P A P E R    T I T L E Accelerated Lifetests for High-Speed 0.5-µm InGaAs PHEMT Switches A U T H O R  /  C R E D I T S Frank Gao and Peter Ersland Engineering & Technology, AMP M/A-COM Division, 100 Chelmsford Street, Lowell, MA 01851 Phone: (978) 656-2847   Fax: (978) 656-2777 E-mail: GAOF@AMP.COM A B S T R A C T AlGaAs/InGaAs pseudomorphic high electron mobility tran-sistors (PHEMT) represent a significant technology and per-formance advancement compared with traditional GaAs HEMTs and MESFETs. High reliability is a critical require-ment for their device applications. M/A-COM has conducted accelerated lifetests on hundreds of PHEMT MMIC switches, using high-temperature reverse biased stress (HTRB) at 225 and 250°C, and unbiased stress at 200, 225, and 250 °C. While some change was observed in the DC characteristics, there was almost no degradation in the switch RF S-parameters after 3,000 hours of stress. A worst-case statistical analysis, using typical values for the lognormal failure distribution parameters and activation energy, projected a mean lifetime of over 106 hours at 125°C, suggesting highly reliable performance. The transmission electron microscopy (TEM) images showed evi-dence of gate-sinking failure mechanism, believed to be respon-sible for the observed gradual degradation in device DC char-acteristics.