Various effects of postimplantation of silicon ions on boron‐implanted layers are reported. The amount of enhanced annealing depends critically on the target temperature during implantation and on the dose of silicon ions used. At 100 keV, a 5×1015/cm2silicon dose is necessary to create an amorphous layer extending up to the surface at room temperature. Close to 100% of the boron ions located in this layer become electrically active after annealing at 600°C. For boron doses approximately greater than 3×1015/cm2, shallow silicon implantations produce stronger enhanced annealing than expected. For boron doses less than 2×1014/cm2, little or no enhanced annealing is observed.