A Comparison of 1% MgAl and 1% SiAl Wire Interconnects

Ultrasonically bonded interconnects have been made to semiconductor devices with both 1% SiAl and 1% MgAl wire. This investigation indicates that 1% MgAl wire is not a dominant cause of electrical degradation in any device studied. On the other hand, the effects of annealing time ue to 1000 hours and annealing temperature up to 300°C on the strength of the wire demonstrate the mechanical superiority of the 1% MgAl wire. The two types of wire have a similar behavior in relation to the effects of ultrasonic power and time on wire deformation and bond strength. A critical amount of energy input, as evidenced by wire deformation, is necessary for a strong bond, and further deformation weakens the interconnection. This investigation indicated that the one mil, 1% MgAl wire has potentially higher reliability than the 1% SiAl wire.