Stable and uniform InAlAs/InGaAs HEMT ICs for 40-Gbit/s optical communication systems

We developed thermally stable InAlAs/InGaAs HEMTs which have uniform offset-voltage in differential amplifiers. The standard deviation of their offset-voltages is only 6.2 mV, and their threshold voltage changes by less than 11 mV when they are annealed for 60 minutes at 330/spl deg/C. These properties are essential for the operation of 40-Gbit/s optical communication circuits.