MONOSTABLE BISTABLE TRANSITION LOGIC ELEMENTS (MOBILES) BASED ON MONOLITHIC INTEGRATION OF RESONANT-TUNNELING DIODES AND FETS

A MOBILE (monostable-bistable transition logic element) is a functional logic gate employing two negative differential resistance devices connected in-series. This logic gate offers the advantages of multiple inputs and multiple functions. In this paper, a novel approach to achieving MOBILE operation is demonstrated based on monolithic integration of resonant tunneling diodes (RTDs) and field-effect transistors (FETs). In our new integrated structure, an RTD and FETs (one or more) are connected in-parallel. This structure offers several advantages including separate optimization of the RTDs and FETs, and flexible circuit design abilities. For a single-input MOBILE gate, inverter operation is demonstrated as an evidence of monostable-to-bistable transition. For a two-input gate, both NAND and NOR operation is achieved with different control voltages, which implies the possibility of a variable-function logic gate.