Damage and strain in high-dose O-implanted material were studied by means of Rutherford back-scattering spectrometry, double-crystal X-ray diffraction and transmission electron microscopy. In the Si over-layer, tensile strain and lattice contraction resulted from a vacancy excess. It was found that the depth of the strain maximum was a function of the O-ion dose. After a low dose, at an implantation temperature of 150C, the strain increased from the surface to the amorphous/crystalline interface. After high doses, relaxation via dislocation formation was observed when the strain exceeded some 6400ppm. The residual strain maximum then moved towards the surface. The strain maximum before relaxation, at a given O dose, decreased as the implantation temperature was increased. This was attributed to dynamic annealing effects and was consistent with thermally-activated dislocation nucleation and movement.

S.L.Ellingboe, M.C.Ridgway: Nuclear Instruments and Methods in Physics Research B, 1995, 106[1-4], 409-14