A method of forming a semiconductor device that includes forming a sacrificial gate structure on a channel portion of a fin structure, wherein the angle at the intersection of the sidewall of the sacrificial gate structure and an upper surface of the channel portion of the fin structure is obtuse. Epitaxial source and drain region structures are formed on a source region portion and a drain region portion of the fin structure. At least one dielectric material is formed on the sidewall of the sacrificial gate structure. The sacrificial gate structure may be removed to provide an opening to the channel portion of the fin structure. A function gate structure is formed in the opening. At least one angle defined by the intersection of a sidewall of the functional gate structure and an upper surface of the channel portion of the fin structure is obtuse.