InGaP/GaAs heterojunction bipolar transistor and RF power amplifier reliability

Electrothermal stress on advanced InGaP/GaAs heterojunction bipolar transistors (HBTs) was carried out experimentally. It showed a long-term stress-induced base current instability and a decrease in the DC current gain. A class-AB RF power amplifier (PA) was also considered to study the stress effect on the amplifier’s RF performance. The SPICE Gummel–Poon (SGP) model parameters were extracted from the pre- and post-stress HBT data and used in Cadence SpectreRF simulation. The amplifier’s post-stress RF characteristics, such as the output power and power-added efficiency (PAE), remained almost unchanged even though the post-stress HBT’s DC current gain had dropped to 73.6% of its initial value.