  
Single Phase ◽  
Threading Dislocation ◽  
Si Substrate ◽  
Step Method ◽  
Mbe Growth ◽  
Gaas Substrates ◽  
High Temperature Anneal ◽  
Threading Dislocation Density

AbstractThe result of GaAs growth on Si using a thin Ge buffer layer (about 0.5μm thick) is presented in this paper. A two-step method with a high temperature anneal between two steps is used to grow the Ge buffer layer. Single phase GaAs is grown on Ge by controlling the growth temperature, substrate miscut and the prelayers. No APD defect is observed by the XTEM and the threading dislocation density of GaAs grown using this method is about 5˜10×107cm-2. The PL intensity of GaAs is 10× less on Si substrate than on GaAs substrates.

Buried Silicon-Nitride by High Temperature Nitrogen Implantation

1987 ◽  
Vol 107 ◽  
Author(s):  
U. Bussmann ◽  
F.H.J. Meerbach ◽  
E.H. Te Kaat
Keyword(s):  
High Temperature ◽  
Silicon Nitride ◽  
Electron Diffraction ◽  
Amorphous Material ◽  
Subsequent Annealing ◽  
High Dose ◽  
Nitrogen Implantation ◽  
Tem Analysis ◽  
Amorphous Si ◽  
Nitride Layers

AbstractBuried silicon nitride layers are formed by high temperature (600-800°C), high dose (0.3-1 x 1018 Ncm -2) nitrogen implantation into silicon. The nitride structure of as-implanted and annealed (6 h at 1200°C) samples is revealed by TEM-analysis. At implantation temperatures up to 600°C an amorphous SixN" layer is formed. At higher temperatures crystalline precipitates are found within an amorphous environment. They are identified as β-Si3N4 by electron diffraction. By subsequent annealing the previously amorphous material crystallizes to a-Si3N4, while the β-grains seem to be stable.

The Effect of Y on the Strength of FeCrAl Alloy/Sapphire Interfaces

2002 ◽  
Vol 751 ◽  
Author(s):  
Soumendra N. Basu ◽  
Vijay K. Gupta
Keyword(s):  
High Temperature ◽  
Interfacial Strength ◽  
Reactive Element ◽  
Crystalline Quality ◽  
Reactive Element Effect ◽  
Laser Spallation ◽  
Fecral Alloy ◽  
High Temperature Anneal ◽  
Free Films

ABSTRACTThe effect of Y on the interfacial strength of the FeCrAl/sapphire system has been quantitatively measured by the laser-spallation technique in order to understand the ‘reactive element effect’. The presence of Y improved the interfacial strength of the FeCrAl/sapphire interface in the as-deposited state from 330±31 MPa to 686±36 MPa. However, after a high temperature anneal of 16 hours at 850°C, the interfacial strength of the Y-free samples increased to 545±68 MPa, while the interfacial strength of Y-containing sample decreased to 599±22 MPa. The increase in the interfacial strength of the Y-free films was attributed to an improvement in the crystalline quality of the interface. The decrease in interfacial strength of the annealed Y-containing film in spite of the improvement in the crystalline quality of the interface was attributed to the depletion of Y at the interface due to formation of Y2O3 precipitates, again consistent with the view that Y improves the strength of FeCrAl/sapphire interfaces significantly.

Influence of low thermal budget pre-anneals on the high temperature redistribution of low energy boron implants in silicon

2001 ◽  
Vol 669 ◽  
Author(s):  
F. Boucard ◽  
M. Schott ◽  
D. Mathiot ◽  
P. Rivallin ◽  
P. Holliger ◽  
...  
Keyword(s):  
High Temperature ◽  
Initial Point ◽  
High Dose ◽  
Thermal Budget ◽  
Enhanced Diffusion ◽  
High Temperature Anneal ◽  
Ultra Shallow Junctions ◽  
Low Thermal Budget ◽  
Temperature Plateau ◽  
Reference Samples

ABSTRACTIt is now well established that the transient enhanced diffusion (TED) of ion implanted boron in silicon limits the formation of the ultra-shallow junctions required for the extreme deep sub- micron devices. It is also known that this TED is linked to the fate (elimination and agglomeration) of ion implantation related excess self-interstitials. Thus it can be expected that the final high temperature redistribution is at least partly governed by the effective initial point defect distribution at the onset of the high temperature plateau.In this contribution we present the experimental evidence that low thermal pre-anneals, by affecting the initial self-interstitials distribution, affects boron redistribution during a subsequent high temperature anneal. Samples implanted with high dose boron at 3 keV were first annealed at 700°C for various durations. These samples, as well as reference samples without the pre-anneal, were then RTA annealed at various high temperatures around 1000°C. The resulting B profiles were measured by SIMS. It is found that the pre-annealed samples exhibits a clear reduction of the TED as compared with the reference ones.

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