Reliability of MgAI Semiconductor Interconnects

Data are presented comparing 1-percent MgAI wire with 1-percent SiAI wire for ultrasonically bonded interconnects on semiconductor devices. The effects of annealing time and temperature on the strength of the wire demonstrate the mechanical superiority of the 1-percent MgAI wire. The effects of ultrasonic power and time on wire deformation and bond pull strength demonstrate similar behavior for both the 1-percent MgAI wire and the 1-percent SiAI wire. It is also shown that there is a critical amount of wire deformation necessary for a strong bond, and that further deformation weakens the interconnection. Although there are very few data on the effects of Mg in Si, there have been fragmentary reports that 1-percent MgAI wire causes degradation of transistor characteristics. This investigation indicates that 1-percent MgAI wire is not the dominant degradation mechanism in any device studied.