[en] Buried damaged or amorphous layers were produced by implantation of 1 MeV As⁺ ions into Si (100) at room temperature. Then the samples were recrystallized by means of ion-beam annealing with 1.6 MeV Si⁺ ions at 300degC. Both the damaged and the annealed samples were observed by cross-sectional transmission electron microscopy (XTEM) and the microstructures were analyzed by high-resolution electron microscopy (HREM). It was found that ion-beam annealing is able to remove defects in the predamaged layer and the amounts of residual defects in this region are much less than that in the case of thermal annealing. For the ion-beam annealed samples, the results of HREM analysis showed that the ''end of range damage'' was mainly composed of small amounts of stacking faults with small size (<10 nm) and the ''clamshell defects'' were a few of the {113} defects with small size (<10 nm). (orig.)