A method for forming conductive structures for a semiconductor device includes depositing a reflow liner on walls of trenches formed in a dielectric layer and depositing a reflow material on the reflow liner. The reflow material is reflowed to collect in a lower portion of the trenches. The depositing and the reflowing steps are repeated until the trenches are aggregately filled with the reflow material. The reflow material is planarized to form conductive structures in the trenches.