Ultra-high-speed GaAs MESFET IC modules using flip chip bonding

This paper describes a distributed amplifier IC module and a distributed 1: 2 signal distributor IC modulo for 40-Gbit/s optical transmission systems. These ICs were designed by the distributed circuit and inverted-microstrip-line design technique and fabricated using 0.1-/im-gate-length GaAs MESFETs with a multilayer interconnection structure. These were mounted on a thin film multilayer substrate in a chip-size-cavity package by means of a flip-chip-bonding technique that uses transferred microsolder bumps. The amplifier module achieved a 3-dB bandwidth of more than 50 GHz and a gain of 8 dB. The 3-dB bandwidth of a 1:2 signal distributor module was 40GHz and the loss was 2 dB. These modules were demonstrated at 40Gbit/s and clear eye openings were confirmed.