Electrical Characteristics of AlGaAs/GaAs Heterostructures With a Pair of 2-D Electron and Hole Channels

To make power devices with lower losses and higher power capabilities, superjunctions (SJs), based on GaN, GaAs, and related materials, are attractive. It is because they have higher breakdown fields than Si and allow the use of heterostructures, where highly conductive layers of 2-D electrons and holes can be formed. As a step toward such SJ devices, we have fabricated AlGaAs/GaAs four-terminal devices in which a pair of electron/hole channels is embedded. Transport properties of electrons and holes are studied by operating the devices as FETs in which the conductance of one channel is controlled by using the other as a gate. Current-voltage and capacitance-voltage characteristics between the two channels are evaluated by operating the devices as p-n diodes. Measured characteristics are examined by comparing them with device simulations with a focus on the carrier depletion process in each channel.