Dynamic redistribution of the electric field of the channel in AlGaN∕GaN high electron mobility transistor with nanometer-scale gate length

Transport peculiarities and the physical origin of noise properties in AlGaN∕GaN-based high electron mobility transistors (HEMTs) with a large ratio of channel length to gate length were investigated. Dependence of deviations of low-frequency noise spectra from the 1∕f law on applied gate voltages was studied in an extended range of frequencies. The behavior is explained in terms of a model based on the dynamic redistribution of the electric field along the two-dimensional channel of the HEMT. The results show that the main contribution to the noise originates from the region under the gate and adjacent to the gate channel regions.