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

Abstract

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 /spl mu/m T-gate pseudomorphic GaAs and InGaAs/InAlAs/InP HEMTs. Operating at accelerated life test conditions, MMIC amplifiers were lifetested at three-temperatures (T/sub 1/=255/spl deg/C, T/sub 2/=270/spl deg/C and T/sub 3/=285/spl deg/C for 0.1 /spl mu/m GaAs PHEMT; T/sub 1/=215/spl deg/C, T/sub 2/=230/spl deg/C and T/sub 3/=250/spl deg/C for 0.1 /spl mu/m InGaAs/InAlAs/InP HEMT). High reliability performance with | /spl Delta/S21 | > 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/sub channel/=125/spl deg/C of pseudomorphic GaAs and InGaAs/InAlAs/InP HEMTs is higher than 1/spl times/10/sup 8/ 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.