Abstract:
The effect of high temperature thermal annealing on the retainment and diffusion behaviour of iodine (I)
and silver (Ag) both individually and co-implanted into 6H-SiC has been investigated using RBS, RBS-C
and heavy ion ERDA (Elastic Recoil Detection Analysis). Iodine and silver ions at 360 keV were both individually
and co-implanted into 6H-SiC at room temperature to fluences of the order of 1 1016 cm 2. RBS
analyses of the as-implanted samples indicated that implantation of Ag and of I and co-implantation of
131I and 109Ag at room temperature resulted in complete amorphization of 6H-SiC from the surface to a
depth of about 290 nm for the co-implanted samples. Annealing at 1500 C for 30 h (also with samples
annealed at 1700 C for 5 h) caused diffusion accompanied by some loss of both species at the surface
with some iodine remaining in the iodine implanted samples. In the Ag implanted samples, the RBS spectra
showed that all the Ag disappeared. SEM images showed different recrystallization behaviour for all
three sets of samples, with larger faceted crystals appearing in the SiC samples containing iodine. Heavy
Ion ERDA analyses showed that both 109Ag and 131I remained in the co-implanted SiC samples after
annealing at 1500 C for 30 h. Therefore, iodine assisted in the retainment of silver in SiC even at high
temperature.
