Graded compound seed layers for semiconductors

摘要

A method is provided for forming semiconductor copper seed layers with the copper alloyed with one of the metals from the group comprising tin, magnesium, and aluminum. The alloy further has a graded nitrogen content with the highest concentration of nitrogen proximate a tungsten nitride barrier layer. The high concentration of nitrogen in the copper alloy provides good adhesion of the seed layer to the barrier layer while the lack of nitrogen away from the barrier layer allows the copper conductive to have good adhesion with the pure copper conductive material.