Resistance Increases in Gold Aluminum Interconnects with Time and Temperature

Increases in the resistance of gold aluminum interconnects with time and temperature were investigated. Aluminum wife was ultrasonically bonded to Cr-Au and TiPd-Au thin-film metallization on ceramic substrates. The interconnects were exposed to temperatures from 150 to 300°C for times up to 400 h. The resistance of the interconnects was measured periodically during the exposure to elevated temperatures. There were significant increases in resistance on both types of metallization. Some measurements indicated electrically open interconnects, but the mechanical strength remained high. If systems containing gold aluminum interconnects axe anticipated to be processed or used at Or above 150°C, serious consideration should be given to the effects of increased resistance on circuit performance.