An embodiment includes a semiconductor apparatus comprising: a redistribution layer (RDL) including a patterned RDL line having two RDL sidewalls, the RDL comprising a material selected from the group comprising Cu and Au; protective sidewalls directly contacting the two RDL sidewalls; a seed layer including the material; and a barrier layer; wherein (a) the RDL line has a RDL line width orthogonal to and extending between the two RDL sidewalls, and (b) the seed and barrier layers each include a width parallel to and wider than the RDL line width. Other embodiments are described herein.