A method of forming a metal feature in a low-k dielectric layer is provided. The method includes forming an opening in a low-k dielectric layer, forming a metal layer having a substantially planar surface over the low-k dielectric layer using spin-on method, and stress free polishing the metal layer. Preferably, the metal layer comprises copper or copper alloys. The metal layer preferably includes a first sub layer having a substantially non-planar surface and a second sub layer having a substantially planar surface on the first sub layer.