Highly Accelerated Stressing of GaAs Bulk Resistors
Edwin Sabin, Jon Scarpulla, Y.C. Chou, C.S. Wu
TRW, Once Space Park, Redondo Beach, CA 90277
During highly accelerated stressing, GaAs bulk resistors fail both due to filament and film formation. Filament and film formation always occurs starting at the negative polarity and moving toward the positive polarity. The formation of a filament occurs in the bulk GaAs while film formation occurs on top of the GaAs but below the plasma nitride. Also filament formation occurs about 10,000 times faster than film formation. The proposed failure mechanism for the filament failure is that the localized ohmic metal temperature is high enough for the gold to diffuse through the nickel barrier and react with the bulk GaAs to form a filament and with the help of the film failure it is proposed that the localized ohmic metal temperature is not high enough for the gold to diffuse through the nickel barrier, so the gold reacts with the surface of the GaAs to form a film and with the help of the electron wind moves slowly across the surface of the GaAs. The data also indicates that failures at highly accelerated stressing are different than failures at the design current density stressing.