Monolithic Integration of Resonant Tunneling Diodes and FET's for Monostable-Bistable Transition Logic Elements (MOBILE's)

A MOBILE (monostable-bistable transition logic element), employing two n-type negative differential resistance devices connected in series, is a functional logic gate with the advantages of multiple inputs and multiple functions. In this paper, a novel approach to achieve MOBILE operation is demonstrated using monolithic integration of resonant tunneling diodes (RTD) and FET's. In our new integration structure, an RTD and FET are connected in parallel. This structure offers several advantages including separate optimization of RTD's and FET's, and flexible circuit design abilities. For a single-input MOBILE gate, inverter operation at room temperature is demonstrated as the evidence of monostable-to-bistable transition.