1/f -noise characteristics of AlGaN/GaN omega shaped nanowire FETs

The AlGaN/GaN omega-shaped nanowire FETs with different nanowire widths (W) have been fabricated. The effects of varying W on the performance of AlGaN/GaN omega-shaped nanowire FETs were investigated using low frequency noise (LFN) measurement. It was found that the noise characteristics of the device with narrow W show improved noise performances due to the accumulation of electrons in the volume of the nanowire which constricts the electron trapping in GaN layer. This volume accumulation of electrons is responsible for the mobility fluctuations because it decreases the probability of channel electrons at surface being captured into the surface traps, and also high carrier concentration screens the effective trapping of electrons in the volume of the nanowire. Whereas, width increases the LFN characteristics tended to be dominated by the carrier number fluctuation because the fin is too wide for volume accumulation and are subjected to the bulk trapping.