EXPERIMENTAL-ANALYSIS OF HIGH-ENERGY BORON IMPLANTATION IN SILICON

Boron ions in the 15-50 MeV energy range were implanted into high resi stivity silicon targets. The range distributions were measured by Spre ading Resistance Profilometry (SRP) and for the first time by Secondar y Ion Mass Spectrometry (SIMS). The two techniques provide accurate ra nge and straggling experimental determinations even at this large dept h (approximately 100 mum). The carrier profile matches quite well the chemical profile in all the investigated samples. The profiles are cha racterized by a long front tail at low boron concentration due to sing le scattering events at large angle. The distribution around the peak is broaded by electronic straggling and in some cases by channeling ef fects. This latter phenomenon introduces an asymmetry around the peak. The Bethe approach in combination with large angle scattering and ele ctronic straggling describes the profiles.