Evolution of DC and RF degradation induced by high-temperature accelerated lifetest of pseudomorphic GaAs and InGaAs/InAlAs/InP HEMT MMICs

The evolution of DC and microwave degradation induced by three-temperature accelerated lifetest of pseudomorphic GaAs and InGaAs/InAlAs/InP HEMTs was investigated. Reliability investigations were performed on monolithic microwave integrated circuit (MMIC) amplifiers fabricated using 0.1 μm T-gate pseudomorphic GaAs and InGaAs/InAlAs/InP HEMTs. Operating at accelerated life test conditions, MMIC amplifiers were lifetested at three-temperatures (T₁=255°C, T₂=270°C and T₃=285°C for 0.1 μm GaAs PHEMT; T₁=215°C, T₂=230°C and T₃=250°C for 0.1 μm InGaAs/InAlAs/InP HEMT). High reliability performance with | ΔS21 | > 1.0 dB as the failure criteria was achieved on both technologies. From the 3-temperature lifetest, while GaAs PHEMT MMICs have activation energy of 1.7 eV, InGaAs/InAlAs/InP HEMT MMICs exhibit the activation energy of 2 eV. The difference is due to the distinct degradation mechanisms, which cause the S21 degradation. For GaAs PHEMTs, S21 degradation is mainly induced by the gradual gate metal sinking through the high-temperature lifetest; on the other hand, for InGaAs/InAlAs/InP HEMTs, the increase of access resistance on the source and drain regions causes the S21 degradation. Nevertheless, MTTF at T_channel=125°C of pseudomorphic GaAs and InGaAs/InAlAs/InP HEMTs is higher than 1×10⁸ hours. This is state-of-the-art of reliability performance reported on both technologies. From this study, the understanding of degradation evolution leads to the different approaches to improving the high-temperature reliability performance on pseudomorphic GaAs and InGaAs/InAlAs/InP HEMTs.