Samples were implanted with B++N+ and B++Ar+ ions, furnace annealed at temperatures of up to 900C, and studied using Rutherford back-scattering spectrometry and electron paramagnetic resonance techniques. An anomalous decrease in defect concentration was observed after subsequent implantation with B and N ions to the same dose (1.2 x 1015/cm2). This was attributed to radiation annealing. The transformation of simple point defects to penta-vacancies during annealing was detected. This depended upon the degree of amorphization. It was found that the defect annealing temperature was a function of the dose and ion species combinations which were used for the first and second implantations.

I.P.Kozlov, V.B.Odzhaev, V.N.Popok, V.Hnatowicz: Semiconductor Science and Technology, 1996, 11[5], 722-5