Thorough Investigation of Low Frequency Noise Mechanisms in AlGaN/GaN and Al2O3/GaN HEMTs

Abstract

This paper investigates the AlGaN/GaN and Al <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> O <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf> /GaN interface quality on GaN MIS-HEMT using low frequency noise (LFN) measurements. To address the issue of noise in the access resistance, we have also tested “non-gated” 2DEG devices. The LFN has a I/f- like behaviour caused by trapping/de-trapping processes which has been well described by carrier number fluctuations (CNF) and correlated mobility fluctuation (CMF) models. The border trap density extracted in optimised devices is better than previously reported GaN data and close to silicon CMOS results. Finally, a noise model for GaN-HEMT with recessed MIS gate including a 2DEG access resistance noise source is proposed.