Characteristics and Degradation Mechanisms under High Reverse Base-Collector Bias Stress in InGaAs/InP Double HBTs

In this paper, the reliability of InP/InGaAs DHBTs under high reverse base-collector bias stress is analyzed by experiments and simulation. The DC characteristics and S parameters of the devices under different stress times were measured, and the key parameters with high field stress were also extracted to fully understand and analyze the high-field degradation mechanism of devices. The measurements indicate that the high-field stress leads to an increase in base current, an increase in base-collector (B-C) and base-emitter (B-E) junction leakage current, and a decrease in current gain, and different degrees of degradation of key parameters over stress time. The analysis reveals that the degradation caused by reverse high-field stress mainly occurs in the B-C junction, access resistance degradation, and passivation layer. The physical origins of these failure mechanisms have been studied based on TCAD simulation, and a physical model is proposed to explain the experimental results.