A process for fabricating an MOS device having a highly-localized halo region includes the formation of a first halo region at a first surface of a silicon substrate, and a second halo region at a second surface of the silicon substrate. The second surface of the silicon substrate is formed by anisotropically etching the first surface of the silicon substrate to remove a portion of the material from the substrate. Both the first and second halo regions are formed by low-energy ion implantation. For the fabrication of an n-channel device, boron is implanted at an energy of no more than about 1 keV. Upon implantation and a subsequent annealing process, the first and second halo regions form a continuous halo region within the semiconductor substrate.