Power and temperature dependence of low frequency noise in AlGaN∕GaN transmission line model structures

The low-frequency noise in AlGaN/GaN transmission line model structures has been investigated for a wide range of ambient temperatures and dissipated powers. A deviation of low-frequency noise from a 1/f dependence has been observed upon increasing the applied voltage. The effect correlates with the nonlinearity of current-voltage characteristics (CVC). The concept of nonequilibrium 1/f noise has been introduced to explain 1/f noise enhancement. A qualitative model connecting non-equilibrium noise with nonlinearity of the CVC via a common origin-nonuniform overheating of the structures-has been suggested. Furthermore, deviations of equilibrium noise from the 1/f law at low temperatures have been observed and studied. (C) 2004 American Institute of Physics.