The gate and drain low-frequency noise (LFN) characteristics of 0.15×200 μm2 AlGaN/GaN HEMTs are reported. The measured gate noise current spectral density is low and insensitive to the applied high reverse bias voltage between the gate and the drain. Typical gate noise level values vary from ∼ 1.9×10-19 to ∼ 3.4×10 -19 (A2/Hz) as the drain voltage increases from 1 V to 12 V (VG= -5V) at 10 Hz. The calculated Hooge parameter is ∼ 5.9×10-4, which is comparable to traditional III-V FETs. Lorentz noise components were observed when VDS is higher than 8 V. The peak of Lorentz component moves toward higher frequency when VDS increases and VGS decreases. The exponent γ of the 1/f f was found to reduce from 1.17 to 1.01 when VDS increases from 8 V to 16 V. The observed trends are discussed in terms of electric field, carrier velocity and trapping-detrapping considerations.
