Atomistic Model of Transient Enhanced Diffusion and Clustering of Boron In Silicon

1997 ◽  
Vol 469 ◽  
Author(s):  
L. Pelaz ◽  
G. H. Gilmer ◽  
M. Jaraiz ◽  
H.-J. Gossmann ◽  
C. S. Rafferty ◽  
...  
Keyword(s):  
Atomistic Model ◽  
Interstitial Diffusion ◽  
Enhanced Diffusion ◽  
Interstitial Concentration ◽  
Early Stages ◽  
Annealing Conditions ◽  
Transient Enhanced Diffusion ◽  
Very High

ABSTRACTAn atomistic model for B implantation, diffusion and clustering is presented. The model embodies the usual mechanism of Si self-interstitial diffusion and B kick-out and also includes the formation of immobile precursors of B clusters prior to the onset of transient enhanced diffusion. These immobile complexes, such as BI2 (a B atom with two Si self-interstitials) form during implantation or in the very early stages of annealing, when the Si interstitial concentration is very high. They then act as nucleation centers for the formation of B-rich clusters during annealing. This model explains and predicts the behavior of B under a wide variety of implantation and annealing conditions.

Simulation of Transient Enhanced Diffusion in Silicon Taking into Account Ostwald Ripening of Defects

2002 ◽  
Vol 717 ◽  
Author(s):  
Masashi Uematsu
Keyword(s):  
Time Dependence ◽  
Diffusion Model ◽  
Low Dose ◽  
Ostwald Ripening ◽  
High Dose ◽  
Enhanced Diffusion ◽  
Annealing Conditions ◽  
Transient Enhanced Diffusion ◽  
High Dose Implantation ◽  
Medium Dose

AbstractThe transient enhanced diffusion (TED) of high-dose implanted P is simulated taking into account Ostwald ripening of end-of-range (EOR) defects. First, we integrated a basic diffusion model based on the simulation of in-diffusion, where no implanted damages are involved. Second, from low-dose implantation, we developed a model for TED due to {311} self-interstitial (I) clusters involving Ostwald ripening and the dissolution of {311} clusters. Third, from medium-dose implantation, we showed that P-I clusters should be taken into account, and during the diffusion, the clusters are dissolved to emit self-interstitials that also contribute to TED. Finally, from high-dose implantation, EOR defects are modeled and we derived a formula to describe the time-dependence for Ostwald ripening of EOR defects, which is more significant at higher temperatures and longer annealing times. The simulation satisfactorily predicts the TED for annealing conditions, where the calculations overestimate the diffusion without taking Ostwald ripening into account.

Dopant segregation to {311} defects during low temperature annealing

1999 ◽  
Vol 568 ◽  
Author(s):  
Kenji Taniguchi ◽  
Tomoya Saito ◽  
Jianxin Xia ◽  
Ryangsu Kim ◽  
Takenori Aoki ◽  
...  
Keyword(s):  
Low Temperature ◽  
Thermal Annealing ◽  
The Self ◽  
Dopant Segregation ◽  
Enhanced Diffusion ◽  
Interstitial Concentration ◽  
Boron Segregation ◽  
Low Temperature Annealing ◽  
Transient Enhanced Diffusion

ABSTRACTBoron segregation to {311} defects and transient enhanced diffusion (TED) of boron atoms during thermal annealing were investigated in detail using implanted superlattice and Si bulk wafers. We observed that (1)boron atoms segregate to {311} defects during low temperature annealing, (2){311} defects were formed in the area where the self-interstitial concentration exceeds 3×1017cm3, (3)free self-interstitials in the region beyond the implanted range causes initial rapid enhanced diffusion prior to the onset of normal TED.

Quantitative Measurement of Reduction of Boron Diffusion by Substitutional Carbon Incorporation

1998 ◽  
Vol 527 ◽  
Author(s):  
M. S. Carroll ◽  
L. D. Lanzerotti ◽  
J. C. Sturm
Keyword(s):  
Quantitative Measurement ◽  
Device Modeling ◽  
Electrical Characteristics ◽  
Boron Diffusion ◽  
Carbon Incorporation ◽  
Combined Process ◽  
Enhanced Diffusion ◽  
Interstitial Concentration ◽  
Transient Enhanced Diffusion ◽  
Boron Diffusivity

ABSTRACTRecently, the suppression of boron diffusion due to both thermal and transient enhanced diffusion (TED) has been demonstrated through the incorporation of 0.5% substitutional carbon in the base of Si/SiGe/Si heterojunction transistor's (HBT)[1,2]. Because the devices are sensitive to diffusion on a scale less than that we can detect with SIMS, in this paper combined process and device modeling (TMA TSUPREM4 and MEDICI) are used to relate observed electrical characteristics (collector saturation currents and Early voltages) of the HBT's to boron diffusion, with a sensitivity of 20-30Å. Boron diffusivity in the SiGeC base is ~8 times slower than that of the boron diffusivity in the SiGe base without implant damage (no TED). In the case of ion implant damage in an overlying layer to cause TED the excess interstitial concentration due to ion implant damage is reduced by approximately 99% through incorporation of 0.5% substitutional carbon in the HBT SiGe bases. This demonstrates that carbon incorporation acts as an effective sink for interstitials.

Influence of Carbon on the Diffusion of Interstitials and Boron in Silicon

2000 ◽  
Vol 610 ◽  
Author(s):  
Mark E. Law ◽  
Michelle D. Griglione ◽  
Misty Northridge
Keyword(s):  
Binding Energy ◽  
Carbon Atom ◽  
Ab Initio ◽  
Point Defects ◽  
Initial Conditions ◽  
Carbon Diffusion ◽  
Reaction Rates ◽  
Interstitial Diffusion ◽  
Enhanced Diffusion ◽  
Transient Enhanced Diffusion

AbstractCarbon is a native impurity in Si which is known to trap self-interstitials and decrease their diffusivity. Carbon has also been observed to decrease B transient enhanced diffusion (TED) in Si through these interstitial interactions. Recently it has been proposed that vacancies must also be considered when accounting for the reduction of B TED. We have incorporated both the kick-out mechanism and the Frank-Turnbull (F-T) mechanism in simulations of interstitial diffusion and carbon diffusion, as well as experiments involving B diffusion in B doped superlattices (DSLs) with varying C concentration regions. We have used the binding energy between a carbon atom and a self-interstitial as a basis for the reaction rates for both mechanisms, and have found that an single energy of 2.25 eV best reproduces the results from several experiments, assuming equilibrium initial conditions for both mechanisms and ab-initio equilibrium values for all point defects.

Transient Enhanced Diffusion of Phosphorus and Defect Evolution in P+ Implanted Si

1999 ◽  
Vol 568 ◽  
Author(s):  
J. Li ◽  
P. Keys ◽  
J. Chen ◽  
M. E. Law ◽  
K. S. Jones ◽  
...  
Keyword(s):  
Enhanced Diffusion ◽  
Interstitial Concentration ◽  
Transient Enhanced Diffusion ◽  
Transmission Electron ◽  
Defect Evolution ◽  
Diffusion Phenomena ◽  
Dopant Atoms ◽  
Relationship Of ◽  
The Relationship ◽  
Secondary Ion

ABSTRACTContinuous scaling of device dimensions requires better understanding of non-equilibrium diffusion phenomena such as transient enhanced diffusion (TED). To this end, it is important to understand the relationship of the defect evolution with TED. Defect evolution in P+ implanted Si has been investigated by transmission electron microscopy (TEM). Secondary ion mass spectroscopy (SIMS) has been used to study phosphorus TED. These studies show that another type of defect, i.e. dot defects are present in P+implanted Si (100 keV, 1.OX104/cm2). The evolution of defects in P+ implants is compared with that in Si+ implants. P+ implants give rise to small dot defects mixed with {311} defects while Si+ implants give rise to only {311} defects. The dot defects and {311} defects in P+ implants dissolve faster than the {311} defects from Si+ implants. The interstitial concentration trapped in the dot defects and the {311} defects from P+ implants is slight lower than that from Si+ implants. Dot defects seem to have only a small role in phosphorus TED. Interaction of silicon interstitials emitted from the dissolution of {311} defects with phosphorus dopant atoms is believed to be the dominant driving force for the TED. There may also be a contribution from dissolution of non-visible phosphorus interstitial clusters (PIC's). Correlation of defect evolution and TED has been addressed.

scholarly journals Enhanced Diffusion of Dopants in Vacancy Supersaturation Produced by MeV Implantation

1997 ◽  
Vol 469 ◽  
Author(s):  
V. C. Venezia ◽  
T. E. Haynes ◽  
A. Agarwal ◽  
H. -J. Gossmann ◽  
D. J. Eaglesham
Keyword(s):  
Surface Layer ◽  
Surface Region ◽  
Silicon On Insulator ◽  
Rich Region ◽  
Near Surface ◽  
Enhanced Diffusion ◽  
Float Zone ◽  
Transient Enhanced Diffusion

ABSTRACTThe diffusion of Sb and B markers has been studied in vacancy supersaturations produced by MeV Si implantation in float zone (FZ) silicon and bonded etch-back silicon-on-insulator (BESOI) substrates. MeV Si implantation produces a vacancy supersaturated near-surface region and an interstitial-rich region at the projected ion range. Transient enhanced diffusion (TED) of Sb in the near surface layer was observed as a result of a 2 MeV Si+, 1×1016/cm2, implant. A 4× larger TED of Sb was observed in BESOI than in FZ silicon, demonstrating that the vacancy supersaturation persists longer in BESOI than in FZ. B markers in samples with MeV Si implant showed a factor of 10× smaller diffusion relative to markers without the MeV Si+ implant. This data demonstrates that a 2 MeV Si+ implant injects vacancies into the near surface region.

Ultra Shallow Junction Formation by B+/BF2+ Implantation at Energy of 0.5 KEV

1998 ◽  
Vol 532 ◽  
Author(s):  
M. Kase ◽  
Y Kikuchi ◽  
H. Niwa ◽  
T. Kimura
Keyword(s):  
Junction Depth ◽  
Shallow Junction ◽  
Enhanced Diffusion ◽  
Transient Enhanced Diffusion ◽  
Junction Formation

ABSTRACTThis paper describes ultra shallow junction formation using 0.5 keV B+/BF2+ implantation, which has the advantage of a reduced channeling tail and no transient enhanced diffusion. In the case of l × 1014 cm−2, 0.5 keV BF2 implantation a junction depth of 19 nm is achieved after RTA at 950°C.

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