AlGaN/GaN Heterojunction Bipolar Transistors With High Current Gain and Low Specific On-Resistance

N-p-n AlGaN/GaN heterojunction bipolar transistors (HBTs) on sapphire substrateswith high current gain beta of 129, low specific ON-resistance (R-ON,R-sp) of 0.28m Omega center dot cm(2) and high current density J(C) of similar to 15 kA/cm2 (if normalized to emitter area, R-ON,R-sp similar to 0.15 m Omega.m(2) and J(C) similar to 28.4 kA/cm(2)) have been demonstrated. The analysis of component of R-ON,R-sp yields the collector resistance is similar to 5.2% of the total R-ON,R-sp, showing the low ON-resistance advantage of GaN HBTs. The open-base avalanche breakdown voltage (BVCEO) is similar to 160 V. High-temperature performance of GaN HBT is also evaluated. The R-ON,R-sp is reduced as temperature increasing in the range of 25 degrees C-100 degrees C due to enhanced hole concentration in the base layer. The cutoff frequency (f(T)) of greater than 4 GHz is determined at V-CE = 9 V. These results dominate that GaN HBTs have been anticipated to become a new technology for next-generation power switches and RF power amplifier circuit.