Samples of n-type material were implanted with 1.6MeV He to fluences ranging from 1016 to 1017/cm2, using a constant dose rate, and were then annealed (800C, 0.5h). The results of cross-sectional transmission electron microscopy indicated that the density of cavities was fluence-dependent, with an homogeneous distribution of cavity sizes, when fluences of 5 x 1016 or 1017/cm2 were used. The threshold fluence which was required in order to form cavities was between 1016 and 2 x 1016/cm2. At the latter dose, loop-punching was observed which was induced by the concerted action of over-pressurized bubbles. Implanted He, at doses of 5 x 1016 or 1017/cm2, led to the formation of {311} defects.

Cavities and Dislocations Induced in Silicon by MeV He Implantation S.Godey, T.Sauvage, E.Ntsoenzok, H.Erramli, M.F.Beaufort, J.F.Barbot, B.Leroy: Journal of Applied Physics, 2000, 87[5], 2158-61