A gate current 1/f noise model for GaN/AlGaN HEMTs

This work presents a theoretical and experimental study on the gate current 1/f noise in Al GaN/GaN HEMTs. Based on the carrier number fluctuation in the two-dimensional electron gas channel of Al GaN/GaN HEMTs, a gate current 1/f noise model containing a trap-assisted tunneling current and a space charge limited current is built. The simulation results are in good agreement with the experiment. Experiments show that, if Vg<Vx(critical gate voltage of dielectric relaxation), gate current 1/f noise comes from the superimposition of trapassisted tunneling RTS(random telegraph noise), while Vg> Vx, gate current 1/f noise comes from not only the trap-assisted tunneling RTS, but also the space charge limited current RTS. This indicates that the gate current 1/f noise of the GaN-based HEMTs device is sensitive to the interaction of defects and the piezoelectric relaxation. It provides a useful characterization tool for deeper information about the defects and their evolution in Al GaN/GaN HEMTs.