Three and six logic states by the vertical integration of InAlAs/InGaAs resonant tunneling structures

Abstract

Double-barrier/single-well resonant tunneling structures based on InAlAs/InGaAs were vertically integrated on an InP substrate to obtain devices with multiple negative-differential resistance (NDR) regions. These devices, with either two or five tunneling structures, exhibited uniform current peaks and valleys and also had NDR regions about equally spaced in bias voltage. The devices were used in simple circuits to demonstrate three or six stable logic levels which could be set with current pulses.