Advantages of metallic-amorphous-Silicon-gate FET's in GaAs LSI applications

Abstract

A Schottky barrier as high as 1 V is obtained for contact between a ternary amorphous film, a-Si-Ge-B, and an n-type GaAs crystal. A metallic-amorphous-silicon-gate FET (MASFET) was made using the amorphous film as a gate contact. GaAs MASFET characteristics are superior to GaAs MESFET characteristics in application to LSI's with a DCFL configuration because the DCFL circuits with the GaAs MASFET's provide a logic level as high as 0.94 V and widen the circuit operation margin. Full operation is obtained from a 1 Kword × 2 bit SRAM with GaAs MASFET's, which is considered to be mainly due to the wide operation margin. The measured propagation delay time of the DCFL inverter is 34 ps at supply voltage V_{DD} = 1.5 V and power consumption of 1.9 mW/gate.