95 GHz f/sub T/ self-aligned selective epitaxial SiGe HBT with SMI electrodes [optical fiber communication equipment]

A static frequency divider operating up to 50 GHz and a multiplexer (MUX) operating at 40 Gb/s are presented for future optical-fiber link systems at 40 Gb/s data rate in global communications applications. These digital circuits are fabricated in self-aligned selective-epitaxial SiGe-base heterojunction bipolar transistors (HBTs) with self-aligned stacked metal/lDP (SMI) electrodes. These HBTs provide a 95 GHz cutoff frequency and 8 ps ECL gate delay in Si bipolar technology.