Flicker noise in GaN/Al_0.15Ga_0.85N doped channel heterostructure field effect transistors

Abstract

We have investigated noise characteristics of novel GaN/Al_0.15Ga_0.85N doped channel heterostructure field effect transistors designed for high-power density applications. The measurements were carried out for various gate bias voltages V_GS and with the drain voltage V_DS varying from the linear to the saturation regions of operation V_DS>5 V. Our results show that flicker, e.g., 1/f noise, is the dominant limiting noise of these devices; and the Hooge parameter is of the order of 10⁻⁵−10⁻⁴. The gate voltage dependence of 1/f noise was observed in the linear region for all examined V_GS and in the saturation region for V_GS>0. These results indicating low values of the Hooge parameter are important for microwave applications.