Investigation of InGaP/InGaAs n- and p-channel pseudomorphic modulation-doped field effect transistors with high gate turn-on voltages

The performances of InGaP/InGaAs camel-gate n- and p-channel pseudomorphic modulation-doped field effect transistors (MODFETs) are demonstrated and compared. In the n-channel (p-channel) device, an extremely high gate turn-on voltage of 1.7 (2.0) V is measured due to the pn depletion in the camel-like gate region and the presence of a large conduction (valence) band discontinuity at the InGaP/InGaAs heterostructure. In addition, a maximum drain saturation current of 425 mA/mm (−345 mA/mm) and a maximum transconductance of 85 mS/mm (63 mS/mm) are obtained for the n-channel (p-channel) device. These excellent characteristics indicate that the devices that are studied are promising for signal amplifiers and inverter circuit applications.