The evolution of cavities in Si co-implanted with Si and He ions1

Different levels of damage were first introduced into CZ p-type Si (100) by the implantation of 80 keV Si ions to different doses ranging from 1014 to 5×1015 cm−2. All the Si implanted samples together with virgin Si were then subjected to 1 MeV 3He ion implantation to the same dose of 5×1016 cm−2. Cross-sectional transmission electron microscopy (XTEM) and nuclear reaction analysis (NRA) measurements were used to quantify the evolution of He-cavities and He desorption from the cavities after subsequent annealing, respectively. Our results show that the presence of high level of damage induced by Si implants tends to inhibit the growth of He-cavities and increase the rate of He desorption. The results are tentatively interpreted on the basis of the evolution of Si induced damage upon annealing and its interaction with He-cavities.