Low-frequency 1/f noise and persistent transients in AlGaN-GaN HFETs

Persistent photoresponse transients and low-frequency 1/f noise were measured in barrier-controlled devices such as AlGaN-GaN heterostructure field-effect transistors (HFETs). The persistent transients and 1/f noise were observed in drain and gate currents. A model describing trapping in a barrier-controlled device introduced, and the appropriate transient evolution and the noise spectra developed. Excellent agreement was obtained between the experimental measurements and the predicted temporal response and noise spectra. Finally, the correlation between drain and gate 1/f noise was measured, confirming that the same noise source (fluctuation in surface potential) is responsible to both currents.