Retention and thermal release behavior of deuterium and helium implanted in SiC

Abstract

Retention and release of ion implanted deuterium (D) and helium (He) in silicon carbide (SiC) were studied with respect to damage accumulation and annealing behavior using ion beam analysis techniques. α-SiC single crystals were irradiated by 10keV D2+ and He+ at 300 and 770K, and depth profiles of retained atoms and lattice disorder were measured during the implantation and successive heat treatments. For the sample pre-irradiated with He at a fluence of 1.0×1021ions/m2, the thermal release of D atoms was completed at an annealing temperature of 1370K, while the retained D atoms still remained in the sample without pre-irradiation. In contrast to the facilitated thermal release of D by He pre-irradiation, the He release temperature increased in the sample followed by D ion implantation. No significant difference of He retention and damage accumulation behavior was observed between the samples implanted at 300 and 770K. The D retention and D-ion-induced disorder for 770K implantation, was reduced to approximately 1/2 comparing to that of the sample implanted at 300K. The D retention at 770K was not affected by the He pre-implantation induced damage.