Original Publication Date: 1989-Feb-01
Included in the Prior Art Database: 2005-Jan-29
The use of polyimide in packaging technologies requires metallization layers on polyimide which give good metal/polyimide adhesion and at the same time low via resistance between the metal overlayer (which goes over the polyimide) and the metal layer underneath the polyimide. Metallurgies currently in development provide one or the other of these, but not both simultaneously: Cr gives excellent adhesion on polyimide but is susceptible to high via resistance due to its inability to dissolve or remove oxide, while Cu gives modest adhesion but can dissolve oxide at the via contact. The solution so far, as in MCP, has been to combine the two, using the high adhesion of Cr but achieving the low via resistance by keeping the Cr layer very thin so that low via resistance is achieved by the Cu.