abstract:Double heterostructure-emitter bipolar transistors DHEBTs with emitter edge-thinning design and DHEBTs without that design have been investigated. In the characteristics modeling, a two-dimensional continuity equation and boundary conditions in the base region are employed to determine the various components of base current in a cylindrical mesa-type DHEBT. The inﬂuence of structure parameters and emitter edge-thinning design on the current gain of the DHEBT is studied. The effect of quasi-electric ﬁeld in the base region is taken into account. Switching mechanisms in the DHEBT are also discussed. In the experimental measurement, a DHEBT with an exposed p+ -GaAs base surface exhibits a small offset voltage of 100 mV and a common-emitter current gain of 17. Due to the emitter edge-thinning to suppress the surface recombination current, a DHEBT with an N-AlGaAs passivated surface has a common-emitter current gain of 140 and a negligible offset voltage of 40 mV. With symmetric structures, both devices present bidirectional switching phenomena. Moreover, the emitter edge-thinning design is found having the capability for reducing the holding power in the switching. Possessing both amplifying and switching features, the DHEBTs show good potentials for circuit applications.