Single crystal <100> Silicon wafers implanted by 1×1016/cm2 boron ions at 30, 80, or 130 KeV are studied. The through thickness strain distribution in the wafer is found to reverse from tension in the as-implanted condition to compression after annealing for 20 minutes at 900°C. The 30 KeV implant generates a partially amorphized region under the wafer surface. Boron diffuses out of this region and accumulates at greater depth during annealing. Higher energy implants do not generate such an amorphous region and many long rod-like defects develop under a band of dislocation loops during annealing. Enhanced boron diffusion was observed at the tail of the boron profile at all three energies.