Annealing of radiation defects in dual-implanted silicon

Silicon samples dual implanted with B+ + N+ and B+ + Ar+ ions and then furnace annealed at temperatures up to 900 degrees C were studied using RBS and EPR. An anomalous decrease of defect concentration after subsequent implantation with boron and nitrogen ions to the same dose (1.2 x 10(15) cm(-2)) was observed due to radiation annealing. A transformation of simple point defects to pentavacancies during annealing was found, which depends on the degree of silicon amorphization. The defect annealing temperature was found to be a function of the dose and ion species combination in the first and second implantations.