Reducing source and drain resistances in InGaP/InGaAs doped-channel HFETs using δ-doping Schottky layer

Doped-channel field effect transistors (DCFETs) have better device linearity, higher current density and higher gate breakdown as well as higher turn-on voltages. The main drawback of DCFET is the high contact and sheet resistances of the devices in the undoped Schottky access region between the alloyed contact and gate electrode. InGaP/InGaAs/GaAs heterostructures were fabricated to improved the performances of DCFET by inserting a δ-doping layer on top of the undoped Schottky layer, which can reduce the ohmic contact resistances of DCFETs. The heterostructures were compared with each other in terms of DC, RF and microwave power performances.