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Damage accumulation and dopant migration during shallow As and Sb implantation into Si

Werner, M; van den Berg, JA; Armour, DG; Vandervorst, W; Collart, EHJ; Goldberg, RD; Bailey, P; Noakes, TCQ

Authors

M Werner

JA van den Berg

DG Armour

W Vandervorst

EHJ Collart

RD Goldberg

P Bailey

TCQ Noakes



Abstract

The damage evolution and concomitant dopant redistribution as a function of ion fluence during ultra shallow, heavy ion implants into Si have been investigated using medium energy ion scattering (MEIS) and secondary ion mass spectrometry (SIMS). These studies involved As and Sb ions implanted at room temperature, at energies of 2.5 and 2 keV to doses from 3 × 1013 to 5 × 1015 cm−2. MEIS is capable of detecting both the displaced atom and implant profiles with sub-nanometre depth resolution. These studies show that for doses up to 1 × 1014 cm−2 (at which an amorphous layer is formed) the damage build up does not follow the energy deposition function. Instead it proceeds through the initial formation of a not, vert, similar4 nm wide amorphous layer immediately under the oxide, that grows inwards into the bulk with increasing dose. This behaviour is explained in terms of the migration of some of the interstitials produced along the length of the collision cascade to the oxide or amorphous/crystal Si interface, where their trapping nucleates the growth of a shallow amorphous layer and the subsequent planar growth inwards of the damage layer. Although for doses greater-or-equal, slanted4 × 1014 cm−2 the As depth profiles agreed well with TRIM calculations, for lower doses As was observed to have a shallower profile, not, vert, similar2 nm nearer to the surface. This behaviour is related the growth of the amorphous layer and ascribed to the movement of As into the near-surface amorphous layer (probably mediated by point defect migration) in which the larger dopant is accommodated more easily. SIMS studies have confirmed this dopant segregation effect. Shallow Sb implants also exhibit this novel dopant movement effect for low doses in combination with a damage evolution similar to As.

Citation

Werner, M., van den Berg, J., Armour, D., Vandervorst, W., Collart, E., Goldberg, R., …Noakes, T. (2004). Damage accumulation and dopant migration during shallow As and Sb implantation into Si. Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 216, 67-74. https://doi.org/10.1016/j.nimb.2003.11.022

Journal Article Type Article
Publication Date Feb 1, 2004
Deposit Date Aug 23, 2007
Journal Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms
Print ISSN 0168-583X
Publisher Elsevier
Peer Reviewed Peer Reviewed
Volume 216
Pages 67-74
DOI https://doi.org/10.1016/j.nimb.2003.11.022
Publisher URL http://dx.doi.org/10.1016/j.nimb.2003.11.022