Lattice-Strained Double Heterojunction InGaAs/GaAs Bipolar Transistors

A study of a series of NpN GaAs/InGaAs/GaAs latticestrained heterojunction bipolar transistors, in which the indium mole fraction has been varied, shows that it is possible to obtain good dc current gain and a high cut-off frequency in this materials system despite relatively small band offsets and the presence of interface lattice irregularities.