Monolithically integrated InP-based minority logic gate using an RTD/HBT heterostructure

In this paper, we report on the design, simulation, and fabrication of an InP-based high-speed monolithically integrated minority (inverted majority) logic gate, which was implemented using an MBE-grown stacked-layer epitaxial heterostructure of a resonant-tunneling-diode (RTD) and heterojunction-bipolar-transistor (HBT). The fabricated RTD's showed a peak-to-valley current ratio of 30 at room temperature and the HBT's demonstrated a current gain of 65 and a cutoff frequency (f/sub T/) of 50 GHz. The minority logic function of the fabricated monolithic RTD-HBT gate was measured using an in-house low-frequency test setup. The detailed full-scale large-signal simulations using the NDR-SPICE simulation program predict that the integrated RTD/HBT minority logic gate can operate up to 10 GHz.