GaInAs/GaInAsP/InP heterostructure bipolar transistors with very thin base (150 Å) grown by chemical beam epitaxy

Abstract
It is demonstrated that chemical beam epitaxy (CBE) is suitable for growing high quality GaInAs(P)/InP heterostructure bipolar transistors. Step‐graded double‐heterostructure bipolar transistors with very thin base (150 Å) and very high p doping (∼5×1019 cm3), and with an added ‘‘grading layer’’ of 200 Å GaInAsP (Eg =0.94 eV) between the GaInAs/InP base‐collector junction, have shown good current drive capability and excellent current gain ( β=2500). In addition, CBE‐grown standard single‐heterostructure bipolar transistors with a 1000 Å base and 2×1018 cm3 p doping are characterized by high gain, β∼3500, which is only weakly dependent on the collector current.