Co-integration of high speed InP-based HBTs and RTDs using chemical beam epitaxy

Abstract CBE is used to co-integrate InP-based heterojunction bipolar transistors (HBTs) and resonant tunneling diodes (RTDs) for the first time to reduce the complexity of conventional digital circuit technology. The integrated transistors have maximum dc and differential current gain of ∼ 53.6 and 122, respectively, with breakdown voltages V ceo ≈ 6 V and V cbo ≈ 9 V. For microwave performance, the maximum f T and f max are ∼ 77 (63) and ∼ 60 (53) GHz after (before) the onset of negative differential resistance. For digital circuit application, the HBT + RTD structure was used to build bistable mode low power monolithic integrated circuits, including a NAND gate, an inverted majority gate and a NOR gate.