A method for forming a semiconductor device, including forming one or more fin structures on a semiconductor substrate, where the fin structure defines source and drain regions. The method includes forming a gate stack, depositing a first contact insulator layer, and applying an etching process to portions of the first insulator layer to form a trench that extends to the source region. The method also includes depositing an epitaxial lower band gap source material into the trench and extending to the source region, depositing a second insulator layer, applying a second etching process to portions of the second insulator layer to form a trench that extends to the source and drain regions, and depositing a metalizing material over the substrate.