Very high gain in carbon-doped base heterojunction bipolar transistor grown by chemical beam epitaxy

Current gains close to 200 are reported in carbon-doped base heterojunction bipolar transistors grown by chemical beam epitaxy, for base sheet resistance of 460Ω/□. This result was made possible by the excellent quality of the carbon-doped GaAs layers, as demonstrated by the hole mobility and the minority carrier lifetime measurements.