Method for gold plating of metallic layers on semiconductive devices

摘要

An integrated circuit semiconductive device has a plurality of copper gang bonding bumps formed on the upper surface thereof. The bumps rise substantially above the surface of the semiconductive device and serve to make electrical connection to a pattern of intraconnect metallization formed on the semiconductive device for making electrical contact to various regions within the semiconductive body of the integrated circuit. The gang bonding bumps are to be thermal compression bonded to metallic leads by an automatic bonding machine. As a final step to the processing of the semiconductive wafers, containing the individual semiconductive devices, the wafers are immersed in an immersion gold plating solution for plating an antioxidant protective coating of gold of a thickness less than 6000 angstroms onto the copper gang bonding bumps to prevent oxidation thereof either before or during the gang bonding step. The thickness of such gold antioxidant coating permitting thermal compression bonding therethrough to the underlying metal layer.