InGaAs/InP Double heterostructure bipolar transistors with near ideal beta Versus I(C) characteristic.

InGaAs/InP double heterostructure bipolar transistors with current gain beta ~ 630 have been realized using gas-source molecular beam epitaxy. These devices exhibit near ideal beta versus I(C) characteristic (i.e. beta independent of I(C)) with a small signal gain h(fe) ~ 180 at I(C) ~ 2nA. In comparison, we find beta ~ I(0.5) (C) for a high quality AlGaAs/GaAs HBT grown by OMCVD. The higher emitter injection efficiency at low collector current levels found in the InGaAs/InP DHBT is due to at least a factor 100 smaller surface recombination current.