A method is presented for forming a semiconductor device. The method includes forming source/drain over a semiconductor substrate, forming a sacrificial layer over the source/drain, and forming an inter-level dielectric (ILD) layer over the sacrificial layer. The method further includes forming trenches that extend partially into the sacrificial layer, removing the sacrificial layer to expose an upper surface of the source/drain, and filling the trenches with at least one conducting material. The sacrificial layer is germanium (Ge) and the at least one conducting material includes three conducting materials.