EXTENDED DEFECT FORMATION AND THE FLUX OF INTERSTITIALS IN SI-ION IMPLANTED SILICON

We have investigated the role of silicon interstitials, released durin g the annealing of self-ion implanted silicon, in the formation of ext ended defects, Levels of implant damage are varied by control of impla nt temperature and ion flux; however, it is shown that the formation o f extended defects depends on the implant fluence, not on the net amou nt of primary damage. Ion implanted delta-doped boron structures are u sed to detect released Si interstitials, It is observed that below a f luence of 1 x 10(14) cm(-2) the excess interstitials escape the implan ted region during annealing and extended defects do not form. Above th is fluence, most of the excess interstitials remain in the implanted r egion, agglomerating into extended defects while a small fraction esca pe, causing enhanced diffusion in boron delta-doped layers outside the implanted region. The data indicate that for self-implantation, exten ded defect formation can be understood in terms of the plus-one model.