The study of lattice damage using slow positrons following low energy B+ implantation of silicon

The drive beyond sub-250 nm device structures requires a concomitant reduct ion in ion implantation energies to below keV. Such low energies are presen ting new challenges for the understanding of defects created by the implant ation process. Although positron annihilation spectroscopy (PAS) is a well- proven technique for studying radiation-induced damage, it has only recentl y been applied to vacancy-type defects induced by low energy implantation. This paper presents measurements of defect profiles following 2-100 keV imp lantation of B; of Ct and epitaxially grown Si. The extraction of data rela ting to the defect profiles and their dependence on impurity content and th e proximity of the surface are described. Further, we discuss results for a nnealed samples that show the sensitivity of diffusing positrons to the pre sence of electric fields following the creation of p-n structures. (C) 2001 Published by Elsevier Science B.V.