InP DHBT-based IC technology for 100-Gb/s ethernet

It is now clear that 112-Gb/s data rate is the next step in the network evolution (100-Gb/s Ethernet). Due to its high speed and high breakdown voltage, the InP double-heterojunction bipolar transistor (DHBT) technology is particularly suited for signal processing and high-speed communication systems. This paper summarizes our InP DHBT device and integrated circuit (IC) technology developed for >= 100-Gb/s-class mediumscale mixed-signal ICs. Key features and issues important for the growth and manufacturing of InP DHBTs with step-graded collectors are first discussed. The molecular-beam-epitaxy-grown transistors have cut-off frequencies (fT and fmax) of over 350 GHz, current gains of ~90, and common-emitter breakdown voltages of >4.5 V. Using this technology, we then fabricated and succeeded in 112-Gb/s testing of multiplexers and integrated clock and data recovery/1:2 demultiplexer ICs and modules with very clear eye waveforms. Using the same technology, a distributed amplifier intended for use as a modulator driver exhibited an output voltage swing of ~2 Vpp. These building-block ICs combine high-speed operation with high signal quality and enable 112-Gb/s optical fiber transmission.