A lattice‐matched In0.53Al0.22Ga0.25As/InP heterojunction bipolar transistor has been fabricated by low‐pressure metalorganic chemical vapor deposition (LP‐MOCVD). No potential spike due to zero conduction band discontinuity at the emitter‐base heterojunction is obtained. Meanwhile, the larger valence discontinuity (&Dgr;EV=460 meV) than AlGaAs/GaAs and InGaAs/InP systems provides this structure with a better hole confinement. An offset voltage as low as 50 mV along with a current gain of 85 is achieved. ©1995 American Institute of Physics.