Medium energy ion scattering analysis of the evolution and annealing of damage and associated dopant redistribution of ultra shallow implants in Si

J. A. Van Den Berg, M. A. Reading, D. G. Armour, G. Carter, P. C. Zalm, P. Bailey, T. C.Q. Noakes

Research output: Contribution to journalArticle

2 Citations (Scopus)

Abstract

As junction depths in advanced semiconductor devices move to below 20nm, the process of disorder evolution during ion implantation at ultra low energies becomes increasingly influenced by the surface. This may also hold for shallow regrowth and dopant redistribution processes during subsequent thermal annealing of the substrate. The investigation of these near-surface processes requires analytical techniques with a depth resolution of1nm. Medium energy ion scattering (MEIS) has the unique capability of simultaneously providing quantitative, high-resolution depth distributions of implant disorder (displaced Si lattice atoms) and of implanted atoms, albeit not of light species. We report here a comparative MEIS investigation into the growth mode of shallow disordered/amorphised layers during1keV B+ and 2.5keV As+ ion implantation into Si. In both cases the growth of the damage depth profiles differs significantly from the energy deposition function, as it is strongly determined on the one hand by the proximity of the surface acting as a nucleation site for migrating point defects formed during implantation, which results in planar growth of the amorphous layer, and on the other by the dynamic annealing processes operating at room temperature. When such defect recombination processes are inhibited, e.g. for low dose, ultra shallow 200eV B+ implants, MEIS shows that defect production yields exceeding the Kinchin-Pease model predictions are achieved. For As implants, a correlation is observed between the movement of the As and the depth of the growing, planar amorphous layer. Thermal annealing of As implanted samples at different temperatures and durations leads to solid phase epitaxial regrowth. During regrowth, MEIS shows that there is a close correlation between damage dissolution, the movement of nearly half of the As dopant into substitutional sites and the snowploughing of a fraction of the As in front of the advancing amorphous/crystalline interface leading to the formation of a less than 1nm wide As pile-up layer trapped under the oxide.
Original languageEnglish
Pages (from-to)481-491
Number of pages11
JournalRadiation Effects and Defects in Solids
Volume164
Issue number7-8
DOIs
Publication statusPublished - Jul 2009

Fingerprint

ion scattering
Doping (additives)
Scattering
Annealing
Ions
damage
annealing
Ion implantation
Atoms
Defects
ion implantation
energy
Point defects
Semiconductor devices
disorders
Oxides
Piles
Dissolution
Nucleation
defects

Cite this

Van Den Berg, J. A. ; Reading, M. A. ; Armour, D. G. ; Carter, G. ; Zalm, P. C. ; Bailey, P. ; Noakes, T. C.Q. / Medium energy ion scattering analysis of the evolution and annealing of damage and associated dopant redistribution of ultra shallow implants in Si. In: Radiation Effects and Defects in Solids. 2009 ; Vol. 164, No. 7-8. pp. 481-491.
@article{165f3c6febda48bc80cad022fc84acd7,
title = "Medium energy ion scattering analysis of the evolution and annealing of damage and associated dopant redistribution of ultra shallow implants in Si",
abstract = "As junction depths in advanced semiconductor devices move to below 20nm, the process of disorder evolution during ion implantation at ultra low energies becomes increasingly influenced by the surface. This may also hold for shallow regrowth and dopant redistribution processes during subsequent thermal annealing of the substrate. The investigation of these near-surface processes requires analytical techniques with a depth resolution of1nm. Medium energy ion scattering (MEIS) has the unique capability of simultaneously providing quantitative, high-resolution depth distributions of implant disorder (displaced Si lattice atoms) and of implanted atoms, albeit not of light species. We report here a comparative MEIS investigation into the growth mode of shallow disordered/amorphised layers during1keV B+ and 2.5keV As+ ion implantation into Si. In both cases the growth of the damage depth profiles differs significantly from the energy deposition function, as it is strongly determined on the one hand by the proximity of the surface acting as a nucleation site for migrating point defects formed during implantation, which results in planar growth of the amorphous layer, and on the other by the dynamic annealing processes operating at room temperature. When such defect recombination processes are inhibited, e.g. for low dose, ultra shallow 200eV B+ implants, MEIS shows that defect production yields exceeding the Kinchin-Pease model predictions are achieved. For As implants, a correlation is observed between the movement of the As and the depth of the growing, planar amorphous layer. Thermal annealing of As implanted samples at different temperatures and durations leads to solid phase epitaxial regrowth. During regrowth, MEIS shows that there is a close correlation between damage dissolution, the movement of nearly half of the As dopant into substitutional sites and the snowploughing of a fraction of the As in front of the advancing amorphous/crystalline interface leading to the formation of a less than 1nm wide As pile-up layer trapped under the oxide.",
keywords = "Disorder formation, Dopant segregation, Kinchin-Pease model, MEIS, Point defect trapping, Shallow implants into Si, Surface effect",
author = "{Van Den Berg}, {J. A.} and Reading, {M. A.} and Armour, {D. G.} and G. Carter and Zalm, {P. C.} and P. Bailey and Noakes, {T. C.Q.}",
year = "2009",
month = "7",
doi = "10.1080/10420150902949944",
language = "English",
volume = "164",
pages = "481--491",
journal = "Radiation Effects and Defects in Solids",
issn = "1042-0150",
publisher = "Taylor and Francis Ltd.",
number = "7-8",

}

Medium energy ion scattering analysis of the evolution and annealing of damage and associated dopant redistribution of ultra shallow implants in Si. / Van Den Berg, J. A.; Reading, M. A.; Armour, D. G.; Carter, G.; Zalm, P. C.; Bailey, P.; Noakes, T. C.Q.

In: Radiation Effects and Defects in Solids, Vol. 164, No. 7-8, 07.2009, p. 481-491.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Medium energy ion scattering analysis of the evolution and annealing of damage and associated dopant redistribution of ultra shallow implants in Si

AU - Van Den Berg, J. A.

AU - Reading, M. A.

AU - Armour, D. G.

AU - Carter, G.

AU - Zalm, P. C.

AU - Bailey, P.

AU - Noakes, T. C.Q.

PY - 2009/7

Y1 - 2009/7

N2 - As junction depths in advanced semiconductor devices move to below 20nm, the process of disorder evolution during ion implantation at ultra low energies becomes increasingly influenced by the surface. This may also hold for shallow regrowth and dopant redistribution processes during subsequent thermal annealing of the substrate. The investigation of these near-surface processes requires analytical techniques with a depth resolution of1nm. Medium energy ion scattering (MEIS) has the unique capability of simultaneously providing quantitative, high-resolution depth distributions of implant disorder (displaced Si lattice atoms) and of implanted atoms, albeit not of light species. We report here a comparative MEIS investigation into the growth mode of shallow disordered/amorphised layers during1keV B+ and 2.5keV As+ ion implantation into Si. In both cases the growth of the damage depth profiles differs significantly from the energy deposition function, as it is strongly determined on the one hand by the proximity of the surface acting as a nucleation site for migrating point defects formed during implantation, which results in planar growth of the amorphous layer, and on the other by the dynamic annealing processes operating at room temperature. When such defect recombination processes are inhibited, e.g. for low dose, ultra shallow 200eV B+ implants, MEIS shows that defect production yields exceeding the Kinchin-Pease model predictions are achieved. For As implants, a correlation is observed between the movement of the As and the depth of the growing, planar amorphous layer. Thermal annealing of As implanted samples at different temperatures and durations leads to solid phase epitaxial regrowth. During regrowth, MEIS shows that there is a close correlation between damage dissolution, the movement of nearly half of the As dopant into substitutional sites and the snowploughing of a fraction of the As in front of the advancing amorphous/crystalline interface leading to the formation of a less than 1nm wide As pile-up layer trapped under the oxide.

AB - As junction depths in advanced semiconductor devices move to below 20nm, the process of disorder evolution during ion implantation at ultra low energies becomes increasingly influenced by the surface. This may also hold for shallow regrowth and dopant redistribution processes during subsequent thermal annealing of the substrate. The investigation of these near-surface processes requires analytical techniques with a depth resolution of1nm. Medium energy ion scattering (MEIS) has the unique capability of simultaneously providing quantitative, high-resolution depth distributions of implant disorder (displaced Si lattice atoms) and of implanted atoms, albeit not of light species. We report here a comparative MEIS investigation into the growth mode of shallow disordered/amorphised layers during1keV B+ and 2.5keV As+ ion implantation into Si. In both cases the growth of the damage depth profiles differs significantly from the energy deposition function, as it is strongly determined on the one hand by the proximity of the surface acting as a nucleation site for migrating point defects formed during implantation, which results in planar growth of the amorphous layer, and on the other by the dynamic annealing processes operating at room temperature. When such defect recombination processes are inhibited, e.g. for low dose, ultra shallow 200eV B+ implants, MEIS shows that defect production yields exceeding the Kinchin-Pease model predictions are achieved. For As implants, a correlation is observed between the movement of the As and the depth of the growing, planar amorphous layer. Thermal annealing of As implanted samples at different temperatures and durations leads to solid phase epitaxial regrowth. During regrowth, MEIS shows that there is a close correlation between damage dissolution, the movement of nearly half of the As dopant into substitutional sites and the snowploughing of a fraction of the As in front of the advancing amorphous/crystalline interface leading to the formation of a less than 1nm wide As pile-up layer trapped under the oxide.

KW - Disorder formation

KW - Dopant segregation

KW - Kinchin-Pease model

KW - MEIS

KW - Point defect trapping

KW - Shallow implants into Si

KW - Surface effect

UR - http://www.scopus.com/inward/record.url?scp=67651210415&partnerID=8YFLogxK

U2 - 10.1080/10420150902949944

DO - 10.1080/10420150902949944

M3 - Article

VL - 164

SP - 481

EP - 491

JO - Radiation Effects and Defects in Solids

JF - Radiation Effects and Defects in Solids

SN - 1042-0150

IS - 7-8

ER -