AlGaN/GaN heterojunction bipolar transistors with low dynamic R ON,sp and V th hysteresis

This paper demonstrates the dynamic characteristics of 150-V-class GaN power HBTs for the first time. At OFF-state collector bias V CEQ = 80 V, the device shows a low dynamic specific on-resistance (R ON,sp ) of 0.316 mΩ·cm 2 , which is only 4.7% higher than static R ON,sp , thanks to current conductive path far from the surface. A threshold voltage (V th ) of 3.58 V extracted at 1 A/cm 2 is achieved with an on/off current ratio of 2×10 7 . The device also show a large base voltage swing of -7 to 7 V with a small V th hysteresis of 50 mV. The low dynamic resistance degradation, high positive V th with low V th hysteresis, and large base voltage swing all demonstrate the great potential of GaN HBT in power switching applications.