Lateral design of InP/InGaAs DHBTs for 40 GBIT/s ICs

Abstract

InP-based HBTs are now available exhibiting cut-off frequency well over 100 GHz even at 1 mA. In this paper, a 40 Gbit/s IC-oriented InP/InGaAs DHBT technology is presented with maximum Ft of 170 GHz and Fmax over 210 GHz with BV/sub ce0/>9 V, specific features of this technology have been developed to increase the design flexibility: high current gain and frequency performances are kept over a large range of collector currents (from 1 mA to 100 mA) and for various dimensions, this is achieved through size-specific lateral transistor design optimization, these features are required for high-performance 40 Gbit/s ICs designed for optical transmission systems, in which careful transistor optimization has to be performed according to its function in the circuit.