RAPID SUBSTITUTION OF COLD FOR ALUMINUM METALLIZATION ON INTEGRATED-CIRCUITS

A rapid procedure for substitution of gold for aluminum metallization on integrated solid-state circuits, such as solid-state chemical multi sensor chips, has been developed. The final product consists of origin al aluminum overlaid with nickel and gold, both deposited by an electr oless process. The final metallization is chemically inert and the res istance of the contacts remains ohmic and unchanged from the original value. The substitution can be performed either at the wafer or at the chip level. After the plasma etching, the metallization process takes only 25 min.