Patents Assigned to Lattice Corporation
  • Patent number: 6593222
    Abstract: A method for manufacturing an integrated circuit improves the reliability of thermosonic bonds formed to attach a gold bond wire to an aluminum interconnect pad by reducing corrosion of the aluminum pad regions. In the method, a gold or silver plating is applied to the aluminum bond pads to prevent corrosion of the aluminum pad surface. Prior to applying the plating, corrosive contaminants are removed from the aluminum pad regions using an argon sputter etch. Annealing is used to remove damage from the argon sputtering, and further serves to alloy the resultant aluminum to gold or aluminum to silver interface. The aluminum pad layer is made very thin, or less than approximately 8000 Å to limit Kirkendall voiding when gold wires are bonded to the pad using a thermosonic bonding process.
    Type: Grant
    Filed: September 7, 2001
    Date of Patent: July 15, 2003
    Assignee: Lattice Corporation
    Inventor: Richard C. Smoak