InP /InGaAs Heterojunction Bipolar Transistors Grown by Gas-Source Molecular

Abstract-The first N-p-n InP/InGaAs heterojunction bipolar transistors (HBT’s) with p-type carbon doping in InCaAs are reported. P-type carbon doping in the InGaAs base has been achieved by gas-source molecular beam epitaxy (GSMBE) using carbon tetrachloride (CCI,) as the dopant source. The resulting hole concentration in the base was 1 x c ~ n- ~. HBT’s fabricated using material from this growth method display good I- V characteristics with dc current gain above 500. This verifies the ability to use carbon doping to make a heavily p-type InGaAs base of an N-p-n HBT. BT technology has received much attention for use in H high-speed digital circuits and high-efficiency mi-crowave devices. The InP/InGaAs HBT has advantages over HBT’s in other material systems: high electron mobility, low turn-on voltage u b e, low surface recombination velocity as compared to GaAs, and use of the same substrates as source