A vertical fin field-effect-transistor and a method for fabricating the same. The vertical fin field-effect-transistor includes a first source/drain disposed in contact with a substrate. A second source/drain is disposed above the first source/drain. At least one fin structure is disposed between and in contact with the first source/drain and the second source/drain. A width of the first source/drain and the second source/drain gradually decreases towards the fin structure. The method includes forming an oxide in contact with an exposed portion of at least one fin structure. During formation of the oxide, different areas of the exposed fin structure portion are oxidized at different rates. This forms a first region and a second region of the exposed fin structure portion. These regions each have a width that is greater than a width of a third region of the exposed fin structure portion situated between the first and second regions.