P-channel InGaN-HFET structure based on polarization doping

A p-channel GaN-based heterostructure field-effect transistor (HFET) concept based on a two-dimensional hole gas (2DHG) induced by polarization doping is presented. The structure employed is a GaN-InGaN-GaN heterostructure without external acceptor doping. The p-channel 2DHG characteristics are verified by operation at low temperature (20 K) and capacitance-voltage profiling. Hall measurements result in a positive Hall-coefficient and indicate a 2DHG hole mobility of approximately 700 cm
²
/Vs at 66 K. For an optimum structure supported by extrinsic doping a simulated output current of approximately 100 mA/mm is predicted for a gate length of 0.5 μm.