A method of fabricating a semiconductor device is disclosed. The method includes separating an interlayer dielectric (ILD) into a plurality of portions. The plurality of portions of ILD, separated from each other along a first lateral direction and a second lateral direction, overlay a plurality of groups of epitaxial regions, respectively. The method includes performing an etching process to expose the plurality of groups of epitaxial regions, wherein the etching process comprises a plurality of stages, each of the stages comprising a respective etchant. The method includes forming a plurality of conductive contacts electrically coupled to the plurality of epitaxial regions, respectively.