Method for manufacturing FinFETs by implanting counter-doped regions in lightly-doped S/D extensions away from the channel

摘要

Fin field-effect transistors and fabrication methods are provided. An exemplary fabrication method includes providing a providing a plurality of fins on a surface of a semiconductor substrate; forming a gate structure across the fins by covering portions of top and side surfaces of the fins, wherein portions of the fins under the gate structure are channel regions; forming lightly doped regions in the fins at both sides of the gate structure by performing a lightly doping ion implantation process; performing a counter doping ion implantation process on a portion of each lightly doped region away from the channel region to form a counter doped region in the lightly doped region; and performing a source/drain doping process on the fins at both sides of the gate structure to form doped source/drain regions.