Integrated circuits with improved gate uniformity and methods for fabricating such integrated circuits are provided. In an embodiment, an integrated circuit includes a semiconductor substrate and a replacement metal gate structure overlying the semiconductor substrate. The replacement metal gate structure includes a first metal and a second metal and has a recess surface formed by the first metal and the second metal. The first metal and the second metal include a first species of diffused foreign ions. The integrated circuit further includes a metal fill material overlying the recess surface formed by the first metal and the second metal.