Manufacture of protected circuit tracks and contact pads on electronic device having diffusion barrier and copper seed layer, by making second negative-resist mask so that copper core and edge region are kept free

摘要

The method involves galvanically depositing the copper cores of the tracks and contact pads in the mask openings of a resist mask made of positive resist, then removing their edges by a further lithographic process. The copper cores are then completely enclosed with a nickel-gold layer before the positive resist mask is removed. To expose the edges, the positive resist mask is completely removed and a second negative-resist mask is created so that the copper core of the track and contact pad including a completely surrounding edge region is kept free.