Low-threshold AlGaN-GaN heterostructure field effecttransistors for digital applications

The fabrication of an AlGaN-GaN based digital inverter circuit is reported, in which a large gain (up to 180) and a noise margin of ~0.5 V have been obtained. The measured temperature coefficient of the switching voltage of the inverter was ~3.5 mV/°C up to 90°C. The simulations predict that such an inverter should operate up to ~230°C.