US Patent 10211288 Vertical transistors with multiple gate lengths

A pair of vertical fin field effect transistors (FinFETs) having different gate lengths, includes, a first bottom source/drain on a first region of a substrate, wherein the first bottom source/drain includes a first tier having a first height adjacent to a first vertical fin and a second tier having a second height greater than the first tier removed from the first vertical fin; and a second bottom source/drain on a second region of the substrate, wherein the second bottom source/drain includes a third tier having a third height adjacent to a second vertical fin and a fourth tier having a fourth height greater than the third tier removed from the second vertical fin, wherein the third height is less than the first height and the fourth height is equal to the second height.