Semiconductor structure and method of forming the same

Abstract

A method includes forming a first semiconductor layer and a second semiconductor layer overlapping the first semiconductor layer. The second semiconductor layer is spaced apart from the first semiconductor layer by a dielectric isolation layer. The method includes performing a first epitaxy process to form a lower source / drain region aside of the first semiconductor layer, forming a dummy contact etch stop layer over the lower source / drain region, forming a dummy inter-layer dielectric over the dummy contact etch stop layer, and performing a second epitaxy process to form an upper source / drain region aside of the second semiconductor layer, The upper source / drain region is over the dummy inter-layer dielectric. The dummy inter-layer dielectric and the dummy contact etch stop layer are removed to form a gap between the upper source / drain region and the lower source / drain region. A dielectric region is formed to fill the gap.