Ionic implantation at low energy: application to the shallow junction accomplishment and surface functionalization

The proposed work deals with rapid thermal processing of ionic boron (¹¹B⁺) and boron difluoride (BF₂⁺), implanted in phosphorusdoped Cz-(100) silicon substrates through protecting oxide films, under different technological parameters. After implantation, the samples were rapidly thermally annealed at temperatures ranging from 900 to 1100 °C, in argon ambient gas, for different annealing durations. The rapid thermal annealings (RTAs) are carried out also, for some samples, after oxide mask removal. The total boron, fluorine as well as oxygen concentrations versus depth profiles, before and after annealing steps, in the SiO₂/Cz-(100) silicon systems were determined using secondary ion mass spectrometry (SIMS). Using a background concentration, the junction depth in the substrate has been investigated under different annealing experimental conditions. The kinetic diffusion process of implanted boron into oxide and monocrystalline silicon during rapid thermal treatments has also been investigated. The reported results show that boron diffusion in the BF₂⁺ case is widely reduced during rapid thermal treatments. Discussions of this are based on the effect of both knocked-on oxygen and fluorine on the boron diffusion kinetics.