Transient enhanced diffusion and defect microstructure in high dose, low energy As+ implanted Si

Abstract(001) CZ silicon wafers were implanted with arsenic (As+) at energies of 10–50keV to doses of 2×1014 to 5×1015/cm2. All implants were amorphizing in nature. The samples were annealed at 700°C for 16hrs. The resultant defect microstructures were analyzed by XTEM and PTEM and the As profiles were analyzed by SIMS. The As profiles showed significantly enhanced diffusion in all of the annealed specimens. The diffusion enhancement was both energy and dose dependent. The lowest dose implant/annealed samples did not show As clustering which translated to a lack of defects at the projected range. At higher doses, however, projected range defects were clearly observed, presumably due to interstitials generated during As clustering. The extent of enhancement in diffusion and its relation to the defect microstructure is explained by a combination of factors including surface recombination of point defects, As precipitation, As clustering and end of range damage.

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

MRS Proceedings ◽

10.1557/proc-717-c5.1 ◽

2002 ◽

Vol 717 ◽

Cited By ~ 1

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.

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Effect of Energy and Dose on Transient-Enhanced Diffusion and Defect Microstructure in Low Energy High Dose As+ Implanted Si

MRS Proceedings ◽

10.1557/proc-439-29 ◽

1996 ◽

Vol 439 ◽

Author(s):

V. Krishnamoorthy ◽

D. Venables ◽

K. Moeller ◽

K. S. Jones ◽

B. Freer

Keyword(s):

Point Defects ◽

Surface Recombination ◽

High Dose ◽

Enhanced Diffusion ◽

Projected Range ◽

Diffusion Enhancement ◽

Defect Microstructures ◽

Dose Dependent ◽

Higher Doses ◽

Defect Microstructure

Abstract(001) CZ silicon wafers were implanted with arsenic (As+) at energies of 10–50keV to doses of 2x 1014 to 5x1015/cm2. All implants were amorphizing in nature. The samples were annealed at 700°C for 16hrs. The resultant defect microstructures were analyzed by XTEM and PTEM and the As profiles were analyzed by SIMS. The As profiles showed significantly enhanced diffusion in all of the annealed specimens. The diffusion enhancement was both energy and dose dependent. The lowest dose implant/annealed samples did not show As clustering which translated to a lack of defects at the projected range. At higher doses, however, projected range defects were clearly observed, presumably due to interstitials generated during As clustering. The extent of enhancement in diffusion and its relation to the defect microstructure is explained by a combination of factors including surface recombination of point defects, As precipitation, As clustering and end of range damage.

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Low Energy Implantation and Transient Enhanced Diffusion: Physical Mechanisms and Technology Implications

MRS Proceedings ◽

10.1557/proc-469-265 ◽

1997 ◽

Vol 469 ◽

Cited By ~ 16

Author(s):

N. E. B. Cowern ◽

E. J. H. Collart ◽

J. Politiek ◽

P. H. L. Bancken ◽

J. G. M. Van Berkum ◽

...

Keyword(s):

Thermal Activation ◽

Crystalline Silicon ◽

Cmos Technology ◽

Low Energy ◽

Defect Engineering ◽

Enhanced Diffusion ◽

Physical Mechanisms ◽

Transient Enhanced Diffusion ◽

Junction Formation ◽

Silicon Cmos

ABSTRACTLow energy implantation is currently the most promising option for shallow junction formation in the next generations of silicon CMOS technology. Of the dopants that have to be implanted, boron is the most problematic because of its low stopping power (large penetration depth) and its tendency to undergo transient enhanced diffusion and clustering during thermal activation. This paper reports recent advances in our understanding of low energy B implants in crystalline silicon. In general, satisfactory source-drain junction depths and sheet resistances are achievable down to 0.18 micron CMOS technology without the need for implantation of molecular species such as BF2. With the help of defect engineering it may be possible to reach smaller device dimensions. However, there are some major surprises in the physical mechanisms involved in implant profile formation, transient enhanced diffusion and electrical activation of these implants, which may influence further progress with this technology. Some initial attempts to understand and model these effects will be described.

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