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

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 250C, 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 125C, 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.