Abstract
An emitter edge-thinning design is used for a lattice-matched InGaAs/InP double-heterostructure-emitter bipolar transistor (DHEBT) grown by low-pressure metalorganic chemical vapor deposition (MOCVD). Using the emitter edge-thinning technique, the surface recombination current is reduced and the current gain is improved. This structure reveals a typical current gain as high as 120 at a collector current density of 241 A/cm2, along with an offset voltage as low as 45 mV. Furthermore, the problem of surface recombination current is also discussed in terms of the emitter size effect on current gain. The Gummel plots are shown to explain the influence of the emitter edge-thinning process on the base current ideality factor.