A method includes forming a gate stack over a semiconductor fin, wherein the semiconductor fin forms a ring, and etching a portion of the semiconductor fin not covered by the gate stack to form a recess. The method further includes performing an epitaxy to grow an epitaxy semiconductor region from the recess, forming a first contact plug overlying and electrically coupled to the epitaxy semiconductor region, and forming a second contact plug, wherein the second contact plug is overlying and electrically coupled to the gate stack.