A study of Si implanted with 1.55MeV 3He and thermally annealed to generate a sub-surface cavity region was performed using neutron depth profiling and transmission electron microscopy. Results showed that about 30% of the initial implanted He was still present in cavities even after annealing (900C, 1h). In addition, transmission electron microscopic measurement of cavity size on annealing temperature yields an activation energy of 1.65eV for the growth of cavities. This value was very close to the activation energy (1.7eV) reported for He diffusion in Si. Cavity growth hence results essentially from exchange of He atoms between cavities.

Growth Mechanism of Cavities in MeV Helium Implanted Silicon. J.Grisolia, A.Claverie, G.Ben Assayag, S.Godey, E.Ntsoenzok, F.Labhom, A.Van Veen: Journal of Applied Physics, 2002, 91[11], 9027-30