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].

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.

Long range enhancement of boron diffusivity by phosphorus diffusion

1980 ◽  
Vol 48 (1-4) ◽  
pp. 101-104 ◽  
Author(s):  
D. Lecrosnier ◽  
G. Pelous ◽  
F. Richou
Keyword(s):  
Long Range ◽  
Phosphorus Diffusion ◽  
Boron Diffusivity

Phosphorus diffusion in silicon; influence of annealing conditions

2001 ◽  
Vol 669 ◽  
Author(s):  
J. S. Christensen ◽  
A. Yu. Kuznetsov ◽  
H. H. Radamson ◽  
B. G. Svensson
Keyword(s):  
Activation Energy ◽  
Diffusion Coefficients ◽  
Activation Energies ◽  
Boron Diffusion ◽  
Diffusion Mode ◽  
Phosphorus Diffusion ◽  
Annealing Conditions ◽  
Boron Doped ◽  
Arrhenius Dependence ◽  
P Diffusion

ABSTRACTPhosphorus diffusion has been studied in both pure epitaxially grown silicon and Cz silicon, with a substantial amount of impurities like oxygen and carbon. Anneals have been performed in different atmospheres, N2 and dry O2, as well as in vacuum, at temperatures between 810 – 1100°C. Diffusion coefficients extracted from these anneals show no difference for the P diffusion in the epitaxially grown or the Cz silicon. The diffusion coefficients follow an Arrhenius dependence with the activation energy Ea=2.74±0.07 eV and a prefactor D0 = (8±5)×10−4 cm2/s. These parameters differ considerably from the previously reported and widely accepted values (3.66 eV and 3.84 cm2/s, respectively). However, vacuum anneals of the same samplesresult in values close to this 3.6 eV diffusion mode. Furthermore, control anneals of boron doped samples, with similar design as the phosphorus samples, suggest the same trend for boron diffusion in silicon – lower versus higher values of activation energies for nitrogen and vacuum anneals, respectively. These results are discussed in terms of the concentration of Si self-interstitials mediating the diffusion of phosphorus and boron.

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.

Monte Carlo simulation of Boron diffusion during low energy implantation and high temperature annealing

1997 ◽  
Vol 469 ◽  
Author(s):  
M.-J. Caturla ◽  
T. Diaz de la Rubia ◽  
J. Zhu ◽  
M. Johnson
Keyword(s):  
Monte Carlo ◽  
High Temperature ◽  
Kinetic Monte Carlo ◽  
Monte Carlo Model ◽  
Low Energy ◽  
High Temperature Annealing ◽  
Boron Diffusion ◽  
Enhanced Diffusion ◽  
Diffusion Enhancement ◽  
High Doses

ABSTRACTWe use a kinetic Monte Carlo model to simulate the implantation of low energy Boron in Silicon, from 0.5 to 1 keV, at high doses, 1015 ions/cm2. The damage produced by each ion is calculated using UT-Marlowe, based on a binary collision approximation. During implantation at room temperature,, silicon self-interstitials, vacancies and boron interstitials are allowed to migrate and interact. The diffusion kinetics of these defects and dopants has been obtained by ab initio calculations as well as Stillinger Weber molecular dynamics. Clustering of both self-interstitials, vacancies and boron atoms is included. We also model the diffusion of the implanted dopants after a high temperature annealing in order to understand the transient enhanced diffusion (TED) phenomenon. We observe two different stages of TED During the first stage vacancies are present in the lattice together with interstitials and the diffusion enhancement is small. The second stage starts after all the vacancies disappear and gives rise to most of the final TED.

Effect of Fluorine on the Diffusion of Boron in Amorphous Silicon

2002 ◽  
Vol 717 ◽  
Author(s):  
J. M. Jacques ◽  
L. S. Robertson ◽  
K. S. Jones ◽  
Joe Bennett
Keyword(s):  
Amorphous Silicon ◽  
Boron Concentration ◽  
Solid Phase ◽  
Amorphous Layer ◽  
Boron Diffusion ◽  
Enhanced Diffusion ◽  
Diffusion Characteristics ◽  
Junction Formation ◽  
Amorphous Surface ◽  
Boron Diffusivity

AbstractFluorine and boron co-implantation within amorphous silicon has been studied in order to meet the process challenges regarding p+ ultra-shallow junction formation. Previous experiments have shown that fluorine can reduce boron TED (Transient Enhanced Diffusion), enhance boron solubility and reduce sheet resistance. In this study, boron diffusion characteristics prior to solid phase epitaxial regrowth (SPER) of the amorphous layer in the presence of fluorine are addressed. Samples were pre-amorphized with Si+ at a dose of 1x1015 ions/cm2 and energy of 70 keV, leading to a deep continuous amorphous surface of approximately 1500 Å. After pre-amorphization, B+ was implanted at a dose of 1x1015 ions/cm2 and energy of 500 eV, while F+ was implanted at a dose of 2x1015 ions/cm2 and energies ranging from 3 keV to 9 keV. Subsequent furnace anneals for the F+ implant energy of 6 keV were conducted at 550°C, for times ranging from 5 minutes to 260 minutes. During annealing, the boron in samples co-implanted with fluorine exhibited significant enhanced diffusion within amorphous silicon. After recrystallization, the boron diffusivity was dramatically reduced. Boron in samples with no fluorine did not diffuse during SPER. Prior to annealing, SIMS profiles demonstrated that boron concentration tails broadened with increasing fluorine implant energy. Enhanced dopant motion in as-implanted samples is presumably attributed to implant knock-on or recoil effects.

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

Onset of Extended Defect Formation and Enhanced Diffusion for Ultra-Low Energy Boron Implants

1999 ◽  
Vol 568 ◽  
Author(s):  
Jinning Liu ◽  
Kevin S. Jones ◽  
Daniel F. Downey ◽  
Sandeep Mehta
Keyword(s):  
Defect Formation ◽  
Low Energy ◽  
Dislocation Loops ◽  
Boron Diffusion ◽  
Extended Defect ◽  
Enhanced Diffusion ◽  
Annealing Conditions ◽  
Diffusion Enhancement ◽  
Spike Anneal ◽  
Low Thermal Budget

ABSTRACTTo meet the challenge of achieving ultra shallow p+/n source/drain extension junctions for 0.1 Oim node devices, ultra low energy boron implant and advanced annealing techniques have been explored. In this paper, we report the extended defect and boron diffusion behavior with various implant and annealing conditions. Boron implants were performed at energies from 0.25keV to lkeV and doses of 5 × 1014 cm−2 and 1 × 1015cm−2. Subsequent anneals were carried out in nitrogen ambient. The effect of energy, dose and oxide capping on extended defect formation and enhanced dopant diffusion was examined. It was observed that a thin screen oxide layer (35Å), grown prior to implantation, reduces the concentration of dopant in the Si by a significant amount as expected. This oxide also reduces the dislocation loops in the lattice and lowers diffusion enhancement of the dopant during annealing. The final junction depth can be optimized by using a low thermal budget spike anneal in a controlled oxygen ambient.

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