High speed selfaligned GaInP/GaAs HBBTs

High speed selfaligned Ga_0.5In_0.5P/GaAs hole barrier bipolar transistors (HBBTs) with a 60 nm carbon doped base layer (p=6.5*10¹⁹ cm^-3) and a 20 nm undoped GaInP barrier have been fabricated. The devices show maximum small signal current gains around 30, independent of emitter size. A current gain cutoff frequency of f_T=95 GHz and power gain cutoff frequency of f_max=110 GHz are reported for 1.5*10 mu m² and 2*1.5*10 mu m² devices, respectively. These results represent the best microwave performance yet reported for Ga_0.5In_0.5P/GaAs based HBTs.