  We report on the fabrication and electrical characterization at millikelvin
temperatures of a novel silicon single-electron transistor (Si-SET). The island
and source-drain leads of the Si-SET are formed by the implantation of
phosphorus ions to a density above the metal-insulator-transition, with the
tunnel junctions created by undoped regions. Surface gates above each of the
tunnel junctions independently control the tunnel coupling between the Si-SET
island and leads. The device shows periodic Coulomb blockade with a charging
energy e$^2$/2C$_\Sigma$ $\sim$ 250 $\mu$eV, and demonstrates a reproducible
and controllable pathway to a silicon-based SET using CMOS processing
techniques.
