Low-frequency noise in AlGaN/GaN heterostructure field effect transistors

We report low-frequency noise characteristics of doped-channel GaN/AlGaN heterostructure field-effect transistors grown on sapphire substrates. In the frequency range 1 Hz-100 kHz the observed noise is of the 1/f character. The Hooge constant is of the order of 10/sup -2/ and is linearly proportional to the channel width. The noise originates in the fluctuation of carrier number in the channel due to relatively high density of defects at the GaN/AlGaN heterointerface.