ion Implantation of boron in germanium


The activation of boron implanted at room temperature into germanium has been studied. In contrast to other group III elements boron forms a p-type layer before any postl.1nplant annealIng steps. Variable temperature Hall effect measurements and deep level trans{ent spectroscopy experiments indicate that all of the boron ions are electricaHy active as shallow acceptor the en.tire dose range (5 X 101l/cm2 to 1 X 1014/cm2 ) and energy range (25-100 keY) mvestlgated, WIthout any postimplant annealing. The concentration of damage rel.ated acceptor is only 10% of the boron related, shaUow accepted centers concentrailon for low-energy implants (25 keY), but becomes dominant at high energies (100 keY) and low doses ( < 1 X 1012/cm2 )0 Three damage related hole traps are produced by . 1 . f11B+ Imp antatlOn 0 . Two of these hole traps have also been observed in y-irradiated Ge and may be oxygen-vacancy related defects, while the third trap may be divacancy related. All three :raps anneal out at low temperatures ( < 300 ·C). Room-temperature implantation of BFt mto Ge, does not lead to substitutionally active boron without annealing. A thermal cycle of 350 ·C for 30 min activates 100% of the boron.

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Cite this paper

@inproceedings{Jones2011ionIO, title={ion Implantation of boron in germanium}, author={K. S. Jones and Eberhard Haller}, year={2011} }