InGaAs-InP DHBTs for increased digital IC bandwidth having a 391-GHz f/sub /spl tau// and 505-GHz f/sub max/
InP-In/sub 0.53/Ga/sub 0.47/As-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/sub /spl tau// and 505-GHz f/sub max/, which is the highest f/sub /spl tau// reported for an InP DHBT-as well as the highest simultaneous f/sub /spl tau// and f/sub max/ for any mesa HBT. The devices have been aggressively scaled laterally for reduced base-collector capacitance C/sub cb/. In addition, the base sheet resistance /spl rho//sub s/ along with the base and emitter contact resistivities /spl rho//sub c/ have been lowered. The dc current gain /spl beta/ is /spl ap/36 and V/sub BR,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/sub clk/=3 to 142.0 GHz while dissipating /spl ap/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.