The present disclosure relates to a method of generating a transistor device having an epitaxial layer disposed over a recessed active region. The epitaxial layer improves transistor device performance. In some embodiments, the method is performed by providing a semiconductor substrate. An epitaxial growth is performed to form an epitaxial layer onto the semiconductor substrate. An electrically insulating layer is then formed onto the epitaxial layer, and a gate structure is formed onto the electrically insulating layer. By forming the epitaxial layer over the semiconductor substrate the surface roughness of the semiconductor substrate is improved, thereby improving transistor device performance.