Narrow Results

This paper provides an overview of recent work and future directions in Gallium Nitride transistor research. We discuss the present status of Ga-polar AlGaN/GaN HEMTs and the innovations that have led to record RF power performance. We describe the development of N-polar AlGaN/GaN HEMTs with microwave power performance comparable with state-of-art Ga-polar AlGaN/GaN HEMTs. Finally we will discuss how GaN-based field effect transistors could be promising for a less obvious application: low-power high-speed digital circuits.

A high-frequency a high-power GaN HEMT was analyzed using our full band Cellular Monte Carlo (CMC) simulator, in order to extract small signal parameters and figures of merit, and to correlate them to carrier dynamics and distribution inside the device. A complete RF and DC characterization of the device was performed using experimental data to calibrate the few adjustable parameters of the simulator. Then, gate-related capacitances, such as C_g, C_gd, and C_gs, were directly and indirectly extracted combining small-signal analysis and DC characterization.