Flicker Noises of AlGaN/GaN Metal-Oxide-Semiconductor High Electron Mobility Transistors

AlGaN/GaN metal-oxide-semiconductor high electron mobility transistors (MOS-HEMTs) with gate insulators grown using the photoelectrochemical oxidation method were fabricated in this work. The pinch-off voltage, maximum extrinsic transconductance, and drain–source saturation current at V GS = 0 V were −9 V, 88.20 mS/mm, and 665 mA/mm, respectively. When the MOS-HEMTs operated at V GS = − 20 and 20 V, the gate leakage current was only 31 and 960 nA, respectively. The normalized noise power spectra of MOS-HEMTs operated in the linear region and the saturation region were fitted well by 1 / f γ law from 4 Hz to 10 kHz. The exponent γ values were all closed to unity and independent of V GS . In the linear region ( V DS = 2 V ) at V GS = − 8 V and V GS = 2 V , the α ch and α s estimated at a frequency of 100 Hz were 8.69 × 10 − 6 and 9.29 × 10 − 5 , respectively. The α ch and α s estimated in the saturation region ( V DS = 10 V ) at V GS = − 8 V and V GS = 2 V at a frequency of 100 Hz were 1.61 × 10 − 4 and 2.08 × 10 − 3 , respectively. The normalized noise power density was a function of V G − 1 , V G − 3 , and V G 0 corresponded to the three regions of V G ≤ 3 V ( V GS ≤ − 6 V ) , 3 V ≤ V G ≤ 9 V ( − 6 V ≤ V GS ≤ 0 V ) , and V G ≥ 9 V ( V GS ≥ 0 V ) , respectively, where V G was the effective gate bias defined as ( V GS − V off ) .