ANNEALING OF DEFECTS CREATED IN SILICON BY MEV ION-IMPLANTATION

Electron paramagnetic resonance has been used to study the annealing b ehaviour of defects created in (100) silicon wafers by implantation at liquid nitrogen temperature of doses of 3 x 10(13) to 10(15) cm-2 of 2 MeV Si+ or 10(12) to 10(14) cm-2 of 3 MeV Au+ ions. Neutral four-vac ancy centres (Si-P3), which are present most obviously after low dose implantation, anneal out at about 200-degrees-C and are replaced by fi ve-vacancy centres (Si-P1) which finally anneal out between 550 and 60 0-degrees-C. In samples which have a continuous amorphous layer the D centres (a-Si centres) gradually anneal between about 100 and 550-degr ees-C before abruptly disappearing at 600-degrees-C; however, in sampl es without such a continuous layer they anneal out by about 350-degree s-C. The annealing behaviour of the Au and Si implanted samples is rem arkably similar for Au doses a factor of about 20 times less than Siwhich suggests that the density of displacements along individual trac ks is not the factor controlling the anneal behaviour.