All-Oxide Inverters Based on ZnO Channel JFETs With Amorphous ZnCo2O4 Gates

We present integrated inverter circuits based on junction FETs (JFETs) with ZnO channels and amorphous ZnCo2O4 gate contacts. The inverters reach high gain values up to 276 and uncertainty ranges down to 0.3 V for an operating voltage of 3 V. The magnitude of the gain is traced back theoretically to the slope of the JFET saturation current. The use of a level shifter is demonstrated, in order to obtain full inverters, which can be integrated into logic circuits.