The evolution of DC and.microwave degradacian induced by threetemperature accelerated lifetest of pseudomorphic GaAs and InGaAslInAIAslInP . HEMTs was investigated. Reliability . investigations were performed on monolithic micmwave integrated ' circuit (MMIC) . amplifiers fabricated. using 0.1 pm 'T-gate .pseudomorphic GaAs and InGaAshAIAs/InP HEMTs. Oper?tin: at accelerated life test conditions, MMlC amplifiers were lifetested at three-temperatures (T1=255~C, T2=2700C and T3=285'C for 0.1 wm, GaAs PHEMT; T1=215'C, T2=230%' and T3=250"C far 0.1' pm InCaAs/InAIAs/InP HEMT). High reliability perfdimance with I AS21 I > 1.0 dB as the failure criteria was achieved on .both technologiei. Fr6m the 3-temperature lifetest, while GaAs PHEMT MMlCs have activation energy of 1.7 eV! InCaAsIlnAIAslInP HEMT MMlCs exhibit *e activation energy of 2 eV. The difference is due to the distinct degradation mechanisms, vjhich 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 InCaAslInAlAslInP HEMTs, the increase of access resistance on the source and drain regions causes the S21 degradation. Nevertheless, MTTF. at Tcb,,,=I25"C of pseudohorphic GaAs and InCaAslInAIAs/lnP HEMTs is higher than 1x10~ hours. ' This is state-of-the-an of @iability performance reported on both techno1ogies:From this study, the understanding of deeradation evolution leads to the different ao6maches to immovitie evolution of DC and RF degradation induced by the hightemperature accelerated lifetest an these two MMlC technologies is still lacking. From the lifetesting point of view; there are two.primary differences between &As PHEMT and InP HEMT MMIC technologies. Firstly, while Schottky gate metal of GaAs PHEMTs sits on AlGaAs material, Schottky gate metal of InP HEMTs is on InAlAs material. Secondly, due to the low power dissipation of InP HEMTs, the typical chamel temperature rise of InP HEMT MMlCs (AT,= 1O'C) at Vds=I.S volr/lds=150 m A / m is much lower than that of GaAs PHEMT! ((AT, = 45°C) at Vds3t.2. voltlIds=150n?a/mm. Therefore, the real ch-el temperatw! of GaAs PHEMTs during the accelerated high temperature lifetest is higher than of InP HEMTs. Owing to these major differences between GaAs PHEMT and InP HEMT MMICs technologies, it is believed that the distinct degradation evolutions of GaAs PHEMTs and InP HEMTs could be developed during the accelerated high-temperature lifetest.In this paper, the high reliability performance has been achieved on GaAs PHEMT and InP HEMT MMlC techhdagies. In addition, the evblution of DC and microwave degradation induced by hightemperature accelerated lifetest has been thoroughly investigata to 6ffer the better insight into the reliability characteristics of these two-'staie-of-the-art compound MMIC technologies. The understanding of the degradation evolution leads to the different approaches to improving the high-temperature reliability performance of pseudomorphic GaAs and InCaAs/lnAIAs/lnP HEMT...
