Quantum-well p-channel AlGaAs/InGaAs/GaAs heterostructure insulated-gate field-effect transistors

The authors report experimental and theoretical results for self-aligned gate quantum-well p-channel pseudomorphic GaAs/InGaAs/AlGaAs heterostructure insulated-gate field-effect transistors (HIGFETs). High transconductances and transconductance parameters, 113 mS/mm and 305 mS/mm/V at room temperature for 0.8- mu m gate length, are reported. The authors discuss the effects of built-in strain on the valence bands, analyze the device data on the gate length dependence of the device parameters, and discuss the subthreshold characteristics and evidence for implant straggle. They also show the importance of the gate current for the device characteristics and propose to reduce the gate current and thus to increase the voltage swing by fabricating p-channel devices with p-doped InGaAs channels and n⁺ AlGaAs gates on the insulating AlGaAs layer.