GROWTH-CHARACTERISTICS OF HYDRIDE-FREE CHEMICAL BEAM EPITAXY AND APPLICATION TO GAINP GAAS HETEROJUNCTION BIPOLAR-TRANSISTORS/

We report on the complete characterization of a hydride-and hydrogen-f ree chemical beam epitaxy (CBE) process for the realization of GaAs/Ga InP heterojunction bipolar transistors. Alternative group V sources te rtiarybutylarsine, tertiarybutylphosphine, and trisdimethylaminoarseni c are used instead of traditionally employed AsH3 and PH3. A very high degree of reproducibility of growth parameters (fluxes, substrate tem perature, doping levels) is demonstrated. Total defect densities lower than 10 def/cm(2) are routinely obtained. Large-area GaInP/GaAs heter ojunction bipolar transistors (HBTs) show a high current gain of 225 f or base sheet resistance of 400 ohm/sq. The devices also exhibit excel lent high-frequency characteristics. A cut-off frequency of 48 GHz and a maximum oscillation frequency of 60 GHz have been obtained. These r esults demonstrate the high potential capability of CBE for high-throu ghput GaInP/GaAs HBT production.