Techniques used to fabricate a gated resonant tunneling diode (GRTD) are presented. Molecular‐beam epitaxy (MBE), image reversal contact photolithography, liftoff metallization, anisotropic reactive ion etching, isotropic liquid etching, and a resulting self‐aligned gate metal deposition technique were used to realize this effort. The physical sizes of the fabricated GRTDs were 2, 4, and 6 μm in diameter. The electrical size of the channel within the vertical resonant tunneling diode, however, was controlled by a simple, self‐aligned rectifying electrode at the well region. Arrays of devices were fabricated to enhance detection while retaining small geometries. The results from these first devices indicate that aninsitutransition from a two‐dimensional resonant tunneling diode (RTD) to a zero‐dimensional quantum dot is feasible using this design. Improvements in the design are realizable from straightforward modifications in the MBE material.