GaAs enhancement mode FET-tunnel diode ultra-fast low power inverter and memory cell

A microtunnel diode load for a normally off enhancement mode gallium arsenide field effect transistor provides a compact inverter circuit of fast switching speed and low power consumption. Level shifting is not required, and direct coupling with multiple fan-out causes a comparatively small decrease in speed. The tunnel diode FET logic (TDFL) should be capable of operation at 2 GHz with a power-delay time product of 3.4 fJ for an output node capacitance of 50 fF. The negative characteristic of the tunnel diode combined with the FET provides a compact memory cell. However, advances in the state of the art for producing microtunnel diodes of precisely controlled peak current will be required before a viable TDFL can emerge.