MULTISTATE SUPERLATTICE-EMITTER RESONANT-TUNNELING BIPOLAR-TRANSISTOR WITH CIRCUIT APPLICATIONS

A superlattice-emitter resonant-tunneling bipolar transistor (SE-RTBT) has been successfully fabricated using GaAs based materials and demonstrated in this paper. In an SE-RTBT, the i-Al0·5Ga0·5As/n+-GaAs superlattice is used as a reflection and resonant tunneling barrier. High emitter injection efficiency and hence high current gain are sustained. In the transistor operation, a current gain of 65 was obtained with double-negative differential resistance. The experimental processes and device D.C. performance were demonstrated first. Then a great number of circuit applications, i.e. frequency multiplier, multiple-valued logic, and parity bit generator, using the SE-RTBT and exhibiting reduced complexities will be discussed. Thus, the SE-RTBT offers strong potential for use in very high-speed and high density integrated circuits. © 1993 Academic Press. All rights reserved.