| abstract |
A metallization scheme for interconnection of elements in thin film and hybrid circuits is described. A thin layer of titanium is first formed, preferably by evaporation or sputtering, on the surface of the insulating substrate. A thin layer of copper is then formed in the same manner over the titanium layer. This is followed by electroplating of copper to a desired thickness onto selected portions of the Ti-Cu multilayer. Successive layers of nickel and gold are then selectively electroplated onto the plated copper regions. An additional layer of palladium may also be included between the titanium and copper layers for improved adhesion. The Ti-Cu-Ni-Au metallization system has been found unusually compatible with the major processing requirements of thin film circuits, for example, thermocompression bonding, soldering, via-hole coverage and resistor stabilization. |