Lattice-matched N-p(+)-n In0.49Ga0.51P/GaAs heterojunction bipolar transistors (HBT's) with heavily beryllium doped base and undoped spacers were grown by gas source molecular beam epitaxy (GSMBE). The epitaxial structure consists of, from the bottom to the top, a 5000 Angstrom n(+)-GaAs sub-collector with Si doping level of 3 x 10(18) cm(-3), a 7000 Angstrom n-GaAs collector doped at concentration of 3 x 10(16) cm(-3), a 60 nm p(+)-GaAs base with Be doping level up to 3 x 10(19) cm(-3) inserted between two undoped GaAs spacers, a 100 nm N-In0.49Ga0.51P emitter doped at 3 x 10(17) cm(-3) The structure was completed with a 150 nm n(+)-GaAs cap layer with Si doping level of 3 x 10(18) cm(-3). Devices with emitter area of 100 x 100 mum were fabricated on the grown wafer by using selective wet chemical etching technique and photolithographic process. AuGeNi/Au was used for the emitter and collector contacts, and Cr/Au was used for the base contact. The turn-on voltages of p(+)-GaAsiN-In0.49Ga0.51P heterojunction and p(+)-GaAs/n-GaAs junction art: 1.0 and 0.65V. The reverse breakdown voltages of the B E and BC junctions are 10 and 12 V. The common-emitter current-voltage characteristics show that the maximum current gain reaches 320 at the collector current of 90 mA.