CARBON-DOPED INGAP GAAS/INGAP DOUBLE-HETEROJUNCTION BIPOLAR-TRANSISTORS WITH A VERY-LOW 1/F NOISE CORNER FREQUENCY OF 108 KHZ GROWN BY CHEMICAL BEAM EPITAXY/

We report on the low frequency noise characteristics of InGaP/GaAs/InG aP double heterojunction bipolar transistors with a carbon-doped base grown by chemical beam epitaxy. Transistors with 2.5 nm base setback l ayer show a very high common emitter current gain of 120 and a very lo w collector saturation voltage of 75 mV at room temperature. Very low 1/f current noise corner frequency of 108 kHz is obtained because of t he use of high quality direct-gap InGaP material as the wide-gap emitt er.