A Unified Drain Current 1/fnoise Model for GaN-based High Electron Mobility Transistors

In this work, we present a theoretical and experimental study on the drain current 1/f noise in the AlGaN/GaN high electron mobility transistor (HEMT). Based on both mobility fluctuation and carrier number fluctuation in a two-dimensional electron gas (2DEG) channel of AlGaN/GaN HEMT, a unified drain current 1/f noise model containing a piezoelectric polarization effect and hot carrier effect is built. The drain current 1/f noise induced by the piezoelectric polarization effect is distinguished from that induced by the hot carrier effect through experiments and simulations. The simulation results are in good agreement with the experimental results. Experiments show that after hot carrier injection, the drain current 1/f noise increases four orders of magnitude and the electrical parameter degradation Delta g(m)/g(m) reaches 54.9%. The drain current 1/f noise degradation induced by the piezoelectric effect reaches one order of magnitude; the electrical parameter degradation Delta g(m)/g(m) is 11.8%. This indicates that drain current 1/f noise of the GaN-based HEMT device is sensitive to the hot carrier effect and piezoelectric effect. This study provides a useful reliability characterization tool for the AlGaN/GaN HEMTs.