Stepper technology in 0.5 mu m GaAs monolithic microwave integrated circuits (MMIC) applications

I-line stepper technology is successfully developed and implemented into Hughes high-volume production in fabricating 0.5- mu m GaAs monolithic microwave integrated circuits (MMICs). A single-layer photoresist process is developed and achieves tight gate-length control, within 10% variation. The rework rate of the gate layer is less than 20%. By combining optimal circuit designs with advanced GaAs wafer processing techniques, several MMIC amplifiers are made with 50% DC-circuit yield and good RF performance. Mix-and-match of wafer stepper and contact aligner is also developed and routinely used. This technology significantly improves the stepper utilization and throughput in a production environment.<<ETX>>