Point defect based modeling of low dose silicon implant damage and oxidation effects on phosphorus and boron diffusion in silicon

1992 ◽  
Vol 72 (8) ◽  
pp. 3431-3439 ◽  
Author(s):  
Heemyong Park ◽  
Mark E. Law
Keyword(s):  
Point Defect ◽  
Low Dose ◽  
Boron Diffusion

Application of High Energy Ion Beam on the Control of Boron Diffusion

2003 ◽  
Vol 792 ◽  
Author(s):  
Wei-Kan Chu ◽  
Lin Shao ◽  
Jiarui Liu
Keyword(s):  
Point Defect ◽  
Point Defects ◽  
Anomalous Diffusion ◽  
Ion Beam ◽  
Surface Region ◽  
High Energy ◽  
Boron Diffusion ◽  
Defect Engineering ◽  
Projected Range ◽  
Ultrashallow Junction

ABSTRACTAnomalous diffusion of boron during annealing is a detriment on the fabrication of ultrashallow junction required by the next generation Si devices. This has driven the need to develop new doping methods. In the point defect engineering approach, high-energy ion bombardments inject vacancies near the surface region and create excessive interstitials near the end of projected range of incident ions. Such manipulation of point defects can retard boron diffusion and enhance activation of boron. We will review the current understanding of boron diffusion and our recent activities in point defect engineering.

Boron diffusion in silicon: the anomalies and control by point defect engineering

2003 ◽  
Vol 42 (3-4) ◽  
pp. 65-114 ◽  
Author(s):  
Lin Shao ◽  
Jiarui Liu ◽  
Quark Y. Chen ◽  
Wei-Kan Chu
Keyword(s):  
Point Defect ◽  
Boron Diffusion ◽  
Defect Engineering ◽  
And Control

Quantitative Measurement of Reduction of Phosphorus Diffusion by Substitutional Carbon Incorporation

1999 ◽  
Vol 568 ◽  
Author(s):  
M. S. Carroll ◽  
J. C. Sturm ◽  
C-L. Chang
Keyword(s):  
Point Defect ◽  
Active Regions ◽  
Absolute Number ◽  
Injection Rate ◽  
Complete Suppression ◽  
Boron Diffusion ◽  
Phosphorus Diffusion ◽  
Probe Point ◽  
Diffusion Enhancement ◽  
Boron Diffusivity

ABSTRACTComplete suppression of transient enhanced boron diffusion (TED) and oxidation enhanced boron diffusion (OED) in silicon have been achieved using substitutional carbon to reduce the excess point defect concentration in the dopant region [1]. Recent efforts have focused on removing the carbon from the active regions of the device [2,3] to avoid device degradation due to electrically active carbon defects [4] and exploring remote carbon's effect on boron TED and OED, while using the boron diffusion to probe point defect concentrations.In this paper we measure quantitatively the effect of remotely located carbon on phosphorus and boron diffusion above a buried SiGeC layer at 850°C in oxygen or nitrogen ambients. Remote carbon, located 1250 A below the phosphorus edge, is found to reduce the phosphorus diffusion enhancement factor due to OED from 8 to 2. The effect of the remotely located SiGeC buried layer on the excess interstitial concentration profile, which is responsible for the enhanced dopant diffusion, is probed by measuring boron and phosphorus diffusivites of in-situ doped boron and phosphorus layers above a buried SiGe(C) layer after oxidation or nitrogen anneals at 850°C. The enhanced boron diffusivity during oxidation is found to have a near linear dependence on depth ranging from 5–1.25. Finally, using x-ray diffraction and photoluminescence measurements of as-grown, buried, strained SiGe(C) structures and annealed SiGe(C) structures in oxygen or nitrogen ambient at 850°C the number of substitutional carbon atoms effectively consumed by oxidation is unambiguously correlated to the absolute number of injected interstitials using published values for the interstitial injection rate during oxidation [5].

Influence of dislocation loops created by amorphizing implants on point defect and boron diffusion in silicon

1996 ◽  
Vol 68 (25) ◽  
pp. 3570-3572 ◽  
Author(s):  
H. S. Chao ◽  
P. B. Griffin ◽  
J. D. Plummer
Keyword(s):  
Point Defect ◽  
Dislocation Loops ◽  
Boron Diffusion

The Role of Vacancies and Interstitials in Transient Enhanced Diffusion of Arsenic Implanted into Silicon

1997 ◽  
Vol 469 ◽  
Author(s):  
D. Venables ◽  
V. Krishnamoorthy ◽  
H.- J. Gossmann ◽  
A. Lilak ◽  
K. S. Jones ◽  
...  
Keyword(s):  
Fermi Level ◽  
Point Defect ◽  
Boron Diffusion ◽  
Direct Role ◽  
Enhanced Diffusion ◽  
Projected Range ◽  
Transient Enhanced Diffusion ◽  
Diffusion Enhancement ◽  
Recombination Centers

ABSTRACTBoron and antimony doped superlattices (DSLs) were implanted with arsenic at 40 keV to doses of 2×1014 cm−2, 5×1015 cm−2 and 2×1016 cm−2. Increasing the arsenic dose above 5×1015 cm−2 resulted in a reduction in the extent of arsenic transient enhanced diffusion (TED) following annealing at 700°C, 16 hr. Concurrent with this reduction in TED was a reduction in the number of free interstitials beyond the end-of-range, as measured by the boron diffusion enhancement in the doped superlattices. No enhancement in antimony diffusivity was observed in this region, indicating that vacancies play no direct role in the diffusion of arsenic in this region, although an indirect role for vacancies as recombination centers for mobile interstitials is not precluded by these experiments. We conclude that interstitials dominate arsenic diffusion in the end-of-range region and beyond. Interpretation of the DSL data in the projected range region is complicated by Fermi level and segregation effects and no definitive conclusion can be reached about the point defect populations in this region.

Antimony and Boron Diffusion in Silicon and Silicon Germanium under the Influence of Point Defects Injection by Rapid Thermal Anneal

2001 ◽  
Vol 669 ◽  
Author(s):  
Aihua Dan ◽  
Arthur F. W. Willoughby ◽  
Janet M. Bonar ◽  
Barry M. McGregor ◽  
Mark G. Dowsett ◽  
...  
Keyword(s):  
Point Defect ◽  
Point Defects ◽  
Silicon Germanium ◽  
Secondary Ion Mass Spectrometry ◽  
Diffusion Time ◽  
Injection Technique ◽  
Boron Diffusion ◽  
Rapid Thermal Anneal ◽  
Vacancy Defects ◽  
Defect Injection

ABSTRACTThe effect of point defect injection on the diffusion of antimony and boron in silicon and silicon-germanium alloys has been studied by comparison of inert with injection diffusions. In this work, Sb and B in Si were used as control wafers to investigate Sb and B diffusion behavior in Si0.9Ge0.1. The point defect injection technique was carried out by rapid thermal annealing (RTA) Sb and B in Si and Si0.9Ge0.1 samples with the various surface coatings in either oxygen or ammonia atmospheres to inject either interstitial or vacancy defects. The diffusion profiles for as-grown and RTA annealed samples were measured by Secondary Ion Mass Spectrometry (SIMS). Diffusivities for B in Si and Si0.9Ge0.1 were obtained using computer simulations of the measured boron profiles for their annealed samples. Sb diffusion in Si and Si0.9Ge0.1 was found enhanced by vacancy injection and retarded by interstitial injection. The enhanced B diffusion in Si and Si0.9Ge0.1 was found by interstitial injection. These results confirm that Sb diffusion in Si0.9Ge0.1 is primarily dominated by vacancy-mediated mechanism, while B diffuses in Si0.9Ge0.1 by an interstitially mediated mechanism. The effect of the RTA diffusion time on the B diffusion in Si and Si0.9Ge0.1 has also been investigated. The diffusivity versus diffusion time of B in Si and Si0.9Ge0.1 for inert and injection samples is presented. It was found that the shorter annealing time had the faster diffusion. This suggested that it caused by transient diffusion effect arising from point defects.

Ovarian Dysfunction in Fetally Irradiated Beagles

1977 ◽  
Vol 35 ◽  
pp. 658-659
Author(s):  
T. M. Seed ◽  
M. H. Sanderson ◽  
D. L. Gutzeit ◽  
T. E. Fritz ◽  
D. V. Tolle ◽  
...  
Keyword(s):  
Gamma Rays ◽  
Low Dose ◽  
Long Term Effects ◽  
Ovarian Dysfunction ◽  
Dose Rates ◽  
Highly Sensitive ◽  
Microscopic Evaluation ◽  
Ovarian Pathology ◽  
Normal Offspring

The developing mammalian fetus is thought to be highly sensitive to ionizing radiation. However, dose, dose-rate relationships are not well established, especially the long term effects of protracted, low-dose exposure. A previous report (1) has indicated that bred beagle bitches exposed to daily doses of 5 to 35 R 60Co gamma rays throughout gestation can produce viable, seemingly normal offspring. Puppies irradiated in utero are distinguishable from controls only by their smaller size, dental abnormalities, and, in adulthood, by their inability to bear young.We report here our preliminary microscopic evaluation of ovarian pathology in young pups continuously irradiated throughout gestation at daily (22 h/day) dose rates of either 0.4, 1.0, 2.5, or 5.0 R/day of gamma rays from an attenuated 60Co source. Pups from non-irradiated bitches served as controls. Experimental animals were evaluated clinically and hematologically (control + 5.0 R/day pups) at regular intervals.

High Resolution Microscopy of Multi-Layered Biological Crystals

1982 ◽  
Vol 40 ◽  
pp. 80-83
Author(s):  
H.A. Cohen ◽  
T.W. Jeng ◽  
W. Chiu
Keyword(s):  
High Resolution ◽  
Low Dose ◽  
Three Dimensional ◽  
Data Interpretation ◽  
Two Dimensional ◽  
Biological Objects ◽  
Density Maps ◽  
Density Map ◽  
Complex Crystal ◽  
High Resolution Microscopy

This tutorial will discuss the methodology of low dose electron diffraction and imaging of crystalline biological objects, the problems of data interpretation for two-dimensional projected density maps of glucose embedded protein crystals, the factors to be considered in combining tilt data from three-dimensional crystals, and finally, the prospects of achieving a high resolution three-dimensional density map of a biological crystal. This methodology will be illustrated using two proteins under investigation in our laboratory, the T4 DNA helix destabilizing protein gp32*I and the crotoxin complex crystal.

Characterization of microtubules by dark-field STEM and replication

1991 ◽  
Vol 49 ◽  
pp. 152-153
Author(s):  
S.B. Andrews ◽  
R.D. Leapman ◽  
P.E. Gallant ◽  
T.S. Reese
Keyword(s):  
Protein Interactions ◽  
Low Dose ◽  
Unit Length ◽  
Dark Field ◽  
Carbon Films ◽  
Microtubule Associated Proteins ◽  
Molecular Weights ◽  
Freeze Dried ◽  
Protein Motors ◽  
Associated Proteins

As part of a study on protein interactions involved in microtubule (MT)-based transport, we used the VG HB501 field-emission STEM to obtain low-dose dark-field mass maps of isolated, taxol-stabilized MTs and correlated these micrographs with detailed stereo images from replicas of the same MTs. This approach promises to be useful for determining how protein motors interact with MTs. MTs prepared from bovine and squid brain tubulin were purified and free from microtubule-associated proteins (MAPs). These MTs (0.1-1 mg/ml tubulin) were adsorbed to 3-nm evaporated carbon films supported over Formvar nets on 600-m copper grids. Following adsorption, the grids were washed twice in buffer and then in either distilled water or in isotonic or hypotonic ammonium acetate, blotted, and plunge-frozen in ethane/propane cryogen (ca. -185 C). After cryotransfer into the STEM, specimens were freeze-dried and recooled to ca.-160 C for low-dose (<3000 e/nm2) dark-field mapping. The molecular weights per unit length of MT were determined relative to tobacco mosaic virus standards from elastic scattering intensities. Parallel grids were freeze-dried and rotary shadowed with Pt/C at 14°.

Sign in / Sign up

Export Citation Format

Share Document