High frequency divider circuits using ion-implanted GaAs MESFET's

A single clock master-slave frequency divider circuit was designed and fabricated using GaAs MESFET's in the direct-coupled FET logic (DCFL) circuit architecture. At room temperature, the maximum operating frequency was 6.2 GHz at a power consumption of 3.5 mW/gate. The complete divider circuit and buffer amplifier was realized in a 65 × 165 µm2area. The MESFET's were fabricated using Si ion implantion directly into GaAs wafers and used a self-aligned recessed gate. The nominal gatelength was 0.6 µm. Corresponding fabricated ring oscillator circuits showed minimum gate delays of 18.5 ps at 3.1 mW/gate for fan-out of one at 300 K and 15.2 ps at 3.5 mW/gate at 77 K.