Characterization and analysis of gate and drain low-frequency noise in AlGaN/GaN HEMTs

Abstract

The gate and drain low-frequency noise (LFN) characteristics of 0.15/spl times/200 /spl mu/m/sup 2/ 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 /spl sim/1.9/spl times/10/sup -19/ to /spl sim/3.4/spl times/10/sup -19/ (A/sup 2//Hz) as the drain voltage increases from 1 V to 12 V (V/sub G/=-5 V) at 10 Hz. The calculated Hooge parameter is /spl sim/5.9/spl times/10/sup -4/, which is comparable to traditional III-V FETs. Lorentz noise components were observed when V/sub DS/ is higher than 8 V. The peak of Lorentz component moves toward higher frequency when V/sub DS/ increases and V/sub GS/ decreases. The exponent /spl gamma/ of the 1/f/sup l/ was found to reduce from 1. 17 to 1.0 1 when V/sub DS/ increases from 8 V to 16 V. The observed trends are discussed in terms of electric field, carrier velocity and trapping-detrapping considerations.