Application of an AlGaAs/GaAs/InGaAs heterostructure emitter for a resonant-tunneling transistor

An AlGaAs/GaAs/InGaAs resonant-tunneling heterostructure-emitter bipolar transistor with negative-differential-resistance (NDR) behavior has been fabricated and demonstrated. Typical device performances with current gain of 140 incorporating an N-shaped NDR with a peak-to-valley current ratio of 5.3 are obtained at room temperature. The NDR behavior is believed to mainly result from a double-barrier-like resonant-tunneling effect. In other words, the on and off electron resonant tunneling from a depleted GaAs emitter through an InGaAs quantum well and ultrathin base toward a collector layer yield the interesting NDR behavior. Consequently, the proposed device provides a good potential for applications in amplifiers, low-power consumption, and logic currents. (C) 1999 American Institute of Physics. [S0003-6951(99)04943-8].