Embodiments of the present invention provide a method of forming contact structure for transistor. The method includes providing a semiconductor substrate having a first and a second gate structure of a first and a second transistor formed on top thereof, the first and second gate structures being embedded in a first inter-layer-dielectric (ILD) layer; epitaxially forming a first semiconductor region between the first and second gate structures inside the first ILD layer; epitaxially forming a second semiconductor region on top of the first semiconductor region, the second semiconductor region being inside a second ILD layer on top of the first ILD layer and having a width wider than a width of the first semiconductor region; and forming a silicide in a top portion of the second semiconductor region.