New self-aligned planar resonant-tunneling diodes for monolithic circuits

Resonant-tunneling diodes (RTDs) with a new planar configuration have been fabricated with a new self-aligned process that is compatible with that of silicon integrated-circuits technology. The size of the RTD is determined by a shallow boron implant, and the individual RTDs are isolated by a deep proton implant. There is no deep mesa etch. Because of the self-alignment nature of the process, the peak current and voltage of the RTDs are highly uniform. The mean of the standard deviation of the peak current for 4-μm
²
RTDs is 2.3% and the smallest RTDs fabricated are less than 1 μm
²
.