A method including forming fin spacers on opposite sidewalls of a semiconductor fin made from a semiconductor substrate, forming a dielectric layer in direct contact with the fin spacers such that a top surface of the fin and a top surface of the fin spacers remain exposed, recessing a portion of the fin between the fin spacers, removing the fin spacers to create an opening, and epitaxially growing an unmerged source drain region in the opening, where lateral growth of the unmerged source drain region is constrained on opposite sides by the dielectric layer.