Implant damage and transient enhanced diffusion in Si

• Published in: Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms Vol. 106; no. 1; pp. 191 - 197
• Main Authors: Eaglesham, D.J., Stolk, P.A., Gossmann, H.-J., Haynes, T.E., Poate, J.M.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.12.1995
• ISSN: 0168-583X; 1872-9584
• DOI: 10.1016/0168-583X(95)00703-2

Transmission electron microscopy is used to address two key questions for ion-implant technology in Si. First, how does ion damage influence the diffusion of implanted dopants: and, second, when and how does damage evolve into extended dislocations seen after prolonged anneals. The answer to both questions turns out to involve “{311} defects”, the interstitial agglomerates also known as “rod-like defects”. At low doses, {311} defects evaporate during annealing, and emit interstitials. The characteristic time for the decay of {311}s, and its activation energy of 3.6 ± 0.1 eV, relate precisely with the observed duration of the burst of interstitials seen in accurate diffusion measurements. We also use {311} counting to assess the accuracy of the “plus one” approximation for the excess interstitials seen after implantation. At higher doses, the {311} defects can also undergo a series of unfaulting reactions. In contrast to earlier reports on {311}s formed during electron irradiation, we observe that {311}s initially “unfault” to yield Frank loops, followed by unfaulting of Frank loops to give a 2〈110〉 s . We relate our observations for a “phase diagram” for {311} behaviour to earlier studies of dislocation loop formation.