Investigation of body bias effect in P-GaN Gate HEMT devices

AlGaN/GaN HEMTs with various field-plate (FP) and gate-to-drain distance extensions are fabricated and investigated. An experiment is carried out on 20 transistors. Their on-state resistance (Ron), off-state breakdown voltage (VBR), RF performance and low frequency noise are measured and studied. The FP extension is found significantly to improve the off-state breakdown voltage. However, the FP extension obviously weakens the frequency response and power added efficiency (PAE) performance, because it increases the feedback Cgd. The FP extension is beneficial to the reduction of the electric field intensity at the gate edge of the device, and reduces the probability of the injection of electrons into traps, resulting in the reduction of the low frequency noise.