Defects formation in the dual B⁺ and N⁺ ions implanted silicon

Silicon wafers were implanted with 40 keV B⁺ ions (to doses of 1.2×10¹⁴ or 1.2×10¹⁵ cm^-2) and 50 or 100 keV N⁺ ions (to doses from 1.2×10¹⁴ to 1.2×10¹⁵ cm^-2). After implantations, the samples were furnace annealed at temperatures from 100 to 450 °C. The depth profiles of the radiation damages before and after annealing were obtained from random and channeled RBS spectra using standard procedures. Two damaged regions with different annealing behaviour were found for the silicon implanted with boron ions. Present investigations show that surface disordered layer conserves at the annealing temperatures up to 450 °C. The influence of preliminary boron implantation on the concentration of radiation defects created in subsequent nitrogen implantation was studied. It was shown that the annealing behaviour of the dual implanted silicon layers depends on the nitrogen implantation dose.