Concentration dependence of the 1/f noise in AlGaN/GaN heterostructure field effect transistors

Abstract

The dependence of the 1/f noise on the 2D concentration in the channel of AlGaN/GaN heterostructure field effect transistors has been obtained taking into account the influence of the contact series resistance and the resistance of the ungated source–gate and gate–drain regions. At low channel concentrations, the Hooge parameter α increases with the decrease of the channel concentration ns approximately as 1/ns. This dependence can be explained by the tunnelling of electrons from 2D electron gas to the traps in GaN or AlGaN layers. At high channel concentrations, the electron spillover from the 2D-channel to a parallel low mobility, noisy ‘parasitic conduction channel’ leads to the increase of α with the concentration increase.