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2003
Conference Paper
Title
Indium in silicon: A study on diffusion and electrical activation
Other Title
Indium in Silicium: Eine Studie der Diffusion und elektrischen Aktivierung
Abstract
In this work we investigate the diffusion and the electrical activation of In atoms implanted in silicon with different energies, in the range 80-360 keV, after rapid thermal processing. Our investigation shows a clear dependence of In out-diffusion and electrical activation on the implant depth, being the electrically active fraction higher with increasing the implant energy for a fixed dose. The data are explained considering the balance between the local In concentrati on and the C background inside the silicon substrate and the formation of C-In complexes, which play a role in the enhanced electrical activation due to the shallower level they introduce into the Si band gap (Ev+0.111 eV), with respect to the rather deep level (Ev+0.156 eV) of In alone. In and C co-implantation has also been studied within this work, in order to confirm the key role of C in the increase of the electrical activation. A large increase of the electrical activation has been detected in the co-implanted samples, up to a factor of about 8 after annealing at 900°C. However, C precipitation occurs at 1100°C, with dramatic effects on the carrier concentration.
Author(s)