A vertical field-effect transistor (FET), comprising a first doped region of a first material, said first doped region having a first doping and being formed on a surface of a substrate, a second doped region of said first material, said second doped region having a second doping and being formed on the first doped region, and a third doped region of said first material, said third doped region having a third doping and being formed on the second doped region, wherein the first doped region has a first width along a first direction parallel to said surface of the substrate, the second doped region has a second width along said first direction, the third doped region has a third width along said first direction, the second width being smaller than the first and third widths.