1000-Å-A thick heavily doped layers have been produced in Si by implanting B at energies as low as 1-2 keV. No preamorphization is required and the near-surface random peak is redistributed by diffusion into the deeper channeled region to provide sharp junctions. Doping levels of ∼ 2 × 1020cm-3can be maintained over a region ∼600-Å-thick while maintaining junction depths as shallow as 1000 Å.