InGaAs-InP DHBTs for increased digital IC bandwidth having a 391-GHz fT and 505-GHz f max

InP-In0.53Ga0.47As-InP double heterojunction bipolar transistors (DHBT) have been designed for use in high bandwidth digital and analog circuits, and fabricated using a conventional mesa structure. These devices exhibit a maximum 391-GHz f(tau), and 505-GHz f(max), which is the highest f(tau) reported for an InP DHBT-as well as the highest simultaneous F-tau and f(max) for any mesa HBT. The devices have been aggressively scaled laterally for reduced base-collector capacitance C-cb. In addition, the base sheet resistance rho(s) along with the base and emitter contact resistivities rho(c) have been lowered. The de current gain beta is approximate to 36 and V-BR,V-CEO = 5.1 V. The devices reported here employ a 30-nm highly doped InGaAs base, and a 150-nm collector containing an InGaAs-InAlAs superlattice grade at the base-collector junction. From this device design we also report a 142-GHz static frequency divider (a digital figure of merit for a device technology) fabricated on the same wafer. The divider operation is fully static, operating from f(clk) = 3 to 142.0 GHz while dissipating approximate to 800 mW of power in the circuit core. The circuit employs single-buffered emitter coupled logic (ECL) and inductive peaking. A microstrip wiring environment is employed for high interconnect density, and to minimize loss and impedance mismatch at frequencies > 100 GHz.