Relaxation of low-frequency noise in AlGaN/GaN HEMTs

Abstract

In this contribution we report on low-frequency (LF) noise spectra of aluminium gallium nitride / gallium nitride (AlGaN/GaN) high electron mobility transistors (HEMTs) subjected to the illumination by photons of energy E <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ph</sub> bellow the energy band gap E <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">g</sub> of GaN. Change of LF noise spectra of the drain voltage noise and the gate current noise during the illumination and its slow relaxation to initial value after the illumination termination during the first 10 minute interval have been observed. These changes were related to time dependent changes of operating parameters (V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">DS</sub> , I <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">DS</sub> and I <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">GS</sub> ) and discussed in terms of the traps located in AlGaN/GaN HEMT structure.