Transient processes in AlGaN/GaN heterostructure field effect transistors

The authors report on the correlation between transient behaviour and 1/f noise in GaN/AlGaN heterostructure field effect transistors (HFETs) and novel GaN/AlGaN metal-oxide-semiconductor heterostructure field effect transistors (MOS-HFETs). When the HFETs were switched from the OFF to ON position, they exhibited non-exponential transient processes with characteristic times from 10^-7 to 10^-2 s. The transient behaviour correlated with the level of 1/f noise. MOS-HFETs fabricated on the same wafer as the HFETs did not exhibit such a transient (within the time resolution of the measurement setup, which was a few nanoseconds)