Low-frequency noise in gallium nitride epitaxial layers with different degrees of order of mosaic structure

Abstract

The correlation between the noise level 1/f and the degree of mosaic-structure order in gallium nitride epitaxial layers was studied for the first time. Samples with a doping level of Nd−Na≈8×1016 cm−3 and a relatively high degree of order were characterized by the Hooge parameter α≈1.5×10−3. This value is unprecedently low for thin GaN epitaxial films. The Hooge parameter was significantly higher for samples with Nd−Na≈1.1×1018 cm−3 and a low degree of order despite the fact that α generally decreases with increasing doping level at the same degree of order. Thus, the degree of mosaic-structure order affects not only the optical and electrical characteristics but also the fluctuation parameters of GaN epitaxial layers.