High Speed and Ultra-Low Power GaAs Mesfet 5×5 Multipliers

We have fabricated high speed and low power GaAs MESFET 5×5 multipliers using a WSi<inf>X</inf> self-aligned gate enhancement-mode MESFET process. The multiplication time demonstrated by these multipliers is 4.0 nanosecond at a 1 V supply voltage, which corresponds to a gate propagation delay of 133 picosecond with an equivalent fan-out of 2.2 and a power dissipation of 0.13 mW/gate. This result is the fastest speed for multipliers fabricated using ion-implanted MESFET technology and the lowest speed-power product ever for any multiplier circuit implemented using MESFET or AlGaAs/GaAs MODFET devices. The yield of fully funtional multipliers across 3-inch wafers is as high as 72%, which we believe is the highest yield ever achieved in GaAs IC's of this MSI complexity.