FinFET with dielectric isolation after gate module for improved source and drain region epitaxial growth

A semiconductor device, comprising:

• a gate structure present on a channel region portion of a plurality of fin structures, the gate structure formed over a substrate;
• a flowable dielectric material present filling a space between adjacent fin structures in the plurality of fin structures;
• a dielectric material encompassing the plurality of fins structures;
• and
• a first epitaxial merge structure formed over a first set of the plurality of fin structures and a second epitaxial merge structure formed over a second set of the plurality of fin structures, wherein the first and second epitaxial merge structures are separate and distinct from each other and each extend over portions of the flowable dielectric material, and wherein the first epitaxial merge structure includes a buffer layer with semi-circular protrusions extending laterally from an upper portion thereof,
• wherein the dielectric material prevents direct contact between the plurality of fins and the flowable dielectric material, and
• wherein the dielectric material prevents directs contact between the flowable dielectric material and the substrate.