Method for forming interconnects on semiconductor substrates and structures formed

A method for forming metal interconnect in a semiconductor structure and the structure formed are disclosed. In the method, a seed layer of a first metal is first deposited into an interconnect opening wherein the seed layer has an average grain size of at least 0.0005 mum. The semiconductor structure is then annealed at a temperature sufficient to grow the average grain size in the seed layer to at least the film thickness. A filler layer of a second metal is then deposited to fill the interconnect opening overlaying the seed layer such that the filler layer has an average grain size of larger than 0.0005 mum and comparable to the annealed seed layer.